Lasse R Clausen

Niels Houbak

Brian Elmegaard

TECHNOECONOMIC ANALYSIS OF A METHANOL PLANT BASED ON GASIFICATION OF BIOMASS AND ELECTROLYSIS OF WATER

Methanol production process configurations based on renewable energy sources have been designed. The processes were analyzed in the thermodynamic process simulation tool DNA. The syngas used for the catalytic methanol production was produced by gasification of biomass, electrolysis of water, CO 2 from post-combustion capture and autothermal reforming of natural gas or biogas. Underground gas storage of hydrogen and oxygen was used in connection with the electrolysis to enable the electrolyser to follow the variations in the power produced by renewables.

Six plant configurations, each with a different syngas production method, were compared. The plants achieve methanol exergy efficiencies of 59-72%, the best from a configuration incorporating autothermal reforming of biogas and electrolysis of water for syngas production. The different processes in the plants are highly heat integrated, and the low-temperature waste heat is used for district heat production. This results in high total energy efficiencies (~90%) for the plants. The

Introduction

The production of alternative fuels for the transportation sector has the potential of being integrated with other production processes in order to reduce cost and increase the energy and exergy efficiency of the production. The Danish power company Elsam created the REtrol vision, which integrates the production of ethanol and methanol with heat and power production [START_REF] Dong Energy | Renewable energy within the transport sector (The REtrol/VEnzin vision)[END_REF] and is the inspiration for this work. The plant modeled in this paper does, however, only produce methanol and district heating.

The modeled methanol plant uses biomass, natural gas and electricity for syngas production as suggested by the REtrol vision. These inputs are supplemented by biogas in order to be able to produce methanol solely based on renewable sources. The biomass input is gasified in a fluid bed gasifier. The natural gas and biogas input are reformed in an autothermal reformer. The electricity input is used to generate hydrogen (for the syngas) and oxygen (for the gasification and autothermal reforming) by water electrolysis. The use of electricity for the syngas production could be interesting if a significant part of the electricity produced for the grid is from intermittent, renewable sources, such as wind power. The electrolyser in the methanol plant could operate when surplus electricity is available in the grid and thereby help to stabilize the grid as well as utilize low cost electricity. The operation of the electrolyser could even be detached from the methanol plant by introducing underground gas storages for hydrogen and oxygen 2 , thereby enabling the rest of the methanol plant to run continuously. This configuration is investigated in the paper.

In the paper, six different plant configurations are investigated:

1. Plant E+B+NG is a reference plant based on the REtrol vision where biomass, electricity and natural gas are used for the syngas production.

2. Plant E+B only uses biomass and electricity to avoid the use of a fossil fuel. All the carbon in the biomass is utilized for methanol production.

3. Plant E+B+CCS is like the previous plant but utilizes all the oxygen from the electrolyser for gasification and uses CO 2 capture to create a syngas with a low concentration of CO 2 , which is more suited for methanol production. [START_REF]Energy Statistics[END_REF]. Plant E+NG is also a reference plant. This plant uses natural gas and electricity for the syngas production because natural gas is the most commonly used feedstock for methanol production.

5. Plant E+BG is like the previous plant but uses biogas instead of natural gas in order to produce methanol based on renewable sources. [START_REF] Mignard | On the use of electrolytic hydrogen from variable renewable energies for the enhanced conversion of biomass to fuels[END_REF]. Plant E+CO 2 only uses electricity and CO 2 for the syngas production. This plant could be used to stabilize the electricity grid as mentioned above.

The objective of this study was to compare the six plant configurations based on economy, thermal efficiencies and the extent of renewables used for the methanol production. The production costs of the methanol produced from the six plants are compared to relevant fuels.

For the economic evaluation of the modeled methanol plants, Denmark is used as a case of a modern, national energy system. This is because:

1. The REtrol vision is developed for the Danish energy system.

2. Electricity from wind turbines accounts for 20% of the electricity production (in 2007) [START_REF]Energy Statistics[END_REF], and this figure is predicted to increase. Thus, the Danish system is an interesting case, because renewable sources account for a significant share of the electricity production.

3. There are high taxes on petrol [START_REF]Energy taxes[END_REF], which means that methanol from renewable sources that is untaxed could be competitive. [START_REF]Energy Statistics[END_REF]. District heating is used to a great extent in Denmark [START_REF]Energy Statistics[END_REF] (the byproduct from the modeled methanol plant is district heating).

The use of hydrogen from electrolysis together with gasification of biomass to produce a biofuel has also been investigated in [START_REF] Mignard | On the use of electrolytic hydrogen from variable renewable energies for the enhanced conversion of biomass to fuels[END_REF][START_REF] Specht | Synthesis of methanol from biomass/CO2 resources[END_REF][START_REF] Gassner | Thermo-economic optimisation of the integration of electrolysis in synthetic natural gas production from wood[END_REF][START_REF] Ouellette | Hydrogen from remote excess hydroelectricity. Part II: Hydrogen peroxide or biomethanol[END_REF]. In [START_REF] Gassner | Thermo-economic optimisation of the integration of electrolysis in synthetic natural gas production from wood[END_REF], the biofuel is synthetic natural gas (SNG). In [START_REF] Mignard | On the use of electrolytic hydrogen from variable renewable energies for the enhanced conversion of biomass to fuels[END_REF][START_REF] Specht | Synthesis of methanol from biomass/CO2 resources[END_REF][START_REF] Ouellette | Hydrogen from remote excess hydroelectricity. Part II: Hydrogen peroxide or biomethanol[END_REF], the biofuel is methanol. The plant investigated in [START_REF] Mignard | On the use of electrolytic hydrogen from variable renewable energies for the enhanced conversion of biomass to fuels[END_REF] resembles plant E+B in this paper, and the plants investigated in [START_REF] Specht | Synthesis of methanol from biomass/CO2 resources[END_REF][START_REF] Ouellette | Hydrogen from remote excess hydroelectricity. Part II: Hydrogen peroxide or biomethanol[END_REF] resemble plants E+B and E+B+CCS in this paper. However, neither the use of electrolysis together with autothermal reforming of a hydrocarbon feed for syngas production nor the use of gas storage for hydrogen and oxygen in connection with a methanol plant has been investigated. Combining gasification and autothermal reforming to avoid production of excess oxygen from the electrolysis is also a new concept generated from the REtrol vision. The production of methanol from biomass is, on the other hand, a well investigated field (e.g. [START_REF] Sues | Exergetic evaluation of 5 biowastes-to-biofuels routes via gasification[END_REF][START_REF] Hamelinck | Future prospects for production of methanol and hydrogen from biomass[END_REF]).

The REtrol vision

The REtrol3 vision (VEnzin-visionen in Danish) is a vision proposed by the Danish power company Elsam (now DONG Energy) and involves the integration of the heat and power production with production of fuel for the transportation sector [START_REF] Dong Energy | Renewable energy within the transport sector (The REtrol/VEnzin vision)[END_REF]. In Denmark, heat and power production are highly integratedabout 50% of the power is produced in cogeneration [START_REF]Energy Statistics[END_REF]. This integration of heat and power production saves fuel for the plants compared to production of heat and power separately, which is both an economical advantage and benefits the environment. By integrating transportation fuel production with the combined heat and power (CHP) plants, the plants increase the number of products from two (heat and power) to three (heat, power and transportation fuel), which would provide advantages in terms of being able to emphasize which product to produce, based on the demand from the market. Depending on what kind and how many different transportation fuels the plant would producee.g., methanol, dimethyl ether (DME) or ethanol -the integration opportunities are different. However compared to stand-alone plants, the plants should be able to receive economical and environmental advantages (due to efficiency increases).

In the REtrol vision, a methanol and ethanol plant is integrated with a CHP plant. Besides the exchange of heat at different temperatures, some of the integration opportunities lie between the ethanol and methanol production. A 2 nd generation ethanol plant 4 would produce a solid lignin residue that can be gasified in the methanol plant and used for methanol synthesis together with CO 2 and H 2 , which are also byproducts from a 2 nd generation ethanol production. If the ethanol plant includes a biogas plant, the biogas could also be used for methanol synthesis by reforming the biogas.

REtrol is thought to consist of petrol with a small percentage (5 -10%) of ethanol and/or methanol.

In the case of ethanol, the input to the production would be biomass (e.g., straw) and the conversion process would be biological. In the case of methanol, the input to the production would be biomass, electricity or natural gas. The biomass would be gasified to produce a syngas that could be catalytically converted to methanol. Electricity from renewable sources would be used in an electrolyser to produce hydrogen for the syngas. Natural gas is, however, not a renewable energy source and could be replaced by biogas.

Design of the methanol plant model

The methanol plant model was designed with strong inspiration from the REtrol vision. This means that the plant feedstocks are based on renewable energy sources and that the plant is flexible in the choice of feedstock: biomass, electricity, natural gas and biogas.

The plant was also designed with the goal of high energy/exergy efficiency, and the methanol efficiency is especially crucial.

The design and analysis of the methanol plant model was done with the thermal system simulation tool DNA5 [START_REF] Elmegaard | DNA -A General Energy System Simulation Tool[END_REF][START_REF]Homepage of the thermodynamic simulation tool DNA[END_REF]. The model of the methanol plant was developed for steady-state operation. The modeled methanol plant was used to investigate six different plant configurations, which are presented in section 3.

The designed methanol plant is different from a commercial methanol plant based on autothermal reforming of natural gas because of the added electrolyser and gasifier. In the modeled methanol plant, the syngas can be produced by three components: the electrolyser, the gasifier and the autothermal reformer (Fig. 1). The product gases from the three components are mixed together to form a syngas. Addition of CO 2 (from, e.g., carbon capture from a power plant or ethanol production) is possible in order to adjust the carbon/hydrogen ratio. The optimal carbon/hydrogen ratio depends on input concentrations of CO and CO 2 . An optimal relation between CO, CO 2 and H 2 in the syngas can be extracted by the chemical reactions producing methanol given in Eqns. 1 and 2.

