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Cet article resume nos recherches recentes sur l’emergence et le developpement typique des capacites de memoire spatiale allocentree chez l’enfant. La memoire spatiale allocentree est une composante essentielle de la memoire episodique, la memoire des evenements autobiographiques qui se sont passes dans des contextes spatio-temporels uniques. Elle depend du bon fonctionnement d’une region particuliere du cerveau appelee l’hippocampe ou la formation hippocampique. Nos recherches ont montre que la capacite de representation spatiale allocentree, integrant les relations entre differents objets presents dans l’environnement et donc independante du point de vue de l’individu, emerge vers l’âge de deux ans. Elle continue de s’ameliorer en termes de resolution spatiale et temporelle au cours des cinq a sept annees suivantes. L’emergence des capacites de memoire allocentree permet egalement la creation de cartes cognitives de l’environnement qui ne dependent pas de la presence d’information visuelle. Des etudes neuroanatomiques sur des animaux suggerent que la maturation de la region CA1 de l’hippocampe contribue a l’emergence d’une memoire spatiale allocentree a basse resolution, tandis que la maturation du gyrus dente et de la region CA3 de l’hippocampe contribue a l’amelioration de la memoire spatiale pendant la petite enfance.

While the deleterious effects of acute ethyl alcohol intoxication on executive control are well-established, the underlying spatiotemporal brain mechanisms remain largely unresolved. In addition, since the effects of alcohol are noticeable to participants, isolating the effects of the substance from those related to expectations represents a major challenge. We addressed these issues using a double-blind, randomized, parallel, placebo-controlled experimental design comparing the behavioral and electrical neuroimaging acute effects of 0.6 vs 0.02 ​g/kg alcohol intake recorded in 65 healthy adults during an inhibitory control Go/NoGo task. Topographic ERP analyses of covariance with self-reported dose expectations allowed to dissociate their neurophysiological effects from those of the substance.While alcohol intoxication increased response time variability and post-error slowing, bayesian analyses indicated that it did not modify commission error rates. Functionally, alcohol induced topographic ERP modulations over the periods of the stimulus-locked N2 and P3 components, arising from pre-supplementary motor and anterior cingulate areas. In contrast, alcohol decreased the strength of the response-locked anterior cingulate error-related component but not its topography. This pattern indicates that alcohol had a locally specific influence within the executive control network, but disrupted performance monitoring processes via global strength-based mechanisms.We further revealed that alcohol-related expectations induced temporally specific functional modulations of the early N2 stimulus-locked medio-lateral prefrontal activity, a processing phase preceding those influenced by the actual alcohol intake.Our collective findings thus not only reveal the mechanisms underlying alcohol-induced impairments in impulse control and error processing, but also dissociate substance- from expectations- related functional effects.

Episodic memories for autobiographical events that happen in unique spatiotemporal contexts are central to defining who we are. Yet, before 2 years of age, children are unable to form or store episodic memories for recall later in life, a phenomenon known as infantile amnesia. Here, we studied the development of allocentric spatial memory, a fundamental component of episodic memory, in two versions of a real-world memory task requiring 18 month- to 5-year-old children to search for rewards hidden beneath cups distributed in an open-field arena. Whereas children 25-42-months-old were not capable of discriminating three reward locations among 18 possible locations in absence of local cues marking these locations, children older than 43 months found the reward locations reliably. These results support previous findings suggesting that allocentric spatial memory, if present, is only rudimentary in children under 3.5 years of age. However, when tested with only one reward location among four possible locations, children 25-39-months-old found the reward reliably in absence of local cues, whereas 18-23-month-olds did not. Our findings thus show that the ability to form a basic allocentric representation of the environment is present by 2 years of age, and its emergence coincides temporally with the offset of infantile amnesia. However, the ability of children to distinguish and remember closely related spatial locations improves from 2 to 3.5 years of age, a developmental period marked by persistent deficits in long-term episodic memory known as childhood amnesia. These findings support the hypothesis that the differential maturation of distinct hippocampal circuits contributes to the emergence of specific memory processes during early childhood.

Allocentric spatial memory, “where” with respect to the surrounding environment, is one of the three fundamental components of episodic memory: what, where, when. Whereas basic allocentric spatial memory abilities are reliably observed in children after 2 years of age, coinciding with the offset of infantile amnesia, the resolution of allocentric spatial memory acquired over repeated trials improves from 2 to 4 years of age. Here, we first show that single-trial allocentric spatial memory performance improves in children from 3.5 to 7 years of age, during the typical period of childhood amnesia. Second, we show that large individual variation exists in children's performance at this age. Third, and most importantly, we show that improvements in single-trial allocentric spatial memory performance are due to an increasing ability to spatially and temporally separate locations and events. Such improvements in spatial and temporal processing abilities may contribute to the gradual offset of childhood amnesia.

