Merriam-Webster's defines a time warp as a "discontinuity, suspension or anomaly" in the otherwise normal passage of time; this year all three terms could apply. It seems like March happened 10 years ago; everyday may as well be Wednesday, and still, somehow, here come the holidays — fast, just like every year.
Brain science has something to say about the relationship between perceived time and the Greenwich Mean variety, and why the two may slip out of sync. A research team based in Dallas reported the first strong evidence to date of so-called "time cells" in the human brain. The finding, posted by the journal PNAS, was not unexpected: In recent years, several research groups have isolated neurons in rodents that track time intervals. It's where the scientists look for these cells, and how they identified them, that provide some insight into the subjective experiences of time.
In the new study, a team led by Dr. Bradley Lega, a neurosurgeon at UT Southwestern Medical Center, analyzed the firing of cells in the medial temporal area, a region deep in the brain that is essential for memory formation and retrieval. Memories must be somehow "time-stamped" to retain some semblance of chronological order.
The team took recordings from 27 people with epilepsy, who were being monitored for surgery; the monitoring requires a few weeks' stay in the hospital, with electrodes implanted through the skull and into the brain. And the medial temporal lobes, located about an inch in from the ears, are almost always monitored, as they are a common source of those seizures.
The researchers found that certain neurons fired during a specific window of the free-recall period — from two to five seconds in. This firing was related only to time. And when those particular cells fired more precisely in a person's temporal sweet spot, he or she did well on the recall, and remembered words close to the order in which they were presented. "These cells are encoding information related to time," Lega said.
There is no constant rhythm or background beat; the time signal is conjured as needed. "There's no internal metronome, or clock," he said. The time cells are "firing to support what you're doing."