Lucie Hobeika

Capucine Diard-Detoeuf

Béatrice Garcin

Richard Levy

Dr Emmanuelle Volle
email: emmavolle@gmail.com

functional imaging studies

Keywords: Analogy, reasoning, rostral prefrontal, abstraction, relational reasoning, functional MRI, neural correlates, meta-analysis

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INTRODUCTION

By identifying similarities between apparently dissimilar objects or situations, humans can solve novel problems, learn and form new concepts, or communicate specific ideas to others. The identification of such similarities allows us to link distinct domains of knowledge and transfer solutions from one domain to another. In analogical reasoning, similarities are typically relational, i.e., they concern the relationships between components of an object or a situation rather than the components themselves [START_REF] Gentner | Reasoning and learning by analogy[END_REF][START_REF] Krawczyk | The cognition and neuroscience of relational reasoning[END_REF]. In this sense, analogical reasoning is a form of relational reasoning that depends on our ability to consider and compare relationships and to integrate or match those relationships. This relational processing yields the inference of an analogy schema, i.e., a pattern of relational similarities between the analogs. The analogy schema is at a more abstract level of similarities than superficial or perceptual similarities would be, reflecting a mechanism by which relational reasoning supports abstract thinking. Relational reasoning is also considered to be a key process of fluid reasoning [START_REF] Waltz | A System for Relational Reasoning in Human Prefrontal Cortex[END_REF] and has implications for learning and education [START_REF] Geake | Neural correlates of intelligence as revealed by fMRI of fluid analogies[END_REF][START_REF] Gentner | The Analogical Mind: Perspectives from Cognitive Science[END_REF], problem solving and creativity [START_REF] Green | Neural correlates of creativity in analogical reasoning[END_REF]. However, the cerebral substrates for this process have not been elucidated.

The cerebral bases of analogical reasoning have been informed primarily through functional imaging. Studies have examined analogical reasoning typically using 4-or sometimes 6-term analogy tasks (e.g., is the A -B relation similar to the C -D relation).

Functional magnetic resonance imaging (MRI) studies using these tasks have shown the involvement of a fronto-parietal system [START_REF] Bunge | Analogical reasoning and prefrontal cortex: evidence for separable retrieval and integration mechanisms[END_REF][START_REF] Cho | Common and dissociable prefrontal loci associated with component mechanisms of analogical reasoning[END_REF][START_REF] Christoff | Evaluating self-generated information: anterior prefrontal contributions to human cognition[END_REF]Geake andHansen, 2010, 2005;[START_REF] Green | Connecting long distance: semantic distance in analogical reasoning modulates frontopolar cortex activity[END_REF][START_REF] Volle | Specialization of the rostral prefrontal cortex for distinct analogy processes[END_REF][START_REF] Wendelken | Rostrolateral prefrontal cortex: domain-general or domain-sensitive?[END_REF]Wendelken et al. , 2008a) and an association with the anterior cingulate cortex [START_REF] Luo | The neural substrate of analogical reasoning: an fMRI study[END_REF][START_REF] Preusse | Fluid intelligence allows flexible recruitment of the parieto-frontal network in analogical reasoning[END_REF]) and the temporal regions [START_REF] Luo | The neural substrate of analogical reasoning: an fMRI study[END_REF][START_REF] Reber | Detecting analogies unconsciously[END_REF]. The most consistent F o r P e e r R e v i e w Volle E 5 region that has been associated with analogical reasoning is the left rostrolateral prefrontal cortex (rlPFC), as was recently demonstrated by a previous meta-analysis [START_REF] Vartanian | Dissociable neural systems for analogy and metaphor: implications for the neuroscience of creativity[END_REF] that analyzed data from 10 functional MRI studies. Similarly, a voxel-based morphometry approach demonstrated a link between individual analogical reasoning abilities and the structure of the left rlPFC [START_REF] Aichelburg | Morphometry of Left Frontal and Temporal Poles Predicts Analogical Reasoning Abilities[END_REF]. This set of results argues for an important role of the rlPFC, particularly the left rlPFC, in analogical process. However, many studies have reported bilateral activation [START_REF] Cho | Common and dissociable prefrontal loci associated with component mechanisms of analogical reasoning[END_REF][START_REF] Geake | Functional neural correlates of fluid and crystallized analogizing[END_REF][START_REF] Preusse | Fluid intelligence allows flexible recruitment of the parieto-frontal network in analogical reasoning[END_REF][START_REF] Wartenburger | Cerebral correlates of analogical processing and their modulation by training[END_REF], or even right activation, of the rlPFC in non-verbal visuospatial analogy tasks [START_REF] Kalbfleisch | The influences of task difficulty and response correctness on neural systems supporting fluid reasoning[END_REF]) and in semantic analogy tasks [START_REF] Luo | The neural substrate of analogical reasoning: an fMRI study[END_REF]. Therefore, the left predominance of the rlPFC for analogical reasoning processing is still unclear and remains to be confirmed.

If the hypothesis of a left dominance of the rlPFC for analogy proves true, the cognitive processes supported by the left rlPFC and underlying a left specialization remain unknown. A left dominance could be explained by the domain of the analogy performed and/or its verbal or semantic nature. Alternatively, some cognitive processes involved in analogical reasoning may require specifically the left rlPFC region. With regard to the first explanation, literature about cognition has historically supported a left dominance for language, including semantics, and a right dominance for spatial information processing [START_REF] Bates | Voxel-based lesion-symptom mapping[END_REF][START_REF] Catani | Perisylvian language networks of the human brain[END_REF][START_REF] Forkel | Anatomical predictors of aphasia recovery: a tractography study of bilateral perisylvian language networks[END_REF][START_REF] Heilman | The right hemisphere: neuropsychological functions[END_REF][START_REF] Mesulam | A cortical network for directed attention and unilateral neglect[END_REF][START_REF] Price | The anatomy of language: a review of 100 fMRI studies published in[END_REF][START_REF] De Schotten | A lateralized brain network for visuospatial attention[END_REF]). In the analogy field, tasks have used various materials requiring the inference of analogies in the semantic domain (i.e., infer semantic relationships such as nose-smell :: mouth-taste) or in the visuospatial domain (i.e., analyze visuospatial relationships to infer a logical, geometrical or mathematical rule such as symmetry or linear increase). Semantic analogies depend on knowledge of the semantic meaning of the terms and of the relationships between them. In visuospatial analogies, the analogy is inferred from the analysis of the visual and spatial relationships between terms that can be conceived as transformations from one term to the other (e.g., changes in shape, color, size, etc.). To our knowledge, only one study has examined directly the question of the specialization of the analogy network as a function of the analogy domain [START_REF] Wendelken | Rostrolateral prefrontal cortex: domain-general or domain-sensitive?[END_REF]). This study did not find a left-right specialization of rlPFC according to the analogy domain: both semantic and visuospatial analogies recruited the left rlPFC. Further studies are needed in order to better understand the role and organization of the left rlPFC for analogy domains, and the involvement of the other prefrontal regions.

This leads us to the second hypothesis relative to the specific or critical processes supported by the left rlPFC region. The few patient studies conducted to date have confirmed the critical role of the prefrontal cortex (PFC) in analogical reasoning [START_REF] Krawczyk | Distraction during relational reasoning: the role of prefrontal cortex in interference control[END_REF][START_REF] Morrison | A neurocomputational model of analogical reasoning and its breakdown in frontotemporal lobar degeneration[END_REF]Schmidt et al. 2012) or in rule inference [START_REF] Reverberi | Specific impairments of rule induction in different frontal lobe subgroups[END_REF], but these studies were unable to determine the role of the rlPFC region specifically. In functional imaging, the left rlPFC has been involved in the processing of abstract information [START_REF] Christoff | Evaluating self-generated information: anterior prefrontal contributions to human cognition[END_REF] and in the comparison (Wendelken et al. 2008a) or the integration of multiple relationships [START_REF] Bunge | Analogical reasoning and prefrontal cortex: evidence for separable retrieval and integration mechanisms[END_REF][START_REF] Cho | Common and dissociable prefrontal loci associated with component mechanisms of analogical reasoning[END_REF][START_REF] Christoff | Rostrolateral prefrontal cortex involvement in relational integration during reasoning[END_REF]).

