fMRI Study Shows Brain Training Effective, but Only for Task at Hand

US physiologists are now saying they do seem to work, but there is a drawback.

The drawback, according to Dr. Elliot T. Berkman, a professor in the department of psychology at the University of Oregon (UO; Eugene, USA), and lead author on a study published in the January 1, 2014, issue of the Journal of Neuroscience, is that training for a specific task does enhance performance, but that advantage does not necessarily carry over to a new challenge.

The training provided in the study caused a proactive shift in inhibitory control. However, it is not certain if the improvement attained extends to other types of executive function such as working memory, because the researchers’ only focus was on inhibitory control, according to Dr. Berkman, who directs the psychology department’s social and affective neuroscience lab. “With training, the brain activity became linked to specific cues that predicted when inhibitory control might be needed,” he said. “This result is important because it explains how brain training improves performance on a given task--and also why the performance boost doesn’t generalize beyond that task.”

Sixty participants (27 male and 33 females aged 18–30) were involved in a three-phase study. Change in their brain activity was monitored with functional magnetic resonance imaging (fMRI) scanning. Half of the subjects were in the research group that was trained with a task that models inhibitory control—one kind of self-control—as a race between a “go” process and a “stop” process. A faster stop process indicates more efficient inhibitory control.

In each of a series of trials, study participants were given a “go” signal—an arrow pointing left or right. The individuals pressed a key corresponding to the direction of the arrow as quickly as possible, launching the go process. However, on 25% of the trials, a beep sounded after the arrow appeared, signaling participants to withhold their button press, initiating the stop process. Participants practiced either the stop-signal task or a control task that did not affect inhibitory control every other day for three weeks. Performance improved more in the training group than in the control group.

Neural activity was monitored using functional magnetic resonance imaging (fMRI), which captures changes in blood oxygen levels, during a stop-signal task. MRI scanning was performed in the UO’s Robert and Beverly Lewis Center for Neuroimaging. Activity in the inferior frontal gyrus and anterior cingulate cortex—brain areas that control inhibitory control—decreased during inhibitory control but increased immediately before it in the training group more than in the control group.

Brain training works, but just for the practiced task. The fMRI findings identified three regions of the brain of the trained subjects that showed changes during the task, prompting the researchers to hypothesize that emotional regulation may have been improved by reducing distress and frustration during the trials. Overall, the size of the training effect is small. A challenge for future research, they concluded, will be to identify protocols that might generate greater positive and lasting effects.

“Researchers at the University of Oregon are using tools and technologies to shed new light on important mechanisms of cognitive functioning such as executive control,” said Kimberly Andrews Espy, vice president for research and innovation and dean of the UO Graduate School. “This revealing study on brain training by Dr. Berkman and his team furthers our understanding of inhibitory control and may lead to the design of better prevention tools to promote mental health.”

These findings add to a growing body of studies that are exploring the impact of brain-training programs, according to the investigators.

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