(Santa Barbara, Calif.) You pick up your cell phone and dial the new number of a friend. Ten numbers. One. Number. At. A. Time. Because you haven't actually typed the number before, your brain handles each button press separately, as a sequence of distinct movements.
After dialing the number a few more times, you find yourself typing it out as a series of three successive bursts of movement: the area code, the first three numbers, the last four numbers. Those three separate chunks allow you to type the number faster, and with greater precision. Eventually, dialed often enough, the number is stored in your brain as one chunk. Who needs speed dial?
"You can think about a chunk as a rhythm," said Nicholas Wymbs, a postdoctoral researcher in UC Santa Barbara's Department of Psychological and Brain Sciences, and the lead author of a new study on motor chunking in the journal Neuron, published by Cell Press. "We highlight the two-part process that seems to occur when we are chunking. This is demonstrated by the rhythm we use when typing the phone number: rapid bursts of finger movements that are interspersed by pauses."
The rhythm is the human brain taking information and processing it in an efficient way, according to Wymbs. "On one level, the brain is going to try to divide up, or parse, long sequences of movement," he said. "This parsing process functions to group or cluster movements in the most efficient way possible."
But it is also in our brain's best interest to assemble single or short strings of movements into longer, integrated sequences so that a complex behavior can be made with as little effort as possible. "The motor system in the brain wants to output movement in the most computational, low-cost way as possible," Wymbs said. "With this integrative process, it's going to try to bind as many individual motor movements into a fluid, uniform movement as it possibly can."
The two processes are at odd
|Contact: George Foulsham|
University of California - Santa Barbara