Visual cortex and the Eriksen-Flanker task: an fMRI study

The Eriksen-Flanker task is generally used to probe mechanisms of high level cognitive processes such as cognitive control and response inhibition. In the present study we aimed at testing whether activity as early as the visual cortex can be indicative of the incongruent and congruent conditions characterizing the Eriksen-Flanker task. Additionally, we examined whether the difference in activity for incongruent relative to congruent trials is systematically modulated along successive stages of the intraparietal sulcus from IPS0 to IPS5. The dataset was obtained from the OpenfMRI database. Twenty-six right-handed adults took part in the study, consisting of a slow event related Eriksen-Flanker task. Functional MRI data were acquired using a Siemens Allegra 3.0T scanner and preprocessing was carried out with AFNI (https://afni.nimh.nih.gov/). At the first level analysis a general linear model (GLM) was performed. Individual regions of interest (ROI) were grouped into ventral-temporal, dorsal-lateral and fronto-parietal locations. ROI activity was first assessed with a one sample t-test to confirm task related activity (Bonferroni corrected), followed by a paired sample t-test and a linear mixed effects model to evaluate the congruency effect within each region and its modulation across successive stages of the visual hierarchy. We observe reliable modulation of the incongruent and congruent conditions in the Eriksen-Flanker task as early as human IPS, indicating a crucial contribution of sensory processing and motor planning in cognitive control tasks.