These operations are often investigated using other relational reasoning tasks, the matrix problem tasks such as Raven's Progressives Matrices [START_REF] Raven | Standardization of progressive matrices[END_REF]. Matrix problems typically require the consideration and integration of visuospatial relationships to infer logical, geometrical or mathematical rules [START_REF] Kalbfleisch | Environmental influences on neural systems of relational complexity[END_REF][START_REF] Kalbfleisch | The influences of task difficulty and response correctness on neural systems supporting fluid reasoning[END_REF][START_REF] Shokri-Kojori | The network architecture of cortical processing in visuo-spatial reasoning[END_REF][START_REF] Yamada | Functional alterations in neural substrates of geometric reasoning in adults with high-functioning autism[END_REF]. Matrix problem tasks thus share several cognitive processes with analogy tasks, such as relational comparison, integration and schema inference. Matrix problems and 4-terms analogies are supposed to measure the same type of relational reasoning functions [START_REF] Krawczyk | The cognition and neuroscience of relational reasoning[END_REF]. In this framework, typical 4-terms analogy tasks and matrix problem tasks might thus engage similar brain regions. Functional imaging studies have shown that bilateral frontal and parietal regions are involved during matrix problem tasks. The most frequently reported regions in these studies were the dorsolateral PFC [START_REF] Christoff | Rostrolateral prefrontal cortex involvement in relational integration during reasoning[END_REF][START_REF] Hampshire | Lateral prefrontal cortex subregions make dissociable contributions during fluid reasoning[END_REF][START_REF] Krawczyk | Distraction during relational reasoning: the role of prefrontal cortex in interference control[END_REF][START_REF] Kroger | Recruitment of anterior dorsolateral prefrontal cortex in human reasoning: a parametric study of relational complexity[END_REF][START_REF] Perfetti | Differential patterns of cortical activation as a function of fluid reasoning complexity[END_REF]) sometimes extending to the rlPFC [START_REF] Golde | Differential role of anterior prefrontal and premotor cortex in the processing of relational information[END_REF][START_REF] Hampshire | Lateral prefrontal cortex subregions make dissociable contributions during fluid reasoning[END_REF][START_REF] Krawczyk | Distraction during relational reasoning: the role of prefrontal cortex in interference control[END_REF], see also Wendelken et al. 2008a), the premotor cortex [START_REF] Golde | Differential role of anterior prefrontal and premotor cortex in the processing of relational information[END_REF][START_REF] Kalbfleisch | The influences of task difficulty and response correctness on neural systems supporting fluid reasoning[END_REF][START_REF] Krawczyk | Distraction during relational reasoning: the role of prefrontal cortex in interference control[END_REF][START_REF] Perfetti | Differential patterns of cortical activation as a function of fluid reasoning complexity[END_REF][START_REF] Yamada | Functional alterations in neural substrates of geometric reasoning in adults with high-functioning autism[END_REF], and posterior parietal areas [START_REF] Hampshire | Lateral prefrontal cortex subregions make dissociable contributions during fluid reasoning[END_REF][START_REF] Krawczyk | Distraction during relational reasoning: the role of prefrontal cortex in interference control[END_REF][START_REF] Perfetti | Differential patterns of cortical activation as a function of fluid reasoning complexity[END_REF]. Some studies have also shown the involvement of the lateral occipitotemporal regions [START_REF] Hampshire | Lateral prefrontal cortex subregions make dissociable contributions during fluid reasoning[END_REF][START_REF] Kalbfleisch | Environmental influences on neural systems of relational complexity[END_REF][START_REF] Yamada | Functional alterations in neural substrates of geometric reasoning in adults with high-functioning autism[END_REF], the anterior cingulate cortex [START_REF] Kroger | Recruitment of anterior dorsolateral prefrontal cortex in human reasoning: a parametric study of relational complexity[END_REF][START_REF] Shokri-Kojori | The network architecture of cortical processing in visuo-spatial reasoning[END_REF]) and the cerebellum [START_REF] Kalbfleisch | The influences of task difficulty and response correctness on neural systems supporting fluid reasoning[END_REF]. A recent and comprehensive review indicated that 4-term analogies and matrix problems might engage differentially the left and right rlPFC [START_REF] Krawczyk | The cognition and neuroscience of relational reasoning[END_REF].

The lesion approach has produced inconsistent results regarding whether the integrity of the rlPFC is required for matrix problem solving (Baldo et al. 2010;[START_REF] Gläscher | Lesion mapping of cognitive abilities linked to intelligence[END_REF]Tranel et al. 2008;[START_REF] Waltz | A System for Relational Reasoning in Human Prefrontal Cortex[END_REF]Woolgar et al. 2010). Overall, previous studies have suggested that analogy and matrix reasoning tasks involve largely similar cognitive processes and engage both common and specific brain regions, and might not equally rely on the rlPFC. A quantitative comparison of functional activation observed during 4-term analogy and matrix problem tasks should help to clarify this question.

In this general context, the aim of the current study was to identify the cerebral network involved in analogical reasoning and its specialization or variation based on domains of information (semantic or visuospatial) and task specificity (4-terms analogy or matrix problem tasks). We conducted a meta-analysis including 27 experiments that used such tasks.

We contrasted semantic and visuospatial analogy tasks to identify domain-oriented regions in the analogy network and to test whether the involvement of the left rlPFC is dependent on the Volle E 8 analogy domain. We expected a left dominance for the involvement of the rlPFC independent of the analogy domain. We additionally compared visuospatial analogy to matrix problem tasks to examine the possible differences in their brain correlates. We hypothesized that visuospatial analogies and matrix problems would engage, at least in part, distinct cerebral networks and involve differently the rlPFC.

METHODS

Study selection

We searched for all published studies about analogical reasoning using fMRI by conducting a Boolean search in the PubMed database. Specifically, we searched for the following keywords in the text and/or the abstract/title: "analogy", "analogies", "analogical reasoning", "relational reasoning", "relational integration", "relational complexity", "analogizing", "fluid reasoning", "analogic reasoning" "progressive matrices", "Ravens' Standard Progressive Matrices", "Advanced Progressive Matrices", "RSPM", "APM", "Cattell's Culture Fair Test", together with "brain imaging", "cerebral imaging", "MRI", "fMRI", "functional MRI", "PET", "neural correlates", "cerebral correlates", "brain activation", "functional magnetic resonance imaging".

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According to these criteria, we ultimately analyzed 27 studies, including 40 fMRI contrasts, 506 subjects and 351 foci of activation (Table 1).

Task categories (Table 1)

We classified each study and experimental contrast according to (1) the type of task used (4term analogy versus matrix problem tasks) and (2) the domain in which the relational reasoning applied (semantic or visuospatial/logical relationships). The included experiments were distributed into three categories: "Semantic Analogy", "Visuospatial Analogy" and "Matrix Problem" (Matrix Problem tasks always concerned the visuospatial domain).

