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International audience; Language processing is a highly integrative function, intertwining linguistic operations (processing the language code intentionally used for communication) and extra-linguistic processes (e.g., attention monitoring, predictive inference, long-term memory). This synergetic cognitive architecture requires a distributed and specialized neural substrate. Brain systems have mainly been examined at rest. However, task-related functional connectivity provides additional and valuable information about how information is processed when various cognitive states are involved. We gathered thirteen language fMRI tasks in a unique database of one hundred and fifty neurotypical adults (InLang [Interactive networks of Language] database), providing the opportunity to assess language features across a wide range of linguistic processes. Using this database, we applied network theory as a computational tool to model the task-related functional connectome of language (LANG atlas). The organization of this data-driven neurocognitive atlas of language was examined at multiple levels, uncovering its major components (or crucial subnetworks), and its anatomical and functional correlates. In addition, we estimated its reconfiguration as a function of linguistic demand (flexibility) or several factors such as age or gender (variability). We observed that several discrete networks could be specifically shaped to promote key functional features of language: coding-decoding (Net1), control-executive (Net2), abstract-knowledge (Net3), and sensorimotor (Net4) functions. The architecture of these systems and the functional connectivity of the pivotal brain regions varied according to the nature of the linguistic process, gender, or age. By accounting for the multifaceted nature of language and modulating factors, this study can contribute to enriching and refining existing neurocognitive models of language. The LANG atlas can also be considered a reference for comparative or clinical studies involving various patients and conditions.

Previous behavioral, clinical, and neuroimaging studies suggest that the neural substrates of adaptation of saccadic eye movements involve, beyond the central role of the cerebellum, several, still incompletely determined, cortical areas. Furthermore, no neuroimaging study has yet tackled the differences between saccade lengthening ("forward adaptation") and shortening ("backward adaptation") and neither between their two main components, i.e. error processing and oculomotor changes. The present fMRI study was designed to fill these gaps. Blood-oxygen-level-dependent (BOLD) signal and eye movements of 24 healthy volunteers were acquired while performing reactive saccades under 4 conditions repeated in short blocks of 16 trials: systematic target jump during the saccade and in the saccade direction (forward: FW) or in the opposite direction (backward: BW), randomly directed FW or BW target jump during the saccade (random: RND) and no intra-saccadic target jump (stationary: STA). BOLD signals were analyzed both through general linear model (GLM) approaches applied at the whole-brain level and through sensitive Multi-Variate Pattern Analyses (MVPA) applied to 34 regions of interest (ROIs) identified from independent 'Saccade Localizer' functional data. Oculomotor data were consistent with successful induction of forward and backward adaptation in FW and BW blocks, respectively. The different analyses of voxel activation patterns (MVPAs) disclosed the involvement of 1) a set of ROIs specifically related to adaptation in the right occipital cortex, right and left MT/MST, right FEF and right pallidum; 2) several ROIs specifically involved in error signal processing in the left occipital cortex, left PEF, left precuneus, Medial Cingulate cortex (MCC), left inferior and right superior cerebellum; 3) ROIs specific to the direction of adaptation in the occipital cortex and MT/MST (left and right hemispheres for FW and BW, respectively) and in the pallidum of the right hemisphere (FW). The involvement of the left PEF and of the (left and right) occipital cortex were further supported and qualified by the whole brain GLM analysis: clusters of increased activity were found in PEF for the RND versus STA contrast (related to error processing) and in the left (right) occipital cortex for the FW (BW) versus STA contrasts [related to the FW (BW) direction of error and/or adaptation]. The present study both adds complementary data to the growing literature supporting a role of the cerebral cortex in saccadic adaptation through feedback and feedforward relationships with the cerebellum and provides the basis for improving conceptual frameworks of oculomotor plasticity and of its link with spatial cognition. ispartof: NEUROIMAGE vol:262 ispartof: location:United States status: published

