Lack of the metabotropic glutamate receptor subtype 7 selectively modulates Theta rhythm and working memory

Metabotropic glutamate receptors (mGluRs) are known to play a role in synaptic plasticity and learning. We have previously shown that mGluR7 deletion in mice produces a selective working memory (WM) impairment, while other types of memory such as reference memory remain unaffected. Since WM has been associated with Theta activity (6-12 Hz) in EEGs, and since EEG abnormalities have been observed in these mice before, we studied the effect of mGluR7 gene ablation on EEG activity in the hippocampus, in particular in the Theta range, during performance of a WM task. In an eight-arm maze with four arms baited, mGluR7 knock-out (KO) and wild-type mice committed the same number of reference memory errors, whereas KOs committed more WM errors. While performing the task, KO mice showed substantially higher Theta amplitudes, and the ratio of Theta to overall EEG power was much increased. No change was seen in the Delta (0-5 Hz), or Gamma (30-40 Hz) EEG bands compared with controls. When recording EEGs during periods of rest in the home cages, no difference was seen between groups. These findings suggest that mGluR7 is important for modulation and control of Theta activity. Since only WM was affected, and only the Theta range of EEG activity was altered, these results show a correlation between Theta rhythm and WM performance, and therefore support the concept that Theta activity in the hippocampus is involved in WM storage.     

An evaluation of the Tripartite Influence Model of body dissatisfaction and eating disturbance with adolescent girls

The Tripartite Influence Model of body image and eating disturbance proposes that three formative influences (peer, parents, and media) affect body image and eating problems through two mediational mechanisms: internalization of the thin-ideal and appearance comparison processes. The current study evaluated this model in a sample of 325 sixth through eighth grade girls. Simple path analyses indicated that internalization and comparison fully mediated the relationship between parental influence and body dissatisfaction and partially mediated the relationship between peer influence and body dissatisfaction. Additionally, internalization and comparison partially mediated the relationship between media influence and body dissatisfaction. Six a priori SEM models based on the full Tripartite Influence Model were also evaluated. A resulting model was found to be an adequate fit to the data, supporting the viability of the Tripartite Model as a useful framework for understanding processes that may predispose young women to develop body image disturbances and eating dysfunction.     

Concurrent validity of the DSM-IV scales Affective Problems and Anxiety Problems of the Youth Self-Report

This study investigated the concurrent validity of the DSM-IV scales Anxiety Problems and Affective Problems of the Youth Self-Report (YSR) in a community sample of Dutch young adolescents aged 10-12 years. We first examined the extent to which the YSR/DSM-IV scales reflect symptoms of DSM-IV anxiety disorders and DSM-IV Major Depressive Disorder, assessed with the Revised Child Anxiety and Depression Scale (RCADS). Second, we examined whether the association between the YSR/DSM-IV scales and the RCADS scales was stronger than the association between the empirically derived YSR narrow-band scales Anxious/Depressed and Withdrawn and the same RCADS scales. Results showed that the YSR/DSM-IV scale Affective Problems had a stronger association with symptoms of DSM-IV Major Depressive Disorder than the YSR narrow-band scales Withdrawn and Anxious/Depressed. However, the YSR/DSM-IV scale Anxiety Problems had a weaker association with symptoms of DSM-IV anxiety disorders, compared to the YSR narrow-band scale Anxious/Depressed. It was concluded that the construction of the DSM-IV scales improved the correspondence with DSM-IV Major Depressive Disorder, but not with DSM-IV anxiety disorders.     

Catching and matching bars with different orientations

The hypothesis that perception enslaves action is examined by assessing whether systematic distortions in perceptual judgments are reflected by inaccuracies in catching. In the first experiment, participants had to align manually the orientation of a reference bar placed at different distances in the frontoparallel plane. In the second experiment participants had to catch differently orientated moving bars, which became invisible at different distances from the interception point. In the matching experiment, systematic errors in the alignment of orientation were found in particular for oblique orientations, the magnitude of which increased with increasing distance of the reference bar. The inaccuracies in the final hand orientation during the catching task, however, did not mirror this pattern of deviations. The findings are interpreted to be more consistent with recent views that vision for perception (i.e., matching) and vision for action (i.e., catching) are dissociated than with the view that perception enslaves action.     