(1) [START_REF]Costs of Storing and Transporting Hydrogen, report[END_REF] It can be seen that production of methanol from CO requires two moles of hydrogen for every mole of CO, but if methanol is produced by CO 2 , three moles of hydrogen are required for every mole of CO 2 . In Eq. 3, the Module M [START_REF] Steynberg | Fischer-Tropsch technology[END_REF] is defined based on mole-fractions of CO, CO 2 and H 2 in the syngas. It can be seen that an M-value of 2 is optimal for methanol synthesis.

(3)

The electrolyser and the gasifier supplement each other with regard to producing a syngas suited for methanol production. This is because the gasification gas is too carbon rich (M=0.9). By supplementing the gasification gas with hydrogen from the electrolyser, a syngas well suited for methanol synthesis is produced. Besides the production of hydrogen, the electrolyser also produces oxygen, which is used in the gasifier or the autothermal reformer.

Electrolysis of water and underground gas storage of hydrogen and oxygen

Alkaline electrolysis of water is used to generate hydrogen and oxygen. The electrolyser is modeled based on data for a large-scale, commercially available electrolyser of 2 MWe (485 Nm 3 -H 2 /h). The electrolyser is operated at 90 C and atmospheric pressure and has an electricity consumption of 4.3 kWh/Nm 3 -H 2 , which corresponds to an efficiency of 70% (LHV) [START_REF]Elkraft System and Eltra. Technology data for electricity and heat generating plants[END_REF]. Higher efficiencies are achieved with PEM or SOEC electrolysers, but these types of electrolysers are still under development and it may take many years before they can compete economically with alkaline electrolysers on a large scale (>50 MWe) [START_REF] Kruse | Hydrogen -Status and Possibilities[END_REF].

In order to produce hydrogen and oxygen when electricity from renewables is available (or when the electricity price is low), underground gas storage of hydrogen and oxygen is assumed to be used. Other types of gas storage (e.g., compressed cylinders or metal hydrides) are not economical at the size needed 6 .

In the report that is the basis of this paper [START_REF] Clausen | Design and modeling of a methanol plant for the REtrol vision (Design og modellering af metanolanlaeg til VEnzin-visionen)[END_REF], the feasibility of using underground gas storage of hydrogen and oxygen in connection with a plant that utilizes hydrogen and oxygen (e.g., a methanol plant) was investigated. The calculations were based on historic electricity prices from western Denmark (from 2000 to 2006) where the installed capacity of wind turbines is about 20% of the total installed capacity. The cost for electrolysers and underground gas storage used in the study are the same as used in this paper. It was shown that with today's electricity prices in western Denmark, electricity cost could be reduced by 5-18%, and total costs could be reduced by up to 12% 7 by using gas storage to exploit daily variations in the electricity price. A gas storage size corresponding to about five days of operation and an electrolyser capacity corresponding to about twice the capacity needed if gas storages were not used were the most economical. These sizes of the electrolysis plant and underground gas storage are thus used in this paper. It should be noted that if the electrolysis plant operates at a partial load (e.g. if the gas storages are filled), higher conversion efficiencies are achieved: at about 300-377 Nm 3 -H 2 /h (62-78% load), the electricity consumption drops to 4.1 kWh/Nm 3 -H 2 (73% efficiency) [START_REF]Elkraft System and Eltra. Technology data for electricity and heat generating plants[END_REF]. This means that at the electricity price used in this paper (40 €/MWh), about the same economics for the electrolyser plant are achieved if operating at 4.3 kWh/Nm 3 -H 2 (100% load) as when operating at 4.1 kWh/Nm 3 -H 2 (62-78% load) at a larger 6 In [START_REF]Costs of Storing and Transporting Hydrogen, report[END_REF], it is stated that if the storage requirement exceeds 1,300 kg of hydrogen, underground gas storage should be considered. The amount of gas storage needed is 0.1-0.9 million kg of hydrogen. 7 These figures refer to calculations done where the model only had knowledge of historic electricity prices. If the model is used to optimize production for a given year and the model knows all the electricity prices for that year at the start of the calculations, even greater reductions in cost can be achieved. electrolysis plant. The extra capital needed for the larger electrolysis plant is saved by lower electricity costs.

Gasification of biomass

The feedstock for the biomass gasifier is wood. Before being fed to the gasifier, the wood is dried in a steam dryer. The gasifier is modeled as a modified Low-Tar BIG gasifier, which is a two-stage fluidized bed gasifier at atmospheric pressure with very low tar content in the gasification product gas [START_REF] Andersen | Modelling the Low-Tar BIG gasification concept[END_REF]. The gas exiting the gasifier is at 800 C with a composition given by an assumption of chemical equilibrium8 at this temperature. The gas is cooled to 60 C before the gas cleaning by preheating oxygen, superheating steam and heating district heating water. The superheated steam is used for steam injection in the gasifier and for steam drying of biomass.

Autothermal reforming of natural gas or biogas

Natural gas or biogas is after a desulfurization process, reformed in an autothermal reformer (ATR) to a reformate gas consisting of H 2 , CO, CO 2 and H 2 O. The heat needed for the reforming is created by partially oxidizing the fuel with oxygen. The composition of the reformate gas is calculated by assuming chemical equilibrium at the exit where the temperature is 950 °C and the pressure is 10 bar. The steam/fuel mass-ratio is set to give an adequately low methane content in the reformate gas (0.5-0.6 mole-%). In the case of natural gas, this ratio is set to 1, and for biogas it is set to 0.2. This corresponds to a steam/carbon mole-ratio of 0.89 for natural gas and 0.29 for biogas (the ratio is 0.44 if the carbon in the CO 2 in the biogas is disregarded). Because the reforming in the case of biogas is mostly done with the CO 2 present in the biogas, a CO 2 -reforming catalyst is most likely needed in order to avoid problems with coke formation. The CO 2 reforming catalysts are under development [START_REF] Gaoa | Methane autothermal reforming with CO2 and O2 to synthesis gas at the boundary between Ni and ZrO2[END_REF]. The oxygen consumption of the ATR is calculated by simulation, and the O/C mole-ratio is 0.94 in the natural gas case and 0.63 in the biogas case (the ratio is 0.97 if the carbon in the CO 2 in the biogas is disregarded). The gas exiting the reformer is cooled by preheating oxygen and natural gas/biogas and by generating steam for the reformer.

Gas cleaning

Gas cleaning of the gasification gas consists of removal of particles, sulfur components and in some cases CO 2 . Particle removal is done by a cyclone and/or a filter. Sulfur removal is either done by a zinc oxide filter (as with natural gas) with COS hydrolysis upstream to convert COS to H 2 S or by a scrubber. CO 2 removal is done by an amine scrubber 9,10 .

Methanol synthesis

The syngas is compressed to 144 bar by intercooled compressors before entering the synthesis reactor. The reactor operates at 235 C, and the composition of the outlet gas is calculated by assuming chemical equilibrium. The gas from the methanol reactor is cooled, and condensation of methanol and water occurs. 95% of the unconverted gas is recirculated to the synthesis reactor, and the remaining 5% is purged. The chemical reactions producing methanol from CO, CO 2 and H 2 are given in Eqns. 1 and 2. Since a mixture of CO and CO 2 is used to produce methanol, the module M given in Eq. 3 is used to characterize how well a gas is suited for methanol synthesis. The hydrogen content of the unconverted syngas is set to 30 mole% instead of setting the module M. This is done to reduce the loss of hydrogen in the 5% of unconverted syngas that is purged. The hydrogen from 9 The heat requirement for CO 2 -capture with an amine solvent is not accounted for. From [START_REF]IPCC Special Report on Carbon Dioxide Capture and Storage[END_REF], this is 2.7-3.2 MJ/kg-CO 2 -captured. Plant 3 is the only plant that uses CO 2 -capture, and the amount of CO 2 captured is 4.6 kg/s. This gives about 14 MJ/s of heat needed. For comparison, the amount of heat generated when cooling the gas from the gasifier is 27 MJ/s. 10 100% CO 2 removal is assumed. For a real CO 2 capture process with an amine solvent, the amount of CO 2 captured is 85-90% [START_REF]IPCC Special Report on Carbon Dioxide Capture and Storage[END_REF].

the electrolyser is the most expensive syngas component; therefore the hydrogen content in the syngas is the lowest possible without significantly affecting the methanol production. To achieve 30 mole% of hydrogen in the unconverted syngas, the module for the syngas is 1.3-1.8 in the simulations, depending on the CO/CO 2 ratio in the syngas. M=1.3 when only CO 2 is in the syngas, and M=1.8 when only CO is in the syngas.

Distillation

The heat generated by the synthesis process is used for the distillation. It is assumed that only water and methanol is in the feed for the distillation column. The column is pressurized to 3.5 bar, which corresponds to a temperature of 100 C in the condenser.

Heat integration

The configuration of the methanol plant is designed to give high total energy efficiency. This is achieved by utilizing the waste heat generated in different areas of the plant: waste heat from the electrolyser, from the condenser of the distillation column and from condensing the steam produced in the steam dryer is used for district heating (Fig. 2). Waste heat from the compressor intercooling is used for district heating and steam drying of biomass.

In Table 1, all the parameters used in the simulation model are shown.

For details about the modeling of the methanol plant, see the report in [START_REF] Clausen | Design and modeling of a methanol plant for the REtrol vision (Design og modellering af metanolanlaeg til VEnzin-visionen)[END_REF].

Methanol plant configurations

The model of the methanol plant has five sources for production of syngas for methanol synthesis.