Allocentric spatial memory, the memory for locations coded in relation to objects comprising our environment, is a fundamental component of episodic memory and is dependent on the integrity of the hippocampal formation in adulthood. Previous research from different laboratories reported that basic allocentric spatial memory abilities are reliably observed in children after 2 years of age. Based on work performed in monkeys and rats, we had proposed that the functional maturation of direct entorhinal cortex projections to the CA1 field of the hippocampus might underlie the emergence of basic allocentric spatial memory. We also proposed that the protracted development of the dentate gyrus and its projections to the CA3 field of the hippocampus might underlie the development of high-resolution allocentric spatial memory capacities, based on the essential contribution of these structures to the process known as pattern separation. Here, we present an experiment designed to assess the development of spatial pattern separation capacities and its impact on allocentric spatial memory performance in children from 18 to 48 months of age. We found that: (1) allocentric spatial memory performance improved with age, (2) as compared to younger children, a greater number of children older than 36 months advanced to the final stage requiring the highest degree of spatial resolution, and (3) children that failed at different stages exhibited difficulties in discriminating locations that required higher spatial resolution abilities. These results are consistent with the hypothesis that improvements in human spatial memory performance might be linked to improvements in pattern separation capacities.

This experiment investigated challenge evaluations in soccer and their relation to prejudice: more precisely, whether skin colour may influence judgments of soccer tackles. Three groups of participants (soccer players, referees, and soccer fans) were asked to evaluate challenges, featuring Black and White players as aggressors and victims in a mixed-design study. Results showed that participants made some differentiations between Black and White players in a challenge evaluation task. Participants were more likely to consider within-group challenges as fouls and were faster to consider challenges made by Black players as fouls. On the other hand, fouls made by White players were seen as more severe. There were no major differences between the participating groups, suggesting that the observed effects were independent of how good players were or whether the participants were referees or not.

Although most research on the effect of tobacco warnings has been focused on attitude changes following the presentation of tobacco warnings, this paper takes a somewhat new perspective by investigating cognitive processing of tobacco warnings by adolescents of different ages (i.e., 14-, 16-, and 18-year-olds). More specifically, this paper investigates the way adolescents encode different textual elements presented in tobacco warnings. By means of a standard psycholinguist paradigm (i.e., sentence evaluation paradigm), we evaluated tobacco warnings differing along three variables: (1) severity, (2) time consequence and (3) target (health vs. others). Our main result demonstrated noticeable differences between the age groups and between smoking experiences in the cognitive processing of tobacco warnings. Our experimental paradigm represents an important step in identifying the mechanisms through which certain types of written warnings are cognitively processed, which in turn may well set a critical base for understanding decision makers' responses to risky behaviors such as smoking and for constructing adequate health warnings.

L’étiologie des allodynies mécaniques est sujette à la controverse. Dans cette recherche, 25 allodynies mécaniques stastiques (AMS), traitées par rééducation sensitive (n = 23 patients), ont été étudiées topographiquement: les AMS cartographiées (allodynographies) rétrécissent en surface. Leur mode de disparition successif a été cartographié, ainsi que l’apparition de leur hypoesthésie. Le centre de la cartographie de la dernière AMS se situe en regard du centre de la dernière cartographie de son hypoesthésie (esthésiographie secondaire): 9,7 mm en moyenne ± ET = 8,0 (étendue: 1–38 mm). Nous concluons que l’AMS disparaît vers le centre de son hypoesthésie. En présence d’une hypersensibilité au toucher, cette observation devrait aider le clinicien à identifier l’étiologie du nerf cutané lésé. The aetiology of mechanical allodynia is still controversial. In the present study, we investigated the precise locations of 25 static mechanical allodynias (SMA) treated by somatosensory rehabilitation (n = 23 patients): the allodynic territory mapped (allodynography) was seen to shrink. The mode of progressive regression and finally disappearance of the SMA was mapped, as was the hypoaesthesia. The center of the final SMA map is aligned with the center of the final hypoaesthesia map (secondary aesthesiography): the inter-center distance was on average 9.7 mm ± SD = 8.0 (range: 1–38 mm). We conclude that the SMA disappears in the direction of the centre of the underlying hypoaesthesia. In cases of hypersensitivity to touch, this observation should help the physician identify the damaged cutaneous nerve.

We tested a densely amnesic patient (P9), with bilateral hippocampal damage resulting from an autoimmune disorder, and 12 age- and sex-matched controls on a series of memory tasks designed to characterize allocentric spatial learning and memory abilities. We compared P9’s ability to perform spatial memory tasks with her ability to perform non-spatial, color memory tasks. First, P9’s performance was impaired as compared to controls even in the simplest versions of an allocentric spatial memory task, in which she had to find repeatedly over ten trials the same location(s) of one, two or three illuminating foot pad(s) among 23 pads distributed in an open-field arena. In contrast, she performed as well as controls when she had to find repeatedly over ten trials the same one, two or three pad(s) marked by color cue(s), whose locations varied between trials. Second, P9’s performance was severely impaired in working memory tasks, when she had to learn on a trial-unique basis and remember the location(s) or the color(s) of one, two or three pad(s), while performing an interfering task during the one-minute interval separating encoding and retrieval. Without interference during the retention interval of the trial-unique tasks, P9’s performance was partially preserved in the color tasks, whereas it remained severely impaired in the allocentric spatial tasks. Detailed behavioral analyses indicate that P9’s memory representations are more limited than those of controls both in their precision (metric coding) and in the number of items that can be maintained in memory (capacity). These findings are consistent with the theory that the hippocampus contributes to the integration or binding of multiple items, in order to produce high-resolution/high-capacity representations of spatial and non-spatial information in the service of short-term/working and long-term memory.