Don't stand so close to me: the effects fo self-construal in interpersonal closeness

Abstract— Three studies investigated the effects of self-construal activation on behavior conducive to interpersonal proximity. Study 1 revealed that compared with control participants, participants who were primed with the independent (or personal) self sat further away from where they anticipated another person would sit in a waiting room. Results of Study 2 indicated that participants primed with the interdependent (or social) self sat closer to the anticipated other person than did those primed with the independent self. Finally, Study 3 used the chronic self-construal of participants to predict the seating distance in dyadic settings. Results showed that greater independence of participants' self-construals was associated with greater spatial distance during the interaction. Together, the studies provide clear evidence that self-construal activation automatically influences interpersonal behavior as reflected in the actual distance between the self and others. Results are discussed in terms of the functions and motives connected to self-construals.     

Light direction from shad(ow)ed random Gaussian surfaces

Three human observers estimated the illumination direction for samples of random Gaussian surfaces illuminated by a collimated beam from random directions. These stimuli appear as 'texture' due to shading and shadowing (the surface on the microscale was Lambertian of uniform albedo; thus texture appears only through shading and shadowing). We found that observers were able to estimate the azimuth of the source with remarkable accuracy. In the shading regime (no shadows) the observers committed 180 degrees azimuth errors with 50% probability, whereas in the shadow-dominated regime they were able to avoid this convex/concave confusion to a large extent. They evidently relied on second-order statistics in the shading regime and used an unidentified first-order cue in the shadow regime. The elevations of the source were also estimated with remarkable precision. We attribute this to the statistical homogeneity of the sample which can apparently be exploited by the observers. Likely cues are the fraction of shadowed surface, average intensity and rms contrast. The ability of human observers to estimate the illumination direction from surface texture no doubt contributes to the ability to estimate the light field in scenes, which is a prerequisite to the photometric parsing of scenes (shape from shading, and so forth).     

Remembering can cause inhibition: retrieval-induced inhibition as cue independent process

Previous experiments have mostly relied on recall as a dependent measure to assess whether retrieval of information from memory causes inhibition of related information. This study aimed to measure this inhibition in a more direct way. In Experiment 1, it was shown that repeated retrieval of exemplars from a category resulted in longer recognition latencies to nonretrieved exemplars from that same category, compared with recognition latencies to control exemplars. Experiment 2 obtained the same pattern of results using a lexical decision task. This was the 1st time that retrieval-induced forgetting was demonstrated on an implicit test of memory. To exclude noninhibitory explanations of the data, the exemplars were presented in both experiments without their categories as cues.     

Verbal fluency over time as a measure of automatic and controlled processing in children with ADHD

The performance of ADHD children on semantic category fluency (SCF) versus initial letter fluency (ILF) tasks was examined. For each participant, word production was recorded for each 15-s time slice on each task. Performance on both fluency tasks was compared to test the hypothesis that children with ADHD are characterized by a performance deficit on the ILF task because performance on this task is less automated than performance on the SCF. Children classified with ADHD (N = 20) were compared to children with other psychopathology (N = 118) and healthy controls (N = 130). Results indicated that the groups could not be differentiated by the total number of words produced in 60 s in either fluency task. As hypothesized, a significant interaction of group by productivity over time by type of fluency task was found: ADHD children had more problems finding words in the first 15 s of the IFL than did children in the other two groups, and as compared with their performance on the SCF. Results were taken to indicate that children with ADHD symptoms show a delay in the development of automating skills for processing abstract verbal information.     

Identity but not expression memory for unfamiliar faces is affected by ageing

We examined age-related differences in memory for identity and emotional expression of unfamiliar faces. Younger and older adults were presented with happy and angry faces and were later asked to recognise the same faces displaying a neutral expression. When a face was recognised, they also had to remember what the initial expression of the face had been. In addition, states of awareness associated with both identity and expression memory were assessed with the remember/know/guess paradigm. Older adults showed less recollective experience than younger adults for identity but not for emotional expressions of the faces. This evidence indicates that age-related differences in memory may depend on the nature of the to-be-remembered information, with emotional/social information being remembered as well in older as in younger adults.     

The role of nonautomatic processes in activity regulation: from Lipps to Galperin

The authors present the historical analysis of one of the central questions in psychology: how and why the nonautomatic, psychological level of regulation (in contrast to automatic physiological processes) emerges both in evolution and in everyday context of activity. They discuss several approaches (by Lipps, Groos, Stern, James, Dewey, Claparède, Pavlov, and Leontiev) that culminated in the system of ideas developed by Galperin, one of the key figures in the cultural -historical activity theory. The authors analyze the relation of Galperin's ideas to Vygotsky's theoretical framework and then focus on Galperin's account of the origin and functions of mental activity. Galperin's contribution is highly relevant for understanding the role of psychological regulation and for contemporary research on cognition, consciousness, and conscious awareness.