ALE methods

General principles

We used the Activation Likehood Estimation (GingerALE) software (http://brainmap.org/ale/cli.html; [START_REF] Eickhoff | Coordinate-based activation likelihood estimation meta-analysis of neuroimaging data: a random-effects approach based on empirical estimates of spatial uncertainty[END_REF][START_REF] Laird | ALE Meta-Analysis Workflows Via the Brainmap Database: Progress Towards A Probabilistic Functional Brain Atlas[END_REF][START_REF] Turkeltaub | Minimizing within-experiment and within-group effects in Activation Likelihood Estimation metaanalyses[END_REF][START_REF] Turkeltaub | Meta-analysis of the functional neuroanatomy of single-word reading: method and validation[END_REF] in our meta-analysis. This method determines the brain areas in which the convergence across all included experiments is greater than would be expected by chance (null distribution of randomly generated activation likelihoods) [START_REF] Eickhoff | Coordinate-based activation likelihood estimation meta-analysis of neuroimaging data: a random-effects approach based on empirical estimates of spatial uncertainty[END_REF]]. This analysis is based on the compilation of the activation peak coordinates from all the functional imaging studies in a same normalized referential. In other words, ALE evaluates how reliable the involvement of brain regions in given processes across distinct experiments is -in this case in relational reasoning tasks.

Global and task category maps

We performed ALE analyses using the GingerALE software version 2. 3.3 (www.brainmap.org;[START_REF] Eickhoff | Activation likelihood estimation meta-analysis revisited[END_REF][START_REF] Eickhoff | Coordinate-based activation likelihood estimation meta-analysis of neuroimaging data: a random-effects approach based on empirical estimates of spatial uncertainty[END_REF][START_REF] Turkeltaub | Minimizing within-experiment and within-group effects in Activation Likelihood Estimation metaanalyses[END_REF]. We converted the Volle E 10 activation peak coordinates reported in Talairach space into MNI space using the converter included in the GingerALE toolbox. Activation foci in the same referential from each included contrast were first modeled as Gaussian distributions and then merged into the same volume. We organized the datasets according to subject groups and used the modified ALE algorithm [START_REF] Turkeltaub | Minimizing within-experiment and within-group effects in Activation Likelihood Estimation metaanalyses[END_REF] to address the issue of the independence of observation within the same study. The algorithm also modeled spatial uncertainty [START_REF] Eickhoff | Activation likelihood estimation meta-analysis revisited[END_REF][START_REF] Eickhoff | Coordinate-based activation likelihood estimation meta-analysis of neuroimaging data: a random-effects approach based on empirical estimates of spatial uncertainty[END_REF], allowing us to adjust the full-width half maximum (FWHM) using an estimation of between-subject and between-experiment variability. GingerALE then modeled the probability of activation across all studies for each brain voxel, returning localized "activation likelihood estimates" or ALE values. ALE values are the statistical maps created by combined probability distributions centered at each coordinate used in the analysis and reflect the coherency across experiments.

In a second step, ALE values were compared to random distributions of foci to identify significantly activated clusters at each voxel. We used a cluster correction for multiple comparisons: the simulated data was thresholded using a "cluster-forming threshold", identifying the contiguous volumes above the threshold, or clusters. Then ALE tracked the distribution of the volume of the clusters and used a "cluster-level threshold" for thresholding the results. We used an uncorrected cluster-forming threshold at p < 0.001 and a cluster-level threshold at p < 0.05 [START_REF] Eickhoff | Activation likelihood estimation meta-analysis revisited[END_REF]. ALE maps were calculated using 1000 permutations. We also reported the results at a stringent voxel-level family-wise error (FWE) correction when significant.

We computed a global map for all included studies (analogy and matrix problem tasks). To analyze the distinct task categories, an ALE analysis was performed separately for each category (Semantic Analogy, Visuospatial Analogy and Matrix problem tasks). A map for each task category was obtained.

Task comparisons and contrast maps

We next conducted contrast analyses between the task categories to look for specific brain correlates. First, we tested whether analogy in the semantic and spatial domains was associated with specific regions ( Contrast analyses were performed by first building ALE maps separately for each condition, and then computing the voxel-wise difference between these two input ALE maps [START_REF] Laird | ALE meta-analysis: controlling the false discovery rate and performing statistical contrasts[END_REF]. ALE contrast maps correspond to the direct subtraction of the two input images, converted into Z-scores. GingerALE creates simulated data of new groupings that are subtracted one from another, and compared to the true data. After 10000 permutations, a voxelwise P value image was obtained, and compared to the true data values. We reported each contrast map with an uncorrected p value < 0.05 and an minimum cluster size of 100 voxels.

ALE results

The anatomical labels of final cluster locations were produced as a GingerALE output. Maps were superimposed on the anatomical Colin27 template [START_REF] Holmes | Enhancement of MR images using registration for signal averaging[END_REF]) using Mricron and MricroGL (http://www.mccauslandcenter.sc.edu/mricro/mricron/) for visualization purposes.

RESULTS

Global analysis (

Task category maps

1) Semantic Analogy tasks map (Table 3, Figure 2)

The ALE map based on grouping semantic analogy tasks revealed a left-lateral prefrontal network. The primary cluster was located in the rostrolateral part of the left IFG and MFG (BA 10/47 and BA 46). A second cluster was located posteriorly in the posterior part of the left IFG (BA 44). Additional clusters were observed in the superior frontal gyrus, including one in the anterior part (BA 9) and one in the dorsal part (BA 8), and in the bilateral caudate heads.

2) Visuospatial Analogy tasks map (Table 4, Figure 2)

The analysis of Visuospatial Analogy tasks revealed four clusters of activation. The primary cluster was centered in the rostrolateral region of the left inferior frontal sulcus and gyrus (BA 10/47/46). Additional clusters were located in the right MFG (BA 9), the right anterior insula, and the cerebellum.

3) Visuospatial Matrix problems map (

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The ALE map for Matrix problems revealed a large, bilateral fronto-parietal network distributed into eight clusters of activation. Larger clusters were located bilaterally in the parietal lobe, extending from superior to inferior regions (BA 7 and 40), and in the precuneus (BA 7/31). In the frontal lobe, significant clusters were found bilaterally in the posterior and dorsolateral PFC centered on the posterior inferior frontal sulcus (IFS) (BA 6, 44, 9) with a right predominance, in the posterior region of the superior frontal regions centered on the posterior SFS (BA 6/8), and bilaterally in the medial PFC. Two additional clusters were located in the anterior region of the right insula and in the left cingulate gyrus (BA 32).

4) Visual overlap (Figure 2)

Semantic Analogy and Visuospatial Analogy commonly recruited the rostrolateral part of the left IFG in a similar cluster, while Matrix Problems did not. This corresponded to the cluster that was significant at a voxel-based FWE correction. This region is hereafter referred to as the "left rlPFC ROI".

Visuospatial Analogy and Matrix problems shared the activation of the right anterior insula.

Contrast maps

1) Comparisons of Semantic and Visuospatial Analogy tasks (Table 6, Figure 3)

The ALE subtraction map of Semantic versus Visuospatial Analogy tasks revealed a cluster located in the rostrolateral part of the left IFG (BA 47) that was located more posterior and ventral to the left rlPFC ROI. The left rostromedial prefrontal cortex (medial BA 10) and the left inferior frontal sulcus (BA 46) were also significantly more strongly activated by Semantic than Visuospatial Analogy tasks.

The ALE subtraction map of Visuospatial versus Semantic Analogy tasks revealed a set of 7, Figure 4)

2) Comparison of Visuospatial Analogy versus Matrix problems maps (Table

The ALE subtraction map of Visuospatial Analogy versus Matrix problem tasks revealed a primary cluster in the left rostral region of the PFC (centered on BA 10, extending to BA 9, 45, 46, and encompassing the anterior MFG and IFG) in similar location to the left rlPFC ROI. A second cluster was observed in the left posterior cerebellum.

