Magnetic Brain Stimulation Could Jog Memory

Some hopeful news for people who can’t remember where they put the keys, or the name of a person they just met – scientists say brain stimulation could help jog people’s memories.

In addition, this type of mental stimulation could help people with mental illnesses, including schizophrenia or depression, they say.

“A lot of mental illness is associated with the inability to choose what to think about,” says Brad Postle, a psychology professor at the University of Wisconsin-Madison. “What we’re taking are first steps toward looking at the mechanisms that give us control over what we think about,” he adds.

Postle’s team is challenging the idea that working memory remembers things through sustained brain activity.

They caught brains tucking less-important information away somewhere beyond the reach of the tools that typically monitor brain activity — and then they snapped that information back into active attention with magnets.

Postle’s group conducted a series of experiments in which people were asked to remember two items representing different types of information (they used words, faces and directions of motion) because they’d be tested on their memories.

When the researchers gave their subjects a cue as to the type of question coming — a face, for example, instead of a word — the electrical activity and blood flow in the brain associated with the word memory disappeared.

But if a second cue came letting the subject know they would now be asked about that word, the brain activity would jump back up to a level indicating it was the focus of attention.

The researchers were also able to bring the seemingly abandoned items back to mind without cueing their subjects by using transcranial magnetic stimulation (TMS), which is a noninvasive procedure that uses magnetic fields to stimulate nerve cells in the brain to improve symptoms of depression.

Using TMS to apply a focused electromagnetic field to a precise part of the brain involved in storing the word, they could trigger the sort of brain activity representative of focused attention.

Furthermore, if they cued their research subjects to focus on a face (causing brain activity associated with the word to drop off), a well-timed pulse of TMS would snap the stowed memory back into attention, and prompt the subjects to incorrectly think that they had been cued to focus on the word, they say of the study, which appears in the journal Science.