These are: gas from gasification of biomass, reformate gas from autothermal reforming of natural gas or biogas, hydrogen from water electrolysis and CO 2 from an ethanol plant or from carbon capture from a power plant. On top of this, CO 2 capture can be used to reduce the carbon content of the gasification gas. In order to determine which combination of these sources produces the most efficient or cost-effective methanol plant, six plant configurations are investigated (Fig. 3). All six plant configurations utilize electrolysis because oxygen from the electrolysis plant is needed for gasification and autothermal reforming.

Plant E+B+NG

The syngas consists of hydrogen from electrolysis of water, gasification gas generated from biomass and reformate gas generated from natural gas. The oxygen generated in the electrolysis is used for the gasification of biomass and the autothermal reforming of natural gas.

Plant E+B

The syngas consists of hydrogen from electrolysis of water and gasification gas generated from biomass. The oxygen generated in the electrolysis is used for the gasification of biomass. The oxygen not used for the gasification is vented or used outside the plant.

Plant E+B+CCS

This plant is similar to plant E+B but with CO 2 capture to reduce the carbon content in the gasification gas. The size of the electrolysis plant is reduced compared to plant E+B. All the oxygen produced is used for gasification. The CO 2 captured can be used for commercial purposes, stored underground or vented since the CO 2 is produced from biomass. If the CO 2 is stored, it could be used for methanol production together with hydrogen from the electrolysis at times when the electricity is cheap.

Plant E+NG+CO 2

The syngas consists of hydrogen from electrolysis of water, reformate gas generated from natural gas and CO 2 from post-combustion capture at a power plant. The oxygen generated in the electrolysis is used for the autothermal reforming of natural gas. This plant configuration is modeled because it is based on natural gas, which is the most commonly used resource in commercial methanol plants [START_REF]Methanol production[END_REF].

Plant E+BG

This plant is similar to plant E+NG but biogas is used instead of natural gas, and since CO 2 is present in the biogas, CO 2 does not have to be added to the syngas.

Plant E+CO 2

The syngas consists of hydrogen from electrolysis of water and CO 2 from post-combustion capture at a power plant. The oxygen generated in the electrolysis is vented or used outside the plant.

Since the plants described above have several sources for the production of syngas, the ratio(s) between the different sources has to be set. For plants E+B, E+BG and E+CO 2 that use two sources for syngas production, the ratio between the two sources is determined by the hydrogen content specified for the unconverted syngas. In the case of plant 2, this means that 0.6 kg/s of hydrogen from the electrolyser and 17.8 kg/s of biomass to the gasifier will produce an unconverted syngas with an H 2 content of 30 mole%. For plants E+B+NG and E+NG+CO 2 that use three sources for syngas production, the ratios between the three sources are determined by the hydrogen content specified for the unconverted syngas and the requirement that all of the oxygen from the electrolysis is used for gasification or autothermal reforming. Plant E+B+CCS only uses two sources for syngas production, but since CO 2 capture is also used, the amount of CO 2 captured and the size of the electrolyser are fitted so that there is no excess oxygen from the electrolyser while still achieving the specified hydrogen content in the unconverted syngas.

Results

Process simulation results

The model of the methanol plant was used to simulate the six plant configurations. All six plants were fixed to produce a methanol output of 10.3 kg/s (205 MW LHV ) 11 . In Table 2 and Table 3, detailed material balances are presented for the plants. These tables show the differences between the plants in syngas composition and flows. From Table 3, it can be seen that the CO 2 /CO ratio of the syngas affects the flows in the methanol synthesis loop. The higher the CO 2 /CO ratio, the higher the amount of unconverted syngas that will be recirculated because the conversion rate per pass is lower for CO 2 than for CO. This ultimately leads to a greater loss of unconverted syngas.

The main difference between the six plant configurations is the kind of energy inputs used for the syngas production. The different energy inputs are electricity, biomass, natural gas and biogas. In Table 4, the distribution between these inputs is shown. It can be seen from this table that the electricity consumption for electrolysis for plant E+B+CCS is considerably lower than for plant E+B. This is because of the use of carbon capture in plant E+B+CCS that reduces the need for hydrogen from the electrolysis. Table 4 also shows the amount of input energy to the plants that comes from renewable energy sources. If the electricity is regarded as a renewable energy source, all of the plants that do not use natural gas only use energy from renewable sources. If electricity is not regarded as a renewable energy source, plant E+B+CCS is the plant where most of the input energy is from renewable sources (75%).

In addition to producing methanol, the plants also produce heat for district heating. Table 5 shows the amount of methanol and district heating produced together with important plant efficiencies. It can be seen that plant E+BG has the highest methanol exergy efficiency of 72%, and the other plants (except E+CO 2 ) have only slightly lower methanol exergy efficiencies (68-71%). Total energy efficiencies for all the plants except E+CO 2 are around 90%. The efficiencies for plant E+CO 2 are lower compared to the efficiencies of the other plants: the methanol exergy efficiency is 59%, and the total energy efficiency is 86%. The reason why plant E+CO 2 has lower methanol efficiencies is mainly due to the 70% efficiency of the electrolyser, which is lower than the 93% cold gas efficiency of the gasifier and the 95-96% efficiency of the autothermal reformer.

Cost estimation

In order to estimate the investment of the methanol plants investigated, the investment of some major plant areas was estimated and shown in Table 6. We found that the gasification part is much more expensive than the other syngas-producing parts, namely the electrolysis and the autothermal reforming parts. The investment costs for the six plant configurations are 175-310 M€.

In Fig. 4, the cost distribution between electricity, biomass, capital cost, etc. can be seen for all six plant configurations (the prices assumed for electricity, biomass, etc. can be seen in Table 7). The largest cost areas for plants E+BG and E+CO 2 are biogas and electricity, respectively; for the other plants, the capital cost is the largest cost area. It is also clear by comparing costs for plants E+B and E+B+CCS that 20 M€/year (43-23) is saved in electricity costs for the electrolyser by using CO 2 capture with a cost of 9 M€/year12 (4 M€/year for CO 2 capture and 5 M€/year for increased biomass use).

The total costs shown in Fig. 4 are to be covered by the produced methanol and district heating (Fig. 5). The specific income of district heating is estimated to be 7 €/GJ. The cost not covered by the district heating is placed on the produced methanol.

In Table 8, the specific methanol costs for all six plant configurations are compared to other fuels. It is clear from this table that the production cost is lowest for plants E+B+NG and E+B+CCS and that plant E+CO 2 has the highest production cost by farmore than twice as high as plants E+B+NG and E+B+CCS. This difference is mainly due to the difference in the electricity consumption. Actually, 23% (plant E+B+CCS) to 65% (plant E+CO 2 ) of the total costs for the six plant configurations are for electricity. In Fig. 6, the relation between the electricity price and the methanol production cost is shown. We see that all plants except E+CO 2 have similar production costs. The figure indicates that the average electricity price has to be below 20 €/MWh before plant E+B produces cheaper methanol than plant E+B+CCS. Above 20 €/MWh, it is more cost-effective to remove carbon from the gas from the gasifier and thereby reduce the need for expensive hydrogen from the electrolyser. Below 20 €/MWh, it is more cost-effective to keep all the carbon in the gas from the gasifier and use the required amount of hydrogen from the electrolyser. The figure also shows that the average electricity price has to be as low as 3-8 €/MWh before plant E+CO 2 can compete with the other five plants. However, if regulation of the electricity grid is needed on a large scale (hundreds of MWe), e.g., if 50% of the electricity production is from wind turbines, as suggested for Denmark [START_REF] Xu | Towards a Danish Power System with 50% Wind -Smart Grids Activities in Denmark[END_REF], plant E+CO 2 seems to be the only possible option out of the six plants and would produce better thermal efficiencies by producing methanol from the stored hydrogen than a plant generating electricity from the stored hydrogen by fuel cells.

From Table 8, it can also be seen that the methanol production cost for plants E+B+NG and E+B+CCS (11.8 and 12.4 €/GJex) can compete with the production cost of 2 nd generation ethanol (12.0 €/GJex) but not with the current commercial methanol price (7.1 €/GJex).

Table 9 presents a summary of some of the main characteristics of the six plant configurations. We find that plants E+B+NG and E+B+CCS would be most appropriate for the current Danish energy system and that plant E+CO 2 will have a high potential in the future system with a high penetration of wind power. This conclusion may apply to other systems as well, but different shares of energy sources may have an influence.

Conclusion

In connection with Elsam's REtrol vision six methanol plants were designed to obtain optimal energy and exergy efficiencies while maintaining reasonable economics.

The design of the plants was based on the use of sustainable energy sources for the methanol production. All six plants used electricity from renewables to produce hydrogen for syngas production and oxygen for either gasification of biomass or autothermal reforming of a hydrocarbon gas. Underground gas storage of hydrogen and oxygen was used to ensure the constant production of methanol while the operation of the electrolyser followed the daily variations in the electricity price induced by the fluctuating production by renewables. The modeling showed methanol exergy efficiencies of 68-72% for five of the six plants. Only plant E+CO 2 that uses electricity as the only exergy source has a significantly lower methanol exergy efficiency of 59%. By heat integrating the different plant processes and using the waste heat from the methanol plant for district heating, the total energy efficiency reached more than 90% for all plants except E+CO 2 .

The estimated methanol costs were 11.8-14.6 €/GJ ex for all plants except E+CO 2 (25.3 €/GJ ex ). The methanol costs achieved for some of the plant configurations can compete with the production cost of 2 nd generation ethanol (12.0 €/GJex) but not with the current commercial methanol price (7.1 €/GJ ex ).

It was also shown that the electricity price has a significant effect on the production cost since 23-65% of the total costs for the six plant configurations are due to electricity consumption.

