Cognitive Enhancement via Neuromodulation and Video Games: Synergistic Effects?

Abstract

Transcranial magnetic stimulation (TMS) is a non-invasive brain stimulation technique able to modulate cortical excitability. This modulation may influence areas and networks responsible for specific cognitive processes, and the repetition of the induced temporary changes can produce long-lasting effects. TMS effectiveness may be enhanced when used in conjunction with cognitive training focused on specific cognitive functions. Playing video games can be an optimal cognitive training since it involves different cognitive components and high levels of engagement and motivation. The goal of this study is to assess the synergistic effects of TMS and video game training to enhance cognition, specifically, working memory and executive functions. We conducted a randomized 2 × 3 repeated measures (stimulation × time) study, randomly assigning 27 healthy volunteers to an active intermittent theta-burst stimulation or a sham stimulation group. Participants were assessed using a comprehensive neuropsychological battery before, immediately after, and 15 days after finishing the video game+TMS training. The training consisted of 10 sessions where participants played a 3D platform video game for 1.5 h. After each gaming session, TMS was applied over the right dorsolateral prefrontal cortex (DLPFC). All participants improved their video gaming performance, but we did not find a synergistic effect of stimulation and video game training. Neither had we found cognitive improvements related to the stimulation. We explored possible confounding variables such as age, gender, and early video gaming experience through linear regression. The early video gaming experience was related to improvements in working memory and inhibitory control. This result, although exploratory, highlights the influence of individual variables and previous experiences on brain plasticity.

Keywords: cognitive enhancement; dorsolateral prefrontal cortex; executive functions; iTBS; theta-burst stimulation; transcranial magnetic stimulation; video games; working memory.

Figure 1

Experimental timeline: neuropsychological assessments (light gray), video game training and transcranial magnetic stimulation (TMS) sessions (dark gray), and non-contact days (white). A structural magnetic resonance imaging (MRI) was obtained for each participant during the enrollment phase to: (1) discard the possibility of brain anomalies that could affect or prevent participation; and (2) locate the stimulation target and navigate the TMS coil position for each participant (see “Transcranial Magnetic Stimulation” section).

Figure 2

Right dorsolateral prefrontal cortex (DLPFC) TMS target visualized over a 3D MRI reconstruction of a participant’s head (reproduced with participant’s permission).

Figure 3

3-back d’ score for the four subgroups and the three assessment points. Error bars indicate the standard error of the mean. The change between Pre and Post1 assessments was statistically significant for the Active+Exp group (solid black line) compared to the two groups without video gaming experience (dashed lines). Differences between the Pre and Post1 assessment were also significant for the two groups with early video gaming experience (solid lines).

Figure 4

Stop signal reaction times (SSRT) for the Stop-switching task with gender as a covariate for the four subgroups and the three assessment points. Error bars indicate the standard error of the mean. Differences were significant between the Pre and Post1 assessments in the two groups without early video gaming experience (dashed lines).