The anatomy of object processing: The role of anteromedial temporal cortex

How objects are represented and processed in the brain remains a key issue in cognitive neuroscience. We have developed a conceptual structure account in which category-specific semantic deficits emerge due to differences in the structure and content of concepts rather than from explicit divisions of conceptual knowledge in separate stores. The primary claim is that concepts associated with particular categories (e.g., animals, tools) differ in the number and type of properties and the extent to which these properties are correlated with each other. In this review, we describe recent neuropsychological and neuroimaging studies in which we have extended our theoretical account by incorporating recent claims about the neuroanatomical basis of feature integration and differentiation that arise from research into hierarchical object processing streams in nonhuman primates and humans. A clear picture has emerged in which the human perirhinal cortex and neighbouring anteromedial temporal structures appear to provide the neural infrastructure for making fine-grained discriminations among objects, suggesting that damage within the perirhinal cortex may underlie the emergence of category-specific semantic deficits in brain-damaged patients.     

The Dr. John Hall story: a case study in putative “Haunted People Syndrome”

ABSTRACT

Research suggests a “Haunted People Syndrome (HP-S)” defined by recurrent and systematic perceptions of anomalous subjective and objective anomalies. Such signs or symptoms are traditionally attributed to “spirits and the supernatural,” but these themes are hypothesised to morph to “surveillance and stalking” in reports of “group-(or gang) stalking,” We tested this premise with a quali-quantitative exercise that mapped group-stalking experiences from a published first-hand account to a Rasch measure of haunt-type anomalies. This comparison found significant agreement in the specific “signs or symptoms” of both phenomena. Meta-patterns likewise showed clear conceptual similarities between the phenomenology of haunts and group-stalking. Findings are consistent with the idea that both anomalous episodes involve the same, or similar, attentional or perceptual processes and thereby support the viability of the HP-S construct.     

The relative effect of cue interaction

It is well established that two predictor cues ( A and B ) of a common outcome interact in that the judgement of the relationship between each cue and the outcome is influenced by the pairing history of the other cue with that outcome. For example, when the contingency of A with an outcome is weaker than the contingency of B with that outcome, the rating of the predictiveness of A is reduced relative to a situation where only A is paired with the outcome. One explanation of such cue interaction effects is provided by the conditional ΔP account. Spellman (1996b) derived a counterintuitive prediction of the conditional ΔP account where cue interaction should not occur under certain conditions even though a relatively poor predictor of an outcome is paired with a relatively good predictor of that outcome. However, Spellman (1996b) did not provide data to evaluate this prediction. In the present paper, we report the relevant data and show that they are consistent with the conditional ΔP account. A competing account of cue interaction is provided by the Rescorla-Wagner (RW) model. We derive the predictions of the RW model for the conditions specified by Spellman (1996b), and show that at asymptote the predictions of the RW model are identical to those of the conditional ΔP account.