Background
We encounter differing rates of sound each day that are important in the perception of the more complex acoustic conditions. Since repetition rate plays a fundamental role in determining how sounds are heard, it is not surprising that there have been numerous neurophysiological studies of rate in animals. Broad trends concerning the coding of rate in the auditory pathway have emerged from this work. For instance, the highest repetition rates at which neurons respond faithfully to each successive sound in a train (or each successive cycle of amplitude modulated stimuli) tends to decrease from brain stem to thalamus to cortex.
While animal studies have shed light on the neural representations of repetition rate, the degree to which the animal findings are related to humans' remains uncertain because of interspecies differences, anesthesia differences, and a paucity of data in humans that can serve as a link to the animal work. In the end, direct neurophysiological data in human listeners is important to understand how repetition rate is represented in the activity patterns of the human brain.
Most previous neurophysiological studies of repetition rate in humans have used noninvasive techniques for probing brain function, such as evoked potential and evoked magnetic field measurements. A limitation of this line of research is that the sites of response generation cannot always be reliably localized. Evoked magneti
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Contact: Donna Krupa
djkrupa1@aol.com
703-527-7357
American Physiological Society
12-Nov-2002