Pablo Fernandez Velasco
email: pfernandezvelasco@ens.frroberto.casati@ens.fr

Roberto Casati

Disorientation and GIS-informed Wilderness Search and Rescue

. Although this method has proven effective, there is a missing link between WiSAR theory and advances in other fields related to disorientation (e.g. psychology and neuroscience). A unified conceptualisation of disorientation is a crucial element for understanding the mind and behaviour of disoriented subjects. The central aim of this chapter is to explore how a unified conceptualisation of disorientation can contribute to GISinformed WiSAR theory.

The paper will open with a review of the work on disorientation coming from different fields, to then introduce the conceptual work that is needed for a unified account of disorientation. We will discuss two different approaches to WiSAR theory: a ring model and a Bayesian model. We end on a discussion on how conceptual work on disorientation and GIS-informed WiSAR theory can help each other advance.

Disorientation Review

Again something dark appeared in front of him. Again he rejoiced, convinced that now it was certainly a village. But once more it was the same boundary line overgrown with wormwood, once more the same wormwood desperately tossed by the wind and carrying unreasoning terror to his heart.

. In 1998, Kenneth Hill

conducted over a hundred interviews with subjects who had become lost in the wilderness, and constructed a list of typical disoriented behaviour that has now become a central reference in the study of lost person psychology.

Hill claimed that when lost, people followed (at least) one of the following patterns and strategies: random traveling (often caused by confusion and high emotional arousal), route traveling (i.e. following a given route in the hope of finding something familiar), direction traveling (trying to follow a given direction), route sampling (using an intersection as a base for exploring different routes), direction sampling (using a visible landmark as a base for exploring different directions), view enhancing (aiming for a high position in order to gain visibility), backtracking, using folk wisdom (e.g. follow streams to civilisation) and staying put (which according to Hill is the most effective strategy if a SAR operation is triggered).

There has been some work relating this taxonomy of lost person behaviour with different categories of lost subjects (e.g. hunters are more likely than others to use direction sampling, while hikers are more likely to use route following). Nevertheless, there isn't any work relating the taxonomy to a broader conceptualisation of disorientation (e.g. how disorientation arises and what makes subjects follow one method over another) or to the work in other fields such as neuroscience.

In an effort to establish a link between the behavioural psychology and the neuroscience of disorientation, Dudchenko holds that humans, unlike other animals, need vision to stay oriented [START_REF] Dudchenko | Why People Get Lost: The Psychology and Neuroscience of Spatial Cognition[END_REF]. This makes sense because landmarks are used to update one's orientation and position within a cognitive map (Scholl, 1987;[START_REF] Knierim | Framing Spatial Cognition: Neural Representations of Proximal and Distal Frames of Reference and Their Roles in Navigation[END_REF]. The notion of cognitive maps was originally developed by Tolman as a hypothesis to explain rat behaviour in labyrinths without reducing the said behaviour to stimulus-response connections. Tolman supports the view that rats construct something similar to a field map with results from different experiments, including shows of initial latent learning that gets activated when reward is offered later [START_REF] Blodgett | The Effect of the Introduction of Reward upon the Maze Performance of Rats[END_REF], rats sampling of the environments [START_REF] Tolman | The Determiners of Behavior at a Choice Point[END_REF], and rats finding shortcuts that they had not learned through stimulus-responseÒ conditioning [START_REF] Tolman | Cognitive Maps in Rats and Men[END_REF].

The discovery of place cells in the rodent hippocampus further supported the idea of a cognitive map [START_REF] O'keefe | The Hippocampus as a Spatial Map: Preliminary Evidence from Unit Activity in the Freely-Moving Rat[END_REF], which has now become central in the study of spatial cognition.

Place cells fire as a function of the rodent's spatial location. Other cells that may play a role in navigation are grid cells (which fire in a hexagonal grid that corresponds with the environment floor, where the grid module is correlated with the size of the animal; [START_REF] Hafting | Microstructure of a Spatial Map in the Entorhinal Cortex[END_REF], head direction cells (which fire depending on head orientation; [START_REF] Ranck | Head Direction Cells in the Deep Cell Layer of Dorsolateral Pre-Subiculum in Freely Moving Rats[END_REF][START_REF] Taube | Head-Direction Cells Recorded from the Postsubiculum in Freely Moving Rats. I. Description and Quantitative Analysis[END_REF]) and boundary vector cells (which fire when the rodent, moving in a certain direction, gets to a specific distance from a boundary element of the environment; [START_REF] Barry | The Boundary Vector Cell Model of Place Cell Firing and Spatial Memory[END_REF]).

An observation is in order. Different classes of spatial features are coded by different cell systems, as per the following table :   Cell type Geometric feature coded Example

Place cells Individual locations

The entrance of the maze, the fork, etc.

Grid cells Metric properties

Distance covered based on number and size of grid modules Head direction cells Angles Azimuth of a landmark relative to body's central plane of symmetry

Boundary vector cells Topological properties

The middle of the room, close to the wall This suggests that the spatial representation system could work in a constraint satisfaction mode, looking for solutions that take into account whichever topological, metric, angular and location representations are available at a given moment.

Of course, an open question is if the same type of cells and the same type of cognitive map exists in humans. Although the invasive single-cell recording techniques that are used in rats have not been used in humans, there is some empirical literature to support the idea that work on rodent spatial cognition can be extrapolated to humans to a substantial degree (see Epstein et al 2017 for a review).

For instance, a much quoted fMRI study of Taxi drivers in London show that they acquire larger right posterior hippocampi as a result of the years-long training they undertake to learn the map of London streets [START_REF] Woollett | Acquiring 'the Knowledge' of London's Layout Drives Structural Brain Changes[END_REF].

If the underpinnings of human spatial cognition do not differ substantially from those of rodent spatial cognition, then the hippocampus can store different maps for different environments, and even represent different conditions of the same environment. Different place cells would then fire for different environments, following a 'global remapping' as the subject changes environments. When the same environment changes conditions, the place cells that fire stay the same, but the rate at which they fire changes (Colgin, Moser and Moser, 2008). It should be noted that landmarks play an important role in anchoring these cognitive maps (Yonder, Clark and Taube, 2011). Finally, when it comes to navigation, the grid cell network computes the direction and distance to the navigational goal [START_REF] Kubie | Linear Look-Ahead in Conjunctive Cells: An Entorhinal Mechanism for Vector-Based Navigation[END_REF], while the hippocampus and enthorinal cortex work together to calculate the optimal path to the goal (Bryne, Becker and Burgess, 2007).