International audience; The use of TMS-EEG coupling as a neuroimaging tool for the functional exploration of the human brain recently gained strong interest. If this tool directly inherits the fine temporal resolution from EEG, its spatial counterpart remains unknown. In this study, we explored the spatial resolution of TMS-EEG coupling by evaluating the minimal distance between two stimulated cortical sites that would significantly evoke different response dynamics. TMS evoked responses were mapped on the sensorimotor region in twenty participants. The stimulation grid was composed of nine targets separated between 10 and 15 mm on average. The dynamical signatures of TMS evoked activity were extracted and compared between sites using both local and remote linear regression scores and spatial generalized mixed models. We found a significant effect of the distance between stimulated sites on their dynamical signatures, neighboring sites showing differentiable response dynamics. Besides, common dynamical signatures were also found between sites up to 25-30 mm from each other. This overlap in dynamical properties decreased with distance and was stronger between sites within the same Brodmann area. Our results suggest that the spatial resolution of TMS-EEG coupling might be at least as high as 10 mm. Furthermore, our results reveal an anisotropic spatial resolution that was higher across than within the same Brodmann areas, in accordance with the TMS induced E-field modeling. Common cytoarchitectonic leading to shared dynamical properties within the same Brodmann area could also explain this anisotropy. Overall, these findings suggest that TMS-EEG benefits from the spatial resolution of TMS, which makes it an accurate technique for meso-scale brain mapping.

Highlights • Strengths and challenges of longitudinal non-human primate MRI are described. • Statistical power calculation of longitudinal and cross-sectional designs are provided. • The impact of template choice on grey matter estimation is demonstrated. • Recommendations for designing and analysing such studies are provided., Longitudinal non-human primate neuroimaging has the potential to greatly enhance our understanding of primate brain structure and function. Here we describe its specific strengths, compared to both cross-sectional non-human primate neuroimaging and longitudinal human neuroimaging, but also its associated challenges. We elaborate on factors guiding the use of different analytical tools, subject-specific versus age-specific templates for analyses, and issues related to statistical power.

Gradients capture some of the variance of the resting-state functional magnetic resonance imaging (rsfMRI) signal. Amongst these, the principal gradient depicts a functional processing hierarchy that spans from sensory-motor cortices to regions of the default-mode network. While the cortex has been well characterised in terms of gradients little is known about its underlying white matter. For instance, comprehensive mapping of the principal gradient on the largest white matter tract, the corpus callosum, is still missing. We hence mapped the principal gradient onto the callosal midsection using the 7T human connectome project dataset. We further explored how quantitative measures and variability in callosal midsection connectivity relate to the principal gradient values. In so doing, we demonstrated that the extreme values of the principal gradient are located within the callosal genu and the posterior body, have lower connectivity variability but a larger spatial extent along the midsection of the corpus callosum than mid-range values. Our results shed light on the relationship between the brain’s functional hierarchy and the corpus callosum. We further speculate about how these results may bridge the gap between functional hierarchy, brain asymmetries, and evolution.

The decision to process an incoming stimulus attentively - and to trigger a follow-up cascade of high-level processes - is strategic for the human brain as it becomes transiently unavailable to subsequent stimulus processing. In this study, we set to identify brain networks that carry out such evaluations. We therefore assessed the time-course of neural responses with intracerebral EEG in human patients during an attentional reading task, contrasting to-be-attended vs. to-be-ignored items. We measured High-Frequency Activity [50–150 ​Hz] as a proxy of population-level spiking activity and we identified a crucial component of a Gate-Keeping Mechanism bilateral in the mid-Ventro-Lateral Prefrontal Cortex (VLPFC), at the interplay of the Ventral and Dorsal Attention Networks, that selectively reacts before domain specialized cortical regions that engage in full stimulus analysis according to task demands.

