RT Journal Article
SR Electronic
T1 Tactile–Auditory Shape Learning Engages the Lateral Occipital Complex
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 7848
OP 7856
DO 10.1523/JNEUROSCI.3399-10.2011
VO 31
IS 21
A1 Jung-Kyong Kim
A1 Robert J. Zatorre
YR 2011
UL http://www.jneurosci.org/content/31/21/7848.abstract
AB Shape is an object property that inherently exists in vision and touch, and is processed in part by the lateral occipital complex (LOC). Recent studies have shown that shape can be artificially coded by sound using sensory substitution algorithms and learned with behavioral training. This finding offers a unique opportunity to test intermodal generalizability of the LOC beyond the sensory modalities in which shape is naturally perceived. Therefore, we investigated the role of the LOC in processing of shape by examining neural activity associated with learning tactile-shape-coded auditory information. Nine blindfolded sighted people learned the tactile–auditory relationship between raised abstract shapes and their corresponding shape-coded sounds over 5 d of training. Using functional magnetic resonance imaging, subjects were scanned before and after training during a task in which they first listened to a shape-coded sound transformation, then touched an embossed shape, and responded whether or not the tactile stimulus matched the auditory stimulus in terms of shape. We found that behavioral scores improved after training and that the LOC was commonly activated during the auditory and tactile conditions both before and after training. However, no significant training-related change was observed in magnitude or size of LOC activity; rather, the auditory cortex and LOC showed strengthened functional connectivity after training. These findings suggest that the LOC is available to different sensory systems for shape processing and that auditory–tactile sensory substitution training leads to neural changes allowing more direct or efficient access to this site by the auditory system.