The concept of auditory stimulus representation in cognitive neuroscience

The sequence of neurophysiological processes elicited in the auditory syste m by a sound is analyzed in search of the stage at which the processes carr ying sensory information cross the borderline beyond which they directly un derlie sound perception. Neurophysiological data suggest that this transiti on occurs when the sensory input is mapped onto the physiological basis of sensory memory in the auditory cortex. At this point, the sensory informati on carried by the stimulus-elicited process corresponds, for the first time , to that contained by the actual sound percept. Before this stage, the sen sory stimulus code is fragmentary, lacks the time dimension, cannot enter c onscious perception, and is not accessible to tap-down processes (voluntary mental operations). On these grounds, 2 distinct stages of auditory sensor y processing, prerepresentational and representational, can be distinguishe d.