Cerebral asymmetries in sleep-dependent processes of memory consolidation

Preference for previously seen, unfamiliar objects reflects a memory bias on affective judgment, known as the “mere exposure effect” (MEE). Here, we investigated the effect of time, post-exposure sleep, and the brain hemisphere solicited on preference generalization toward objects viewed in different perspectives. When presented in the right visual field (RVF), which promotes preferential processing in the left hemisphere, same and mirrored exemplars were preferred immediately after exposure. MEE generalized to much dissimilar views after three nights of sleep. Conversely, object presentation in the left visual field (LVF), promoting right hemisphere processing, elicited a MEE for same views immediately after exposure, then for mirror views after sleep. Most importantly, sleep deprivation during the first post-exposure night, although followed by two recovery nights, extinguished MEE for all views in the LVF but not in the RVF. Besides demonstrating that post-exposure time and sleep facilitate the generalization process by which we integrate various representations of an object, our results suggest that mostly in the right hemisphere, sleep may be mandatory to consolidate the memory bias underlying affective preference. These interhemispheric differences tentatively call for a reappraisal of the role of cerebral asymmetries in wake- and sleep-dependent processes of memory consolidation.     

Analyzing head roll and eye torsion by means of offline image processing

Ocular torsion is a key problem in the understanding of many visual perceptual effects. However, since it is difficult to record, its integration with other sensorimotor signals is still poorly understood. Unfortunately, eyetracker systems are generally not dedicated to the monitoring of eye torsion. In addition, the classical methods used with video-based systems present some limits in the accuracy of torsion calculation. These limits are especially related to the detection of pupil center and the effects of pupil size changes. This article aims at (1) proposing a solution to analyze ocular torsion together with head roll using EyeLink II or similar equipment, (2) reviewing and adapting classical polar cross-correlation methods in order to improve the accuracy of torsion measurement, (3) providing a lower-cost method compared with the existing ones. Video sequences issued from the EyeLink II host computer monitor were recorded by means of a second computer equipped with a video acquisition card and converted into image sequences. Images were analyzed with algorithms of pupil center detection (median-based algorithm), torsion analysis (adapted polar cross-correlation method which takes into account pupil size variations) and marker tracking (head roll analysis). This method was tested on virtual eye images. Results are discussed with respect to other algorithms found in the literature.     

Verbal,mathematics, and physical education self-concepts and achievements: An extension and test of the Internal/External Frame of Reference Model

ObjectivesThe Internal/External Frame of Reference Model (I/E model; e.g., Marsh, 1986) posits that verbal achievement (Ach) produces a lower mathematics self-concept (SC) and that, conversely, mathematics Ach fosters a lower verbal SC after controlling for prior Ach in each domain. The present study extended this model by adding another school subject that has not been previously investigated, namely physical education (PE). The central goal was to verify whether Ach in PE positively or negatively predicts academic SC in the mathematics and verbal domains.DesignProspective study over one school year.MethodsParticipants were 451 French high school students (mean age = 13.5). Ach scores in mathematics, French and PE were gathered at the beginning of the school year. At the end of this one, students completed a questionnaire to assess their SC in the three school subjects. Results: Structural Equation Modelling results revealed, according to the I/E model, negative paths between mathematics Ach and verbal SC, and between verbal Ach and mathematics SC. Results also revealed singular relationship patterns between the two traditional school subjects and PE. A positive path between PE Ach and mathematics SC was observed whereas the path with the verbal SC was non-significant.ConclusionPE could have benefits to increase SC in other school subject such as mathematics. Broader implications of results for the I/E model are discussed.     

Genetics and personality affect visual perspective in autobiographical memory

Major depression is associated with a decrease of 1st person (versus 3rd person) visual perspective in autobiographical memory, even after full remission. This study aimed to examine visual perspective in healthy never-depressed subjects presenting with either genetic or psychological vulnerability for depression. Sixty healthy participants performed the Autobiographical Memory Test with an assessment of visual perspective. Genetic vulnerability was defined by the presence of at least one S or L_G allele of the polymorphism of the serotonin-transporter-linked promoter region (5-HTTLPR). Psychological vulnerability was defined by high scores of harm avoidance measured by the Temperament and Character Inventory. Life stress exposure, depressive mood, rumination, and familial history of depression were assessed through standardized procedures. Visual perspective for positive memories was independently predicted by both harm avoidance and a gene by environment interaction between the 5-HTTLPR polymorphism and life stress exposure. Visual perspective and vulnerability for depression may share some biological bases.     

An Initial Test of the Cosmetics Dehumanization Hypothesis: Heavy Makeup Diminishes Attributions of Humanness-Related Traits to Women

Sex Roles - Objectification theory suggests that sexualization has significant dehumanizing consequences for how perceivers see women. To date, research has mostly documented how sexualized bodies...     

Relationships between executive function,working memory,and decision-making on the Iowa Gambling Task: Evidence from ventromedial patients,dorsolateral patients,and normal subjects

The results of previous studies are inconsistent in regard to the relationship between the Iowa Gambling Task (IGT), working-memory (WM), and executive tasks, and whether these cognitive processes could be considered as mechanisms underlying a decision-making deficit. Moreover, the relationship between the IGT and executive measures is examined based on a limited number of executive tasks, within different populations showing diffuse damage. In addition, there are fewer studies carried out within control participants, with those studies also being inconclusive. It is also suggested that the association of the IGT performance with executive tasks depends on whether the IGT was running under ambiguity or under risk. In this work, all of these issues are studied. Results showed that both patients with ventromedial (VMPFC, N = 10) and dorsolateral (DLPFC, N = 10) prefrontal cortex lesions are significantly impaired on almost all executive tasks, WM tasks, and the IGT. Furthermore, when the IGT is run under risk, there are significant correlations between executive measures and the IGT for the DLPFC patients and the control participants (N = 34) but not the VMPFC patients. No correlation was found between WM tasks and the IGT for both frontal subgroups and control participants. These findings suggested that the mechanisms underlying the IGT deficit differ according to the lesion locations.