There seem to be a lot of brain studies related to music coming out these days. But have you ever wondered what it’s like to be a part of one? Natalie Angier of The New York Times participated in a new study on the effect of sounds on the brain…and gives us an inside look.
I’m not claustrophobic or fidgety. I love music, though I’m not a musician. For all the times I had written about neuroscience studies that rely on the brain-mapping technique called functional magnetic resonance imaging, or F.M.R.I., I had never seen a scan performed. This was my chance.
Take me, I begged Nancy Kanwisher, a professor of neuroscience at M.I.T. Take me through the experiment recently reported in the journal Neuron and show me where in the brain – my brain – the music-specific pathway resides. Let me lie in the dark, narrow chamber of the scanner with my head braced in place as I listen to a series of carefully selected sound clips.
I assured her the enclosed quarters would not make me panic. I promised I would give good, clean data, by remaining as still as roadkill and avoiding the little head wiggles that are the bane of F.M.R.I. research. Dr. Kanwisher agreed to my request, and I was ushered to the scanning room, in the basement, by Sam Norman-Haignere, a postdoctoral fellow and an author on the new report, who is thin and light-eyed and looks a little like a Renaissance troubadour, and Alex Kell, a graduate student with a cheerful smile and a blond beard.
A magnetic resonance imaging device uses radio waves and powerful magnetic fields to track blood flow in the brain, an indirect measure of neural activity. I was instructed to remove my boots, belt, earrings, anything metallic that might interfere with the magnetic coils. My titanium dental implants? I asked anxiously. Not to worry: They’d be fine.
And so, outfitted with customized, scanner-compatible headphones that would pipe in the sound clips and muffle the deafening clanks of the vibrating coils, I settled onto a gliding platform bed to be conveyed into the cylindrical bowels of the $3 million machine, and the experiment began.
For 90 minutes, I listened to 25 sound clips, each two-second “stimulus” played three times in a row, followed by the muted banging of the coils, a quiet interregnum, and then on to the next thrice-played clip.
After calculating the relative intensity of each voxel, or three-dimensional pixel, on the scan of the auditory portions of my brain, Dr. Norman-Haignere showed me the results. Inside a major groove, or sulcus, that runs through the auditory cortex, there was a “hot spot of music selectivity,” he said, above and a little forward of the ear. I had a second, smaller musical hot spot toward the back of my head, which at first I hoped was evidence of my exceptional musicality, until Dr. Norman-Haignere told me they saw a similar backup circuit in nearly half the subjects tested. My speech-specific hot spot sat just below my ear.
The researchers are now exploring the music pathway in greater detail. The first round of scanned subjects were, like me, nonmusicians. Does mastering an instrument make the hot spot burn brighter? They’ll be scanning children of different ages, to see when musical attentiveness first shows up in the brain. And what lies downstream of simple do-re-mi recognition? How do the music-perception pathways tap into the brain’s limbic system, to arouse great swells of joy, sorrow, yearning, excitement, as only music can do?