It is beyond the scope of this paper to explore in-depth the empirical literature on spatial cognition, but in addition to the brief review above, we should refer to some of the work that is of special relevance for the study of disorientation. An example of this work are experiments exploring what happens to the rodent's place field map and HD cells when disorientation occurs. The geometry of the environment (disregarding useful non-geometric cues) determines the realignment of the cognitive map, which determines in turn the behaviour of the animal during navigation [START_REF] Keinath | Environmental Geometry Aligns the Hippocampal Map during Spatial Reorientation[END_REF]. An interesting distinction is to be made between orientation and context retrieval. Orientation refers to one's location and direction within a cognitive map of a given place, and context retrieval refers to the retrieval of the specific map that is appropriate for the place in question. In mice, context retrieval and orientation have been found to be mediated by dissociable cognitive processes, and it is not inappropriate to think that the same could be the case for humans [START_REF] Julian | Place Recognition and Heading Retrieval Are Mediated by Dissociable Cognitive Systems in Mice[END_REF].

Although there is an increasingly clear picture of human orientation coming from spatial cognition, the study of lost person behaviour is not connected to this body of research. The result is that there is no unified account of disorientation that can draw on the different fields that deal with the phenomenon. Conceptual work is needed to link spatial cognition and the psychology of lost person behaviour (see Casati and Fernandez Velasco, forthcoming). Establishing this link will advance the understanding of disorientation and will allow WiSAR to profit from the progress coming from a broad variety of disciplines.

Disorientation. Conceptual Issues.

There are several impediments that keep the different fields concerned with disorientation from

associating. An important one is that these fields operate at different levels of analysis. Even within neuroscience, where most explanations appertain to the neural level, there is a chasm between the single-cell study that is possible in non-human cognition and the non-invasive neuroimaging studies done in human cognition. Moreover, functional magnetic resonance imaging cannot be done while subjects travel physically through space, which restricts investigation to non-ecological, purely represented settings. Although some lost person psychology relies on first person reports (Hill, 1982),

for the most part it is concerned with the third-person analysis of behaviour. In the case of WiSAR the separation from spatial cognition goes one step further, as most of WiSAR work operates at the level of statistical patterns emerging from lost person behaviour [START_REF] Koester | Lost Person Behavior: A Search and Rescue[END_REF].

Another important element that separates these fields is that they tend to draw from different A symptom of this divergence among fields is a divergence among characterisations of the phenomenon of disorientation itself. Disorientation could be understood, among others: as being unable to find one's way [START_REF] Dudchenko | Why People Get Lost: The Psychology and Neuroscience of Spatial Cognition[END_REF]; as the failure of the way-finding process (Golledge, 1999); or as not knowing the directions and distances to get to a given point (Rieser, 1999). These all seem to point to the same phenomenon, but it should be noted that they each characterise disorientation in a proprietary way: as an issue of ability, failure or knowledge, respectively.

Although the above characterisations each capture some of the features of disorientation, they all have certain shortcomings. A central issue here is that while being lost in an objective condition, disorientation is a strongly subjective one. Being lost can be easily characterised as being unable to find one's way, but this characterisation does not necessarily extend to disorientation. Take the following case, for instance:

Maggie is following a path through the woods that leads to the Dorlcote Mill. The path is very hilly and sinuous, changing directions often, which makes Maggie feel disoriented.

Disregarding her disorientation, she keeps going and eventually gets to the Dorlcote Mill.

In this case, Maggie is not lost (i.e. she is able to find her way), but she is disoriented; a distinction that Duchenko's characterisation fails to capture. And while Dudchenko's characterisation fails to capture some cases of disorientation, Golledge's characterisation overshoots, mistakingly identifying certain cases of being lost as disorientation. Let us look at the following example:

Pierre is confident that he is at Place Denfert Rochereau, when in fact he just emerged at the Port Royal crossing, because he skipped one metro stop.

Here, Pierre's way-finding process failed (he failed to keep track of the stations when he was in the metro), but he doesn't feel disoriented. Golledge would characterise Pierre as being disoriented, but a more precise characterisation would identify Pierre as someone who is lost, not disoriented. Finally, below is a last case that raises some problems for Rieser's characterisation:

John is a tourist in Paris. He is outside the Metro stop Odeon and he wants to go to walking to Place de la Concorde. He is told that if he follows Boulevard St. Germain and then crosses the Seine he will get there. Boulevard St. Germain curves north as it advances west, but this is not a problem for John. He just follows the street without knowing the exact direction of Concorde.

He ends up at the Seine, crosses the river and is at Place de la Concorde.

In the case above John doesn't know the direction or the distance of his destination, but he is neither lost nor disoriented. Overall, there are many elements related to disorientation, such as knowledge of distances and directions, the way-finding process or navigational ability. However, casting disorientation in such terms overlooks that disorientation is primarily a feeling. Characterising disorientation as a feeling captures the subjective aspects of disorientation, and it can serve to develop a conceptualisation of the phenomenon that helps us understand how elements such as a failure in the way-finding process can lead to the emergence of the feeling of disorientation.

Elsewhere, we have proposed to sharply distinguish being lost and feeling disoriented, and have argued that disorientation should be better understood as the metacognitive feeling of unconfidence in the subject's online spatial representation (Casati and Fernandez Velasco, forthcoming). That is, disorientation is a feeling that evaluates the level of confidence in the cognitive subsystem responsible for spatial representation.

Bridging the gap among these different fields is not only an empirical endeavor, but a conceptual one.

An important first step is a characterisation of disorientation that can be effectively applied to different fields. As for the gap between levels of analysis, it can be bridged indirectly. That is, results at one level can be used to speculate and produce hypotheses at other levels. Ultimately, one would want to have an overall theory of disorientation that draws on the progress from the variety of fields dealing with disorientation into a unified conceptualisation of the phenomenon that can serve to generate testable hypothesis for different settings and levels of analysis.

In what follows, we will look at different models that have been developed for WiSAR theory, and speculate how novel conceptualisations of disorientation can contribute to the models generating better predictions.

