Abstract
The speed of visual search depends on bottom-up stimulus features (e.g., we quickly locate a red item among blue distractors), but it is also facilitated by the presence of top-down perceptual predictions about the item. Here, we identify the nature, source, and neuronal substrate of the predictions that speed up resumed visual search. Human subjects were presented with a visual search array that was repeated up to 4 times, while brain activity was recorded using magnetoencephalography (MEG). Behaviorally, we observed a bimodal reaction time distribution for resumed visual search, indicating that subjects were extraordinarily rapid on a proportion of trials. MEG data demonstrated that these rapid-response trials were associated with a prediction of (1) target location, as reflected by alpha-band (8-12 Hz) lateralization; and (2) target identity, as reflected by beta-band (15-30 Hz) lateralization. Moreover, we show that these predictions are likely generated in a network consisting of medial superior frontal cortex and right temporo-parietal junction. These findings underscore the importance and nature of perceptual hypotheses for efficient visual search.
Original language | English |
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Pages (from-to) | 4327-4336 |
Number of pages | 10 |
Journal | Cerebral Cortex |
Volume | 26 |
Issue number | 11 |
Early online date | 22 Sept 2015 |
DOIs | |
Publication status | Published - 17 Oct 2016 |
Keywords
- expectation
- MEG
- perception
- rapid resumption
- visual search