International audience; Cognitive decline during aging includes impairments in frontal executive functions like reduced inhibitory control. However, decline is not uniform across the population, suggesting individual brain response variability to the aging process. Here we tested the hypothesis, within the oculomotor system, that older adults compensate for agerelated neural alterations by changing neural activation levels of the oculomotor areas, or even by recruiting additional areas to assist with cognitive performance. We established that the observed changes had to be related to better cognitive performance to be considered as compensatory. To probe this hypothesis we used the antisaccade paradigm and analyzed the effect of aging on brain activations during the inhibition of prepotent responses to visual stimuli. While undergoing a fMRI scan with concurrent eye tracking, 25 young adults (21.7 y/ o ± 1.9 SDM) and 25 cognitively normal older adults (66.2 y/o ± 9.8 SDM) performed an interleaved pro/ antisaccade task consisting of a preparatory stage and an execution stage. Compared to young adults, older participants showed a larger increase in antisaccade reaction times, while also generating more antisaccade direction errors. BOLD signal analyses during the preparatory stage, when response inhibition processes are established to prevent an automatic response, showed decreased activations in the anterior cingulate and the supplementary eye fields in the older group. Moreover, older adults also showed additional recruitment of the frontal pole not seen in the younger group, and larger activations in the dorsolateral prefrontal cortex during antisaccade preparation. Additional analyses to address the performance variability in the older group showed distinct behavioral-BOLD signal correlations. Larger activations in the saccade network, including the frontal pole, positively correlated with faster antisaccade reaction times, suggesting a functional recruitment of this area. However, only the activation in the dorsolateral prefrontal cortex during the antisaccade events showed a negative correlation with the number of errors across older adults. These findings support the presence of two dissociable age-related plastic mechanisms that result in different behavioral outcomes. One related to the additional recruitment of neural resources within anterior pole to facilitate modulation of cognitive responses like faster antisaccade reaction times, and another related to increased activation of the dorsolateral prefrontal cortex resulting in a better inhibitory control in aging.

International audience; Despite dissimilarities among scripts, a universal hallmark of literacy in skilled readers is the convergent brain activity for print and speech. Little is known, however, whether this differs as a function of grapheme to phoneme transparency in beginning readers. Here we compare speech and orthographic processing circuits in two contrasting languages, Polish and English, in 100 7-year-old children performing fMRI language localizer tasks. Results show limited language variation, with speech-print convergence evident mostly in left frontotemporal perisylvian regions. Correlational and intersect analyses revealed subtle differences in the strength of this coupling in several regions of interest. Specifically, speech-print convergence was higher for transparent Polish than opaque English in the right temporal area, associated with phonological processing. Conversely, speech-print convergence was higher for English than Polish in left fusiform, associated with visual word recognition. We conclude that speech-print convergence is a universal marker of reading even at the beginning of reading acquisition with minor variations that can be explained by the differences in grapheme to phoneme transparency. This finding at the earliest stages of reading acquisition conforms well with claims that reading exhibits a good deal of universality despite writing systems differences.

Episodic memory (EM) is classically conceived as a memory for events, localized in space and time, and characterized by autonoetic consciousness (ANC) allowing to mentally travel back in time and subjectively relive an event. Building on recent evidence that the first-person visual co-perception of one's own body during encoding impacts EM, we used a scene recognition task in immersive virtual reality (VR) and measured how first-person body view would modulate peri-encoding resting-state fMRI, EM performance, and ANC. Specifically, we investigated the impact of body view on post-encoding functional connectivity in an a priori network of regions related either to EM or multisensory bodily processing and used these regions in a seed-to-whole brain analysis. Post-encoding connectivity between right hippocampus (rHC) and right parahippocampus (rPHC) was enhanced when participants encoded scenes while seeing their body. Moreover, the strength of connectivity between the rHC, rPHC and the neocortex displayed two main patterns with respect to body view. The connectivity with a sensorimotor fronto-parietal network, comprising primary somatosensory and primary motor cortices, correlated with ANC after - but not before - encoding, depending on body view. The opposite change of connectivity was found between rHC, rPHC and the medial parietal cortex (from being correlated with ANC before encoding to an absence of correlation after encoding), but irrespective of body view. Linking immersive VR and fMRI for the study of EM and ANC, these findings suggest that seeing one's own body during encoding impacts the brain activity related to EM formation by modulating the connectivity between the right hippocampal formation and the neocortical regions involved in the processing of multisensory bodily signals and self-consciousness.