GIS-based WiSAR models

When a person becomes lost in the wilderness, the WiSAR manager faces a difficult challenge, which is to figure out where the different SAR teams are more likely to locate the lost person. The areas that need to be covered are often vast areas of difficult terrain, and the SAR team needs to coincide with the lost person not only in space, but also in time (i.e. if the SAR team and the lost person pass the same place at different times the lost person will not be found). These difficulties should not be overlooked. WiSAR operations often have limited resources, and past two days, or about fifty hours of search, the lost person's chances of survival decrease significantly [START_REF] Adams | Search Is a Time-Critical Event: When Search and Rescue Missions May Become Futile[END_REF].

To guide the search effort, the most common strategy is to develop a probability map stemming from the Initial Planning Point (IPP), which is usually the point where the lost person was last seen or known to be (i.e. relying on cues). Geographic Information Systems (GIS) provides WiSAR the planning tools (such as the ArcGIS planning tool, see [START_REF] Ferguson | GIS for wilderness search and rescue[END_REF] to create and update probability maps [START_REF] Doherty | An Analysis of Probability of Area Techniques for Missing Persons in Yosemite National Park[END_REF]). Here, we will discuss two methods of establishing probability maps: a ring model and a Bayesian model.

The ring model, based on mathematical search theory [START_REF] Koopman | Search and screening: general principles with historical applications[END_REF], is the most common way of establishing probability areas. The main dependent variable of the ring model is Euclidean distance from IPP. The statistics of past WiSAR cases are analysed to produce four concentric rings stemming from IPP. These rings represent probability areas, and are established at the distances equivalent to the probability quartiles 25%, 50%, 75% and then at 95%. That is to say, within the first concentric ring, the probability of finding the lost person is 25%, within the second concentric ring, the probability of finding the lost person is 50%, and so on.

An important finding for WiSAR is that different subject categories correspond to different probability distributions. For example, the 25% probability area of a hiker is much larger than that of a child, because the hiker can cover bigger distances and tends to follow either trails or directions rather than staying put or walking randomly. Syrotuck first analysed 242 cases from New York and Washington states and established probability distributions for eight subject categories [START_REF] Syrotuck | Analysis of lost person behavior: An aid to search planning[END_REF]. Koester has recently created ISRID, a large database unifying thousands of cases from around the world and dividing them into 41 categories based on scenario, age, medical or mental status, and activity [START_REF] Koester | Lost Person Behavior: A Search and Rescue[END_REF]. Although other parameters (such as the type of terrain) can be added, the subject category is the main determinant of the distribution of probability map that will guide the search efforts.

A recent development in WiSAR is Lin and Goodrich's Bayesian approach [START_REF] Lin | A Bayesian Approach to Modeling Lost Person Behaviors Based on Terrain Features in Wilderness Search and Rescue[END_REF].

The main parameters of their model are the topography, vegetation coverage and local slope of the terrain. One of the innovative elements of their model is that it uses expert opinions to determine the probability of the lost subject transitioning from one terrain type to another (e.g. a WiSAR manager's estimation of the likelihood of a given lost subject moving from a plain to a hill). This opinion-based probability is expressed in the form of mean and variance (to account for uncertainty). These probabilities are used as priors to create a state transition matrix (specifying the probability of the subject transitioning from each state to all other states) from which to generate a predictive probability distribution map. As a person can only travel to adjacent cells, all of the cells that are not adjacent to the current cell have probability zero. Of course, as the person moves, new cells will become adjacent.

Assuming a process in which only present states affect the probability of future states (i.e. assuming a first-order Markov process), it is then possible to predict the lost person's trajectory as time progresses (i.e. the continuous posterior beliefs of the lost person's position at different times).

While in the ring model the terrain is divided in concentrical rings, in Lin and Goodrich's model the whole terrain gets divided into tessellated hexagons. In their hypothetical scenario these hexagons are 24m wide. Each state in the transition matrix is a hexagonal cell in the tessellation. Each row in the matrix is composed of the transitional probabilities of transitioning from one cell to each cell in the tessellation (and of staying in the same cell). Given a point at which the person was last seen (in which the probability of the person being in that cell at the time when she was last seen is 1), it is possible to compute the probability of the person being in different cells at different points in time, thus generating a probability distribution map to guide WiSAR efforts.

One advantage of Bayesian models is that existing observations (e.g. GPS track logs and their associated terrain) can be used to update prior beliefs and thus reduce experts' uncertainty. Progress in the conceptualisation of disorientation is much more promising when it comes to Lin and Goodrich's Bayesian model. In their example, expert opinion is used to generate a prior distribution regarding the transitions between three dimensions of terrain (vegetation, slope and topography).

What is promising is that their method offers a way to incorporate different sources for the generation of a prior distribution. One such source could be a unified theory of disorientation, or the opinion of an expert informed by such a theory.

An adequate conceptualisation of disorientation, together with Lin and Goodrich's Bayesian model offers a way in which developments coming from a broad range of fields can be exploited for improving GIS-informed WiSAR operations. With a working theory of disorientation, knowledge about the phenomenon could then be used for establishing the prior distribution that determines the initial probability map. What is more, such distribution could be updated with GIS observation, by using the observations such as GPS logs to generate a posterior distribution. Such posterior distribution could then be used to discover elements of disorientation that have been overlooked by the overall theory, thus highlighting ways in which the theory can be improved.

Lastly, conceptual work can help us improve the models themselves and choose between different models for different scenarios. For instance, Lin and Goodrich's Bayesian model assumes that the lost person's traveling ressembles a first-order Markov process, in which only present states affect the probability of future states. This might not be the case for route sampling, a strategy that involves the lost subject starting on an intersection and following different routes for a while, always returning to the intersection, as a way to explore the surrounding terrain. In this case, there is a certain length that the subject is likely to follow (say 1km), so that the likelihood of the subject turning around is less likely after she has walked 10m than after she has walked 10km on the same path. The traveling of such an individual would not ressemble a first-order Markov process. It might well be that Lin and Goodrich's model works better for children than for hikers (as hikers are more prone to route sampling), and a good theory of disorientation would give us the conceptual apparatus to tell if this is the case.

Conclusions

We opened this paper by reviewing the progress in different fields related to disorientation, such as lost person psychology and the neuroscience of spatial cognition. We then outlined several challenges to unite these separate fields (i.e. differences in levels of analysis and differences in settings) to show that conceptual work was needed to connect these fields. We defended the idea that an adequate conceptualisation of disorientation would permit us to use the findings in one field to produce hypothesis in a different field. Afterwards, we reviewed two different methods of GIS-informed WiSAR (a ring model and a Bayesian model) to then analyse how an adequate conceptualisation of disorientation could help WiSAR profit from the developments in a broad range of research areas.

