Aging reduces neural specialization in ventral visual cortex

Abstract

The present study investigated whether neural structures become less functionally differentiated and specialized with age. We studied ventral visual cortex, an area of the brain that responds selectively to visual categories (faces, places, and words) in young adults, and that shows little atrophy with age. Functional MRI was used to estimate neural activity in this cortical area, while young and old adults viewed faces, houses, pseudowords, and chairs. The results demonstrated significantly less neural specialization for these stimulus categories in older adults across a range of analyses.

Fig. 1.

Examples of stimuli from the categories of faces, houses, chairs, pseudowords, and phase-scrambled versions of the same stimuli (which served as control).

Fig. 2.

Mean t values as a function of age and stimulus category. (Top) The 10 voxels most activated by faces, places, pseudowords, and chairs. (Middle) The 15 voxels most activated by faces, places, pseudowords, and chairs. (Bottom) The 20 voxels most activated by faces, places, pseudowords, and chairs.

Fig. 3.

Mean t values as a function of age and stimulus category in the 10 voxels most active in the fusiform face area (Left), the parahippocampal place area (Center), and the left fusiform word form area (Right).

Fig. 4.

Dedifferentiation score for each category type. A higher number reflects more dedifferentiation.