Tensor-ICA maps demonstrate temporally correlated activity between auditory and visual cortex. Significant auditory to anterior calcarine connectivity was present bilaterally. Note the common patterns of connectivity across the tensor-ICA and fcMRI maps presented in Figure 1 and Supplementary Figure 2. The color bar represents the probabilities of correlated activity between 0.5 and 1.

Functional connectivity results-left hemisphere. (a) Activity correlated with A1: Voxels in the anatomically defined left A1 ROI demonstrated significant correlated activity with the MGN, contralateral HG and STG, anterior calcarine, and MT+ while subjects were exposed to scanner noise and rested with their eyes closed. (b) Activity correlated with V1: Voxels from the anatomically defined left V1 ROI exhibited significant correlated activity throughout the visual system and with the left medial Heschl’s gyrus. The sagittal sections displayed in (a) and (b) are from the left hemisphere. FDR P < 0.05, cluster extent P < 0.01. The color scale represents the t-scores. A1 = putative primary auditory cortex/Heschl’s gyrus; STG, superior temporal gyrus; MGN, medial geniculate nucleus.

Direct comparisons of correlated activity between auditory and visual cortex during the resting state as compared with the checkerboard tasks. (a) Correlated activity between auditory cortex and the entire V1 ROI: t-scores in the putative primary auditory cortex were derived from the functional connectivity results with the V1 ROI. Correlated activity was significantly reduced when subjects viewed the flashing checkerboard as compared with the resting-state task. (b) Correlated activity between auditory cortex and the anterior calcarine region identified in the resting-state analysis: t-scores in the peripheral V1 were extracted from the functional connectivity results with the Heschl’s gyrus ROI. There was no significant difference between the two tasks in this case. (c) The t-score map representing the correlation between the A1 ROI and visual cortex during the resting state task was subtracted from the t-score map representing the correlation between the A1 ROI and visual cortex during the visual task. This comparison was limited to the V1 ROI, as well as the anterior calcarine region significantly correlated with the A1 ROI during the resting state task. The blue-green regions are areas that showed decreases in correlated activity with the presentation of visual stimuli when compared with the resting state task (thresholded for t = −1.07, which represents P < 0.05 for a one-tailed t-test involving 14 subjects). Results for the left and right hemisphere A1 ROI analyses are presented together. Please note the relative decrease in t-score in posterior and middle calcarine regions in comparison with the anterior calcarine regions.