We concluded that while for the ring model conceptual work can only help develop new subject categories, for the Bayesian theory conceptual work can be used to generate more accurate probability maps. Furthermore, these Bayesian-based probability maps can in turn be used as input for improving our theories of disorientation. Finally, the main claim of our contribution is that conceptual work can help us improve the various WiSAR models (by examining their underlying assumptions) and choose between different models.

  experimental and study settings. A big part of the work in psychology takes place in non-ecological conditions (seeLi, Mou and McNamara, 2012 for an example). WiSAR theory is based on ecological non-experimental conditions (i.e. analysis of existing cases of lost people), and the work in cognitive science is usually simulation-based (Ruddle, Volkova, Bülthoff, 2011). Finally, as mentioned above, neuroimaging studies are stationary, and thus based on virtual reality, spatial recollections or imagined navigation. Consequently, in order to extrapolate results from one field to another, one has not only to extrapolate from one level of analysis to another, but also from one setting to another (e.g. from simulations to the actual behaviour of people lost in the wilderness).

  It is impossible to determine the continuous posterior beliefs about the lost person's position in closed form, so Lin and Goodrich employ a Markov Chain Monte Carlo (MCMC) algorithm to approximate the posterior distribution needed to generate the updated probability distribution map (following the methods ofGelman et al 2004). The MCMC method consists on a massive iteration of different transformations from prior distributions (based on expert opinion) to observations (based on GPS track logs) to generate a series of distributions (21 in their hypothetical scenario) that approximate the posterior distributions (see Lin and Goodrich 2010 for mathematical detail). These posterior distributions are used in the place of the original prior distributions to update the probability distribution map.To conclude this section, the table below sums up some of the distinctions between Koester´s ring model and Lin and Goodrich's Bayesian model:

	Model	Sources	Updating	Terrain sub-division
	Ring Model	Actual cases (ISRID) Based on time	Concentric Circles
	Bayesian Model	Expert Opinion	Based on both time	Hexagonal Tesselation
			and observations
	Conceptualising disorientation for GIS WiSAR
	The traditional ring model of WiSAR seems to be 'blind' to different conceptualisations of
	disorientation. What we mean by this is that what is used to generate the probability map are the
	statistics of different subject categories, which are unaffected by different models of lost person
	behaviour. For example, what determines the distribution of the probability map is not whether a
	subject in a given category is perceived to be more likely to give preference to a given reorientation
	strategy, but simply how far from the IPP subjects in the same category where found in previous
	WiSAR cases. However, this doesn't mean that conceptualising disorientation plays no role in WiSAR
	operations that use the ring model. After all, WiSAR teams use their beliefs about lost person
	behaviour (based on a certain conceptualisation of disorientation) to prioritise the search within the
	sub-areas of a given probability ring.
	One of the ways in which conceptual work can help improve the ring model itself is by determining
	which subject categories should be used for generating the probability map. From a cohesive theory

of disorientation one can hypothesise the existence of new categories, and then use GIS to see if these categories are statistically relevant. Furthermore, a good conceptualisation of disorientation is expected to generate predictions as to what parameters (e.g. age, terrain…) might be statistically relevant for determining new subject categories.


Daniel R Montello

Pablo Fernandez Velasco
email: p.fernandezvelasco@gmail.com

Roberto Casati

Pablo Orcid

Fernandez Velasco

The many faces of disorientation: a response to

Keywords: Disorientation, phenomenology, metacognition

Daniel Montello's commentary on our article "Subjective Disorientation as a Metacognitive Feeling" raises many interest-ing points. In this response, we hope to show that what might at first seem like strong disagreements are for the most part minor issues and that the disagreements that remain are of the fruitful kind that encourage further discussion and research.

Introducing disorientation

Discussing our introduction to the empirical findings related to disorientation, Montello observes that the idea of a mentally represented environment has been around since [START_REF] Trowbridge | On fundamental methods of orientation and"imaginary maps[END_REF] and that there is no clear need for neuroscience or rodent studies to establish that humans mentally represent environments. We agree that in a relatively uncontroversial sense, we only need to introspect to find mental representations of our environment. In a less trivial sense, a lot can be learned about mental representations of our environments without the help of neuroscience, as plenty of work in psychology shows (some of Montello's own work being a telling example). However, what Trowbridge was referring to as "imaginary maps" might be slightly different from Tolman's cognitive maps. Trowbridge seems to construe them in picture-like terms and is quite clear to point out that only humans can have such "imaginary maps" and that other creatures "know only the region which they have traversed " (p. 889, Trowbridge, 1913). Of course, Tolman is going in quite a different direction, and he actually takes rats being able to infer information about regions which they have not traversed as support for the idea of the cognitive map. Mental maps are theoretical constructs, the result of an inference to the best explanation of the ability to figure out shortcuts and detours. At the end, it is Tolman's line of research that has influenced much of the work in neuroscience, which is not to say that neuroscientists do not recognize Trowbridge's workthe seminal work "the Hippocampus as a Cognitive Map" references Trowbridge's 1913 article as early evidence for mental mapping, together with [START_REF] Gulliver | Orientation of maps[END_REF] and De [START_REF] De Hutorowicz | Maps of primitive peoples[END_REF] work, but the book is nevertheless dedicated to "E. C. Tolman, who first dreamed of cognitive maps in rats and men " (p. v, O'Keefe & Nadel, 1978).

Historical ramifications in the study of spatial cognition aside, what made us focus on this line of research was a matter of scope. We never intended to provide an in-depth overview of spatial cognition research, and we had to be selective. An important reason for discussing neuroscientific research is that one of the major and most comprehensive recent works in disorientation is Paul Dudchenko's Why People Get Lost, and much of that book pivots around the neuroscience of spatial cognition [START_REF] Dudchenko | Why people get lost: The psychology and neuroscience of spatial cognition[END_REF]. Likewise, it was outside of the scope of our paper to provide an exhaustive account of the rich variety of multidisciplinary research that deals with spatial disorientation. Instead, we directed the reader to Schmidt Di [START_REF] Friedberg | Geographies of disorientation[END_REF], who does a thorough job at precisely that. Needless to say, we totally agree with Montello's claim that geography, cartography, geographic information science, anthropology, planning, and architecture have a lot to contribute to our understanding of disorientation. The works he mentions are particularly relevant and deserve to be brought into focus.

