Contrasting hippocampal and perirhinal cortex function using immediate early gene imaging.

The perirhinal cortex and hippocampus have close anatomical links, and it might, therefore, be predicted that they have close, interlinked roles in memory. Lesion studies have, however, often failed to support this prediction, providing dissociations and double dissociations between the two regions on tests of object recognition and spatial memory. In a series of rat studies we have compared these two regions using the expression of the immediate early gene c-fos as a marker of neuronal activity. This gene imaging approach makes it possible to assess the relative involvement of different brain regions and avoids many of the limitations of the lesion approach. A very consistent pattern of results was found as the various hippocampal subfields but not the perirhinal cortex show increased c-fos activity following tests of spatial learning. In contrast, the perirhinal cortex but none of the hippocampal subfields show increased c-fos activity when presented with novel rather than familiar visual objects. When novel scenes are created by the spatial rearrangement of familiar objects it is the hippocampus and not the perirhinal cortex that shows c-fos changes. This double dissociation for gene expression accords with that found from lesion studies and highlights the different contributions of the perirhinal cortex and hippocampus to memory.     

Development of social role understanding

The concepts of social roles and role intersections have been used to explain adults' social competence. However, children's social competence in terms of developing role concepts has not been systematically delineated. After a brief review of the few developmental studies that have been performed in this area, a systematic developmental sequence of role understanding in children from 1 to 13 years of age is discussed and a method for assessing such sequences is described. The sequence, which was based on K. W. Fischer's (1980, Psychological Review, 87, 477–531) construction-inclusion model of conceptual skill development, was tested in several studies using two sets of social roles and tasks and was found to be highly scalable and age related. The significance of role concept development is also discussed as it relates to the development of social competence in other domains.     

Debating with Fists and Fallacies: Vācaspati Miśra and Dharmakīrti on Norms of Argumentation

International Journal of Hindu Studies - The tradition of Nyāya philosophy centers on a dispassionate quest for truth which is simultaneously connected to soteriological and epistemic aims....     

Dichhaptic laterality and field dependence

Relationships among laterality, field dependence, and sex were investigated using right handed subjects. Dichhaptic measures of laterality showed a significant left-hand advantage for the discrimination of irregular shapes. No significant relationships were found between laterality and sex or sex role perceptions nor between laterality and field dependence. A modality of response effect on the laterality task was interpreted in terms of the functional cerebral space principle.