It’s something you often hear – or see in movies – blind people have better hearing. But is this correct? This study by Sabourin and colleagues, which I found via Dan Willingham, wants to answer this question once and for all. And the answer is:
There is now overwhelming evidence that early-blind individuals do indeed possess hearing abilities that are superior to sighted people. The combination of auditory psychophysical investigations and functional imaging studies has identified that specific, rather than general, auditory enhancements in the early blind can be linked to activation in extrastriate visual cortex, providing evidence of crossmodal plasticity. Furthermore, areas of visual cortex demonstrating increased activation during the performance of either spatial or feature acoustic tasks in the early blind align well with the trajectory of the dorsal and ventral visual processing streams, respectively. Whether the ventral auditory and visual stream remain functionally distinct or adjoin as a single processing pathway following vision loss remains unclear. Finally, many visual areas appear to preserve their functional specificity following blindness despite adapting to auditory input, suggesting that the cortex can either adapt to a range of cognitive functions or is organized based on specific functions rather than by sensory input.
Abstract of the study:
For centuries, anecdotal evidence such as the perfect pitch of the blind piano tuner or blind musician has supported the notion that individuals who have lost their sight early in life have superior hearing abilities compared with sighted people. Recently, auditory psychophysical and functional imaging studies have identified that specific auditory enhancements in the early blind can be linked to activation in extrastriate visual cortex, suggesting crossmodal plasticity. Furthermore, the nature of the sensory reorganization in occipital cortex supports the concept of a task-based functional cartography for the cerebral cortex rather than a sensory-based organization. In total, studies of early-blind individuals provide valuable insights into mechanisms of cortical plasticity and principles of cerebral organization.