Brief 'Brain Training' Rapidly Boosts Neural Networks

Damian McNamara

June 26, 2019

Healthy volunteers who imagined moving their hands in a specific way during real-time functional magnetic resonance imaging (fMRI) neurofeedback showed white matter changes and enhanced communication between brain regions in as little as 1 hour, new research shows.

The study is the first to demonstrate that 'brain training' can prompt changes in white matter fractional anisotropy — a measure of myelination in the brain — and shows just how rapidly neuroplasticity occurs.

"We were happy to be able to identify changes in less than 1 hour. We designed the study to detect such changes, but we did not have high expectations when we started," study investigator Fernanda Tovar-Moll, MD, PhD, of the Brain Connectivity Unit at the D'Or Institute for Research and Education and Federal University of Rio de Janeiro, Brazil, told Medscape Medical News.

"Our study is about neuroplasticity. The take-home message is we can induce and measure changes in the brain in real time," she added.  

The study was published in the July 1 issue of NeuroImage.

A Promising Tool

Improving motor behavior through neurofeedback in healthy volunteers could lead to development of therapeutic approaches for patients living with Parkinson's disease or recovering from a stroke, the researchers note.

Previous studies suggest a possible mechanism — that motor imagery promotes recruitment of nearby brain regions spared by a stroke, thereby improving motor recovery. The approach holds potential as a cost-effective strategy, Tovar-Moll said.

To find out more, the investigators randomly assigned 19 volunteers to brain training and another 17 to a placebo intervention.

Participants completed behavioral and motor assessments before and after brain imaging. At the same time, participants underwent resting-state and diffusion-weighted imaging. They completed the motor imagery task without any neurofeedback training as a baseline measure. For this task, researchers instructed them to imagine moving their hands in a specific finger-tapping sequence.

Volunteers in both groups completed three runs of the motor imagery task during fMRI. Participants saw their results represented as a bar graph displaying the differences between brain patterns during motor execution and rest. 

Individuals were encouraged to adopt mental strategies to increase the level of the graphs, "which meant they were reproducing motor execution brain pattern during a motor imagery task, with no overt movement," the researchers note.

After the three runs, participants completed the same task one more time without neurofeedback. The researchers conducted post-task resting-state and diffusion-weight imaging to detect changes in motor performance.

Total scanning time lasted approximately 1 hour.

The motor imagery neurofeedback training was associated with strengthening of the neural network that controls body movements. "It seems that the whole system became more robust," Tovar-Moll noted.

The same enhancement effect was not seen in the control group.

The investigators also observed effects beyond the sensorimotor networks. The corpus callosum — the cerebral bridge connecting the left and right hemispheres — exhibited increased integrity.

Brain training also increased activity in the default mode network, specifically the bilateral medial prefrontal cortex, precuneus, posterior cingulate cortex, angular gyrus, and left parahippocampal. At the same time, no similar increases were observed in the sham neurofeedback group.

The findings may be clinically relevant because the default mode network is often impaired following a stroke, and in patients with Parkinson's disease or depression, the researchers note.

Comparison of imaging before and after the neurofeedback tasks revealed the areas of the brain that were most discriminative between groups, with a mean accuracy of 83%. These areas included the left supplementary motor area, left anterior cingulate cortex, left superior frontal gyrus, left parahippocampal gyrus, and left fusiform gyrus.

The neurofeedback helps to induce more effective neuroplasticity.

"We saw structural and connectivity changes in the brain using functional MRI. This is the novelty of our research," Tovar-Moll said.

The results will not immediately translate to the clinical setting, she said. "Instead, the findings can be used to develop new interventions and new therapies for stroke patients and others."

"Our results suggest that when associated with neurofeedback, motor imagery can be used to strengthen brain patterns related with motor execution, which in turn may provide a promise tool for stroke rehabilitation in future studies," the researchers note.

"Moreover, the present study emphasizes the notion that neurofeedback should be considered a promising tool to investigate subtle physiological and anatomical aspects of brain plasticity."

The investigators plan to continue studying healthy volunteers to test more protocols and to collect additional robust evidence on the changes in connectivity.

"We are also starting a protocol with people with pain and another looking at long-term stroke survivors," said Tovar-Moll.

Evidence of Remodeling

Commenting on the findings for Medscape Medical News, Alessandro Di Rocco, MD, director of the Movement Disorders Program at Northwell Health Physician Partners Neuroscience Institute in Great Neck, New York, said the study demonstrates the intrinsic ability of the brain to remodel its network.

"With sustained exercise, the brain can remodel itself and compensate for the loss of network efficiency or network alterations thorough a process of activity-induced neuroplasticity," said Di Rocco, who was not involved with the current study.

This mechanism underlies rehabilitation strategies like physical therapy or speech therapy, he added.

"This study demonstrates that this process of brain remodeling can occur in the absence of actual physical exercise, and just imagining the movement exercise, with the support of techniques of neurofeedback, can lead to changes in connectivity," Di Rocco said. In this case, the changes were "unequivocally demonstrated on MRI."

At this point, he said, it is unclear whether the findings are generalizable patients with Parkinson's disease or other neurologic disorders.

He noted that the study used healthy volunteers and, therefore, "the ability of the brain to activate those mechanisms of network reorganizations in people who already have neurological diseases may be impaired or less effective."

The Research Support Foundation of the State of Rio de Janeiro (FAPERJ) , the National Council for Scientific and Technological Development (CNPq),  as well as intramural grants from D'Or Institute for Research and Education (IDOR) , supported the study. Tovar-Moll and Di Rocco have disclosed no relevant financial relationships.

NeuroImage. Published July 1, 2019. Abstract

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