Being lost versus being disoriented

Contrasting our distinction between being disoriented and being lost, Montello traces a distinction between being geographically disoriented and being misoriented. This is a distinction that he first introduced in a recent article [START_REF] Montello | Cognition and spatial behavior[END_REF], although it builds on his previous characterization of geographic disorientation [START_REF] Montello | Geographic orientation and disorientation: getting lost and getting found in real and information spaces[END_REF]. As we acknowledge in footnote 1, our respective distinctions are fairly similar. The difference may appear to be only terminological, but it also reflects each author's particular characterization of disorientation. This becomes a bit harder to see in Montello's commentary, because he uses "being disoriented"' and "lost" interchangeably. The reason for this is that he construes "being lost'" to be a colloquial expression and "disorientation" to be a technical term. Indeed, "being lost" is often used colloquially and "disorientation" is often used technically. Nevertheless, "being lost" is also used in a technical way, as in "lost person behavior", or in some wayfinding [START_REF] Carlson | Getting lost in buildings[END_REF] and neurology studies [START_REF] Lemoncello | When directions fail: Investigation of getting lost behaviour in adults with acquired brain injury[END_REF]. And "feeling disoriented" is by no means only a technical term the way that "topographical disorientation" is. People talk about feeling disoriented in colloquial ways. At the end, this is largely a matter of clarifying how we use our terms. 1 If what we refer to as "disoriented" is synonymous to what Montello refers to as "geographically disoriented" and what we refer to as "lost" is synonymous to what Montello refers to as "misoriented", then the disagreement is a superficial one. What is important is whether the underlying concepts be aligned, and that we can locate and discuss our theoretical differences regarding those concepts that do not appear to be aligned.

Terminologically, there are two reasons for using the disorientation/lost rather than the disorientation/misorientation distinction. The first one is that (as Montello points out) "objective disorientation" is an oxymoronic term.

Being "objectively lost", however, is not. The second one is that "misorientation" has existent technical uses that do not correspond to Montello's use of the terms. The term is mostly used in crystallography, in a way that is unrelated to issues of spatial cognition (e.g. [START_REF] Kocks | Texture and anisotropy: Preferred orientations in polycrystals and their effect on materials properties[END_REF]. Most importantly, in spatial cognition research, [START_REF] Dudchenko | Why people get lost: The psychology and neuroscience of spatial cognition[END_REF] already made a distinction between disorientation and misorientation, and it does not correspond to Montello's later distinction. For Dudchenko, during misorientation the subject may represent the spatial relations between out-ofview landmarks, but their heading relative to those landmarks is misaligned, while during disorientation, the spatial representation itself becomes unstable [START_REF] Dudchenko | Why people get lost: The psychology and neuroscience of spatial cognition[END_REF]. Given that "misorientation" has established uses both within and outside the study of spatial cognition, it is perhaps advisable to steer clear of the term. Hence, rather than adding new terms to the mix, we think that it suffices to clarify our usage of the terms "disoriented" and "lost".

To get a sense of the similarities and differences between Montello's understanding of disorientation and ours, the following paragraph from his commentary is most illustrative:

That an awareness of spatial uncertainty is a critical component of being geographically disoriented is certainly true. So much so that the authors' skeptical claim that "there is no unified account of the phenomenon" does not strike me as accurate. In fact, this description of feeling unsure provides just such a clear, unified account of being disoriented (lost), and a definition based on this account is widely consistent with the explicit or implicit conceptualizations of disorientation held by various academic research communities, professional search and rescue, art and literary traditions, lay usage, etc. -p. 1, [START_REF] Montello | Cognition and spatial behavior[END_REF] There is thus an agreement between Montello and us that an awareness of spatial uncertainty is a critical component of being disoriented. Moreover, he claims that this description of feeling unsure provides a unified account of the phenomenon that in consistent with other implicit and explicit characterizations. This is precisely the central point of our paper. Our aim is not to defenestrate other characterizations of disorientation, but to provide conceptual tools and phenomenological insights that serve to unify different understandings of the phenomenon under one characterization. That we broadly agree on the matter is clear when Montello states that "disorientation is about your phenomenology of uncertainty; misorientation [our being lost] is about the objective correspondence between your spatial belief and your actual location or route" (p. 5, [START_REF] Montello | Cognition and spatial behavior[END_REF]. As for our actual disagreement with Montello, it seems to come down to the way we each understand the type of awareness that is characteristic of disorientation, an issue that we will focus on in the final section of this response.

Regarding objectively being lost (Montello's "misorientation"), there are some misunderstandings and some substantive issues. Misunderstandings first: when we say that disorientation and being lost are generally concomitant, we do not mean that they are not potentially distinct and separate. They are, and they just tend to converge. And when we mean that they come apart only in borderline cases, we do not mean to say that they are uncommon. In fact, we provide several accounts of both illusions of orientation and of disorientation when we introduce both concepts. We simply mean that these are non-paradigmatic cases. People tend to feel disoriented when they are lost, and they tend to be lost when they feel disoriented. It is not only a matter of prevalence; it is simply that subjects will tend to realize whether or not they are lost. As a result, the paradigmatic cases of disorientation happen when the subject in question is both disoriented and lost. The double dissociation of people being disoriented/lost actually has equivalences with other metacognitive feelings: it is a general phenomenon of which disorientation is a specific case. People can feel confident about the result of a simple multiplication but be actually wrong. Conversely, people can feel unsure about the result, which they nevertheless got right. Just as with disorientation, the subjective feelings of rightness and wrongness do not always coincide with objective rightness and wrongness, but they will tend to coincide, because the feelings are designed to be tracking rightness and wrongness.

As for the substantive issues, it all seems to come down to the fact that characterizing being lost objectively is not an easy task, no matter what term you use to refer to it. We characterize being objectively lost as the subject's inability to find her way. We also provide Golledge's and Rieser's characterizations as an alternative: a failure of the way-finding process, and not knowing the directions and distances to get to a given point, respectively [START_REF] Golledge | Wayfinding behavior: Cognitive mapping and other spatial processes[END_REF][START_REF] Rieser | Dynamic spatial orientation and the coupling of representation and action[END_REF]). Montello's characterization (of misorientation) relates to the objective correspondence between your spatial belief and your actual location or route, which seems close to Rieser's. The important thing is that none of these characterizations are cast in first-person terms and none of them have subjective experience as their primary target explanandum. We mentioned an epistemological issue regarding the characterization of being objectively lost (that we might need first-person data to determine if a subject is lost) and we showed some ways in which objective characterizations of being lost have led to objective measures in the literature.

