Abstract
Perceptual judgments can be based on two kinds of information: state-based perception of specific, detailed visual information, or strength-based perception of global or relational information. State-based perception is discrete in the sense that it either occurs or fails, whereas strength-based perception is continuously graded from weak to strong. The functional characteristics of these types of perception have been examined in some detail, but whether state- and strength-based perception are supported by different brain regions has been largely unexplored. A consideration of empirical work and recent theoretical proposals suggests that parietal and occipito-temporal regions may be differentially associated with state- and strength-based signals, respectively. We tested this parietal/occipito-temporal state/ strength hypothesis using fMRI and a visual perception task that allows separation of state- and strength-based perception. Participants made same/different judgments on pairs of faces and scenes using a 6-point confidence scale where "6" responses indicated a state of perceiving specific details that had changed, and "1" to "5" responses indicated judgments based on varying strength of relational match/mismatch. Regions in the lateral and medial posterior parietal cortex (supramarginal gyrus, posterior cingulate cortex, and precuneus) were sensitive to state-based perception and were not modulated by varying levels of strengthbased perception. In contrast, bilateral fusiform gyrus activation was increased for strength-based "different" responses compared with misses and did not show state-based effects. Finally, the lateral occipital complex showed increased activation for statebased responses and additionally showed graded activation across levels of strength-based perception. These results offer support for a state/strength distinction between parietal and temporal regions, with the lateral occipital complex at the intersection of state- and strength-based processing.
Original language | English (US) |
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Pages (from-to) | 792-809 |
Number of pages | 18 |
Journal | Journal of Cognitive Neuroscience |
Volume | 26 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2014 |
ASJC Scopus subject areas
- Cognitive Neuroscience
- Language and Linguistics
- Linguistics and Language