Easy-to-hard effects in perceptual learning depend upon the degree to which initial trials are “easy”

Psychonomic Bulletin & Review - Starting perceptual training at easy levels before progressing to difficult levels generally produces better learning outcomes than constantly difficult training...     

Psychotic manifestations in a patient with mental retardation and a 6.2 megabase deletion at the distal short arm of chromosome 12

Genetic factors are known to contribute to the development of schizophrenia and related psychoses. Cytogenetic abnormalities have been occasionally found in patients with psychotic disorders and, thus, have helped identify candidate gene contributors for these conditions. The individual described here first presented with mental retardation and anxiety disorder in his mid-childhood. In his early 20s, the patient started exhibiting various psychotic manifestations, including delusions and hallucinations. His psychotic symptoms were difficult to control with psychotropic medications. The family history was negative for psychiatric disorders. This patient was found to have a 6.2 megabase deletion of the terminal portion of the short arm of chromosome 12 that was characterized using fluorescence in situ hybridization and microarray comparative genomic hybridization analysis. The maternal chromosomes were normal, but the paternal chromosomes could not be tested. To-date such a chromosomal abnormality has not been described in association with schizophrenia/psychosis. This case suggests that psychosis-associated gene(s) may be located in the terminal region of the short arm of chromosome 12.     

Modeling possible effects of atypical cerebellar processing on eyeblink conditioning in autism

Autism is unique among other disorders in that acquisition of conditioned eyeblink responses is enhanced in children, occurring in a fraction of the trials required for control participants. The timing of learned responses is, however, atypical. Two animal models of autism display a similar phenotype. Researchers have hypothesized that these differences in conditioning reflect cerebellar abnormalities. The present study used computer simulations of the cerebellar cortex, including inhibition by the molecular layer interneurons, to more closely examine whether atypical cerebellar processing can account for faster conditioning in individuals with autism. In particular, the effects of inhibitory levels on delay eyeblink conditioning were simulated, as were the effects of learning-related synaptic changes at either parallel fibers or ascending branch synapses from granule cells to Purkinje cells. Results from these simulations predict that whether molecular layer inhibition results in an enhancement or an impairment of acquisition, or changes in timing, may depend on (1) the sources of inhibition, (2) the levels of inhibition, and (3) the locations of learning-related changes (parallel vs. ascending branch synapses). Overall, the simulations predict that a disruption in the balance or an overall increase of inhibition within the cerebellar cortex may contribute to atypical eyeblink conditioning in children with autism and in animal models of autism.     

Uncovering the diverse cultural bases of social identity: Ingroup ties predict self‐stereotyping among individualists but not among collectivists

On what basis do people form their social identities? To investigate this issue, the present research investigates cross‐cultural differences in self‐stereotyping, a key outcome of social identification. In particular, the research tests the hypothesis that ingroup ties are a stronger predictor of self‐stereotyping among people from individualist cultures than among people from collectivist cultures. In Study 1, university students (N = 117) completed measures of ingroup ties and self‐stereotyping with respect to an intimacy group (family and friends). Consistent with predictions, ingroup ties significantly predicted self‐stereotyping among individualists but not among collectivists. Study 2 (N = 104) found a similar pattern of results among members of the global internet community who considered either an intimacy group (their friends), a task group (their work group) or a social category (their gender). These results indicate that people in individualist cultures are more likely than those in collectivist cultures to base their social identities on ingroup ties. The implications of these results are discussed in relation to self‐categorization theory's depersonalization account of social identification.     

First trial outcome but not training difficulty predicts performance in goldfish visual discrimination

Animal Cognition - The easy-to-hard effect in perceptual learning shows that training with easier examples can facilitate initially difficult or impossible distinctions between very similar...