In his commentary, Montello highlights a different challenge for objective characterizations of being misoriented (i.e., objectively lost), which is that subjects will never know their exact location (e.g. their exact GPS coordinate), and we therefore require a metric (established subjectively) to define how far the subject's believed and real locations need to be for us to consider the subject to be misoriented. The problem here comes from the possible uses of the word "objective". In a strong sense, "objective" can be understood as something like "not influenced by subjectivity". This is the sense in which Montello seems to be using it. With this strong understanding of objectivity, Montello's challenge raises a spatial issue and a broader ontological issue. The spatial issue is that, following Montello's characterization, a subject is lost if and only if they believe to be in a different place than they actually are, and to make sense of that definition we need to establish, to the right degree of metric specification, what a place is, and what it means for a subject to be in that place. A city is probably too wide of a place, a point expressed in latitude and longitude coordinates probably too narrow. The problem is that somewhere down the line, we will need to make an arbitrary subjective decision, either drawing on a case by case scenario or tracing the line for a stable criterion (e.g. a 10 m radius from estimated location).

Note that our characterization of being lost is cast in terms of ability and is therefore not actually affected by the spatial issue. However, it is probably affected by the ontological issue arising from Montello's challenge, which is that the right metric to judge whether or not someone is lost (misoriented) depends on the task at hand, and this lands us right back outside of objectivity (in the strong sense). In a similar way, the possibility of ascertaining whether or not the subject is able to find their way depends on the task at hand. However, we never intended to use "objectivity" in such a strong sense. We simply meant to characterize being objectively lost in a way that did not necessarily pertain to the subjective experience of disorientation, i.e. that did not require subjective awareness of the phenomenon. Illusions of orientation (during which the subject is lost objectively but does not feel disoriented) show that such a characterization is both possible and useful. If it were not possible, we would be unable to differentiate illusions of orientation from paradigmatic cases of orientation (in which the subject is neither disoriented nor lost). That said, the issues with an objective characterization of being lost that Montello raises are not negligible. On the contrary, they are extremely interesting and should be explored more in depth. Unfortunately, this is certainly outside of the scope of both our paper and the present response. At the end, our main focus is subjective disorientation, not objectively being lost, and we stay neutral for now regarding the precise way in which the latter should be characterized.

Disorientation and emotion

We have indicated that we offer an affective account of disorientation while Montello offers a doxastic account of disorientation (i.e. an account cast in terms of belief). In the beginning of the third section of his commentary, Montello offers us two horns of the following dilemma regarding our claim that disorientation is primarily an affective state: If our claim is that disorientation is a metacognitive feeling, then our account is not any more affective than his account is; and if our claim is based on the emotional states that accompany disorientation, then we are mixing the cognitive, behavioral and affective aspects of the phenomenon. As is probably clear from the title of our paper, we choose the first horn of the dilemma. In what follows, we will first show why our claim that disorientation is a metacognitive feeling results in the claim that disorientation is an affective state. Then, we will discuss some of the issues Montello raised in discussing the second horn of the dilemma (i.e. the emotions associated with disorientation). Finally, we will contrast our characterization with Montello's.

Montello is quite succinct when it comes to discussing the first horn of the dilemma. He claims that if our account is that disorientation is a metacognitive feeling, then it is not a particularly affective account. To support his claim, he simply says that a psychologist might refer to a metacognitive feeling not as an affective state but as a cognitive state of awareness, which does not always require the subject being aware of a referent or antecedent for the state. When we dig into it, this horn of the dilemma is not as sharp as it might have first seemed. We agree that metacognitive feelings do not always require the subject being aware of a referent or antecedent for the state, although this awareness is most commonly the case. And, of course, we claim that disorientation is a cognitive state of awareness, although it all depends on how one thinks of the terms. It is a state of awareness (i.e. a phenomenal state with a particular phenomenology) that reflects on a cognitive process (in this case, the online system of spatial representation). And yet, all of this is perfectly compatible with metacognitive feelings being affective states.

That metacognitive feelings are affective states is widely acknowledged not only in philosophy [START_REF] Dokic | Seeds of self-knowledge: Noetic feelings and metacognition[END_REF][START_REF] Proust | The representational structure of feelings[END_REF], but also in psychology (for a review, see Schwarz and Clore, Montello goes on to explain his position that metacognitive feelings are not affective by saying that they are something like an intuition, as in a "gut feeling". We imagine that Montello points to intuitions because they seem to be states of awareness that are paradigmatically cognitive. However, there is no prima facie reason to believe that this implies that they are not affective (unless one has extreme cognitivist leaningsfor an early rebuttal of such positions, see [START_REF] Zajonc | Feeling and thinking: Preferences need no inferences[END_REF]. In fact, feelings of error, confidence, etc. are all affective states related to cognitive processes. They are phenomenal experiences, they have valence, and they guide behavior (including mental behavior), just like other feelings. They also appraise a particular object (the cognitive process in question) in a feeling characteristic way (e.g. as defective in the case of the feeling of error), which corresponds to their formal object. Asher Koriat, one of the leading researchers in metacognition, is quite explicit in saying that not only are metacognitive feelings affective states, but also that they have underlying mechanisms in common with other types of affective states: "The studies that have attempted to elucidate the bases of the metacognitive feelings underlying JOLs, FOK judgments [Judgments of Learning and Feelings of Knowing], and subjective confidence seem to suggest that such feelings are based on the feed-back from behavior, as William James suggested for emotional feelings" (p. 88, [START_REF] Koriat | Are we frightened because we run away? Some evidence from metacognitive feelings[END_REF]. Only this year, an empirical study of what might be considered the paragon of intellectual activity, the feeling of insight, made headways in uncovering the said dynamic mechanisms, of which positive affect is a crucial component [START_REF] Skaar | The phenomenology of Aha-experiences[END_REF]; a result that is in line with previous theoretical (Topolinski & Reber, 2010a) and empirical [START_REF] Shen | In search of the 'Aha!'experience: Elucidating the emotionality of insight problem-solving[END_REF] work in psychology.

