Category-selective functional connectivity during episodic encoding and retrieval in younger and older adults
Regions within ventral occipito-temporal cortex exhibit category-selective BOLD responses during episodic encoding and retrieval of visual information. How these regions interact with other brain areas during successful encoding and retrieval, and whether these interactions relate to memory performance, remains unclear. The present study examined category-selective functional connectivity using psychophysiological interaction (PPI) analyses in younger and older adults during the encoding and retrieval of word-image associations. Seed regions comprised three scene-selective regions - the parahippocampal place area, medial place area, and occipital place area - and one object-selective region, the lateral occipital complex (LOC). During encoding, scene-selective regions exhibited greater connectivity with posterior occipital and occipitotemporal regions during scene relative to object encoding, whereas the LOC exhibited less extensive connectivity with similar posterior regions during object encoding. During retrieval, both scene- and object-selective regions demonstrated increased connectivity with left lateral prefrontal and parietal cortices during the retrieval of their preferred category. Age differences in scene-selective connectivity were evident at both phases. Moreover, associations between source memory performance and scene-selective connectivity were significant only in younger adults. These findings suggest that scene- and object-selective regions exhibit convergent patterns of functional connectivity during encoding and retrieval which, for scenes, vary with age.