c-fos mRNA induction in acute and chronic audiogenic stress: possible role of the orbitofrontal cortex in habituation

To study putative brain circuits involved in habituation to stress, rats were exposed daily (30 min for 15 days) to an environment in the presence (Chronic) or absence (Acute) of loud noise (105 dB sound pressure level--SPL A Scale). Behavioral and endocrine measures of stress were taken throughout this habituation period, and both measures displayed strong habituation in the Chronic group. All rats were killed immediately after the day 16 exposure, constituting an acute stressor for the Acute group, and regional brain activity was assessed using c-fos mRNA induction with in situ hybridization. Hearing damage could not easily explain these results because additional rats exposed to a similar stress protocol exhibited no changes in auditory brainstem evoked potentials. c-fos mRNA induction in the central auditory system was similar between the Acute and Chronic groups, particularly at lower auditory processing levels, also arguing against a simple reduction in auditory processing in the chronically stressed rats. However, c-fos mRNA expression was reduced in chronically, as compared to acutely, stressed rats in several regions previously implicated in audiogenic stress (lateral septum, bed nucleus of the stria terminalis, some preoptic areas, and the paraventricular hypothalamic nucleus). Interestingly, the orbitofrontal cortex was the only region displaying higher c-fos mRNA induction in the chronically as compared to acutely stressed rats. This region has connections to several stress-responsive areas and may thus be a critical region actively inhibiting stress.     

Focused attention is not enough to activate discontinuities in lines, but scrutiny is

We distinguish between the roles played by spatial attention and conscious intention in terms of their impact on the processing of segmentation signals, like discontinuities in lines, associated with the act of scrutinizing. We showed previously that the processing of discontinuities in lines can be activated. This is evidenced by an impairment in the detection of a gap between parallel elements when it follows a gap between collinear elements in the same location and orientation. This effect is no longer observed if attention is divided between two gaps in the first stimulus. The results from this study show that focusing attention on a gap between collinear elements is not enough to observe a modulation, consistently with the need to integrate, rather than to separate, collinear elements in usual conditions. The modulation is sensitive to the conscious expectations of subjects, suggesting that an intention can trigger modulations that spatial attention cannot.     

Social dominance orientation,prejudice, and discrimination: A new computer-based method for studying discriminatory behaviors

A number of studies have shown that the scale of social dominance orientation (SDO), used to measure the degree of preference for inequality among social groups, is a predictive measure of social and political attitudes toward stigmatized outgroups. However, the relationship between SDO and discrimination has received little attention. The main goal of this study was to assess the validity of a new computer-based method used to measure discriminatory behaviors in a laboratory setting. An additional goal was to test the mediating role of prejudice in the relation between SDO and discrimination. The results provide a first validation of this new method and demonstrate that the effect of SDO on discrimination is mediated by prejudice.     

Phenomenal characteristics of cryptomnesia

Qualitative characteristics of cryptomnesia, or unintentional plagiarism were investigated. In Experiment 1 we compared accurate and inaccurate source attributions in terms of their level of confidence using instructions that did not require a fixed number of responses. Confidence was lower for plagiarised responses than for correct responses. Nevertheless, participants provided high ratings of certainty for a large proportion of their plagiarised responses. In Experiment 2 the phenomenological differences between plagiarised recall and veridical recall were compared by using an adaptation of the memory characteristics questionnaire (Johnson, Foley, Suengas, & Raye, 1988). Correct responses were associated with more experiential detail than plagiarised responses. However, a considerable number of plagiarised responses were accompanied by a confident memory of at least one qualitative characteristic. Results are discussed in terms of the source monitoring framework developed by Johnson, Hashtroudi, and Lindsay (1993).     

Personal self and collective self: when academic choices depend on the context of social comparison

This research examines the impact of same-sex versus opposite-sex social comparisons on the perception of one’s own abilities at school and subsequent reported marks and academic choices. During their final year, male and female high school students were asked to describe themselves either in comparison with boys in their class, in comparison with girls in their class or without any explicit social comparison (control group). The interaction effects of gender and comparison context on academic selfconcept, school marks and academic choices indicated that gender differences depend on the comparison context. Particularly, as predicted, gender differences disappeared in the same-sex social comparison condition, and even became inverted for the intended academic choices. Here, boys intended to choose more than girls Preparatory Courses for Higher Education (PCHE) in the opposite-sex social comparison condition, while girls more often chose a prestigious PCHE than boys in the same-sex social comparison condition. The theoretical, methodological and practical implications of these findings are discussed.     