Discussing the second horn of the dilemmai.e. conflating disorientation with strong emotions related to the phenomenon -, Montello argues that we have to keep these separate to understand how the emotions arise in response to the subject's belief that they are lost. We agree that we should not conflate these aspects. In particular, we should not confuse the feeling of disorientation with other associated feelings such as frustration, confusion or vulnerability (all of which have been reported in our corpus). However, we should not prioritize cold cognition (e.g. the belief that one is lost) over affect (e.g. the feeling of being disoriented). Metacognition is a dynamic and richly affective process. In most cases, affective states will be the primary form of subjective awareness of metacognitive processes monitoring orientation. When a subject is disoriented, the affective awareness of disorientation will emerge much faster than the corresponding cold cognition belief. Moreover, it is the affective aspects of disorientation which will shape subjective experience (Fernández Velasco and Casati, forthcoming). Disorientation is primarily affective, not a belief resulting in affect. And it is qua affective state that disorientation goes on to elicit a cascade of related emotions. Affective states do not just arise in response to a belief, as Montello defends. Affective states are the underlayer from which a belief emerges. Cognition and affect operate at different timescales and interact in dynamic ways that an overly rigid emotion-cognition divide risks failing to recognize.

Montello makes two extremely interesting points. The first one is that, as he nicely puts it, getting lost has long been recognized as a universal wellspring of strong emotions (he illustrates this by pointing to a rich source of references). The second one is that we need to differentiate among moments in the time course of disorientation episodes. Regarding the first point, the strongly emotional instances of disorientation are particularly useful when it comes to phenomenological analysis, because they bring to the fore some of the essential aspects of the experience (Fernández Velasco, 2020). Moreover, that disorientation should tend to result in strong emotions is very much what one would expect based on our characterization, because metacognitive feelings (e.g. the feeling of uncertainty) have been shown to modulate and in particular intensify other affective reactions (Bar-Anan, Wilson and Gilbert 2009). However, we do not take this to mean that disorientation is always a strongly emotional state. There will be some low-stakes situations in which the affective aspects of the experience will be relatively subdued. This is again consistent with other metacognitive feelings, which often reside in the fringe of consciousness [START_REF] James | The principles of psychology[END_REF][START_REF] Mangan | Taking phenomenology seriously: The "fringe" and its implications for cognitive research[END_REF][START_REF] Mangan | What feeling is the "feeling of knowing?[END_REF][START_REF] Norman | Fringe consciousness: A useful framework for clarifying the nature of experience-based metacognitive feelings[END_REF][START_REF] Reber | Processing fluency as the source of experiences at the fringe of consciousness[END_REF]).

Montello's second pointthat we need to differentiate among moments in the time course of disorientation episodesprovides us with a novel research direction. It would be interesting to explore how disorientation emerges and changes in levels of valence and arousal, how it elicits other affective states, how it guides behavior, and how it subsides once the subject finds their way (probably giving rise to a different affective state). The upshot of characterizing disorientation as a metacognitive feeling is that affective forms of metacognition evaluate and regulate navigation in a dynamic way. This is in line with the dynamic nature of metacognitive feelings, which work in such a way that "monitoring drives control, and feedback from control operations then produces monitoring output, which in turn drives control, and so on" (p. 98, [START_REF] Koriat | Are we frightened because we run away? Some evidence from metacognitive feelings[END_REF] for empirical evidence see [START_REF] Koriat | The combined contributions of the cue-familiarity and accessibility heuristics to feelings of knowing[END_REF].

Affective and doxastic characterizations of disorientation

We hope that in discussing the two horns of Montello's dilemma, we have further clarified our characterization of disorientation. To conclude, let us now contrast it with Montello's characterization: Geographic disorientation (being lost) occurs when people are aware they are not certain about where they are and/or where they need to go to get to their destination.

-p.5, [START_REF] Montello | Cognition and spatial behavior[END_REF] There is a potential ambiguity in Montello's definition concerning the use of awareness, because the characterization does not specify the way in which subjects are aware of uncertainty: they could believe that something is uncertain, or they could be undergoing a feeling of uncertainty. Later, Montello makes an explicit commitment to a doxastic characterization: "you cannot be disoriented or lost unless you believe you're not sure of your location or your way" (p. 5, [START_REF] Montello | Cognition and spatial behavior[END_REF]. There is a worrying lack of parsimony in the resulting adjusted characterization: "Geographic disorientation occurs when people are aware that they believe that they are not certain about where they are and/or where they need to go to get to their destination." Contrast it with an affective rendition of the same characterization2 "disorientation occurs when people feel uncertain about where they are and/or where they need to go to get to their destination". Moreover, our actual definition does not involve an inclusive disjunction.

This lack of parsimony is not just an esthetic worry. It reflects a lack of simplicity and frugality in the required forms of metacognition to bring the state about. [START_REF] Koriat | Processes underlying metacognitive judgments: Information-based and experience-based monitoring of one's own knowledge[END_REF] make a useful distinction between metacognitive feelings and metacognitive judgments (theory-based judgments based on a deliberate and explicit inferential process). We claim that disorientation is at heart a metacognitive feeling. It seems that Montello claims disorientation is a metacognitive judgment. The literature on metacognitive feelings provides us with plenty of examples of reliable affective mechanisms that monitor cognition and control behavior (for a review see [START_REF] Koriat | Are we frightened because we run away? Some evidence from metacognitive feelings[END_REF]. Ceteris paribus, one expects cognition to favor fast and frugal cognitive processes [START_REF] Gigerenzer | Fast and frugal heuristics: The adaptive toolbox[END_REF]. In other words, to favor metacognitive feelings over metacognitive judgments.

We do not claim that deliberate and explicit inferential process cannot result in subjects believing that they are lost. We simply claim that these cases are the minority, and that in the majority of cases, the feeling of disorientation will emerge from fast and frugal, affective process of metacognition monitoring and controlling navigation. Of course, metacognitive feelings give rise to beliefs, and if a subject feels disoriented they will tend to think that they are lost. Moreover, if a subject feels disoriented, this is likely to prompt a deliberate process of inference (as was often reported in our corpus). Take the Feeling of Rightness (FOR) as a case in point. A series of experiments by Thompson and colleagues showed that when subjects had to solve problems, not only did their FOR underlay whether or not the subjects judged their initial response to be right, it also influenced for how long the subjects engaged in further, explicit deliberation about the problem [START_REF] Thompson | Intuition, reason, and metacognition[END_REF].