International audience; The neuronal processes underlying dance observation have been the focus of an increasing number of brain imaging studies over the past decade. However, the existing literature mainly dealt with effects of motor and visual expertise, whereas the neural and cognitive mechanisms that underlie the interpretation of dance choreogra-phies remained unexplored. Hence, much attention has been given to the action observation network (AON) whereas the role of other potentially relevant neuro-cognitive mechanisms such as mentalizing (theory of mind) or language (narrative comprehension) in dance understanding is yet to be elucidated. We report the results of an fMRI study where the structural coherence of short contemporary dance choreographies was manipulated parametrically using the same taped movement material. Our participants were all trained dancers. The whole-brain analysis argues that the interpretation of structurally coherent dance phrases involves a subpart (superior parietal) of the AON as well as mentalizing regions in the dorsomedial prefrontal cortex. An ROI analysis based on a similar study using linguistic materials (Pallier et al., 2011) suggests that structural processing in language and dance might share certain neural mechanisms.

International audience; How movements are continuously adapted to physiological and environmental changes is a fundamental question in systems neuroscience. While many studies have elucidated the mechanisms which underlie short-term sensorimotor adaptation (∼10-30 min), how these motor memories are maintained over longer-term (>3-5 days) -and thanks to which neural systems-is virtually unknown. Here, we examine in healthy human participants whether the temporo-parietal junction (TPJ) is causally involved in the induction and/or the retention of saccadic eye movements' adaptation. Single-pulse transcranial magnetic stimulation (spTMS) was applied while subjects performed a ∼15min size-decrease adaptation task of leftward reactive saccades. A TMS pulse was delivered over the TPJ in the right hemisphere (rTPJ) in each trial either 30, 60, 90 or 120 msec (in 4 separate adaptation sessions) after the saccade onset. In two control groups of subjects, the same adaptation procedure was achieved either alone (No-TMS) or combined with spTMS applied over the vertex (SHAM-TMS). While the timing of spTMS over the rTPJ did not significantly affect the speed and immediate after-effect of adaptation, we found that the amount of adaptation retention measured 10 days later was markedly larger (42%) than in both the No-TMS (21%) and the SHAM-TMS (11%) control groups. These results demonstrate for the first time that the cerebral cortex is causally involved in maintaining long-term oculomotor memories.

Item does not contain fulltext Effective human interaction depends on our ability to rapidly detect faces in dynamic visual environments. Here we asked how basic units of visual information (spatial frequencies, or SF) contribute to this fundamental brain function. Human observers viewed initially blurry, unrecognizable natural object images presented at a fast 12 Hz rate and parametrically increasing in SF content over the course of 1 min. By inserting highly variable natural face images as every 8th stimulus we captured an objective neural index of face detection in participants' electroencephalogram (EEG) at exactly 1.5 Hz. This face-selective signal emerged over the right occipito-temporal cortex at 50 cycles/image, potentially supporting higher-level recognition functions (e.g., facial identity recognition). 12 p.

Scientific and mathematical thinking relies on the ability to evaluate whether conclusions drawn from conditional (if-then) arguments are logically valid. Yet, the neural development of this ability -- termed deductive reasoning -- is largely unknown. Here we aimed to identify the neural mechanisms that underlie the emergence of deductive reasoning with conditional rules in children. We further tested whether these mechanisms have their roots in the neural mechanisms involved in judging the likelihood of conclusions. In a functional Magnetic Resonance Imaging (fMRI) scanner, 8- to 13-year-olds were presented with causal conditional problems such as “If a baby is hungry then he will start crying; The baby is crying; Is the baby hungry?”. In Validity trials, children were asked to indicate whether the conclusion followed out of necessity from the premises. In Likelihood trials, they indicated the degree of likelihood of the conclusion. We found that children who made accurate judgments of logical validity (as compared to those who did not) exhibited enhanced activity in left and medial frontal regions. In contrast, differences in likelihood ratings between children were related to differences of activity in right frontal and bilateral parietal regions. There was no overlap between the brain regions underlying validity and likelihood judgments. Therefore, our results suggest that the ability to evaluate the logical validity of conditional arguments emerges from brain mechanisms that qualitatively differ from those involved in evaluating the likelihood of these arguments in children.

