Thawing out brain freeze

Embarrassing memory lapses are everyday occurrences, but why do they happen and can they be prevented, writes TARA PARKER-POPE

SOMETIMES EVEN a healthy brain doesn’t work the way it is supposed to. Nobody may know that better than Rick Perry, the Texas governor, who suffered an embarrassing memory lapse during the US Republican presidential debate last week.

Perry stopped mid-sentence as he struggled to remember the name of the Department of Energy, one of three federal agencies he has often said should be eliminated. A pained look crossed his face. He stammered. He started over. He changed the subject. But the words did not come.

How the gaffe will affect Perry’s political aspirations is not known. But among brain researchers, the moment is a fascinating display of a common human experience: the brain freeze.

“There are a lot of potential explanations for why it happened,” says Daniel Weissman, a University of Michigan neuroscientist who studies attention. “A lot of things are going on when we try to recall memories, and problems at any stage could lead to failure.”

Perry is hardly the first public figure to suffer an embarrassing memory lapse. US chief justice John G Roberts jnr misplaced a word in the oath at the swearing-in ceremony for president Barack Obama, prompting him to administer the oath again the next day.

Brain researchers note that people have memory lapses like these every day, whether it is walking into a room and forgetting why they are there or being unable to recall a name that is on the tip of the tongue. Some memories, like a child’s birthday, are so strong that recalling them is effortless.

But when the information is relatively new or used less often, people must rely on the brain’s ability to strategically search their memories for hard-to-retrieve data.

During this process, the brain’s prefrontal cortex is engaged, and interacts with the medial temporal lobe, the part of the brain that forms and retrieves memories of facts and events.

When all goes well, the medial temporal lobe acts like a library’s card catalogue system, pointing to the locations in the brain where different parts of the memory are stored and allowing the memory to be recalled.

But in Perry’s case, it appears that something went wrong, and the search turned up the wrong card or looked in the wrong place or was interrupted.

The culprit could have been distraction, experts say. Just before the gaffe, Perry looked directly at his opponent Ron Paul, which suggests the glance may have disrupted his train of thought. Or it is possible that Perry’s mind may have started moving ahead to his next point too quickly, leaving him muddled in the moment.

Stress also can impair the function of the hippocampus, which is involved in memory retrieval.

“Trying desperately to fulfil the promise you made at the beginning of your utterance, then, under the bright lights, with the stakes still very high and getting higher, stress bad and only getting worse, the time late and getting ever later, grasping for straws offered to you by your competitors in a debate – the problem is only compounded,” says Neal J Cohen, a University of Illinois professor of psychology who studies human learning and memory.

Another possibility is that Perry has had other budget-cutting conversations with his campaign strategists, and those memories were interfering with his ability to recall the details of his current plan.

Such interference from past memories occurs, for example, when a person is leaving a supermarket and staring at a sea of vehicles in the car park, and realises he has forgotten where he parked.

“As you search in your memory, there are all these very similar memories of parking at the grocery store that are interfering with each other,” says Weissman.

“If there had been discussions of cutting other departments, it’s possible that there was somehow interference from those memories, and that’s why he couldn’t recall it.”

Recent brain research has used functional magnetic resonance imaging scans to watch brain activity during lapses of attention during a monotonous task.

The real-world equivalent would be driving along the highway, only to discover you have driven well past your exit. The research suggests that during familiar tasks, a brain region called the default mode network kicks in and the brain gets lazy.

“We think that it gets lazier – or less diligent – with respect to the external task because it thinks it knows what is going happen next,” says Tom Eichele, a neurophysiologist at the University of Bergen in Norway.

Whether it was stress, competing memories or distraction that caused Perry’s brain freeze, it’s clear that he’s not alone. “I thought it was a pretty everyday experience,” Weissman says. “We’ve all had this happen.”

– (New York Times)