Abstract
Over the last decades the majority of studies that investigated the neuronal basis of visual attention and the tightly coupled oculomotor system employed paradigms in which the attention shifts and associated eye movements were highly controlled by a given task and a distinct set of artificial stimuli. Few studies examined how attention and eye-movement control interact during a complex and rich visual input which simultaneously drives bottom-up as well as the top-down attention. This study investigates where in the human cortex gaze and attention shifts made during dynamic visual stimulation are represented. We recorded fMRI data as well as gaze position in two independent subjects groups (10 subjects each) while they freely watched the action movie "Indiana Jones: Raiders of the Lost Ark". Subjects showed highly similar eye movements over the full length of the movie. This allowed for establishing a common model of spatial distribution of gaze position and visuospatial attention. Using a searchlight approach we identified brain areas showing correlated similarity structures of gaze heatmaps and fMRI data by using representational similarity analysis as a multivariate pattern measure. We could confirm the association with parts of dorsoparietal (MNI x 50, y -24, z 32) attentional network and the dorsolateral prefrontal cortex (MNI x 54, y 38, z 10) being linked to the deployment of visual attention in a complex audiovisual environment. The corresponding areas show a strong right hemispheric bias. Additionally, activity patterns in the medial frontal cortex (MNI x 8, y 54, z4) may reflect the deployment of visuospatial attention. Our results demonstrate that a widely distributed network including ventral and dorsal parts of the attention system contributes to the deployment of location specific attention during movie watching.
Meeting abstract presented at VSS 2013