What's the Best Sound?

The neurons of the brain that first receive input from the senses detect elementary features--such as lines or movement--and then relay that information to the next higher stage of sensory processing, where more complex features are assembled. This principle was established based on work in the visual pathway, and now a report in this issue ([ deCharms et al. ][1]) describes a method to determine the elementary features for the auditory system. As Young explains in his commentary, a neuron exposed to a broad array of chords can pick out the relevant ones and respond only to them, defining for the researcher its own optimal stimulus. [1]: http://www.sciencemag.org/cgi/content/short/280/5368/1439