Linguists have argued about the neurological bases of speech and music for a long time, with most evidence and argumentation coming from anthropology and evolution – all cultures produce music, all cultures have language – these adaptations must be good for something. Noted neuroscientist and linguist Steven Pinker, for example, has called music “auditory cheesecake,” assuming it to be an outgrowth of the human capacity for language. Others, like the late Dr. Oliver Sacks, believed it to be its own uniquely human adaptation.
Until now, there has been scant evidence of a neurological structure designed to process music inside the human brain. Excitingly, a just-released study by Nancy Kanwisher, Josh H. McDermott, and Sam Norman Haignerea at M.I.T. has provided some very strong evidence that Dr. Sacks was right. In an article in the journal Neuron, the researchers describe a neural apparatus, a regular pathway of neural activations in the auditory cortex, that they claim is responsible for processing music.
The methodology is interesting – researchers gathered a library of samples of all types of commonly recognized sounds, from non-musical interrupts like a barking dog or a toilet flushing to the work of Bach. FMRI readings were gathered from 10 subjects (brainscan studies tend to have frustratingly low numbers of subjects) as a loop of 162 sounds played through for them. The sounds were played more than once per subject to establish that the same brainscan patterns obtained for the same sounds in the same person over time.
The results were categorical and conclusive. As in the visual cortex, where the brain seems hard-wired to recognize certain patterns, such as a human face, the auditory cortex is specially equipped to process different categories of information. In addition to a pathway for processing music, the researchers confirmed existing evidence for a separate pathway for the processing of regular (non-musical) human speech. In all, the researchers identified six distinctive pathways. In addition to the two for music and speech, the other four allow the brain to process discrete properties of sound like pitch.
Much work remains, but it’s exciting to have the musical world win this one – it’s been my perception that much of the linguistic world has viewed speech as more fundamental than music. The New York Times article by Natalie Angier in which I found this study written up allows a researcher to muse further, “There are theories that music is older than speech or language,” [Georgetown’s Dr. Rauschecker] said. “Some even argue that speech evolved from music.”
Only time will tell.
Thanks for reading.