Of the six plant configurations, plants E+B+NG and E+B+CCS are the most appropriate for the current energy system. Plant E+CO 2 may be competitive in the future system. 4 (consumption data, Table 2 for the consumption of CO 2 and for the amount of CO 2 captured), Table 7 (prices) and the following. The specific cost of CO 2 capture is assumed to be 30 €/ton-CO 2 [START_REF]Elkraft System and Eltra. Technology data for electricity and heat generating plants[END_REF]. The capital cost per year is calculated as 15% of the total investment [START_REF] Kreutz | Fischer-Tropsch Fuels from Coal and Biomass[END_REF], and 4% of the total investment is used for O&M per year [START_REF] Kreutz | Fischer-Tropsch Fuels from Coal and Biomass[END_REF]. The total cost seen at the end of each bar matches the total cost seen in Fig. 4. b The electricity consumption of the compressors is lower because the biogas is assumed to be pressurized to 10 bar outside the plant (like the natural gas). The electricity consumption for compression of biogas from 1 to 10 bar is about 6 MW.

Figure list : Fig. 1 .

 :1 Figure list:

Fig. 2 .

 2 Fig. 2. Heat integration in the methanol plant model.

Fig. 3 .

 3 Fig. 3. Flow sheets showing the differences between the six plant configurations.

Fig. 4 .Fig. 5 .

 45 Fig. 4. Production cost distribution for the six plant configuration Fig. 5. Annual production costs of methanol and district heating.

Fig. 6 .

 6 Fig. 6. Methanol cost as a function of the electricity price.

Fig. 1 .Fig. 2 .Fig. 3 .

 123 Fig. 1. Simplified flow sheet for the methanol plant model used to generate the six plant configurations.

Fig. 4 .

 4 Fig. 4. Production cost distribution for the six plant configuration

Fig. 5 .

 5 Fig. 5. Annual production costs of methanol and district heating.

Fig. 6 .

 6 Fig. 6. Methanol cost as a function of the electricity price.

Table 1

 1 Parameters used for the plant simulations.

	E+B+NG
	E+B
	E+B+CCS
	E+NG+CO2
	E+BG
	E+CO2
	Commercial methanol price	Electricity price
		used

Table 3

 3 Gas composition for specific nodes in Fig.1for all six plant configurations (in mole%).

			Plant E+B+NG			Plant E+B			Plant E+B+CCS
		10	17	23	24	27	10	23	24	27	10	23	24	27
	H 2	46.0 57.7 60.6 24.4 30.0	46.0 61.9 23.9 30.0	45.6 60.7 22.8 30.0
	CO	42.7 22.5 29.2	3.3	4.0	42.7 30.1	3.9	4.9	32.2 34.0	5.2	6.9
	CO 2	5.2	5.1	4.5 46.4 57.1	5.2	3.7 44.1 55.4	9.4	0.0 40.3 53.1
	H 2 O	5.2 14.2	5.1	2.9	0.0	5.2	3.7	2.3	0.0	12.3	4.8	1.5	0.0
	CH 4	0.5	0.6	0.4	4.8	5.9	0.5	0.3	4.1	5.2	0.2	0.2	2.3	3.0
	N 2	0.3	0	0.1	1.3	1.6	0.3	0.2	2.1	2.7	0.2	0.2	3.3	4.3
	Ar	0.1	0	0.1	0.6	0.8	0.1	0.1	1.0	1.3	0.1	0.1	1.6	2.1
	CH 3 OH	0	0	0 16.3	0.6	0	0 18.6	0.6	0	0 22.9	0.6
	kmol/s 0.55 0.45 1.12 2.05 0.08	0.77 1.09 1.79 0.07	1.11 1.06 1.45 0.06
	M	0.9	1.9	1.7	--0.4	0.9	1.7	--0.4	0.9	1.8	--0.4
		Plant E+NG+CO 2			Plant E+BG		Plant E+CO 2
		17	23	24	27	17	23	24	27	23	24	27
	H 2	57.7 61.6 25.3 30.0	46.1 60.4 24.7 30.0	69.8 25.3 30.0
	CO	22.5 16.5	1.9	2.3	31.9 26.6	2.8	3.4	0	1.5	1.8
	CO 2	5.1 15.3 53.4 63.4	8.2	6.8 50.6 61.5	30.2 57.0 67.7
	H 2 O	14.2	6.2	6.0	0.1	13.4	5.8	3.8	0.0	0	8.0	0.1
	CH 4	0.6	0.4	3.2	3.8	0.5	0.4	3.7	4.5	0	0	0
	N 2	0	0	0	0	0	0	0	0	0	0	0
	Ar	0	0	0	0	0	0	0	0	0	0	0
	CH 3 OH	0	0 10.3	0.5	0	0 14.4	0.5	0	8.2	0.4
	kmol/s 1.03 1.31 3.27 0.14	1.01 1.16 2.33 0.09	1.48 4.14 0.17
	M	1.9	1.5	--0.5	0.9	1.6	--0.5	1.3	--0.5

Table 4

 4 Energy and exergy inputs for all six plant configurations.

		E+B+NG E+B E+B+CCS E+NG+CO 2 E+BG E+CO 2
	Electricity
	for electrolyser (MW)	64 111	46	87	88	357
	for compressors (MW)	23	24	25	23	19 b	33
	Total (MW)	87 135	71	110	107	390
	Biomass
	Energy (MW LHV ) Exergy (MW) a	121 172 145 205	214 256	--	--	--
	Natural gas
	Energy (MW LHV ) Exergy (MW) a	92 96	--	--	210 219	--	--
	Biogas
	Energy (MW LHV ) Exergy (MW) a	--	--	--	--	204 216	--
	Total energy input (MW LHV )	300 307	285	320	311	390
	Total exergy input (MW)	328 340	327	329	323	390
	Renewables used, incl. electricity (%)	69 100	100	34	100	100
	Renewables used, excl. electricity (%)	40	56	75	0	66	0

a Calculated by the simulation tool DNA as done in

[START_REF] Bejan | Thermal design & optimization[END_REF]

.

Table 8

 8 Fuel prices for a number of relevant fuels for comparison of the production cost of methanol for the six plant configurations. Price at €159/ton[START_REF] Methanex | Commercial methanol price in Europe[END_REF]. HHV= 17.7 MJ/l, density = 0.79 kg/l. b Danish price excl. VAT and taxes, HHV= 35 MJ/l. c Assumed price at $60/bbl (1 bbl = 159 l), HHV= 37,8 MJ/l. d Production cost of 2 nd generation ethanol = $1.36/gal[START_REF] Biogasol | Cost of 2 nd generation ethanol. www.biogasol[END_REF]. HHV= 23.4 MJ/l

	Fuel	Price/Cost
		(€/L) (€/GJ ex )
	Methanol
	E+B+NG	0.20	11.8
	E+B	0.25	14.0
	E+B+CCS	0.21	12.4
	E+NG+CO 2	0.23	13.2
	E+BG	0.25	14.6
	E+CO 2	0.44	25.3
	Commercial methanol a	0.13	7.1
	Gasoline b	0.35	10.0
	Crude oil c	0.29	7.7
	Ethanol d (2 nd generation) 0.28	12.0

a

Table 9

 9 Advantages and disadvantages of the six plant configurations.

		E+B+NG	E+B	E+B+CCS
	Advantages:	No excess oxygen from	Total utilization of the	No excess oxygen from
		electrolyser	carbon in the biomass	electrolyser
		Low cost		Low cost
				Possibly a negative CO 2 -
				emission if captured CO 2 is
				stored.
	Disadvantages:	Fossil fuel input
		E+NG+CO 2	E+BG	E+CO 2
	Advantages:	No excess oxygen from	No excess oxygen from	High regulating ability for
		electrolyser	electrolyser	the electricity grid
	Disadvantages:	Fossil fuel input		High cost
				Relatively low methanol
				efficiencies

Underground storage of hydrogen is used today[START_REF]Costs of Storing and Transporting Hydrogen, report[END_REF], underground storage of oxygen has not been demonstrated yet but is referred to as an option in some studies (e.g.[START_REF] Forsberg | Economics of meeting peak electricity demand using hydrogen and oxygen from base-load nuclear or off-peak electricity[END_REF]).

The word REtrol is a mix of the phrase "Renewable Energy" and the word "petrol".

Production of ethanol from cellulosic material by fermentation (and other biological processes).

Exergy calculations were also done by DNA using the method described in[START_REF] Bejan | Thermal design & optimization[END_REF].

Typically, the methane content will be higher than what is given by chemical equilibrium at this temperature and pressure[START_REF] Ahrenfeldt | Validation of a Continuous Combined Heat and Power (CHP) Operation of a Two-Stage Biomass Gasifier[END_REF]. A catalyst could be added at the exit to convert the methane.

The output corresponds to one plant being able to cover the addition of methanol to petrol used for Danish road transport so that 7%[START_REF] Dong Energy | Renewable energy within the transport sector (The REtrol/VEnzin vision)[END_REF] of the energy content in the mixture would be methanol. Petrol used for Danish road transport in 2004: 84.6 PJ[START_REF]Energy Statistics: Construct your own tables and graphs[END_REF].

Disregarding the potential income for the unused oxygen from the electrolyser in plant E+B.

