Anne Trafton, MIT News Office
October 20, 2009
Keeping track of time is one of the brain’s most important tasks. As the brain processes the flood of sights and sounds it encounters, it must also remember when each event occurred. But how does that happen? How does your brain recall that you brushed your teeth before you took a shower, and not the other way around?
For decades, neuroscientists have theorized that the brain “time stamps” events as they happen, allowing us to keep track of where we are in time and when past events occurred. However, they couldn’t find any evidence that such time stamps really existed — until now.
An MIT team led by Institute Professor Ann Graybiel has found groups of neurons in the primate brain that code time with extreme precision. “All you do is time stamp everything, and then recalling events is easy: you go back and look through your time stamps until you see which ones are correlated with the event,” she says.