Repetition and Spacing Effects on True and False Recognition in the DRM Paradigm

Dubuisson, J.-B., Fiori, N. & Nicolas, S. (2012) Repetition and spacing effects on true and false recognition in the DRM paradigm. Scandinavian Journal of Psychology 53, 382-389. With the Deese-Roediger-McDermott (DRM) paradigm, the repetition effect on false memory had never been clarified. More importantly, the spacing effect on false memory was never directly investigated. So, we carried out two experiments to examine these effects on true and false recognition. In experiment 1, participants studied DRM lists which were presented one, three or five times. In experiment 2, we manipulated the repetition mode (massed vs. spaced with a short interval or a long interval) to explore the spacing effect. The results showed that true recognition increased monotonically with list repetition (experiment 1) and repetition spacing (experiment 2). The most striking finding was a similar spacing effect but no repetition effect on false recognition. Thus, these results were principally discussed in the light of the activation-monitoring framework.     

The role of need satisfaction as a distinct and basic psychological component of autobiographical memories: a look at well-being

The purpose of the present research was to show that satisfaction of the psychological needs of autonomy, competence, and relatedness constitutes a basic component characterizing autobiographical memories. In Study 1, a coding scheme and a self-rating method for measuring need satisfaction in memories were developed and shown to be highly related to each other. Across 3 studies using graduate and undergraduate students (Study 1: N=244; Study 2: N=309; Study 3: N=159), need satisfaction was found to be moderately associated with well-being measures, over and above several other memory components usually assessed in research on autobiographical memories. In addition, this association between need satisfaction in autobiographical memories and well-being held, even after controlling for person-level measures, such as personality traits, self-determined orientation, or experience of need satisfaction in general in one's life, thus suggesting that autobiographical memory and semantic self-knowledge are distinct databases.     

Neuroticism and extraversion are associated with amygdala resting-state functional connectivity

The personality traits neuroticism and extraversion are differentially related to socioemotional functioning and susceptibility to affective disorders. However, the neurobiology underlying this differential relationship is still poorly understood. This discrepancy could perhaps best be studied by adopting a brain connectivity approach. Whereas the amygdala has repeatedly been linked to neuroticism and extraversion, no study has yet focused on the intrinsic functional architecture of amygdala-centered networks in relation to both traits. To this end, seed-based correlation analysis was employed to reveal amygdala resting-state functional connectivity (RSFC) and its associations with neuroticism and extraversion in 50 healthy participants. Higher neuroticism scores were associated with increased amygdala RSFC with the precuneus, and decreased amygdala RSFC with the temporal poles, insula, and superior temporal gyrus (p < .05, cluster corrected). Conversely, higher extraversion scores were associated with increased amygdala RSFC with the putamen, temporal pole, insula, and several regions of the occipital cortex (p < .05, cluster corrected). The shifts in amygdala RSFC associated with neuroticism may relate to the less-adaptive perception and processing of self-relevant and socioemotional information that is frequently seen in neurotic individuals, whereas the amygdala RSFC pattern associated with extraversion may relate to the heightened reward sensitivity and enhanced socioemotional functioning in extraverts. We hypothesize that the variability in amygdala RSFC observed in the present study could potentially link neuroticism and extraversion to the neurobiology underlying increased susceptibility or resilience to affective disorders.     

The accuracy of memory for faces of personally known individuals

The present study was aimed at evaluating whether the very high accuracy of memory for familiar faces, demonstrated by Ge et al (2003, Perception 32 601-614) with a very familiar famous person, generalises to faces of personally known individuals. The accuracy of participants' perceptual memory for a close colleague's face and for their own face was evaluated by presenting original and manipulated pictures of these two targets. The manipulation consisted of increasing or decreasing the interocular distance. As in Ge et al's study, results indicated that proportions of correct recognition of the original faces, and just noticeable differences for the detection of alterations in the recognition task, were not significantly different from the corresponding measures in a perceptual discrimination task performed by a sample of participants who did not know the target persons at all. High accuracy of memory generalises to faces of personally known individuals.