Auditory perception - time and rhythms
Slow cortical rhythmic activity may be a crucial determinant of auditory perception. Electrical imaging studies show that slow oscillations entrains to the rhythmic structure of naturalistic sounds such as speech. Assuming that slow oscillations also reflect changes in the excitation-inhibition balance of local cortical networks this suggests that the auditory system may sample the environment in a rhythmic, rather than continuous mode. Our recent work provides direct evidence for this, along two lines. First, in a human imaging study (EEG) we find that the subjects perception of a brief acoustic target depends on the alignment of this with the ongoing oscillatory activity. And second, in studies of single neurons in auditory cortex we find that their temporal sensitivity profiles show key evidence of periodic temporal sampling. This evidence will be discussed in the light of similar work in other sensory modalities and the rising popularity to study oscillatory activity in the auditory system.