Close Your Eyes and I’ll…

Every young neuroscience student learns about a classic experiment that was published in 1956 by Raul Hernandez-Peon, in which he had an electrode in the acoustic nerve of a cat, while a metronome was ticking. Every tick caused a pulse of electricity in the nerve. But as soon as the cat saw or smelled a mouse, the electrical activity plummeted: now all of his attention was on lunch, and his brain damped down the unnecessary ticking of the metronome. Something similar happens with the “Cocktail Party Phenomenon:” our ability to focus our listening attention on a single talker and ignoring other conversations that are going on.

A study by researchers from Wake Forest University Baptist Medical Center and the University of North Carolina was presented at the Society for Neuroscience conference in San Diego this week, suggesting that our brains can turn down our ability to see, so that we are better able to listen and focus on music and complex sounds.

The research used functional Magnetic Resonance Imaging in 20 non-musicians and 20 musical conductors aged 28-40, and found that both groups diverted brain activity away from visual areas during listening tasks. The activity fell in the visual regions areas as it rose in auditory ones. But during harder tasks the changes were less marked for conductors than for non-musicians.

While being scanned the subjects were asked to listen to two different musical tones played a few thousandths of a second apart and identify which was played first. The task was made harder for the professional musicians than for the non-musicians, to allow for the differences in their background.

As the task was made progressively more difficult, the non-musicians carried on diverting more and more activity away from the visual parts of the brain to the auditory, as they struggled to concentrate on the music. However, the conductors did not suppress their brains, suggesting that their years of training had given them an advantage in the way that their brains were organized and functioning. They are less likely to be distracted and are highly tuned to musical sounds.

This is like closing your eyes to listen to music and the advantage of the trained musicians is similar to the advantage that we see in the brain of the chess master compared with the amateur. Years of study and practice enable the chess player to move without much conscious thought.

It shows how well we are able to divert activity from one part of the brain to another as needed. It is that ability to be flexible and to recruit more brain when we need it that lies at the heart of the neurocognitive revolution that is changing the way that we think about the brain and mind.