The ALE subtraction map of Matrix problems versus Visuospatial Analogy tasks revealed a large frontoparietal network containing the bilateral posterior and dorsolateral PFC centered on the posterior IFS (BA 6, 44, 9) with a right predominance, the posterior part of the superior frontal regions centered on the posterior SFS (BA 6/8), the medial PFC (BA 9/32), the left IPL and SPL (BA 7), the right precuneus (BA 7, 19 and 31), and the postcentral gyrus (BA 2 and 3). A left rostral PFC region (BA 10) was also observed, which was in a more medial location than the "left rlPFC ROI".

DISCUSSION

Using the ALE method, our coordinate-based meta-analysis combined data from 27 functional neuroimaging experiments to reveal three lines of findings: (i) the rostral part of the left rlPFC was consistently engaged during analogical reasoning tasks, regardless of the

The left rlPFC is a reliable domain-general region for analogical reasoning

First, the results from our global analysis of the 27 experiments revealed a reliable activation in the left rlPFC (BA 10/47), which is a region at the rostral end of the IFS that we labeled the "left rlPFC ROI". Previous meta-analyses also reported significant and informative results despite the relatively small number of experiments analyzed [START_REF] Gonen-Yaacovi | Rostral and caudal prefrontal contribution to creativity: a meta-analysis of functional imaging data[END_REF][START_REF] Vartanian | Dissociable neural systems for analogy and metaphor: implications for the neuroscience of creativity[END_REF][START_REF] Prado | The brain network for deductive reasoning: a quantitative meta-analysis of 28 neuroimaging studies[END_REF]. Our currently identified association between analogical reasoning and activity in the left rlPFC, and confirmed the findings of [START_REF] Vartanian | Dissociable neural systems for analogy and metaphor: implications for the neuroscience of creativity[END_REF] when we added 17 new experiments to the meta-analysis. This result is also in agreement with previous findings from different approaches such as morphometry [START_REF] Aichelburg | Morphometry of Left Frontal and Temporal Poles Predicts Analogical Reasoning Abilities[END_REF]Krawczyk et al. 2010), and developmental studies in children. The latter studies suggested that maturation of the PFC and especially of the rlPFC is critical for relational reasoning in Matrix problems [START_REF] Crone | Neurocognitive development of relational reasoning[END_REF], for semantic analogies [START_REF] Wright | Neural correlates of fluid reasoning in children and adults[END_REF], and visuospatial analogies [START_REF] Bazargani | Developmental changes in effective connectivity associated with relational reasoning: DCM of Relational Reasoning Development[END_REF][START_REF] Thibaut | The development of analogy making in children: Cognitive load and executive functions[END_REF][START_REF] Wendelken | Increased Functional Selectivity over Development in Rostrolateral Prefrontal Cortex[END_REF]. These studies showed functional and structural changes in the left rlPFC during development, with decreasing grey matter volume and increasing specificity of left rlPFC activation for relational integration (for a review [START_REF] Dumontheil | Development of abstract thinking during childhood and adolescence: The role of rostrolateral prefrontal cortex[END_REF]. Changes in functional connectivity were also reported between rlPFC and anterior insula, posterior frontal, and posterior parietal cortices [START_REF] Bazargani | Developmental changes in effective connectivity associated with relational reasoning: DCM of Relational Reasoning Development[END_REF], regions that were also reliably observed in the current meta-analysis. Overall developmental studies suggest that the left rlPFC is critical for different types of relational reasoning tasks and domains of relationships used.

In the current meta-analysis, Semantic and Visuospatial Analogy maps overlapped in the "left rlPFC ROI", suggesting that analogies in distinct domains share a common brain correlate within the rlPFC. For each analogy map, ALE values were significant in the "left rlPFC ROI" but not in the right rlPFC, suggesting a left lateralization of the rlPFC for analogical reasoning regardless of the task domain. As mentioned earlier, left prefrontal dominance for analogical reasoning has been shown in previous functional imaging studies [START_REF] Vartanian | Dissociable neural systems for analogy and metaphor: implications for the neuroscience of creativity[END_REF][START_REF] Crone | Neurocognitive development of relational reasoning[END_REF][START_REF] Krawczyk | The cognition and neuroscience of relational reasoning[END_REF]) and a repetitive transcranial magnetic stimulation study [START_REF] Boroojerdi | Enhancing analogic reasoning with rTMS over the left prefrontal cortex[END_REF]. It is unlikely that this left-lateralization could be due solely to verbal or semantic requirements because we observed an activation in the left rlPFC during both Semantic and Visuospatial Analogy tasks, as has been also reported by [START_REF] Wendelken | Rostrolateral prefrontal cortex: domain-general or domain-sensitive?[END_REF]. As shown in a functional imaging study, the activation of the rlPFC across a large range of different tasks using various domains of stimuli (verbal, spatial, visual) reinforces the interpretation of a domain-general function for the rlPFC [START_REF] Gilbert | Functional specialization within rostral prefrontal cortex (area 10): a meta-analysis[END_REF].

Functional imaging studies have indeed shown the involvement of the rlPFC in various cognitive functions related to analogical reasoning such as working memory [START_REF] Christoff | The frontopolar cortex and human cognition: Evidence for a rostrocaudal hierarchical organization within the human prefrontal cortex[END_REF][START_REF] Narayanan | The role of the prefrontal cortex in the maintenance of verbal working memory: an eventrelated FMRI analysis[END_REF], multitasking and task switching [START_REF] Braver | The role of frontopolar cortex in subgoal processing during working memory[END_REF][START_REF] Burgess | Strategy application disorder: the role of the frontal lobes in human multitasking[END_REF][START_REF] Burgess | The cognitive and neuroanatomical correlates of multitasking[END_REF][START_REF] Koechlin | The role of the anterior prefrontal cortex in human cognition[END_REF], abstract reasoning and problem-solving [START_REF] Badre | Cognitive control, hierarchy, and the rostro-caudal organization of the frontal lobes[END_REF][START_REF] Christoff | Evaluating self-generated information: anterior prefrontal contributions to human cognition[END_REF][START_REF] Christoff | Rostrolateral prefrontal cortex involvement in relational integration during reasoning[END_REF][START_REF] Kroger | Recruitment of anterior dorsolateral prefrontal cortex in human reasoning: a parametric study of relational complexity[END_REF][START_REF] Smith | Localizing the rostrolateral prefrontal cortex at the individual level[END_REF]). However, the precise role of the rlPFC in analogical reasoning, and more widely in cognition, has not been elucidated. Clinical observations have tended to confirm that damage to this region could cause high-level cognitive disorders [START_REF] Burgess | Mesulam's frontal lobe mystery re-examined[END_REF][START_REF] Burgess | Strategy application disorder: the role of the frontal lobes in human multitasking[END_REF]. Relatively recent theories propose that the rlPFC (or frontal pole) is an integrative and coordinating region, the role of which could be to integrate the outcomes of separate cognitive operations and information of different nature, in the pursuit of long-term or more global behavioral goals [START_REF] Ramnani | Anterior prefrontal cortex: insights into function from anatomy and neuroimaging[END_REF][START_REF] Stuss | Functions of the Frontal Lobes: Relation to Executive Functions[END_REF]. Hierarchical models of PFC organization inferred from functional imaging studies place the rlPFC at the top of a cognitive hierarchy in which more anterior portions of the frontal lobes support increasingly abstract representations, greater relational complexity in reasoning, or higher levels of adaptive control [START_REF] Badre | Cognitive control, hierarchy, and the rostro-caudal organization of the frontal lobes[END_REF][START_REF] Christoff | Prefrontal organization of cognitive control according to levels of abstraction[END_REF][START_REF] Koechlin | An information theoretical approach to prefrontal executive function[END_REF] in interaction with more posterior regions. Because analogies engage relational integration and the formation of abstract concepts, the involvement of the rlPFC in analogical reasoning is consistent with these theories from both the perspectives of abstraction and relational integration (see also [START_REF] Shokri-Kojori | The network architecture of cortical processing in visuo-spatial reasoning[END_REF]. The rlPFC might also play a role in the coordination or integration of internally (inferred analogy schema) versus externally (stimuli) oriented thoughts (Gilbert et al. 2000;Burgess et al. 2007). The critical role of the rlPFC in these integration, control-related or complexity-dependent functions remains to be tested in patients. These interpretations assume that the role of the rlPFC in the integration of visuospatial, semantic or rule-based relational representations is supported by its interactions with other regions of the analogy network.

