Abstract
OBJECTIVE: Developmental prosopagnosia is a disorder of face recognition. Recent work has shown differences between those with prosopagnosia and controls in matter connectivity of the inferior longitudinal fasciculus. Amusia is another developmental disorder which has been shown to have grey matter abnormalities in non-primary perisylvian regions and is associated with white matter connectivity in the arcuate fasciculus (Loui et al, 2009). Based on anecdotal reports of some subjects, we hypothesized that there may be instances in which these two disorders overlap. METHOD: Eight subjects with prosopagnosia were compared to healthy controls on three measures. The Montreal Battery of Evaluation of Amusia examined melodic organization, temporal organization, and memory. Subjects also completed pitch discrimination and beat perceptual threshold tasks (Loui et al., 2009; Fujii & Schlaug, 2014). RESULTS: On the Montreal Battery of Evaluation of Amusia, the prosopagnosic sample was impaired relative to normative data on their overall score [p< 0.01] as well as pitch interval perception [p< 0.0001]. At the individual level, 3 subjects were impaired on scale (1), contour (2), interval (3), meter (1), and memory (1). While the prosopagnosia group was not impaired on the pitch discrimination task, there was a group difference on the rhythm perception task and 4 of the subjects with prosopagnosia performed at least 2 s.d. outside of the control mean. DISCUSSION: At least some cases of developmental prosopagnosia also show deficits found in congenital amusia. This association could be explained by a common structural cause, such as a focal cortical migration disorder or aberrant white matter connectivity. Whether this is a primary white matter disconnection or secondary to a cortical migration disorder is not yet clear. Future work will include high resolution MRI to reveal neural substrates that are common between both disorders to determine the anatomic substrate of this behavioral observation.
Meeting abstract presented at VSS 2016