International audience; It is now well established that communicators interpret others' mental states through what has been called "Theory of Mind" (ToM). From a linguistic-pragmatics perspective, this mentalizing ability is considered critical because it is assumed that the linguistic code in all utterances underdetermines the speaker's meaning, leaving a vital role for ToM to fill the gap. From a neuroscience perspective, understanding others' intentions has been shown to activate a neural ToM network that includes the right and left temporal parietal junction (rTPJ, lTPJ), the medial prefrontal cortex (MPFC) and the precuneus (PC). Surprisingly, however, there are no studies - to our knowledge - that aim to uncover a direct, on-line link between language processing and ToM through neuroimaging. This is why we focus on verbal irony, an obviously pragmatic phenomenon that compels a listener to detect the speaker's (dissociated, mocking) attitude (Wilson, 2009). In the present fMRI investigation, we compare participants' comprehension of 18 target sentences as contexts make them either ironic or literal. Consider an opera singer who tells her interlocutor: "Tonight we gave a superb performance!" when the performance in question was clearly awful (making the statement ironic) or very good (making the statement literal). We demonstrate that the ToM network becomes active while a participant is understanding verbal irony. Moreover, we demonstrate - through Psychophysiological Interactions (PPI) analyses - that ToM activity is directly linked with language comprehension processes. The paradigm, its predictions, and the reported results contrast dramatically with those from seven prior fMRI studies on irony.

International audience; Sensory attenuation of voluntary action effects has been widely reported in both somatosensory and auditory domains. However, relatively little research has focused on physiological measures of sensory attenuation of visual action effects. One previous study found, perhaps surprisingly, that both auditory and visual sensory attenuation were manifested as decreased ERP amplitude over the vertex. The present study aimed to extend these findings using a novel paradigm in which voluntary actions were either associated with a visual action effect or to no effect. Crucially, this allowed us to explore both sensory attenuation (by comparing ERPs to action-triggered versus externally triggered stimuli) and action effect prediction (by comparing actions that triggered a stimulus with actions that did not). With regard to sensory attenuation, we found that attenuation of cortical responses to visual action effects was manifested in a reduced activation of a frontoparietal network, from 150 ms after stimulus. Differences between actions that produced an effect and those that did not were observed in lateralized motor potentials and may reflect the cortical correlates of the action effect prediction. We also observed a re-activation of lateralized motor activity following onset of the action effect, suggesting a common representation of action effects in visual and motor cortices. Taken together, these findings help to elucidate the cortical mechanisms of voluntary action as well as their sensory consequences and inform how our interaction with the external world is processed and controlled.

To optimise speed and accuracy of motor behaviour, we can prepare not only the type of movement to be made but also the time at which it will be executed. Previous cued reaction-time paradigms have shown that anticipating the moment in time at which this response will be made (“temporal orienting”) or selectively preparing the motor effector with which an imminent response will be made (motor intention or “motor orienting”) recruits similar regions of left intraparietal sulcus (IPS), raising the possibility that these two preparatory processes are inextricably co-activated. We used a factorial design to independently cue motor and temporal components of response preparation within the same experimental paradigm. By differentially cueing either ocular or manual response systems, rather than spatially lateralised responses within just one of these systems, potential spatial confounds were removed. We demonstrated that temporal and motor orienting were behaviourally dissociable, each capable of improving performance alone. Crucially, fMRI data revealed that temporal orienting activated the left IPS even if the motor effector that would be used to execute the response was unpredictable. Moreover, temporal orienting activated left IPS whether the target required a saccadic or manual response, and whether this response was left- or right-sided, thus confirming the ubiquity of left IPS activation for temporal orienting. Finally, a small region of left IPS was also activated by motor orienting for manual, though not saccadic, responses. Despite their functional independence therefore, temporal orienting and manual motor orienting nevertheless engage partially overlapping regions of left IPS, possibly reflecting their shared ontogenetic roots., Research Highlights ►Anticipating when and how to respond can be functionally and neurally dissociated. ►Temporal orienting (when) engages left IPS for both oculomotor and manual responses. ►Motor orienting (how) engages left IPS only for manual, not oculomotor, responses. ►Manual action circuits may be functionally recycled for anticipating when to respond.