Global network of relational reasoning

In addition to the "left rlPFC ROI", the global map showed a distributed set of brain regions bilaterally encompassing the insula, posterior prefrontal regions, posterior parietal cortex, and medial SFG. These regions appeared to belong to distinct brain networks that have been described by resting state functional imaging studies: the fronto-parietal executive/control network, the salience network and the dorsal attentional network [START_REF] Cole | Global connectivity of prefrontal cortex predicts cognitive control and intelligence[END_REF][START_REF] Power | Control-related systems in the human brain[END_REF][START_REF] Power | Functional network organization of the human brain[END_REF][START_REF] Vincent | Evidence for a frontoparietal control system revealed by intrinsic functional connectivity[END_REF])

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The fronto-parietal control network includes the dorsolateral prefrontal cortex and the posterior parietal cortex. This network has been largely associated with complex functions related to analogical reasoning, including fluid intelligence [START_REF] Hampshire | Lateral prefrontal cortex subregions make dissociable contributions during fluid reasoning[END_REF][START_REF] Jung | The Parieto-Frontal Integration Theory (P-FIT) of intelligence: converging neuroimaging evidence[END_REF][START_REF] Prado | The brain network for deductive reasoning: a quantitative meta-analysis of 28 neuroimaging studies[END_REF][START_REF] Reineberg | Restingstate networks predict individual differences in common and specific aspects of executive function[END_REF][START_REF] Wendelken | Meta-analysis: how does posterior parietal cortex contribute to reasoning? Front[END_REF], working memory [START_REF] Champod | Dissociation within the frontoparietal network in verbal working memory: a parametric functional magnetic resonance imaging study[END_REF][START_REF] Courtney | Attention and cognitive control as emergent properties of information representation in working memory[END_REF][START_REF] Curtis | Prefrontal and parietal contributions to spatial working memory[END_REF]Smith and Jonides 1999), structuration of mental representations into chunks [START_REF] Bor | Encoding Strategies Dissociate Prefrontal Activity from Working Memory Demand[END_REF][START_REF] Bor | A Common Prefrontal-Parietal Network for Mnemonic and Mathematical Recoding Strategies within Working Memory[END_REF]; see also Wendelken et al., 2008b), and deliberate control of thoughts and actions [START_REF] Badre | Functional Magnetic Resonance Imaging Evidence for a Hierarchical Organization of the Prefrontal Cortex[END_REF][START_REF] Koechlin | The role of the anterior prefrontal cortex in human cognition[END_REF][START_REF] Hampshire | Fractionating attentional control using event-related fMRI[END_REF][START_REF] Petrides | Lateral prefrontal cortex: architectonic and functional organization[END_REF]. The salience network includes the anterior insula and the adjacent ventrolateral prefrontal (posterior IFG) and anterior cingulate cortices [START_REF] Seeley | Dissociable intrinsic connectivity networks for salience processing and executive control[END_REF][START_REF] Sridharan | A critical role for the right fronto-insular cortex in switching between central-executive and default-mode networks[END_REF]). An important role of the salience and the fronto-parietal executive networks for fluid reasoning in healthy individuals has been suggested by Yuan and colleagues (2012) using voxel-based morphometry and resting state imaging. Recent studies have postulated that the salience network drives switching between the fronto-parietal control and the default mode networks [START_REF] Goulden | The salience network is responsible for switching between the default mode network and the central executive network: replication from DCM[END_REF][START_REF] Jilka | Damage to the Salience Network and interactions with the Default Mode Network[END_REF][START_REF] Sridharan | A critical role for the right fronto-insular cortex in switching between central-executive and default-mode networks[END_REF], allowing for the engagement of the brain's attentional and higher-order control processes while disengaging other systems that are not task-relevant [START_REF] Sridharan | A critical role for the right fronto-insular cortex in switching between central-executive and default-mode networks[END_REF]. This process could be involved in analogical reasoning. Finally, the dorsal attentional system includes regions of the frontal eye fields (posterior SFS), the premotor cortex and the superior parietal lobule. It is associated with externally directed cognition, including covert and overt shifts of spatial attention [START_REF] Corbetta | Control of goal-directed and stimulus-driven attention in the brain[END_REF] and is engaged in tasks involving spatial search and detection. This network could be more involved in visuospatial than semantic analogy tasks, as is discussed below.

Specialization into domain-oriented regions

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In contrast to the "left rlPFC ROI", which was recruited in both Semantic and Visuospatial Analogies, we observed differences in the pattern of brain activity in other areas, depending on the analogy domain.

Compared with Visuospatial Analogy tasks, Semantic Analogy tasks more specifically recruited the left anterior IFG (BA 47), located ventrally and posteriorly to the left rlPFC ROI. The left anterior IFG has been associated with controlling or selecting the retrieved information during semantic retrieval [START_REF] Badre | Left ventrolateral prefrontal cortex and the cognitive control of memory[END_REF][START_REF] Barde | Models of functional organization of the lateral prefrontal cortex in verbal working memory: evidence in favor of the process model[END_REF][START_REF] Sl | Neuroimaging studies of semantic memory: inferring « how » from « where[END_REF], with executive aspects of semantic processing [START_REF] Dronkers | Lesion analysis of the brain areas involved in language comprehension[END_REF][START_REF] Monti | Functional neuroanatomy of deductive inference: a language-independent distributed network[END_REF], and with abstract interpretation of metaphors [START_REF] Rapp | Neural correlates of metaphor processing[END_REF]).

Therefore, it is likely that this region plays a role in the semantic retrieval of relational and abstract information when solving semantic analogies, as has been shown by [START_REF] Bunge | Analogical reasoning and prefrontal cortex: evidence for separable retrieval and integration mechanisms[END_REF].

In addition to the left anterior IFG, Semantic Analogy tasks recruited the posterior region of the left IFG (BA 44) and the anterior and medial region of the left SFG (BA 10)

[figure 3]. Rostromedial frontal clusters have been suggested to be part of the semantic memory network [START_REF] Buckner | The brain's default network: anatomy, function, and relevance to disease[END_REF]) and might play a role in relational integration across semantic distance, as has been proposed by [START_REF] Green | Frontopolar cortex mediates abstract integration in analogy[END_REF][START_REF] Price | The anatomy of language: a review of 100 fMRI studies published in[END_REF] and [START_REF] Brunyé | Increasing breadth of semantic associations with left frontopolar direct current brain stimulation: a role for individual differences[END_REF].

