Spatially distributed encoding of covert attentional shifts in human thalamus.

ABSTRACT: Spatial attention modulates signal processing within visual nuclei of the thalamus--but do other nuclei govern the locus of attention in top-down mode? We examined functional MRI (fMRI) data from three subjects performing a task requiring covert attention to 1 of 16 positions in a circular array. Target position was cued after stimulus offset, requiring subjects to perform target detection from iconic visual memory. We found positionally specific responses at multiple thalamic sites, with individual voxels activating at more than one direction of attentional shift. Voxel clusters at anatomically equivalent sites across subjects revealed a broad range of directional tuning at each site, with little sign of contralateral bias. By reference to a thalamic atlas, we identified the nuclear corre

SUBMITTER: Hulme OJ 

PROVIDER: S-EPMC3007633 | biostudies-literature | 2010 Dec

REPOSITORIES: biostudies-literature