The parieto-frontal network plays a crucial role in the transformations that convert visual information into motor commands for hand reaching movements. Here we use electroencephalography to determine whether the planning of reaching movements to visual and somatosensory targets involves a similar spatio-temporal pattern of neural activity. Subjects performed reaching movements toward spatial locations defined either by visual (light-emitting diode) or somatosensory (vibration of a fingertip of the contralateral hand) stimuli. To identify the activations associated with sensorimotor transformations, we subtracted the event-related potentials recorded in a "static" task (the stimuli were presented but no movement was initiated) from those recorded in a "reach" task (a reach had to be initiated toward the spatial location of the stimuli). In the visual condition, reach-related activities were observed over parietal, premotor and sensorimotor areas contralateral to the reaching hand. Activation was first observed over parietal areas 140 ms after stimulus onset and progressed to frontal areas. The proprioceptive condition recruited a similar set of structures as for visual targets. However, the temporal pattern of activity within these cortical areas differed greatly. Activity was sustained over premotor and sensorimotor areas throughout the reaction time interval, occurring simultaneously with the parietal activation. These results suggest that a common cortical network serves to transform visual and somatosensory signals into motor commands, but that the interactions between the structures of this network differ. This raises the possibility that different coordinate frames are used to encode the motor error for the two target modalities.

The vestibular system constitutes the silent sixth sense: It automatically triggers a variety of vital reflexes to maintain postural and visual stability. Beyond their role in reflexive behavior, vestibular afferents contribute to several perceptual and cognitive functions and also support voluntary control of movements by complementing the other senses to accomplish the movement goal. Investigations into the neural correlates of vestibular contribution to voluntary action in humans are challenging and have progressed far less than research on corresponding visual and proprioceptive involvement. Here, we demonstrate for the first time with event-related TMS that the posterior part of the right medial intraparietal sulcus processes vestibular signals during a goal-directed reaching task with the dominant right hand. This finding suggests a qualitative difference between the processing of vestibular vs. visual and proprioceptive signals for controlling voluntary movements, which are pre-dominantly processed in the left posterior parietal cortex. Furthermore, this study reveals a neural pathway for vestibular input that might be distinct from the processing for reflexive or cognitive functions, and opens a window into their investigation in humans. (C) 2015 The Authors. Published by Elsevier Inc.

International audience; Complex number words (e.g., "twenty two") are formed by merging together several simple number words (e.g., "twenty" and "two"). In the present study, we explored the neural correlates of this operation and investigated to what extent it engages brain areas involved processing numerical quantity and linguistic syntactic structure. Participants speaking two typologically distinct languages, French and Chinese, were required to read aloud sequences of simple number words while their cerebral activity was recorded by functional magnetic resonance imaging. Each number word could either be merged with the previous ones (e.g., 'twenty three') or not (e.g., 'three twenty'), thus forming four levels ranging from lists of number words to complex numerals. When a number word could be merged with the preceding ones, it was named faster than when it could not. Neuroimaging results showed that the number of merges correlated with activation in the left inferior frontal gyrus and in the left inferior parietal lobule. Consistent findings across Chinese and French participants suggest that these regions serve as the neural bases for forming complex number words in different languages.

