OPTIMIZING SOUND FEATURES FOR CORTICAL-NEURONS

The brain's cerebral cortex decomposes visual images into information about oriented edges, direction and velocity information, and color. H ow does the cortex decompose perceived sounds? A reverse correlation t echnique demonstrates that neurons in the primary auditory cortex of t he awake primate have complex patterns of sound-feature selectivity th at indicate sensitivity to stimulus edges in frequency or in time, sti mulus transitions in frequency or intensity, and feature conjunctions. This allows the creation of classes of stimuli matched to the process ing characteristics of auditory cortical neurons. Stimuli designed for a particular neuron's preferred feature pattern can drive that neuron with higher sustained firing rates than have typically been recorded with simple stimuli. These data suggest that the cortex decomposes an auditory scene into component parts using a feature-processing system reminiscent of that used for the cortical decomposition of visual imag es.