Sensitive Period for a Multimodal Response in Human Visual Motion Area MT/MST

• DOI: 10.1016/j.cub.2010.09.044
• Publication Date: 2010-10-22T08:33:27Z
• Authors: Marina Bedny; Talia Konkle; Kevin Pelphrey; Rebecca Saxe; Alvaro Pascual-Leone
• Keywords: Adult; Male; 0301 basic medicine; Brain Mapping; Agricultural and Biological Sciences(all); Biochemistry, Genetics and Molecular Biology(all); Age Factors; Motion Perception; Middle Aged; Blindness; 03 medical and health sciences; Acoustic Stimulation; Humans; Female; Visual Cortex

The middle temporal complex (MT/MST) is a brain region specialized for the perception of motion in the visual modality. However, this specialization is modified by visual experience: after long-standing blindness, MT/MST responds to sound. Recent evidence also suggests that the auditory response of MT/MST is selective for motion. The developmental time course of this plasticity is not known. To test for a sensitive period in MT/MST development, we used fMRI to compare MT/MST function in congenitally blind, late-blind, and sighted adults. MT/MST responded to sound in congenitally blind adults, but not in late-blind or sighted adults, and not in an individual who lost his vision between ages of 2 and 3 years. All blind adults had reduced functional connectivity between MT/MST and other visual regions. Functional connectivity was increased between MT/MST and lateral prefrontal areas in congenitally blind relative to sighted and late-blind adults. These data suggest that early blindness affects the function of feedback projections from prefrontal cortex to MT/MST. We conclude that there is a sensitive period for visual specialization in MT/MST. During typical development, early visual experience either maintains or creates a vision-dominated response. Once established, this response profile is not altered by long-standing blindness.