These findings are also in agreement with previous functional imaging and lesion studies that have demonstrated a left specialization of the PFC for verbal abstraction using proverb interpretation [START_REF] Murphy | Impairments in proverb interpretation following focal frontal lobe lesions[END_REF] Volle E 20 consistent with the brain systems that support visual and spatial processing and spatial attention. The posterior parietal cortex, including both SPL and IPL, is thought to be involved in spatial cognition and has been associated with the formation of spatial representations and the processing of spatial relationships during analogy tasks [START_REF] Amorapanth | The neural basis for spatial relations[END_REF][START_REF] Wendelken | Meta-analysis: how does posterior parietal cortex contribute to reasoning? Front[END_REF]. The fusiform gyrus has previously been shown to participate in visual mental imagery and in the formation of the mental images of the visuospatial schema during analogical thinking [START_REF] Luo | The neural substrate of analogical reasoning: an fMRI study[END_REF]).

In addition, Visuospatial Analogy tasks compared to the Semantic Analogy tasks recruited the anterior MFG (BA 10). This additional rostral PFC region is located dorsal to the shared "left rlPFC ROI" and thus could be associated with the cognitive processes required by spatial and geometrical analogies that are not involved in semantic tasks. Previous authors have emphasized a more dorsal recruitment of the rostral PFC for spatial versus semantic analogies [START_REF] Wendelken | Rostrolateral prefrontal cortex: domain-general or domain-sensitive?[END_REF], at the individual level. A greater schema complexity in visuospatial compared to semantic analogies could explain the additional recruitment of a dorsal network, including the anterior MFG and the posterior parietal cortex, as reported by [START_REF] Hampshire | Lateral prefrontal cortex subregions make dissociable contributions during fluid reasoning[END_REF] and [START_REF] Krawczyk | The cognition and neuroscience of relational reasoning[END_REF].

In sum, in addition to the shared domain-general "left rlPFC ROI", semantic and visuospatial analogies recruited unique domain-oriented brain regions. Some of these domainoriented regions were located in the lateral PFC and were organized along the dorsoventral axis: MFG for Visuospatial Analogies and IFG for Semantic Analogies (Fig. 3). These findings suggest, as has been proposed by [START_REF] Babcock | The interaction of process and domain in prefrontal cortex during inductive reasoning[END_REF] for inductive reasoning, that analogical reasoning relies on common processes supported by the left rlPFC and recruits content information from domain-oriented regions. This hypothesis is consistent with models of the prefrontal functional architecture that describe a dorsoventral dissociation as a function of the domain of information [START_REF] Courtney | Attention and cognitive control as emergent properties of information representation in working memory[END_REF][START_REF] Sakai | Prefrontal interactions reflect future task operations[END_REF]Smith and Jonides, 1999;[START_REF] Volle | The functional architecture of the left posterior and lateral prefrontal cortex in humans[END_REF].

It is important to mention some limitations in the task comparisons that were performed. A variety of analogy tasks have been used, that employed verbal, figurative or abstract material, and involved semantic, visuospatial, mathematical, or logical relationships (Table 1). Task differences may induce some variability between fMRI studies that decreases the ability of meta-analyses to observe significant results. For instance, stimuli in semantic tasks were relatively homogeneous (written words), but the relationships involved in the analogies varied between studies. The visuospatial tasks were more heterogeneous in terms of materials or stimuli used, such as geometric shapes [START_REF] Preusse | Fluid intelligence allows flexible recruitment of the parieto-frontal network in analogical reasoning[END_REF][START_REF] Wartenburger | Cerebral correlates of analogical processing and their modulation by training[END_REF], symbol strings (Geake andHansen, 2010, 2005;[START_REF] Volle | Specialization of the rostral prefrontal cortex for distinct analogy processes[END_REF], pictures [START_REF] Cho | Common and dissociable prefrontal loci associated with component mechanisms of analogical reasoning[END_REF], colors and forms [START_REF] Christoff | Evaluating self-generated information: anterior prefrontal contributions to human cognition[END_REF][START_REF] Watson | A bilateral frontoparietal network underlies visuospatial analogical reasoning[END_REF], or abstract line drawings [START_REF] Wendelken | Rostrolateral prefrontal cortex: domain-general or domain-sensitive?[END_REF]), but involved quite similar categories of relationships, for instance increase in size, symmetry, pattern. Thus, we cannot exclude the possibility that these factors impacted the results, and that task-related differences are due to variability in experimental paradigms or materials used rather than to the analogy domain.

Dissociable Visuospatial Analogy and Matrix Problem task networks

The current meta-analysis identified dissociable neural systems activated by the Visuospatial Analogy and the Matrix Problem tasks across fMRI studies, in both the PFC and other brain regions.

In the rostral PFC, a region overlapping the "left rlPFC ROI" was recruited to a significantly greater extent in Visuospatial Analogy than in Matrix Problem tasks (Table 7).

This could indicate that the "left rlPFC ROI", located at the anterior end of the IFS, is a region that is relatively specific to analogical reasoning and is thus less involved in other Conversely when Matrix Problem tasks were compared to Analogy tasks, we observed the recruitment of a set of brain regions including a rostral prefrontal cluster that was located in the anterior part of the SFG and SFS. This cluster was dorsal and medial to the "left rlPFC ROI". This result suggests a functional specialization within the left frontal pole between a ventral region at the end of the IFS that supports analogical reasoning and a more medial region at the end of the SFS supporting relational reasoning in matrix format. However, this interpretation should be taken with caution because this medial rlPFC cluster was not observed in the Matrix Problem tasks map (task related activation) and was significant only when contrasting Matrix Problem to Analogy tasks. In addition, when compared to Analogy tasks, Matrix Problem tasks more consistently recruited a large set of brain regions that can be organized into a superior and an inferior fronto-parieto-occipital brain system with a right predominance. These significant regions appeared to belong to the attentional and frontoparietal executive networks (Rojkova et al. 2014;[START_REF] De Schotten | A lateralized brain network for visuospatial attention[END_REF].

The between-task differences in brain activation observed in the current meta-analysis raise the question as to which cognitive processes differ between these two types of visuospatial relational reasoning tasks. Both Analogy and Matrix Problem tasks require inductive and relational reasoning and are considered to be measures of fluid reasoning, i.e., the capacity to think logically and to solve problems in novel situations, independent of acquired knowledge. The two types of tasks may nevertheless differ regarding (1) evaluation versus completion requirements of the task designs;

(2) variable visuospatial loads during stimulus display or response choices; and (3) the number of relationships to integrate. First, analogy and matrix problem tasks could involve distinct cognitive processes because their response requirements are different (Table 1). Two main experimental conditions were used in the included studies: (1) evaluate a proposed analogy ("is A to B as C is to D'') ("Evaluate Yes/No" in Table 1) or (2) complete an analogy ("A is to B as C is to?''), in which participants were asked to select one among several alternatives ("Forced choice completion" in Table 1). All but two studies that used Matrix problems involved a forced choice completion between multiple alternatives, so that all of the lines and columns of the matrix share the same relationships, i.e., are analogs. Among analogy studies, all but four studies involved an evaluation type of response. In only one study the response type was a forced choice completion comparable to the response type in Matrix problem tasks. In two studies participants were to select a target given a source (different from the completion of an incomplete target), and in one study participants freely generated verbally the completion of a target (no forced choice). Therefore, differences in evaluation and completion requirements between analogy and matrix problems could be a confounding factor in our meta-analysis, that can not be controlled for, and might explain some of the differences in their brain correlates. For instance, Wendelken and colleagues' study (2008a) demonstrated that the left rlPFC was involved in evaluating analogies but not in completing a 4-term analogy, which instead was associated with the medial PFC. Here, matrix problem studies rarely included an evaluation condition, which could account for the absence of significant activation in the "left rlPFC ROI", while they recruited a more medial PFC region. Among the two Matrix problem studies that used evaluative responses, one recruited the left rlPFC while the other did not, which did not help to clarify this point. Alternatively, compared to evaluation, completion responses could increase interindividual variability in performance or solving strategy [START_REF] Shokri-Kojori | The network architecture of cortical processing in visuo-spatial reasoning[END_REF], and then decrease the power of fMRI to detect significant activation across subjects or increase variability between studies. The issue of response type Second, it is likely that the visual and spatial load is greater in matrix problems compared to visuospatial analogy tasks because a greater number of stimuli are usually displayed with regard to both the test items and choice alternatives. Indeed, analogy tasks are usually composed of 4 terms (A:B as C:D) [or sometimes 6 terms for visuospatial analogies;