10.1 10 891 0 -- a Calculated by the simulation tool DNA as done in [START_REF] Bejan | Thermal design & optimization[END_REF]. b Calculated by using the exergy difference between a stream at 90 C and a stream at 50 C (both at 1 bar). Reference is at 20 C and 1 bar. c The higher energy efficiencies seen for the plants using gasification are because the biomass input energy (LHV) used in the calculation is for the wet biomass entering the dryer. If instead the biomass input energy (LHV) was calculated based on the dried biomass entering the gasifier, the efficiencies (both methanol efficiencies and total efficiencies) would have been at the same level as plants E+NG+CO 2 and E+BG. a It is assumed that the same cost can be used for oxygen storage. The capacity for one cavern is: 28,000 MWh of hydrogen (840,000 kg of hydrogen). The cost are very dependent on the type of underground gas storage (e.g., if the cavern has to be mined or not). c The costs for the three plant areas: autothermal reforming, methanol synthesis and distillation are calculated from a total plant investment for commercial GTL plants given in [START_REF] Fleisch | Emergence of the Gas-to-Liquids Industry: a Review of Global GTL Developments[END_REF]. It is assumed that each of the three plant areas accounts for 1/3 of the total plant investment. The model for the methanol plant is used to determine the relationship between the methanol production (50,000 barrels/day) and the three parameters stated in the "reference size" column for the three plant areas. 15.0 €/ton [START_REF]Elkraft System and Eltra. Technology data for electricity and heat generating plants[END_REF]


Ethan Weed

William Mcgregor

Jørgen Feldbaek Nielsen

Andreas Roepstorff

Uta Frith

Theory of Mind in adults with right hemisphere damage: What's the story?

Keywords:

Why do people with right hemisphere damage (RHD) have difficulty with pragmatics and communication? One hypothesis has been that pragmatic impairment in RHD is the result of an underlying impairment in Theory of Mind (ToM): the ability to infer the mental states of others. In previous studies evaluating ToM abilities in people with RHD, researchers have used judgment tasks based on story or still cartoon stimuli. However, ToM is likely to draw on kinetic information as well, and these tasks ignore this aspect. The aim of this study was to assess ToM abilities in people with RHD using participants' evaluations of animated films with moving geometric shapes. Participants were presented with eight films of animated triangles. Four of the films represented the triangles as intentional agents with mental states, while the other four represented the triangles as simply inanimate, though moving, objects. Films were evaluated by both button-press response and by oral descriptions. Analysis of the transcriptions revealed that participants with RHD had a reduced ability to discriminate between the film categories, and a bias toward reduced mental-state ascription in the ToM condition.

Introduction

The importance of the left cerebral hemisphere in supporting language has been known since the 1800s, and there has been a massive amount of research on this topic. The past few decades, however, have seen a growing awareness that the right hemisphere may also make important contributions to our ability to use language, particularly in the context of daily social interactions [START_REF] Myers | Right hemisphere damage: Disorders of communication and cognition[END_REF][START_REF] Tompkins | Right hemisphere communication disorders: Theory and management[END_REF].

People with right hemisphere damage (RHD) can show a variety of language-related impairments, which tend to lie at least partially within the realm of pragmatics [START_REF] Cummings | Pragmatics and adult language disorders: Past achievements and future directions[END_REF]. This can include impairment on tasks tapping humor comprehension [START_REF] Bihrle | Comprehension of humorous and nonhumorous materials by left and right brain-damaged patients[END_REF][START_REF] Brownell | Surprise but not coherence. Sensitivity to verbal humor in right-hemisphere patients[END_REF][START_REF] Winner | Distinguishing lies from jokes: Theory of mind deficits and discourse interpretation in right hemisphere brain-damaged patients[END_REF], indirect requests [START_REF] Brownell | Making requests: Illustrations of how righthemisphere brain damage can affect discourse production[END_REF][START_REF] Foldi | Appreciation of pragmatic interpretations of indirect commands: Comparison of right and left hemisphere brain-damaged patients[END_REF][START_REF] Hirst | Constraints on the processing of indirect speech acts: Evidence from aphasiology[END_REF][START_REF] Stemmer | Production and evaluation of requests by right hemisphere brain-damaged individuals[END_REF][START_REF] Weylman | Appreciation of indirect requests by left-and right-brain-damaged patients: The effects of verbal context and conventionality of wording[END_REF], and narrative [START_REF] Brownell | Inference deficits in right brain-damaged patients[END_REF][START_REF] Schneiderman | Story arrangement ability in right brain-damaged patients[END_REF][START_REF] Wapner | The role of the right hemisphere in the apprehension of complex linguistic materials[END_REF].

It has been suggested that an underlying deficit in Theory of Mind (ToM) may be the cause of these pragmatic impairments [START_REF] Brownell | Cerebral lateralization and theory of mind[END_REF][START_REF] Griffin | Theory of mind and the right cerebral hemisphere: Refining the scope of impairment[END_REF][START_REF] Happé | Acquired 'theory of mind' impairments following stroke[END_REF][START_REF] Martin | Weak coherence, no theory of mind, or executive dysfunction? solving the puzzle of pragmatic language disorders[END_REF][START_REF] Winner | Distinguishing lies from jokes: Theory of mind deficits and discourse interpretation in right hemisphere brain-damaged patients[END_REF]. Briefly, ToM refers to the ability to infer the mental states of others. According to this account, successful communication rests on the ability to make inferences about the mental states of one's interlocutor. The idea that impairments in humor, indirect requests, and narrative comprehension might be related to difficulty in attributing mental states finds theoretical support in [START_REF] Sperber | Relevance: Communication and cognition[END_REF] Relevance Theory, which proposes a central role for the attribution of and understanding of mental states in all communication. The relationship between mental-state attribution and comprehension of non-literal language has also been demonstrated experimentally in people with autism [START_REF] Happé | Communicative competence and theory of mind in autism: A test of relevance theory[END_REF].

To date, empirical support for a deficit in ToM in people with RHD has been suggestive, but inconclusive [START_REF] Weed | Theory of mind impairment in right hemisphere damage: A review of the evidence[END_REF], perhaps due to the type of experimental task used to measure social cognition. Tasks often require making judgments about the mental states of characters in single-frame cartoons, or in short stories. This type of task has been criticized, however, most prominently by Tompkins, who points out that these tasks usually require making meta-linguistic judgments about hypothetical situations, and may not accurately measure the underlying cognitive processes 0093-934X/$ -see front matter Ó 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.bandl.2010.01.009 in question [START_REF] Tompkins | Theory of mind' in adults with right hemisphere brain damage[END_REF][START_REF] Weed | Theory of mind impairment in right hemisphere damage: A review of the evidence[END_REF].

A more direct means of assessing participants' ability to impute mental states may be to measure their capacity to intuitively anthropomorphize. The spontaneous use of anthropomorphic language when describing animated objects moving and interacting in a purposeful way is a robust and well-known effect (see [START_REF] Rimé | The perception of interpersonal emotions originated by patterns of movement[END_REF] for a review). However, to our knowledge, animated geometric-shape stimuli have not yet been used to measure social cognition in people with damage to the right hemisphere. Body movements are an important reflection of an agent's intentions, and the importance of this kinetic information in mental-state attribution cannot be assessed using stories or line drawings.

Frith and Happé have developed a set of short, animated sequences involving moving geometric shapes [START_REF] Abell | Do triangles play tricks? Attribution of mental states to animated shapes in normal and abnormal development[END_REF][START_REF] Castelli | Movement and mind: A functional imaging study of perception and interpretation of complex intentional movement patterns[END_REF]. Based on the classic experimental stimulus used by [START_REF] Heider | An experimental study of apparent behavior[END_REF], these new stimuli consist of several animations in three categories: ToM (animations intended to evoke spontaneous anthropomizing), Random (animations in which the geometric shapes moved in a self-propelled fashion, but were not intended to evoke an anthropomorphic reading) and Goal-Directed (a middle category, intended to evoke a description of intention, but not explicit reference to mental states). All stimuli featured the same two triangles, one small and one large, as the protagonists. For example, in one of the ToM animations, the small triangle appears to tease the large triangle by knocking on a door, and then hiding when the large triangle pokes its head out and looks around. In contrast, a typical animation from the Random category has the two triangles moving mechanically back and forth across the screen, or bouncing aimlessly like billiard balls. The triangles have no other features that would suggest an anthropomorphic reading, such as eyes or faces; it is the human-like movement alone that promotes an anthropomorphic reading of the ToM films and differentiates them from the other films [START_REF] Scholl | Perceptual causality and animacy[END_REF]. Samples of the stimuli can be seen at http://sites.google.com/site/utafrith/ research.

Frith and colleagues have validated these animations with a healthy population and used them to investigate ToM in children with autism [START_REF] Abell | Do triangles play tricks? Attribution of mental states to animated shapes in normal and abnormal development[END_REF], in a woman with medial frontal brain damage [START_REF] Bird | The impact of extensive medial frontal lobe damage on 'theory of mind' and cognition[END_REF], and in healthy participants in a brain-imaging experiment [START_REF] Castelli | Movement and mind: A functional imaging study of perception and interpretation of complex intentional movement patterns[END_REF]. Other groups have used the animations to evaluate ToM abilities in women with Turner syndrome [START_REF] Lawrence | The development of mental state attributions in women with Xmonosomy, and the role of monoamine oxidase B in the sociocognitive phenotype[END_REF], in relation to fetal testosterone levels [START_REF] Knickmeyer | Fetal testosterone and empathy[END_REF], high-IQ children with autism [START_REF] Campbell | Meanings in motion and faces: Developmental associations between the processing of intention from geometrical animations and gaze detection accuracy[END_REF], alexithymia [START_REF] Moriguchi | Empathy and judging other's pain: An fMRI study of alexithymia[END_REF], and schizophrenia [START_REF] Russell | Do you see what I see? Interpretations of intentional movement in schizophrenia[END_REF]. The aim of this study was to use these same animated stimuli as a new means of assessing ToM in people with RHD.

