Feel the Noise: Relating individual differences in auditory imagery to the structure and function of sensorimotor systems
Lima, C. F., Lavan, N., Evans, S., Agnew, Z., Halpern, A. R., Shanmugalingam, P., Meekings, S., Boebinger, D., Ostarek, M., McGettigan, C., Warren, J. E., & Scott, S. K.
Feel the Noise: Relating individual differences in auditory imagery to the structure and function of sensorimotor systems. Cerebral Cortex., 2015
(25), 4638-4650. doi:10.1093/cercor/bhv134.
Humans can generate mental auditory images of voices or songs, sometimes perceiving them almost as vividly as perceptual
experiences. The functional networks supporting auditory imagery have been described, but less is known about the systems
associated with interindividual differences in auditory imagery. Combining voxel-based morphometry and fMRI, we
examined the structural basis of interindividual differences in how auditory images are subjectively perceived, and explored
associations between auditory imagery, sensory-based processing, and visual imagery. Vividness of auditory imagery
correlated with gray matter volume in the supplementary motor area (SMA), parietal cortex, medial superior frontal gyrus, and
middle frontal gyrus. An analysis of functional responses to different types of human vocalizations revealed that the SMA and
parietal sites that predict imagery are also modulated by sound type. Using representational similarity analysis, we found that
higher representational specificity of heard sounds in SMA predicts vividness of imagery, indicating a mechanistic link
between sensory- and imagery-based processing in sensorimotor cortex. Vividness of imagery in the visual domain also
correlated with SMA structure, and with auditory imagery scores. Altogether, these findings provide evidence for a signature
of imagery in brain structure, and highlight a common role of perceptual–motor interactions for processing heard and
internally generated auditory information.