Geake and Hansen, 2010; [START_REF] Volle | Specialization of the rostral prefrontal cortex for distinct analogy processes[END_REF][START_REF] Watson | A bilateral frontoparietal network underlies visuospatial analogical reasoning[END_REF], whereas matrix tasks usually display a 3-by-3 (or 3-by-2) matrix of terms. Thus, the greater visuospatial processing requirement in matrix problems could explain the additional recruitment of visuospatial regions and the attentional network [START_REF] Kalbfleisch | Environmental influences on neural systems of relational complexity[END_REF].

Finally, a greater number of stimuli to analyze also implies more relationships to consider and integrate during matrix problems, which possibly involves additional brain regions [START_REF] Ackerman | Spatial relations and spatial locations are dissociated within prefrontal and parietal cortex[END_REF]. The need to consider and manipulate a greater number of relationships could explain the stronger activation observed in the fronto-parietal control network [START_REF] Ackerman | Spatial relations and spatial locations are dissociated within prefrontal and parietal cortex[END_REF]Hamsphire et al. 2011;[START_REF] Jia | Prefrontal and parietal activity is modulated by the rule complexity of inductive reasoning and can be predicted by a cognitive model[END_REF][START_REF] Volle | The functional architecture of the left posterior and lateral prefrontal cortex in humans[END_REF]. This also raises the question of the involvement of "multitasking" or "branching" operations in matrix problem solving, i.e., the need to hold goals in mind while exploring and processing secondary goals [START_REF] Dreher | Damage to the fronto-polar cortex is associated with impaired multitasking[END_REF][START_REF] Koechlin | The role of the anterior prefrontal cortex in human cognition[END_REF].

Therefore, visuospatial analogy and matrix problem tasks appear to engage dissociable neural systems across fMRI studies, with more visuospatial, executive, and possibly multitasking requirements in matrix reasoning and possibly greater comparison and matching processing required for analogy tasks.

Conclusion

Volle E 25

The current findings showed the distinct brain systems that are involved in relational reasoning and described their task specificities. Several bilateral fronto-parietal systems contributed to different aspects of relational reasoning. The results revealed that the left rlPFC is a domain-general region that is specialized for analogy tasks and is co-activated with different brain regions along the dorsoventral axis as a function of the analogy domain. This suggests that the connectivity of this region with domain-oriented regions has a crucial role in analogical reasoning capacities. Conversely, matrix Problems showed a greater recruitment of the attention network and a fronto-parietal control network compared to analogy tasks, possibly due to greater demands on visuospatial processing and/or the coordination of a greater number of relationships prior to integration. The contrast between matrix problems and analogy tasks also revealed a possible specialization within this region. These findings provide some predictions about the respective roles of distinct brain regions or networks in relational reasoning, which could be tested in neurological patients. Despite the importance of these high-level functions in human cognition, the consequences of brain damage on analogical reasoning are poorly known. The current results provide new anatomical and functional hypotheses to test in patients with focal lesions, and suggest that future neurological studies should use distinct experimental analogy tasks in both semantic and nonsemantic domains. For instance, the current results predict that a left rlPFC lesion would alter relational reasoning abilities for all domains of relationships, including real world analogies, whereas lesions in more posterior lesions would impact semantic and non-semantic analogies differently depending on lesion location along the ventral-dorsal axis. Only lesion studies would answer the question of the critical role of the left rlPFC in Matrix problem solving.

Such focal lesion studies are needed in order to assess the validity of the results regarding real world analogies, and finally to inform patients and clinicians on the expected deficits after a given lesion. template (Holmes et al. 1996) in the MNI space. A cluster correction for multiple comparisons was used with an uncorrected cluster-forming threshold at p < 0.001 and a cluster threshold at p < 0.05. (Holmes et al. 1996) in the MNI space. These contrast maps were thresholded at an uncorrected p value < 0.05 following 10,000 permutations with a minimum cluster size of 100 voxels.

F

  map pooling Analogy and Matrix Problem tasks primarily revealed a bilateral fronto-parietal network including a large cluster located in the left rostrolateral PFC that was centered at Brodmann area (BA) 10 and extended to BA 47, 45 and 46, bilateral insula, posterior parietal cortex (BA 7 and 40), several clusters in the posterior region of the inferior frontal gyrus (IFG), middle frontal gyrus (MFG), superior frontal sulcus (SFS), and medial PFC. The clusters in the left rostrolateral PFC, the right dorsolateral region (BA 9, posterior part of the IFG) and the right insular area (BA 13) were significant at a p < 0.05 FWE corrected threshold.

  should be addressed in further specific experiments controlling for the task type and domain of relationships.

FIGURE CAPTIONS Figure 1 :

 CAPTIONS1 FIGURE CAPTIONS

Figure 2 :

 2 Figure 2: Task category maps. Semantic Analogy map (in green), Visuospatial Analogy

Figure 3 :

 3 Figure 3: Analogy domain subtraction maps. Semantic versus Visuospatial Analogy map

Figure 4 :Fig. 1 :Fig. 2 :Fig. 3 :Fig. 4 :

 41234 Figure 4: Task subtraction maps. Visuospatial Analogy versus Matrix problems map (in

  Table 1, columns 5 and 6) by building subtraction ALE maps that contrasted Semantic versus Visuospatial Analogy tasks. Second, we tested whether Analogy and Matrix Problem tasks had distinct brain correlates by building subtraction ALE maps comparing Visuospatial Analogy versus Visuospatial Matrix Problem tasks.

Table 2

 2

, Figure

1

)

Table 5 , Figure 2) Page 12 of 56 John

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	relational reasoning tasks such as the Matrix Problems. No other regions were significantly
	different in terms of activation when contrasting Visuospatial Analogy to Matrix Problem
	tasks.
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Table 2 : Locations of clusters with significant ALE values for the global analysis.

 2

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	Columns number 3-7 represent data associated with the left hemisphere and 8-12 represent
	data associated with the right hemisphere. The clusters displayed in bold were significant at a
	p < 0.05 FWE corrected threshold. Abbreviations: BA: approximate Brodmann area; ALE:
	activation likelihood estimation; S: sulcus; G: gyrus; IFG: inferior frontal gyrus; IFS: inferior
	frontal sulcus; MFG: middle frontal gyrus; SFG: superior frontal gyrus; SFS: superior frontal
	sulcus; x, y, z coordinates: peak voxel in the Montreal Neurologic Institute (MNI) space.
			Left					Right
	Location	BA	Cluster	ALE	x	y	z	Cluster	ALE	x	y	z
			number					number
			& size					& size
			(mm3)					(mm3)
	Frontal lobe
	Rostral part of IFS and IFG	10	1 (5192) 0.034	-48	44	-8
	Posterior IFG/
	MFG and IFS /	9/44/6	2 (1728) 0.023	-48	12	18	5 (1208) 0.028	50	10	26
	Precentral G
	Superior and
	lateral part of the	9	11 (528) 0.018	-46	26	34	6 (936)	0.019	46	30	30
	MFG
	Medial SFG / Cingulate	6/32						4 (1296) 0.021	6	20	48
	Posterior MFG /
	SFS / Precentral	6	10 (776) 0.015	-28	0	62	8 (800)	0.023	30	0	56
	S
	Parietal lobe
	Superior parietal lobe	7	3 (1552) 0.023	-30	-52	48	9 (776)	0.022	34	-60	52
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Table 3 : Location of the clusters with significant ALE values for Semantic Analogy tasks.