Methods

Materials

Eight animations were selected from the animations used by [START_REF] Abell | Do triangles play tricks? Attribution of mental states to animated shapes in normal and abnormal development[END_REF]: the four 'Random' animations and the four 'ToM' animations from the original experiment. We did not use the middle category ('Goal-Directed') for this experiment; pre-testing indicated that these were more ambiguous, and we assumed that the two extremes would give the clearest results, while reducing the amount of time we required patients to attend to the task. Two of the unused animations were used in the practice session. A detailed description of the stimulus materials, their development, and validation can be found in [START_REF] Abell | Do triangles play tricks? Attribution of mental states to animated shapes in normal and abnormal development[END_REF]. The stimulus animations were presented using the software extension Cogent 2000 (Wellcome Department of Imaging Neuroscience, University College London, London, UK; http://www.fil.ion.ucl.ac.uk) for MATLAB (Mathworks Inc., Sherborn, MA, USA), and oral descriptions of the animations were recorded using an Olympus digital voice recorder.

Testing procedures

All participants were tested in a quiet room. Prior to testing, the participants in the RHD group were given a clinical evaluation for hemispatial neglect. In addition, the participants were shown a picture on the computer screen, and were asked to describe what they saw in each of the four corners. All participants were able to satisfactorily describe the entire picture. Participants were instructed to view each film and then judge, by means of buttonpress, whether or not the film suggested a story to them, following which they were asked to describe the film they had just seen aloud. Participants completed two practice trials with the experimenter present, to insure they had understood the instructions. The experimenter then left the room while the participant completed the rest of the test alone.

The animations were presented in a randomized order on a computer screen. Following each animation, the participant was presented with the on-screen question ''Synes du der var en historie?" (do you think/feel there was a story?). The wording of this test question was designed to encourage participants to rely on their intuitions about the films, rather than to make a more calculated judgment. Participants responded to this question by button-press. Following the button-press response, an on-screen instruction appeared asking participants to describe the animation they had just seen. Both the button-press and oral description tasks were selfpaced.

Coding procedures

The oral descriptions were transcribed and coded by the primary investigator and two independent coders. The independent coders were both graduate students at the University of Aarhus, and were native speakers of Danish. Prior to coding, the individual transcriptions were randomly mixed together, so that the coders had no information about the identity of the speaker, or to which group the speaker belonged.

Coding for ToM

Transcripts were first categorized according to the procedure described by [START_REF] Abell | Do triangles play tricks? Attribution of mental states to animated shapes in normal and abnormal development[END_REF], adapted to Danish. Each film description was categorized as either (1) a description of action, with no ascription of either intentional or mental states to the triangles, (2) a description in which the speaker appeared to ascribe intentions to the triangles, but made no reference to specific mental states, or (3) a description in which specific mental states are ascribed to the triangles. Although we did not use the Goal-Directed category from the original set of animations, we felt it was important to maintain the intentional language coding category, as this would allow for a more fine-grained analysis of the participants' descriptions.

Following [START_REF] Abell | Do triangles play tricks? Attribution of mental states to animated shapes in normal and abnormal development[END_REF], descriptions such as ''the red one tried to knock the blue one over" were categorized as ascribing intentions but not mental states. Verbs such as ''to try" were not sufficient to categorize a description as a mental state description. However, a description such as ''. . . it was a shy person on his way in, who knocked on the door but is a little bashful. . ." were categorized as mental state descriptions. In this example, the key word is ''bashful", as this makes an explicit reference to the internal mental states of the character.

Coding for attribution of intentions

Using the mental-state coding rules, adapted from [START_REF] Abell | Do triangles play tricks? Attribution of mental states to animated shapes in normal and abnormal development[END_REF], neither the control group nor the RHD group made many references to mental states at all. On closer examination, however, it seemed that both groups used many expressions that implied mental-state attribution, although the mental states were not mentioned explicitly. As an example, consider the following: ''The red had caught the blue and put it in jail and guarded the entrance, and then the little one runs away at the end and the red goes out after it". In this description, taken from our data, there were no words that explicitly ascribed a mental state to the triangles. Nonetheless, several of the phrases, such as ''put it in jail and guarded the entrance" and ''the little one runs away" certainly seem to imply that the speaker is attributing mental states to the triangles. Putting the blue triangle in jail and guarding the entrance implies that the red triangle desires that the blue triangle remain imprisoned, and ''the little one runs away" implies that the little triangle wants to escape but is aware that the red one wants to keep it imprisoned. We therefore performed a second coding procedure, in which coders counted instances of expressions suggesting attribution of intentions to the triangles. Each transcription was first divided into linguistically meaningful phrases, consisting of a subject, a verb, and an object, to the degree that this was possible given the spontaneous spoken material. The coders underlined each whole phrase that they felt implied an ascription of intentions by the speaker to the triangles, and the number of underlined phrases was divided by the total number of phrases in each transcription to give an index of intention-ascription that was independent of the total number of words spoken in each description.

Participants

Participants with RHD (N = 11, 8 male, median age 65 years) with their first clinical stroke (Table 1) were recruited from the body of patients admitted to the Hammel Neurorehabilitation and Research Center in Hammel, Denmark. Only participants with right hemisphere cortical lesions were included. All participants were right handed. Lesions were located by CT or MRI-scans and ischemic lesions were classified in accordance with the Bamford classification system [START_REF] Bamford | Classification and natural history of clinically identifiable subtypes of cerebral infarction[END_REF]). An overall index of disability was estimated using the functional independence measure (FIM), an 18-item, 7-level scale that rates the ability of persons with disabilities to perform independently in self-care, sphincter control, transfers, locomotion, communication and social cognition [START_REF] Ottenbacher | The reliability of the functional independence measure: A quantitative review[END_REF]. A total score is obtained by summing the scores across all 18 items; scores range from 18 (maximally dependent) to 126 (maximally independent). All participants gave written informed consent to participate in the study. The local ethical committee reviewed and approved the study, and the experiment was conducted according to the standards set by the Declaration of Helsinki. The non brain-damaged (NBD) control group (N = 10, 4 male, median age 65 years) was matched as closely as possible for years of education. The control participants reported that they were not using any medication that affected their cognitive function, nor had they incurred any form of brain damage. All participants were native speakers of Danish.

Results

Button-press task

The RHD group performed at about chance level in the buttonpress task, making more errors (NBD: M = 2.14, SD = 1.86; RHD: M = 3.82, SD = 0.75) than the NBD group (t(7) = 1.9, p < 0.05, onetailed). An error was defined as categorizing an animation from the Random Action condition as a story, or categorizing an animation from the ToM condition as a non-story.

Coding for theory of mind

Inter-rater reliability for the first, categorical coding procedure was satisfactory (mean pairwise Cohen's kappa = 0.488). Both the RHD group and the NBD group used relatively little language that could be categorized as ascribing specific mental states to the triangles. There were no substantial differences between the groups in the total number of description types used for any one category; both groups used roughly equal amounts of Action, Intention, and Theory of Mind descriptions. There was a difference, however, in the way the groups differentiated their language (Fig. 1).

The three description types were first assessed together in a MANOVA. There was a significant main effect for condition (F(2, 37) = 4.849, p < 0.05) and a significant group by condition interaction (F(2, 37) = 3.796, p < 0.05). There was no significant main effect for group (F(2, 37) = .57, p = 0.57). A separate ANOVA was then performed on each of the three description types. For action descriptions, there was a significant main effect of condition (F(1, 19) = 8.014, p < 0.05), and a significant condition by group interaction (F(1, 19) = 7.140, p < 0.05). For ToM descriptions, there was a significant main effect of condition (F(1, 19) = 13.209, p < 0.05), and a significant condition by group interaction (F(1, 19) = 5.999, p < 0.05). For descriptions coded as descriptions of interaction without reference to specific mental states, the NBD group used nearly twice as many of these descriptions in the ToM condition as in the Random Action condition (ToM: M = 0.6, Random Action: M = 0.31), while the RHD group did not differentiate greatly between the categories (ToM: M = 0.36, Random Action: M = 0.39). However, this condition by group interaction failed to reach significance in the mixed-model ANOVA (F(1, 19) = 3.001, p = 0.09) (Fig. 1).

Coding for attribution of intentions

Inter-rater reliability for the second coding procedure was good (average measures intraclass correlation = 0.679). The proportions of the total number of clauses coded as intentional language by the three coders for the individual descriptions were averaged together, resulting in a mean score for each item. These item means were then averaged, resulting in an overall proportion of intentional language for each participant for each condition (Fig. 2). These mean scores were tested with a mixed-model ANOVA. There was a significant main effect of condition (F(1, 19) = 22.7, p = < 0.001) and a significant condition by group interaction (F (1, 19) = 6.96, p = < 0.05). As Fig. 2 illustrates, the interaction effect was driven by a difference between groups in the ToM condition, and a separate t-test (two-tailed) performed solely on the data from the ToM condition supported this; t(19) = 2.57, p < 0.05 (see Table 2).

Discussion

We found that the RHD group displayed a reduced ability to discriminate between the stimulus categories, and a bias toward reduced ascription of mental states in the ToM condition. In the following, we discuss these findings, and relate them to current issues in the literature.

The two coding procedures

The coding procedure used by [START_REF] Abell | Do triangles play tricks? Attribution of mental states to animated shapes in normal and abnormal development[END_REF] only allows for a description to be counted as a ToM ''hit" when the description includes an explicit reference to a mental state, for instance, ''to feel bashful." This is a fairly strict procedure, and it excludes a good number of descriptions that might otherwise seem to imply the ascription of mental states. However, we felt it important to include this procedure for two reasons. First, since this was the first time these stimuli had been used to investigate ToM in an RHD group, we felt it important to maintain a certain degree of continuity with previous studies using the same stimuli.

Our second reason for distinguishing between language that made explicit reference to mental states and language that merely referred to intentions was to avoid accidentally coding metaphoric or ambiguous phrases as instances of ToM. For instance, one might say something like ''the road approached the city." Although the word ''approach" might suggest a sort of intentional movement, the speaker of this sentence probably does not actually mean to ascribe a mental state to the road.

