Large-scale functional distinctions in object cortex are reflected in resting state networks

Konkle & Caramazza

Within the occipito-temporal cortex, object responses have a large-scale alternating organization related to two core dimensions of objects: animacy and real-world object size. To what extent is this large-scale functional organization of object responses related to differences in whole-brain network architecture?

Participants underwent functional neuroimaging in which brain responses were recorded during (1) stimulus presentations of big and small animal and object images, and (2) resting state.

We found large cortical zones with response preferences for either big objects, animals, or small objects, arranged in a spoked organization around the occipital pole, duplicated on the ventral and lateral surface of occipito-temporal cortex.

Critically, regions with similar functional preferences were also more correlated with each other at rest than with the spatially proximate regions (t(11)=2.2, p<0.05), and this was also reflected in the correlation of the whole-brain networks (t(11)=2.7, p<0.05).

Specifically, the two animate regions on the ventral and lateral surfaces (Fusiform, LO) were more correlated with each other than with adjacent big-object zones along ventral and lateral surface (PHC-parahippocampal, TOS-transverse occipital sulcus), and the same relationship held for the the big object regions. The small object zone (inferior temporal gyrus), was more correlated with the big object zones than the with adjacent animate regions, preserving the inanimate distinction.

Thus, the large-scale organization of object response preferences across occipito-temporal is also evident in the structure of the neural correlations during rest. To the extent that resting state correlations reflect direct and indirect long-range connectivity, these results raise the intriguing possibility that the large-scale functional organization of object responses is in part caused by differences in whole-brain network architecture.

Konkle, T., & Caramazza, A. (2013). Large-scale functional distinctions in object cortex are reflected in resting state networks. Poster presented at the annual meeting of the Vision Sciences Society, May 12-15, Naples, FL.