Abstract
Vision has an intrinsic affinity for spatial information, such that visual processing and spatial representations are often confounded in neuroimaging research. Recently, our laboratory used fMRI to demonstrate that directly contrasting visual and auditory attention or working memory robustly identifies discrete visual- and auditory-biased structures in caudolateral frontal cortex. Further, these areas are recruited cross-modally depending on task demands, with auditory spatial tasks recruiting visual-biased areas, and visual temporal tasks recruiting auditory-biased areas (Michalka 2015). Resting state functional connectivity between frontal cortex and posterior visual (IPS/TOS) and auditory (STG/S) structures identified additional frontal regions with preferential connectivity to one or the other posterior seed. In individual subjects, we identified four bilateral sensory-biased structures in the vicinity of the precentral sulcus and inferior frontal sulcus using a direct contrast of visual and auditory attention. We additionally defined four adjacent sensory-biased structures using individual subjects' resting state functional connectivity; these areas ("buddy regions") have similar degrees of preferential connectivity to the task-defined posterior structures, but are not selectively recruited in contrasts of visual vs. auditory cognition. Using auditory and visual working memory tasks in which subjects either remembered locations (spatial memory) or time intervals (temporal memory), we tested the degree of recruitment in task-defined visual- and auditory-biased frontal structures, as well as in the buddy regions. Preliminary results suggest that the buddy regions are strongly cross-modally recruited during modality-inappropriate tasks. In auditory spatial memory, the task-defined superior precentral sulcus, a visual-biased structure, is recruited, but the adjacent connectivity-defined region is driven substantially more strongly. These buddy regions, with sensory-biased connectivity but minimal sensory-biased task recruitment, may play important roles in flexible human cognition, allowing the brain to translate between representations depending on task demands (Marr 1982).
Meeting abstract presented at VSS 2017