Two distinct neural mechanisms for category-selective responses

Noppeney, Uta, Price, Cathy J, Penny, Will D. and Friston, Karl J (2006) Two distinct neural mechanisms for category-selective responses. Cerebral Cortex, 16 (3). pp. 437-445. ISSN 1047-3211

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Abstract

The cognitive and neural mechanisms mediating category-selective responses in the human brain remain controversial. Using functional magnetic resonance imaging and effective connectivity analyses (Dynamic Causal Modelling), we investigated animal- and tool-selective responses by manipulating stimulus modality (pictures versus words) and task (implicit versus explicit semantic). We dissociated two distinct mechanisms that engender category selectivity: in the ventral occipito-temporal cortex, tool-selective responses were observed irrespective of task, greater for pictures and mediated by bottom-up effects. In a left temporo-parietal action system, tool-selective responses were observed irrespective of modality, greater for explicit semantic tasks and mediated by top-down modulation from the left prefrontal cortex. These distinct activation and connectivity patterns suggest that the two systems support different cognitive operations, with the ventral occipito-temporal regions engaged in structural processing and the dorsal visuo-motor system in strategic semantic processing. Consistent with current semantic theories, explicit semantic processing of tools might thus rely on reactivating their associated action representations via top-down modulation. In terms of neuronal mechanisms, the category selectivity may be mediated by distinct top-down (task-dependent) and bottom-up (stimulus-dependent) mechanisms.

Item Type: Article
Uncontrolled Keywords: adult,brain mapping,cerebral cortex,computer simulation,female,humans,male,neurological models,nerve net,neural pathways,speech perception,visual perception,clinical trial
Faculty \ School: Faculty of Social Sciences > School of Psychology
Depositing User: Pure Connector
Date Deposited: 19 Aug 2017 05:06
Last Modified: 25 Jul 2019 00:08
URI: https://ueaeprints.uea.ac.uk/id/eprint/64606
DOI: 10.1093/cercor/bhi123

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