At the same time, there were passages of text, such as the one cited above with the triangle that ''guarded the entrance", which seemed to imply that the speaker was attributing mental states to the triangles, but which counted as ToM ''misses" according to the first coding procedure. Since our interest was in trying to measure the participants' ascriptions of mental states to the triangles, and not the linguistic form used to express the ascription, we performed the second coding procedure as well. This second procedure was based more heavily on the coders' intuitions about the speakers' ascriptions, rather than strictly on the linguistic form as in the first coding procedure. Although the coding procedures were slightly different, the main results were similar in both cases.

Reduced ability to discriminate

The two film categories were distinguished solely by the motion of the triangles. Although the triangles moved and came in close contact with each other in both categories, only in the ToM animations did this movement strongly suggest an interaction between two sentient beings with intentions toward one another; the movement in the Random Action category was mechanical.

The RHD group was less able than the NBD group to accurately categorize the films by button-press. The question (''do you feel there was a story?") was open-ended, and members of the NBD group did also categorize some of the Random Action animations as ToM. The RHD group, however, appeared to make their categorical decisions at random. As indicated by Fig. 1, the NBD group varied their language according to the stimulus condition, while the RHD group did not. As shown in Fig. 2, this was also true of the second coding procedure, in which the RHD group did not modulate their language in terms of the amount of ''intentional" clauses used when describing the films. The NBD group, in contrast, increased the amount of ascriptions of intentions when viewing the ToM films significantly more than the RHD group. Together, these results suggest that the RHD group either had difficulty perceiving or, having perceived, difficulty making use of the kinetic information embedded in the films when making their categorical decisions or describing the films.

Complex motion perception

Two of the RHD participants in the present study had incurred temporal-parietal damage, as confirmed by either MR or CT scan. Five others had lesions clinically diagnosed as a total anterior circulation infarct, which is likely to have affected large areas of the right hemisphere, including temporal and parietal areas. A number of studies have indicated that a temporal region, encompassing the posterior superior temporal sulcus (pSTS) and the adjacent posterior superior temporal gyrus (pSTG), plays a crucial role in the perception of complex motion, including intentional and biological motion.

Although both the left and right pSTS/pSTG seem to be involved in biological motion perception, there is some evidence that the right pSTS may be of particular importance. Saxe, in particular, has argued for a special role for the right temporal sulcus in biological motion and social cognition [START_REF] Saxe | Uniquely human social cognition[END_REF][START_REF] Saxe | Making sense of another mind: The role of the right temporo-parietal junction[END_REF][START_REF] Saxe | A region of right posterior superior temporal sulcus responds to observed intentional actions[END_REF], and [START_REF] Grossman | Brain areas involved in perception of biological motion[END_REF] found the right STS to be more active than the left during biological motion perception. [START_REF] Saygin | Superior temporal and premotor brain areas necessary for biological motion perception[END_REF], however, reports impairments among both RHD and LHD (left-hemisphere damage) participants in a biological motion task.

Closely related to the perception of biological motion is the perception of animacy. In two PET studies using the same animated stimuli that we used in the present study, [START_REF] Castelli | Movement and mind: A functional imaging study of perception and interpretation of complex intentional movement patterns[END_REF] and [START_REF] Castelli | Autism, asperger syndrome and brain mechanisms for the attribution of mental states to animated shapes[END_REF] have found activation around pSTS related to perception of the triangles as intentional agents. [START_REF] Schultz | Activation of the human superior temporal gyrus during observation of goal attribution by intentional objects[END_REF] and [START_REF] Schultz | Activation in posterior superior temporal sulcus parallels parameter inducing the percept of animacy[END_REF] report from fMRI studies using similar animated geometric shapes, in which anima-tions representing intentional actions elicited increased activation in pSTS and pSTG. Although the stimuli used in these studies were not, strictly speaking, biological motion stimuli of the point-light sort, they suggested animacy, and elicited activation in the same areas often implicated in point-light studies of biological motion [START_REF] Blake | Perception of human motion[END_REF].

Taken together, these studies are strong evidence for the importance of the pSTS and pSTG, areas likely to be affected in many of the RHD participants in the present study, in the perception of both biological and animate, intentional motion. This would account for the RHD participants' reduced ability to discriminate between the stimulus conditions. If participants from the RHD group were impaired in their ability to perceive animacy and intentionality because of damage to pSTS or pSTG, this information, which is critical for both the categorization and description tasks, would be unavailable to them. An impairment in perception of animacy could also explain the bias toward reduced mentalizing in the ToM condition seen in the RHD group. Perception of biological motion, animacy, and intention are thought to be key elements in an extensive brain network responsible for social cognition [START_REF] Frith | The social brain?[END_REF]. Ascribing intentions and mental states to the animated triangles relies on the ability to extrapolate beliefs, desires, and goals from the kinetic information embedded in the animations. Without access to or with reduced access to the perception of biological/ animate motion, participants would have difficulty describing what the triangles might be doing or thinking.

Damage to frontal systems

Although an impairment in perception of animacy resulting from damage to the pSTS/pSTG region seems a likely explanation for our results, it is also the case that not all of our RHD participants had damage to this area. At least one of the participants had solely frontal damage, and several had frontal damage in addition to potential temporal and parietal damage. Might there then also be a frontal component to the impairments we observed?

Four of the participants from the RHD group (numbers 2, 5-7) stood out from the others, because they seemed to have a strong inclination to apply a single interpretive frame to all of the films. These four participants answered consistently either ''yes" or ''no" to the question ''do you feel there was a story?" for all films. Furthermore, their verbal descriptions of these same films suggest that they interpreted the eight films as a single film in eight episodes, rather than eight separate films, each with their own storyline.

Although we had no tools to assess this point quantitatively, this appeared to be a tendency among many members of the RHD group. One seemed to see all eight films as installments in an extended battle of wills between the triangles, saying at one point: ''. . . [the film] ends with the remaining triangle enjoying total hegemony over the area. We shall see. . . I do not think it will -I think there will be a continuation" and at another point, ''. . . the fight ends with the red one driving the blue one out, but one is nonetheless certain that there will be a continuation -they are not finished with this business!" Another participant from the RHD group begins a description of a new film by saying, ''We continue the story. . ." and a third begins a description by saying ''This story is, in fact, the same. . .". Other members of the RHD group seemed to adopt a ''physical story" frame, narrating all of the films in terms of the physical movements of the triangles, and making little or no mention of intentional, emotional, or mental states. This is compatible with much of the earlier research on RHD and right-hemisphere processes in general, such as Coulson's idea that impaired frame-shifting may explain people with RHD's reported difficulties with humor comprehension [START_REF] Coulson | Hemispheric asymmetry and pun comprehension: When cowboys have sore calves[END_REF][START_REF] Coulson | Hemispheric asymmetries and joke comprehension[END_REF], Tompkins' idea that a suppression deficit may undermine people with RHD's ability to revise inferences [START_REF] Tompkins | Mechanisms of discourse comprehension impairment after right hemisphere brain damage suppression in lexical ambiguity resolution[END_REF][START_REF] Tompkins | Suppression and discourse comprehension in right brain-damaged adults: A preliminary report[END_REF][START_REF] Tompkins | Mechanisms of discourse comprehension impairment after right hemisphere brain damage suppression in inferential ambiguity resolution[END_REF], as well as classic work on the integration of information in humor and narrative comprehension in people with RHD [START_REF] Brownell | Inference deficits in right brain-damaged patients[END_REF][START_REF] Wapner | The role of the right hemisphere in the apprehension of complex linguistic materials[END_REF].

An ongoing debate in the literature has been the extent to which the discourse impairments observed in people with RHD are the result of damage to the right hemisphere in general, or whether it is more specifically frontal damage that causes discourse impairment [START_REF] Channon | Interpretation of mentalistic actions and sarcastic remarks: Effects of frontal and posterior lesions on mentalising[END_REF][START_REF] Cheang | A study of humour and communicative intention following right hemisphere stroke[END_REF][START_REF] Shamay-Tsoory | The neuroanatomical basis of understanding sarcasm and its relationship to social cognition[END_REF][START_REF] Shammi | Humour appreciation: A role of the right frontal lobe[END_REF]. Results reported by Aron and others [START_REF] Aron | Stop-signal inhibition disrupted by damage to right inferior frontal gyrus in humans[END_REF][START_REF] Aron | Inhibition and the right inferior frontal cortex[END_REF] suggest a special role for the right inferior frontal cortex in the suppression of initially-activated scripts in favor of others. Although [START_REF] Shallice | Mapping task switching in frontal cortex through neuropsychological group studies[END_REF] do not ascribe the same importance in suppression to the right frontal cortex that [START_REF] Aron | Stop-signal inhibition disrupted by damage to right inferior frontal gyrus in humans[END_REF][START_REF] Aron | Inhibition and the right inferior frontal cortex[END_REF]) do, they do see an important role for the right frontal cortex in task-monitoring, that is, deciding when it is time to switch from one task to the other. Both interpretations are consistent with the idea that patients with RHD have difficulty in using context, or in the case of the present study, visual kinetic cues, to choose the appropriate interpretation of a stimulus, be it linguistic or otherwise.

Although the evidence is not unequivocal, there is further evidence from lesion-overlap studies suggesting a role for the RH in linguistic tasks that might be assumed to involve suppression of dominant but incorrect meanings. A study by [START_REF] Channon | Interpretation of mentalistic actions and sarcastic remarks: Effects of frontal and posterior lesions on mentalising[END_REF] found that right frontal lesions were associated with impairment in selecting among alternatives when judging sarcasm. [START_REF] Shamay-Tsoory | The neuroanatomical basis of understanding sarcasm and its relationship to social cognition[END_REF] also found that right frontal damage was associated with difficulty in comprehending sarcasm. However, they pinpoint ventral-medial areas, rather than inferior frontal areas, and interpret their results as related to emotional circuits, rather than inhibitory circuits.

