Poster C5, Sunday, March 25, 1:00-3:00 pm, Exhibit Hall C
Convergent functional network connectivity changes in stimulus-driven attention and awareness
Hana Eaton1, Hongyang Sun1, Jocelyn Sy1, Doug Godwin1, Padma Raghavan1, Rene Marois1; 1Vanderbilt University
Salient, unexpected events are known to powerfully capture attention and disrupt goal-oriented behavior. However, little is known about how attention capture alters connectivity across the brain’s functional networks. Recent work showed that perceptual awareness of a task-relevant target is associated with an increase in functional connectivity across diverse neuronal networks of the cerebral cortex (Godwin et al., PNAS, 2014). Given the intricate relationship between awareness and stimulus-driven attention, we hypothesized that the exogenous capture of attention by unexpected ‘oddball’ stimuli may require large-scale changes in functional connectivity that are similar to the changes seen with perceptual awareness. FMRI data was collected as 30 participants monitored a rapid serial visual presentation of letters for a target. The presentation of task-irrelevant oddballs (faces) in a small proportion of trials (6 out of 40) captured attention and disrupted target detection, especially with the first two oddball presentations. Using graph-theoretic analysis, we found that, like with awareness, the brain's connectivity across functional networks increased – as measured by the modularity and participation coefficient metrics – with the presentation of the first two oddballs relative to subsequent oddball presentations or during target search alone. These results suggest that the capture of attention by an unexpected event is associated with an increase in functional integration of the brain’s networks. Moreover, together with the findings in Godwin et al (2014), these results suggest that awareness and stimulus-driven attention are associated with similar integrative, global changes in the brain’s functional connectivity.
Topic Area: ATTENTION: Nonspatial