Causal influences between spontaneous fluctuations in resting state fMRI of central and peripheral eccentricity representations in the human visual cortex

Functional magnetic resonance imaging (fMRI) is widely used to study and understand interactions between brain structures. The purpose of our work is to examine contemporaneous relationships between central and peripheral eccentricity signals within and between visual areas of the human visual cortex to better understand functional connectivity in this region of human brain. Indeed, based on the analysis of a large set of fMRI signals, it was concluded that there is only a limited connectivity between central and peripheral eccentricity bands within the first and second visual areas; but, there is no evidence of connectivity between those eccentricity bands within the third visual area. In addition, it was found that the effects of central eccentricity signals on peripheral ones are extremely large in visual areas V1 and V2. Conversely, the effects of peripheral eccentricity bands on central ones are small in all visual areas. The obtained results are a further step toward understanding the organization of spontaneous activity in visual cortical regions of the human brain.