Structural properties of white matter circuits necessary for face perception

Suzy Scherf

(Penn State)

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Date: May 16, 2014

Description:

White matter tracts, which communicate signals between cortical regions, reportedly play a critical role in the implementation of perceptual functions. We examine this claim by evaluating structural connectivity, and its relationship to neural function, in the domain of face recognition in both developing individuals and those with face recognition deficits. In all studies, we derived the micro- as well as macro-structural properties of the inferior longitudinal fasciculus (ILF) and of the inferior fronto-occipital fasciculus (IFOF), which connect distal regions of cortex that respond preferentially to faces. In participants aged 6-23 years old, we observed age-related differences in both the macro- and micro-structural properties of the ILF. Critically, these differences were specifically related to an age-related increase in the size of the functionally defined fusiform face area. We then demonstrated the causal nature of the structure-function relationship in individuals who are congenitally prosopagnosic (CP) and in an aging population (who exhibits an age-related decrement in face recognition). The CPs exhibited reduced volume of the IFOF and ILF, which was related to the severity of their face processing deficit. Similarly, in the older population there were also significant reductions in the structural properties of the ILF and IFOF that were related to their behavioral performance. Finally, we are exploring whether individual differences in face-processing behavior of normal adults are related to variations in these structure-function relations. This dynamic association between emerging structural connectivity, functional architecture and perceptual behavior reveals the critical role of neural circuits in human cortex and perception.

Further Information:

Co-Authors: Marlene Behrmann, Carnegie Mellon University; Cibu Thomas, NIH; Galia Avidan, Beer Sheva University; Dan Elbich, Penn State University




Created: Friday, May 23rd, 2014