Auditory imagery

In psychology and neuropsychology, auditory imagery is the subjective experience of hearing in the absence of auditory stimulation. It occurs when one mentally rehearses telephone numbers, or has a song "on the brain": the phenomenon is usually defined to be spontaneous (that is, not under direct conscious control); it can be distressing. Auditory imagery is used by neuropsychologists for investigating aspects of human cognition.

Writing in Nature, David J. M. Kraemer and coworkers use magnetic resonance imaging to determine whether the auditory cortex is recruited during auditory imagery of popular music.

Kraemer played excerpts of songs with lyrics (including Satisfaction by the Rolling Stones), and to instrumentals that contained no lyrics (including the theme from The Pink Panther).

Each subject rated each piece of music as either familiar or unknown. The music was then played to the subjects, but with short (2-5 seconds portions of the track replaced with silent gaps of equal length. The neural activity in the subjects was then monitored during these gaps.

Kraemer then compared neural activity in the Brodmann area of the brain during gaps in familiar music with activity during gaps in unfamiliar music (auditory imagery being assumed to occur during gaps in the familiar music but not in the unfamiliar music). Silent gaps embedded in familiar songs induced greater activation in auditory association areas than did silent gaps embedded in unknown songs, indicating that auditory imagery has elements in common with visual imagery.

This research thus suggests a neural basis for the familiar experience of hearing a familiar melody in one's head. Kraemer emphasises the obligatory nature of the phenomenon: muting short gaps of familiar music was sufficient to trigger auditory imagery.

Reference

 * Nature 434, 158 (10 March 2005); doi:10.1038/434158a