 3 Columns number 3-7 represent data associated with the left hemisphere and 8-12 represent data associated with the right hemisphere. Abbreviations: BA: approximate

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	Brodmann area; ALE: activation likelihood estimation; IFG: inferior frontal gyrus, MFG:
	middle frontal gyrus; SFG: superior frontal gyrus; x, y, z coordinates: peak voxel in the
	Montreal Neurologic Institute (MNI) space.
			Left					Right
	Location	BA Cluster	ALE	x	y	z	Cluster	ALE	x	y	z
			number					number
			& size					& size
			(mm3)					(mm3)
	Frontal lobe
	Rostral part of the MFG	47 1 (1800) 0.018	-44	48	-16
	Rostral part of the IFG	46 1 (1800) 0.016	-50	42	-6
	Posterior part of the IFG	44 2 (432)	0.014	-48	14	18
	Anterior part of the SFG	10 5 (272)	0.010	-10	64	22
	Dorsal part of the SFG	8	6 (272)	0.010	-6	42	50
	Basal ganglia
	Caudate Head		3 (424)	0.015	-10	18	-4	4 (296)	0.012	14	16	-4
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Table 4 : Location of the clusters with significant ALE values for Visuospatial Analogy tasks.

 4 Columns number 3-7 represent data associated with the left hemisphere and 8-12 represent data associated with the right hemisphere. Abbreviations: BA: approximate

	Page 51 of 56
	Brodmann area; ALE: activation likelihood estimation; IFS: inferior frontal sulcus; IFG:
	inferior frontal gyrus; MFG: middle frontal gyrus; x, y, z coordinates: peak voxel in the
	Montreal Neurologic Institute (MNI) space.
		Left					Right
	Location	BA Cluster	ALE	x	y	z	Cluster	ALE	x	y	z
		number					number
		& size					& size
		(mm3)					(mm3)
	Frontal lobe
	Rostral part of IFS and IFG	10 1 (1784) 0.021	-48	44	-10
	MFG	9					4 (304)	0.013	54	28	34
	Insula
	Insula	13					2 (368)	0.013	30	28	-4
	Cerebellum
	Posterior lobe (declive)	3 (320)	0.013	-18	-92	-20

Table 5 : Location of the clusters with significant ALE values for Visuospatial Matrix problem tasks.

 5 Columns number 3-7 represent data associated with the left hemisphere and 8-12 represent data associated with the right hemisphere. Abbreviations: BA: approximate

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	Brodmann area; ALE: activation likelihood estimation; G: gyrus; IFG: inferior frontal gyrus;
	IFS: inferior frontal sulcus; MFG: middle frontal gyrus; SFG: superior frontal gyrus; SFS:
	superior frontal sulcus; x, y, z coordinates: peak voxel in the Montreal Neurologic Institute
	(MNI) space.
			Left				Right
	Location	BA	Cluster	ALE x	y	z	Cluster	ALE x	y	z
			number				number
			& size				& size
			(mm3)				(mm3)
	Frontal lobe
	Posterior IFG/
	MFG and IFS /	9/44/6	6 (1040) 0.020 -42	6	26	2 (1696)	0.027 50	10	26
	Precentral G
	Posterior MFG / SFS	6/8	3 (1416) 0.015 -38	-4	56	4 (1160)	0.022 30	0	54
	Medial SFG / Cingulate	6/32	12 (384) 0.016 -10	20	40	5 (1144)	0.016 6	18	48
	Insula
	Insula						10 (464)	0.014 32	28	-2
	Parietal lobe
	Superior parietal lobe	7	1 (1864) 0.018 -30	-52 48	9 (536)	0.015 32	-62	54
	Inferior parietal lobe	40	1 (1864) 0.017 -34	-46 38	11 (456)	0.017 34	-44	40
	Precuneus	19/31	8 (648)	0.019 -26	-70 28	7 (656)	0.017 32	-74	24
	Precuneus	7					9 (536)	0.010 26	-56	50
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Table 6 : Locations of the clusters with significant ALE values for the contrast of Semantic Analogy versus Visuospatial Analogy and the reverse contrast.

 6 Columns number 3-7 represent data associated with the left hemisphere and 7-12 represent data associated with the right hemisphere. Abbreviations: BA: approximate Brodmann area; G: gyrus; IFG: inferior frontal gyrus; IFS: inferior frontal sulcus; MFG: middle frontal gyrus; SFG: superior frontal gyrus; ALE: activation likelihood estimation; x, y, z coordinates: peak voxel in the Montreal Neurologic Institute (MNI) space.

	Page 53 of 56			Human Brain Mapping
	Semantic Analogy versus Visuospatial Analogy
			Left				Right
	Location	BA	Cluster	x	y	z	Cluster		x	y	z
			number	ALE			number	ALE
			& size				& size
			(mm3)				(mm3)
	IFG	47	1 (896)	2.404 -47.5 31.8 0
	Medial part of the SFG	10	2 (368)	1.913 -5	59.6 7.5
	SFG	9	3 (280)	1.672 -2.3	62.3 25.6
	IFS	9 / 46 4 (232)	2.028 -32	26	20
	Visuospatial Analogy versus Semantic Analogy
			Left				Right
	Location	BA	Cluster	ALE x	y	z	Cluster	ALE	x	y	z
			number				number
			& size				& size
			(mm3)				(mm3)
	Frontal lobe
	Anterior part of the MFG	10	1 (2696) 2.181 -46	54	4
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Table 7 : Locations of the clusters with significant ALE values for the contrast of Visuospatial Analogy versus Visuospatial Matrix problem tasks and the reverse contrast.

 7 Columns number 3-7 represent data associated with the left hemisphere and 7-12 represent data associated with the right hemisphere. Abbreviations: BA: approximate Brodmann area; G: gyrus; IFG: inferior frontal gyrus; IFS: inferior frontal sulcus; MFG: middle frontal gyrus; SFG: superior frontal gyrus; SFS: superior frontal sulcus; ALE: activation likelihood estimation; x, y, z coordinates: peak voxel in the Montreal Neurologic Institute (MNI) space.

	Page 55 of 56				Human Brain Mapping
	Visuospatial Analogy versus Visuospatial Matrix problems
			Left					Right
	Location	BA	Cluster	ALE	x	y	z	Cluster	ALE	x	y	z
			number					number
			& size					& size
			(mm3)					(mm3)
	Frontal lobe
	Rostral part of the IFG	10/47	1 (1392)	2.478	-52	50.3 -8
	Cerebellum
	Posterior lobe		2 (456) 1.812	-18	-86	-16
	(Declive, Uvula)
	Visuospatial Matrix problems versus Visuospatial Analogy
			Left					Right
	Location	BA	Cluster	ALE	x	y	z	Cluster	ALE	x	y	z
			number					number
			& size					& size
			(mm3)					(mm3)
	Frontal lobe
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ACKNOWLEDGMENTS

Funding

This work was supported by the Agence Nationale de la Recherche [grant number ANR-09-RPDOC-004-01, ev], the Société Française de Neurologie (LH) and Journées de Neurologie de Langue Française (CDD). The research leading to these results received funding from the Investissements d'avenir program ANR-10-IAIHU-06.

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Conflict of Interest Statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as potential conflicts of interest.

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