A last way in which a doxastic characterization falls short is with regards to phenomenology. To push this point, let us look at footnote one, where Montello remarks that people get disoriented in ways that are not literally spatial but metaphorical. It is true that people often talk of being temporally disoriented, politically disoriented, etc. Elsewhere Montello says that people are often said to get lost in databases and other information systems, but that this disorientation is only metaphorical [START_REF] Montello | Geographic orientation and disorientation: getting lost and getting found in real and information spaces[END_REF]. He then goes on to discuss the differences between navigating physical and web space (e.g. web space does not exhibit distance decay). What the metaphors of disorientation actually exemplify is that the similarity between spatial and metaphorical forms of disorientation is first and foremost a phenomenological similarity. Feeling spatially disoriented is (at some level) phenomenologically similar to feeling temporally disoriented (e.g. when you wake up and don't know what time it is). Metaphors of disorientation is another interesting topic for future work. What matters for the present discussion is that there is something it is like to be disoriented. However, different beliefs are hardly characterized from their phenomenology the way that different affective states are. As a result, an affective characterizing of phenomenology is more consistent with disorientation having a particular phenomenology.

To summarize, the affective characterization of disorientation is preferable to the doxastic characterization because:

• It is more parsimonious.

• Metacognitive feelings are faster and more frugal than metacognitive judgments.

• It builds on previous research on metacognitive feelings (e.g. how they arise and how they guide behavior). • It captures the phenomenology of disorientation.

The affective-doxastic difference results in a minor disagreement regarding Montello's claim that a subject must have a destination to be disoriented. We agree with Montello (and with Tolkien) that not all those who wander are lost. However, the lesson we take from that verse is not that it is impossible to feel disoriented if one is wandering, just that it is possible to wander without feeling disoriented. The requirement to have a destination to be lost arises from the way in which Montello has structured his characterization of disorientation. If a person is wandering in a what is assumed to be a familiar environment and suddenly encounters an unexpected place, that person will most likely feel disoriented. Reversals of orientation illusions are a good example of this principle [START_REF] Binet | Vertigo of Direction[END_REF][START_REF] Binet | Reverse illusions of orientation[END_REF]:

Instead of taking the right to return to the Place de la Republique, I took the left toward the Hotel de Ville … While on my way I felt sure of meeting the Place de la Republique. Thus my confusion was extreme on coming to the Hôtel de Ville … I was some moments in recognizing it.

-report in p. 341, [START_REF] Binet | Reverse illusions of orientation[END_REF].

These are fairly common occurrences. It is not hard to imagine that one is wandering (e.g. in the third "arrondissement" of Paris), goes into a shop, comes out and takes a right instead of a left so that, after a while, instead of seeing the place one expected (e.g. Place de la Republique) sees a place at the other end of the street (e.g. Hôtel de Ville), and that as a result on feels disoriented.This poses a problem not only for Montello's assertion about wandering, but also for his requirement that one needs to be uncertain about one's place and/or destination to be disoriented. One might know where one is (e.g. in front of Hôtel de Ville) and the route from there to one's destination (e.g. if one were trying to go to Place de la Republique it would suffice to turn around) and still feel disoriented. This is something that is better accommodated by our characterization: if there is a rapid disintegration in the subject's online system of spatial representation (e.g. a 180º degree switch with respect to a global environment), we can expect the subject to feel disoriented.

Still, it seems harder to become disoriented when wandering. This is part of the larger topic of context, which we already acknowledged when we said that the evaluation process that gives rise to disorientation is contextsensitive.3 Context-sensitivity, of course, is a well-known attribute of affective states [START_REF] Davidson | Emotion, plasticity, context, and regulation: Perspectives from affective neuroscience[END_REF] and is particularly important for negative affective states [START_REF] Coifman | When distress does not become depression: Emotion context sensitivity and adjustment to bereavement[END_REF]. As we indicate in our paper, whatever spatial representation is being monitored will be an action-oriented representation of a meaningful space. If the subject is wandering, there will be very few things of relevance that could prompt the feeling of disorientation. Generally speaking, if the task does not require a subject to be oriented, then that subject might undergo what we would dub 'disorientation indifference', which extends beyond the case of wandering. 'Disorientation indifference' is likely to occur if we are following a guide or if we are a passenger in a cab. Again, 'disorientation indifference' is context-sensitive because disorientation is context-sensitive; it does not imply that nothing can make a wanderer feel disoriented. If we are wandering and we find ourselves in an extremely unexpected place, or if we find ourselves unable to find our way back, we will in all likelihood feel disoriented. When we are wandering, we don't much care where to go, but that indifference has limits.

"Would you tell me, please, which way I ought to go from here?" "That depends a good deal on where you want to get to," said the Cat.

"I don't much care where -" said Alice.

"Then it doesn't matter which way you go," said the Cat.

"so long as I get somewhere," Alice added as an explanation.

-Adventures in Wonderland, Lewis Carrol (2011[START_REF] Carroll | Alice's adventures in wonderland[END_REF]

A potential misunderstanding that we need to clarify is that we do not think that the distinction between being lost and being disoriented is a matter of severity, but a matter of objectivity (third person reports) and subjectivity (first person reports). If people do indeed tend to reserve the term lost for severe episodes of disorientation, that would be an interesting empirical finding about the colloquial use of the terms, but not one that relates to our distinction.

Note however that in our paper we characterize disorientation in terms of confidence, not uncertainty.

Even if the case of wandering does not impel us to change our characterization, the strong degree of contextsensitivity exhibited by disorientation might mean that our characterization needs to widen. We find more than enough ground to assert that disorientation is a metacognitive feeling. What precise process disorientation is evaluating and regulating, and the specific mechanisms involved is rather a question to be settled empirically. In the standard case, we believe the evaluated process to be the online system of spatial representation. However, it might be better to talk of disorientation evaluating and regulating active navigational processes broadly understood, because this wider understanding encompasses cases like following a GPS, a guide, being on a plane, etc.

Funding

This work was supported by the Agence Nationale de la Recherche [ANR-10-IDEX-0001-02 PSL,ANR-17-EURE-0017 FrontCog].