Non-invasive brain stimulation can induce paradoxical facilitation. Are these neuroenhancements transferable and meaningful to security services?

Abstract

For ages, we have been looking for ways to enhance our physical and cognitive capacities in order to augment our security. One potential way to enhance our capacities may be to externally stimulate the brain. Methods of non-invasive brain stimulation (NIBS), such as repetitive transcranial magnetic stimulation (rTMS) and transcranial electrical stimulation (tES), have been recently developed to modulate brain activity. Both techniques are relatively safe and can transiently modify motor and cognitive functions outlasting the stimulation period. The purpose of this paper is to review data suggesting that NIBS can enhance motor and cognitive performance in healthy volunteers. We frame these findings in the context of whether they may serve security purposes. Specifically, we review studies reporting that NIBS induces paradoxical facilitation in motor (precision, speed, strength, acceleration endurance, and execution of daily motor task) and cognitive functions (attention, impulsive behavior, risk-taking, working memory, planning, and deceptive capacities). Although transferability and meaningfulness of these NIBS-induced paradoxical facilitations into real-life situations are not clear yet, NIBS may contribute at improving training of motor and cognitive functions relevant for military, civil, and forensic security services. This is an enthusiastic perspective that also calls for fair and open debates on the ethics of using NIBS in healthy individuals to enhance normal functions.

Keywords: cognitive function; motor function; neuroenhancement; non-invasive brain stimulation; security; transcranial direct current stimulation (tDCS); transcranial magnetic stimulation.

Figure 1

Examples of electrode montage and coil location for two modern non-invasive brain stimulation techniques. (A) Example of transcranial Electrical Stimulation electrodes montage with anode (gray) applied over the left dorsolateral prefrontal cortex and cathode (black) applied over the left parietal cortex according to 10–20 EEG international system; (B) Example of transcranial magnetic stimulation location with a figure-8 coil applied over the left dorsolateral prefrontal cortex (DLPFC). The gray spots over the transcranial magnetic stimulation coil represent navigator markers, the coil is placed over the DLPFC according to subject's MRI (on a computer screen, top of the figure).

Figure 2

Main brain areas targeted in NIBS studies inducing motor and cognitive (attention, risk-taking, planning and deceptive abilities) enhancements in healthy volunteers. L: Left; R: Right; DLPFC: Dorso Lateral Prefrontal Cortex (attention, risk-taking/impulsivity, planning and deceptive abilities); IFC: Inferior Frontal Cortex (attention and deceptive abilities); PPC: Posterior Parietal Cortex (attention); M1: Primary Motor Cortex (motor); TPJ: temporoparietal junction (working memory).