International audience; The ability to figure out whether a person is being honest or deceitful is an important part of social competence. Reactions to deceit may however differ depending on whether one is being deceived oneself or observes a deceitful exchange between others. In the present study, we investigated whether personal involvement influenced the neural responses associated with the detection of deceit. Subjects watched videos of actors lifting a box and judged whether the actors had been misled about the real weight of the box. Personal involvement was manipulated by having the participants themselves among the actors. The critical finding was that there was activity in amygdala and fusiform gyrus only for the condition in which participants observed themselves being deceived. In contrast, the superior temporal sulcus and anterior cingulate cortex were activated irrespective of whether the participants detected that the experimenter had deceived themselves or another. These four brain areas are all interconnected and are part of the discrete neural system subserving social cognition. Our results provide direct evidence, using judgments of deceit in a social context, that the crucial factor for amygdala activation is the involvement of the subjects because they are the target of the deceit. We interpret the activation of the amygdala in this situation as reflecting the greater affective reaction when one is deceived oneself. Our results suggest that when one is personally involved, deceit is taken as a potential threat.

Psychological and neurophysiological models of visual processing have traditionally emphasized hierarchical models to explain how separate features of visual stimuli are combined. This concept has been challenged recently with the demonstration of simultaneous activation of multiple visual areas and rapid feedback to primary cortices. Here, we show human visual processing may involve similar mechanisms. Subjects discriminated targets from nontargets as a function of shape, color, or the conjunction of these features while event-related brain potentials (ERPs) were recorded. ERP components from 100 to 200 ms across posterior occipital-temporal cortices were fastest and largest for conjunction targets. These enhanced early responses were followed by task-specific sustained posterior activity (300-500 ms). Faster reaction times were correlated with enhanced and faster early processing in the visual ventral areas. These data demonstrate the human visual system conjoins features rapidly, accelerating and amplifying the processing of relevant stimulus dimensions.

International audience; Repetition suppression, a robust phenomenon of reduction in neural responses to stimulus repetition, is suggested to consist of a combination of bottom-up adaptation and top-down prediction effects. However, there is little consensus on how repetition suppression is related to attention in functional magnetic resonance imaging (fMRI) studies. It is probably because fMRI integrates neural activity related to adaptation and prediction effects, which are respectively attention-independent and attention-dependent. Here we orthogonally manipulated stimulus repetition and attention in a target detection task while participants' electroencephalography (EEG) was recorded. In Experiment 1, we found a significant repetition effect on N1 amplitude regardless of attention, whereas the repetition effect on P2 amplitude was attention-dependent. In Experiment 2 where the attentional manipulation was more stringent than that in Experiment 1, we replicated a significant repetition effect on N1 amplitude regardless of attention, whereas the repetition effect on P2 amplitude was eliminated. The results show that repetition suppression comprises both attention-independent and attention-dependent components.

International audience; Performing a voluntary action involves the anticipation of the intended effect of that action. Interaction with the environment also requires the allocation of attention. However, the effects of attention upon motor predictive processes remain unclear. Here we use a novel paradigm to investigate attention and motor prediction orthogonally. In an acquisition phase, high and low tones were associated with left and right key presses. In the following test phase, tones were presented at random and participants attended to only one ear whilst ignoring tones presented in the unattended ear. In the test phase a tone could therefore be presented at the attended or unattended ear, as well as being congruent or incongruent with prior action-effect learning. We demonstrated early and late effects of attention as well as a later independent motor prediction effect with a larger P3a for incongruent tones. Interestingly, we demonstrated an intermediate interaction, showing an action-effect negativity (N AE) for tones which were unattended, whilst no motor prediction effect was found for attended tones. This interaction pattern suggests that attention and motor prediction are not opposing processes but can both operate to modulate prediction, providing valuable new insight into the relationship between attention and the effects of motor prediction.

