Temporal patterns of human cortical activity reflect tone sequence structure

Despite growing interest in temporal aspects of auditory neural processing( 1,2), little is known about large-scale timing patterns of brain activity d uring the perception of auditory sequences(3). This is partly because it ha s not been possible ro distinguish stimulus-related activity from other, en dogenous brain signals recorded by electrical or magnetic sensors. Here we use amplitude modulation of unfamiliar, unfamiliar, similar to 1-minute-lon g tone sequences to label stimulus-related magnetoencephalographic neural a ctivity in human subjects(4-9). We show that temporal patterns of activity recorded over particular brain regions track the pitch contour of tone sequ ences, with the accuracy of tracking increasing as tone sequences become mo re predictable in structure. In contrast, temporal synchronization between recording locations, particularly between sites over the left posterior hem isphere and the rest of the brain, is greatest when sequences have melody-l ike statistical properties(10,11) which may reflect the perceptual integrat ion of local ant; global pitch patterns in melody-like sequences(12). This method is particularly well suited to studying temporal neural correlates o f complex auditory sequences (such as speech or music) which engage multipl e brain areas as perception unfolds in time.