Target processing in overt serial visual search involves the dorsal attention network: A fixation-based event-related fMRI study

Anja Ischebeck, Hannah Hiebel, Joe Miller, Margit Hofler, Iain D Gilchrist, Christof Korner

Research output: Contribution to journalArticle (Academic Journal)peer-review

Abstract

In serial visual search we shift attention successively from location to location in search for the target. Although such search has been investigated using fMRI, overt attention (i.e., eye movements) was usually neglected or discouraged. As a result, it is unclear what happens in the instant when our gaze falls upon a target as compared to a distractor. In the present experiment, we used a multiple target search task that required eye movements and employed an analysis based on fixations as events of interest to investigate differences between target and distractor processing. Twenty young healthy adults indicated the number of targets (0–3) among distractors in a 20-item display. Compared to distractor fixations, we found that target fixations gave rise to wide-spread activation in the dorsal attention system, as well as in the visual cortex. Targets that were found later during the search activated the left inferior frontal gyrus and the left supramarginal gyrus more strongly than those that were found earlier. Finally, areas associated with visual and verbal working memory showed increased activation with a larger number of targets in the display.
Original languageEnglish
JournalNeuropsychologica
Volume153
Issue number12
Early online date2 Feb 2021
DOIs
Publication statusE-pub ahead of print - 2 Feb 2021

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