In a review article in the October 2005 Nature Reviews Neuroscience, Buhusi and Meck discuss the current state of understanding of one of the brain's most important, and mysterious, clocks -- the one governing timing intervals in the seconds to minutes range. Such interval timing occupies the middle neurological ground between two other clocks -- the circadian clock that operates over the 24-hour light-dark cycle, and the millisecond clock that is crucial for such functions as motor control and speech generation and recognition. Meck is a professor and Buhusi is an assistant research professor in the Department of Psychological and Brain Sciences.
Interval timing is central to broader coordination of tasks such as walking, manipulating objects, carrying on a conversation and tracking objects in the environment, they said.
"Interval timing is necessary for us to understand temporal order of events, for example when carrying on a conversation," said Meck. "To understand speech, I not only have to process the millisecond intervals involved in voice onset time, but also the duration of vowels and consonants. Also, to respond, I need to process the pacing of speech, to organize my thoughts coherently and to respond back to you in a timely manner. That's all interval timing, and in fact it's hard to find any complex behavioral process that timing isn't involved in."
Deciphering the neural mechanisms of such clocks may be even more fundamental to understanding the brain than figuring out, for example, neural processing of spatial position and movement, they said.