Abstract
Efficiently searching for a target in complex environments is a fundamental skill of the human cognitive system. One of the highly possible mechanism ensuring efficient visual search is inhibition of return (IOR). It refers to slower response to targets at previously cued locations than uncued locations and has been considered to facilitate foraging behavior by preventing attention from returning to previously inspected locations (Klein 2000). While traditional theories attribute IOR to a deficit in attention at the previously attended locations, a more recent theory proposed by Lupiáñez and colleagues (2001, 2007) suggested that IOR results from a competition process between integration of the target into an object representation created by the cue onset at cued locations (integration) and creation of a new representation at uncued locations (segregation). The integration vs. segregation theory (IS) has been demonstrated to be more robust than traditional theories in interpreting the effect of IOR under wide variety of experiment situations. However, there is few neuroimaging evidence for the IS theory. Here we aimed to seek for the neuroimaging evidence for the IS theory by using fMRI technique with an optimized stimuli sequence. fMRI data were acquired while the participants performed a cue-target task. The results revealed distinct activity patterns for the cued vs. the uncued condition. While the orbitofrontal cortex and the parahippocampal gyrus expressed smaller activity under the cued than the uncued condition, the frontal eye field and supplement eye field area expressed a reversed pattern of activity. Given the former areas is usually involved in encoding new information and the later areas is believed to be correlated with orienting of attention, the current results provided, for all we know, the first neuroimaging evidence for the IS theory.
Meeting abstract presented at VSS 2016