Executive Functions, Brain Games, and Brain Stimulation: An RCT for Mild TBI

Traumatic brain injury (TBI) is a major public health problem. Each year in the United States, about 1.7 million people, or about 1 in every 200, will sustain a TBI, with about 80% classified as mild TBI (mTBI), or concussion. Among military personnel, rates are far higher: nearly 15% of those returning from deployment report mTBI, largely from blast exposures.

TBI impact

Today, about 400,000 military service members and veterans are living with the effects of TBI, which can cause brain abnormalities and cognitive impairments that inhibit daily functioning. For example, mTBI is strongly associated with deficits in executive function, which includes remembering tasks, shifting attention, maintaining focus, planning activities, and other daily life activities. TBI also can affect fluid intelligence, including general reasoning and problem-solving abilities. That helps explain why as many as 43% of civilians with TBI develop long-term disability and why high rates of TBI in the military can weaken military readiness.

Limited treatment options

Despite the critical need, effective, accessible treatments are lacking. “Holistic” and computer-based rehabilitation methods are available, but both only modestly improve specific executive functions and have little impact on overall cognitive function. In addition, holistic therapies are lengthy and must be delivered by professionals. Computer-based rehab can be boring and repetitive, producing fatigue and reducing compliance.

A promising—and engaging—new approach

A STRONG STAR-affiliated trial led by Thomas Coyle, PhD, of The University of Texas at San Antonio aims to provide wounded warriors—and eventually the larger public—with an effective treatment that is actually fun for patients and can be made broadly available.

This randomized clinical trial will evaluate two treatment components, both individually and in combination. The first is a computerized brain game called Robot Factory, an interactive video game designed to be fun, engaging, and maintain interest for hours. Robot Factory has been found to improve executive functions and fluid intelligence in healthy adults and holds great promise in improving outcomes in mTBI patients. In Robot Factory, players are factory employees who must build robots to specifications quickly and accurately. Players work through 15 task blocks of 2 minutes each. Each block targets three executive functions: working memory, flexibility, and inhibition. The game provides feedback and modifies difficulty level depending on performance.

As part of the study, Robot Factory will be compared to an active control visual search brain game, which targets low-level sensory and perceptual processes. Both brain games will be paired with transcranial direct current stimulation (tDCS) or sham tDCS with no brain stimulation. tDCS is a safe therapy that involves passing an electrical current to the brain cortex via scalp electrodes. In tests with healthy individuals, tDCS coupled with Robot Factory has produced synergistic effects, eliciting changes in brain activity in both executive function and fluid intelligence greater than either intervention alone.

Study design

The study will involve active duty military and DEERS-eligible veterans in Killeen, Texas, impacted by mTBI. It will include 3 weeks of daily 30-minute sessions of (1) Robot Factory with tDCS, (2) Robot Factory with sham tDCS, (3) visual search with tDCS, or (4) visual search with sham tDCS. This will allow investigators to examine the treatment effects of Robot Factory alone, tDCS alone, and the synergistic effects of the two used in combination, which they expect to be superior.

Expected benefits

Potential benefits for study participants include improvements in general cognitive function and life outcomes. Findings also will shed light on how each intervention affects specific cognitive functions, including in different combinations. If these interventions are effective at improving cognitive function, this study will have identified evidence-based approaches for cognitive rehabilitation of mTBI that are effective, fast acting, cost effective, and easy to distribute.

This should make them an optimal resource for overburdened military providers and help with broad implementation. Information on how brain games work individually and when coupled with tDCS also would increase options for providers seeking to tailor treatment to improve outcomes, including with complex cases, such as service members with co-occurring posttraumatic stress disorder.

The ultimate benefit will be for almost 400,000 post-9/11 service members diagnosed with TBI. A quick, effective, engaging, and tailorable treatment has the greatest potential to improve cognitive function and help maintain fitness for duty for service members. The results will also be easily transferrable to the treatment of veteran and civilian populations.