Frontal cortex differentiates between free and imposed target selection in multiple-target search

• Published in: NeuroImage (Orlando, Fla.) Fla.), 2019-11, Vol.202, p.116133-116133, Article 116133
• Main Authors: Ort, Eduard, Fahrenfort, Johannes J., Reeder, Reshanne, Pollmann, Stefan, Olivers, Christian N.L.
• Format: Article
• Language: English
• Subjects: Cognitive ability; Cortex (frontal); Cortex (parietal); Eye movements; Functional magnetic resonance imaging; Neural networks; Proactive cognitive control; Reactive cognitive control; Visual attention; Visual cortex; Visual perception; Visual search
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2019.116133

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. •We compared free versus imposed target selection in visual search.•Imposed target switches result in performance costs unlike self-initiated switches.•A frontoparietal control network differentiates between free and imposed selection.