Although the application of a single interpretive framework that we observed in our several of the participants from the RHD group resembled what one might expect from frontal damage, there was no obvious correlation between lesion location and persistence in applying the same story framework. Of the four RHD participants mentioned above, two had frontal damage, and two did not. In addition, the other RHD participants who seemed to exhibit this tendency did not have damage restricted to the frontal cortex. Thus, while our results may support a general RH involvement in frame-shifting, they lend no support to a decidedly frontal-executive interpretation.

Reduced mental-state ascription

The RHD group was capable of attributing intentions to the triangles, but did so inappropriately. As a group, the participants with RHD used less language coded as indicating an explicit ascription of mental states. However, one individual from the RHD group showed the opposite pattern, tending to over-ascribe mental states. This participant described a film in which the triangles bounce back and forth across the screen in a rather aimless, ping-pong-like fashion in the following way:

Here we see the red and the blue triangle again, and they still have not become allied or connected with each other. They live in a peaceful coexistence, they have created a neutral area known as the blue square, in which there is an opening so that on the face of things they could enter the square, but none of them do it. They circle around it, both are clearly interested in the square but they do not step over the line and they do not take anything where the other one would be able to say that they had taken something that was less-that is, that they had gotten more than that which they are apparently allotted by a sort of mutual agreement and that mutual agreement states that the square is a neutral area. This is reminiscent of results reported by Champagne-Lavau and Joanette (2007), who found that participants with RHD tended to make significantly more errors in the interpretation of direct requests than did a control group. Champagne-Lavau and Joanette (2007) suggest that people with RHD may over-attribute intentions to the protagonists in a story task. Although one subject from the present study exhibited this behavior, the tendency of the group was to under-attribute mental states.

Our results support the results of previous studies reporting reduced performance on ToM tasks in people with RHD [START_REF] Brownell | Cerebral lateralization and theory of mind[END_REF][START_REF] Griffin | Theory of mind and the right cerebral hemisphere: Refining the scope of impairment[END_REF][START_REF] Happé | Acquired 'theory of mind' impairments following stroke[END_REF][START_REF] Winner | Distinguishing lies from jokes: Theory of mind deficits and discourse interpretation in right hemisphere brain-damaged patients[END_REF], and point to the need to investigate means of training ToM skills as a part of a post-stroke rehabilitation program [START_REF] Lundgren | Training theory of mind following right hemisphere damage: A pilot study[END_REF]. Whether the performance of people with RHD on ToM tasks is due to a specific ToM deficit or whether performance on ToM tasks is reduced in people with RHD because of impairments in a variety of cognitive domains is still an open question, however, and cannot be answered with the results from the present study. However, our data indicate that impairment on ToM tasks can arise from damage to a variety of cortical areas in the RH, suggesting that more than one cognitive mechanism may affect performance on ToM tasks. Our study included RHD participants with both frontal and/or temporal-parietal damage. As we have seen, impaired perception of animacy and impaired frame-shifting abilities may both have influenced our results. Although both of these abilities are important for social cognition, neither of them is specific to social cognition. We therefore find it likely that the performance of participants with RHD on ToM tasks is not due to a domain-specific ToM impairment. Further research will be needed, however, to firmly establish this.

Problems and potential sources of error

Three factors present potential problems for the interpretation of the data presented here. First, because of the small sample size, and the normal variation among both the RHD and the NBD groups, we must be careful about making generalizations to the population level. Second, the open-ended nature of the task makes a quantitative analysis of the data challenging. This is a problem that has also plagued previous investigations of linguistic production in RHD [START_REF] Heath | Spontaneous humor among right hemisphere stroke survivors[END_REF]. One promising method of avoiding the issue of variability in open-ended self-reports is to employ eyetracking methods, as recently shown by [START_REF] Klein | Animated triangles: An eye tracking investigation[END_REF]. Use of eye-tracking equipment would also allow the inclusion of an LHD group for comparison, which was impossible in the present study due to the general linguistic impairments among patients with LHD. Finally, the task, as we posed it, may have led participants in the both the control and the RHD groups to feel that they were expected to read stories into the films, when they might not naturally have done so otherwise. An interesting manipulation would be tell participants ahead of time whether or not a given film was or was not intended as a story, to see whether the participants in the present study were responding more to the films directly, or the experimental situation and the perceived need to make up a story for the films.

Unanswered questions and future research

We have suggested that either of two separate cognitive systems may have affected the performance of the RHD group on our task: a temporal-parietal system involved in the perception of biological motion, and a frontal system involved in task-monitoring or task-switching. In future studies, it will be useful to see whether performance on tasks specifically tapping these systems correlates with impairment on ToM tasks, including tasks using animated stimuli like the Frith-Happé triangles. It will also be useful to compare the same RHD participants on a wider range of ToM tasks, to see whether they are impaired on all, or only some of them. Finally, the inclusion of an LHD control group is an important next step; this could potentially be accomplished using eye-tracking methods.

Conclusions

Impaired communication is an important symptom often associated with right hemisphere damage. This can manifest itself in different ways, but a common theme is a reduced ability to function normally in social settings. Theory of Mind has been identified as a critical cognitive component in normal communication and social interactions. The aim of this study was to measure Theory of Mind abilities in RHD using animated stimuli. The RHD group showed a reduced ability to discriminate between the two stimulus categories, and a bias toward under-attribution of mental states when viewing the ToM animations, suggestion that they either had difficulty perceiving or using the kinetic information embedded in the animations, or both. We suggest that either an impairment in complex motion perception, or an impairment in higher-level frame-shifting may have affected the RHD group's performance on the task.

Fig. 1 .Fig. 2 .

 12 Fig. 1. Proportions of description types for the two film categories (Random Action and ToM). Proportions reflect averages across all coders. Error bars represent standard error of the mean.

Table 1

 1 Description of participants with right hemisphere lesion.

	Participant	Diagnosis	Location a	Gender	Age	F1M b	Months since stroke
	1	Hemorrhage/infarction	Frontal a TACI	Male	71	110	3
	2	Hemorrhage	Frontal	Female	67	116	4
	3	Infarction	TACI	Male	63	c	5
	4	Hemorrhage/infarction	Frontal + TACI	Female	46	34	7
	5	Infarction	PACI	Male	61	93	3
	6	Infarction	TACI	Male	57	121	2
	7	Hemorrhage	Frontal a PACI	Female	52	104	3
	8	Hemorrhage	Temporo-parietal	Male	73	103	1
	9	Infarction	PACI	Male	155	57	2
	10	Hemorrhage	Fronto-parieto-temporal	Male	159		1
	11	Infarction	TACI	Male	63	116	3

a Bamford classification (TACI = total anterior circulation infarct, PACT = partial anterior circulation infarct). b Functional independence measure, range (18-126). c Missing value.

Table 2

 2 Individual results for RHD group.

	Participant	Proportion of	Number of ''no"	Number of
	(RHD	descriptions of ToM	answers to button-	errors on
	group)	stimuli using action	press question 'do	button-press
		language (ToM as	you feel there was a	task (out of
		act)	stoy?'	eight possible)
	1	0	2	2
	2	0	0	4
	3	1	3	4
	4	0.66	6	4
	5	0.08	0	4
	6	0.33	8	4
	7	0.83	8	4
	8	0.41	4	5
	9	0.33	4	4
	10	0.5	2	3
	11	0.75	2	4

Please cite this article in press as: Weed, E., et al. Theory of Mind in adults with right hemisphere damage: What's the story? Brain & Language (2010), doi:10.1016/j.bandl.2010.01.009

Please cite this article in press as: Weed, E., et al. Theory of Mind in adults with right hemisphere damage: What's the story? Brain & Language (2010),

Acknowledgments

The authors wish to thank Chris Frith, Morten Overgaard, Mads Jensen, and Martin Dietz for their kind help and expertise during the course of this experiment. Thanks also to two anonymous reviewers, whose comments greatly improved the quality of this manuscript. This work was supported by the Aarhus University Faculty of Humanities and the Danish National Research Foundation's grant to the Center for Functionally Integrative Neuroscience.

Appendix A. Instructions to coders

Our instructions to coders for the first coding procedure were adapted from [START_REF] Abell | Do triangles play tricks? Attribution of mental states to animated shapes in normal and abnormal development[END_REF]. Our data were collected and scored in Danish; we present here an English translation of the coding instructions.

A.1. Intentions

Count each phrase in which an expression is used that suggests that the speaker is ascribing intentions to the triangles. Underline each phrase you include. The texts are divided with slashes -the phrases between the slashes count as one unit.

Ex.:

The triangles flew around on the screen/at one point the red one tried to get out of the square/later the blue one tried to open the door/but it gave up/.

In this example, the score would be 3.

A.2. Description type

Read each description and decide whether it describes Random Actions, intentional actions, or whether the speaker ascribes specific mental states to the triangles.

Each description may only belong to one category. Random Action is the lowest category, and mental state the highest. Each description always receives the highest possible category (intentional trumps Random Action, and mental state trumps intentional). NB: this time, you should rate the description as a whole: give one number per description, no matter how many or how few references to mental states there occur in the description.

Random Action

Ex. 1 ''They just flew around on the screen and I don't think there was a story" = Random Action (1). NB: ''I don't think" does not count as a mental state, because the speaker is referring to herself, not to the triangles.

Ex. 2 ''One might almost think that the red tried to capture the blue one" = intentional (2). NB: ''tried to" is not enough by itself for the description to count as a 3. NB: just as ''I don't think" refers to the speaker and not the triangles, ''one might almost think" does not refer to the triangles, and does not count as a mental-state ascription.

Ex. 3 ''The red and the blue triangle wanted to make contact with each other" = mental-state ascription (3). NB: the key phrase in this case is ''wanted to": the triangles wanted something from each other.