Being exposed to fear or anger signals makes us feel threatened and prompts us to prepare an adaptive response. Yet, while fear and anger behaviors are both threat signals, what counts as an adaptive response is often quite different. In contrast with fear, anger is often displayed with the aim of altering the behavior of the agent to which it is addressed. To identify brain responses that are common or specific to the perception of these two types of threat signals, we used functional magnetic resonance imaging and asked subjects to recognize dynamic actions expressing fear, anger and neutral behaviors. As compared with neutral actions, the perception of fear and anger behaviors elicited comparable activity increases in the left amygdala and temporal cortices as well as in the ventrolateral and the dorsomedial prefrontal cortex. Whereas the perception of fear elicited specific activity in the right temporoparietal junction, the perception of anger triggered condition-specific activity in a wider set of regions comprising the anterior temporal lobe, the premotor cortex and the ventromedial prefrontal cortex, consistent with the hypothesis that coping with threat from exposure to anger requires additional contextual information and behavioral adjustments.

Subjects sedated by noradrenergic alpha2 agonists can switch rapidly from a state of extremely low to almost full consciousness following phasic increases in arousal or cognitive demand. Such flexibility is not displayed by traditional sedatives, such as the benzodiazepine diazepam. Experimentally, the phasic modulation of alpha2 effect by arousing or distracting stimuli can counteract the deleterious cognitive effects of alpha2 agonists. We used behavioural and fMRI indices of brain function to investigate the phasic modulatory effect that presentation of loud white noise would have on attentional dysfunction induced by administration of dexmedotomidine, an alpha2 agonist. Dexmedotomidine and midazolam were compared to placebo during performance of a target detection task, which was presented in the presence or absence of white noise. Compared to placebo, both dexmedotomidine and midazolam impaired task performance. This impairment was significantly attenuated by presentation of white noise in the dexmedotomidine condition only. This functional improvement corresponded to selective increase in activity of left medial pulvinar nucleus of the thalamus. This regional increase is suggested to index increases in phasic arousal, which counteract dexmedotomidine's detrimental attentional effects. Finally, despite sedating subjects to equivalent degrees, dexmedotomidine and midazolam had strikingly different regional effects on task-induced brain activity. Therefore, for the same level of sedation, the behavioural and anatomical attributes identifying the quality of sedation can vary.

International audience; The ability to make judgments about mental states is critical to social interactions. Simulation theory suggests that the observer covertly mimics the activity of the observed person, leading to shared states of mind between the observer and the person observed. We tested this hypothesis by investigating the neural networks activated while subjects watched videos of themselves and of others lifting a box, and judged the beliefs of the actors about the weight of the box. A parietal premotor circuit was recruited during action perception, and the activity started earlier when making judgments about one's own actions as opposed to those of others. This earlier activity in action-related structures can be explained by simulation theory on the basis that when one observes one's own actions, there is a closer match between the simulated and perceived action than there is when one observes the actions of others. When the observers judged the actions to reflect a false belief, there was activation in the superior temporal sulcus, orbitofrontal, paracingulate cortex and cerebellum. We suggest that this reflects a mismatch between the perceived action and the predicted action's outcomes derived from simulation.

Despite the importance and frequent use of Bayesian frameworks in brain network modeling for parameter inference and model prediction, the advanced sampling algorithms implemented in probabilistic programming languages to overcome the inference difficulties have received relatively little attention in this context. In this technical note, we propose a probabilistic framework, namely the Bayesian Virtual Epileptic Patient (BVEP), which relies on the fusion of structural data of individuals to infer the spatial map of epileptogenicity in a personalized large-scale brain model of epilepsy spread. To invert the individualized whole-brain model employed in this study, we use the recently developed algorithms known as No-U-Turn Sampler (NUTS) as well as Automatic Differentiation Variational Inference (ADVI). Our results indicate that NUTS and ADVI accurately estimate the degree of epileptogenicity of brain regions, therefore, the hypothetical brain areas responsible for the seizure initiation and propagation, while the convergence diagnostics and posterior behavior analysis validate the reliability of the estimations. Moreover, we illustrate the efficiency of the transformed non-centered parameters in comparison to centered form of parameterization. The Bayesian framework used in this work proposes an appropriate patient-specific strategy for estimating the epileptogenicity of the brain regions to improve outcome after epilepsy surgery.