PT  - JOURNAL ARTICLE
AU  - Eduard Ort
AU  - Johannes J. Fahrenfort
AU  - Reshanne Reeder
AU  - Stefan Pollmann
AU  - Christian N. L. Olivers
TI  - The Role of Proactive and Reactive Cognitive Control for Target Selection in Multiple-Target Search
AID  - 10.1101/559500
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 559500
4099  - http://biorxiv.org/content/early/2019/02/24/559500.short
4100  - http://biorxiv.org/content/early/2019/02/24/559500.full
AB  - Cognitive control can involve proactive (preparatory) and reactive (corrective) mechanisms. Using a gaze-contingent eye tracking paradigm combined with fMRI, we investigated the involvement of these different modes of control and their underlying neural networks, when switching between different targets in multiple-target search. Participants simultaneously searched for two possible targets presented among distractors, and selected one of them. In one condition, only one of the targets was available in each display, so that the choice was imposed, and reactive control would be required. In the other condition, both targets were present, giving observers free choice over target selection, and allowing for proactive control. Switch costs emerged only when targets were imposed and not when target selection was free. We found differential levels of activity in the frontoparietal control network depending on whether target switches were free or imposed. Furthermore, we observed core regions of the default mode network to be active during target repetitions, indicating reduced control on these trials. Free and imposed switches jointly activated parietal and posterior frontal cortices, while free switches additionally activated anterior frontal cortices. These findings highlight unique contributions of proactive and reactive control during visual search.