A Society for Neuroscience news release (pointed out to me by colleague Robin Chapman) focuses on a new imaging study that shows that when we learn a new action with associated sounds, the brain quickly makes links between regions responsible for performing the action and those associated with the sound. The findings may contribute to understanding how we acquire language and how we think of actions if we only hear their sounds. Lahav et al. taught nine subjects with no previous musical training to play a five-note, 24-second song on a keyboard. Then they ran functional magnetic resonance imaging (fMRI) scans while the subjects listened to the song they had just learned, a different song using the same five notes, and a third song made up of additional notes. From Lahav et al.'s abstract: "Although subjects listened to the music without performing any movements, activation was found bilaterally in the frontoparietal motor-related network (including Broca's area, the premotor region, the intraparietal sulcus, and the inferior parietal region), consistent with neural circuits that have been associated with action observations, and may constitute the human mirror neuron system. Presentation of the practiced notes in a different order activated the network to a much lesser degree, whereas listening to an equally familiar but motorically unknown music did not activate this network. These findings support the hypothesis of a "hearing–doing" system that is highly dependent on the individual's motor repertoire, gets established rapidly, and consists of Broca's area as its hub."
Figure 1. Action–listening illustration. A, Music performance can be viewed as a complex sequence of both actions and sounds, in which sounds are made by actions. B, The sound of music one knows how to play can be reflected, as if in a mirror, in the corresponding motor representations.
Figure 2. Action–listening activation. A, B, Extensive bilateral activation in the frontoparietal motor-related brain regions was observed when subjects listened to the trained-music they knew how to play (A), but not when they listened to the never-learned untrained-different-notes-music (B). C, Activation maps are shown in areas that were significantly more active during listening to the trained-music versus the untrained-different-notes-music. L, Left; R, right.