Enhancing performance in numerical magnitude processing and mental arithmetic using transcranial Direct Current Stimulation (tDCS)

Abstract

The ability to accurately process numerical magnitudes and solve mental arithmetic is of highest importance for schooling and professional career. Although impairments in these domains in disorders such as developmental dyscalculia (DD) are highly detrimental, remediation is still sparse. In recent years, transcranial brain stimulation methods such as transcranial Direct Current Stimulation (tDCS) have been suggested as a treatment for various neurologic and neuropsychiatric disorders. The posterior parietal cortex (PPC) is known to be crucially involved in numerical magnitude processing and mental arithmetic. In this study, we evaluated whether tDCS has a beneficial effect on numerical magnitude processing and mental arithmetic. Due to the unclear lateralization, we stimulated the left, right as well as both hemispheres simultaneously in two experiments. We found that left anodal tDCS significantly enhanced performance in a number comparison and a subtraction task, while bilateral and right anodal tDCS did not induce any improvements compared to sham. Our findings demonstrate that the left PPC is causally involved in numerical magnitude processing and mental arithmetic. Furthermore, we show that these cognitive functions can be enhanced by means of tDCS. These findings encourage to further investigate the beneficial effect of tDCS in the domain of mathematics in healthy and impaired humans.

Neurocognitive Effects of Transcranial Direct Current Stimulation in Arithmetic Learning and Performance: A Simultaneous tDCS-fMRI Study

“…Based on our previous studies [13,16,17], we used a tDCS protocol with anodal stimulation of left parietal and cathodal stimulation of right prefrontal areas. We used the same electrode configuration for the active and sham stimulation.…”

“…However, the observed effects strongly depended on the cognitive processes involved in the arithmetic operation as well as the placement of the tDCS electrodes. Solving complex arithmetic problems (twodigit subtractions, typically solved using procedures) were found to be enhanced by anodal tDCS of left but not right or bilateral parietal cortex [13,17]. For solving simple arithmetic problems (which is typically done by fact retrieval), in contrast, the same stimulation had detrimental effects.…”

“…In the arithmetic domain, first studies have demonstrated that tDCS can affect arithmetic performance and learning [13][14][15][16]. However, the observed effects strongly depended on the cognitive processes involved in the arithmetic operation as well as the placement of the tDCS electrodes.…”

Augmenting Visual Search Performance with Transcranial Direct Current Stimulation (tDCS)

“…In previous research studies ( Eun-Kyoung & Nam-Jong, 2011;Hauser, Rotzer, Grabner, Merillat, & Jancke, 2013;Coffman et al, 2012), wet sponge electrodes were used to administer the electrical current for tDCS. Here, we used a custom design of silver/silver chloride electroencephalographic (EEG) electrode.…”

How Non-invasive Brain Stimulation Might Invade Our Sphere of Justice

“…Despite the caution and even skepticism of the scientific community, numerous studies report improvements in the performance of specific tasks following the application of tDCS. Among the areas of enhancement for which there are published studies, we wish to highlight memory, reading, mood, learning, perception, mathematical cognition, decision-making, motor skills, creativity, motivation, and moral reasoning (Cohen Kadosh et al 2010;Callaway 2013;Snowball et al 2013;Meinzer et al 2013;Chi and Snyder 2012;Hauser et al 2013;McKinley et al 2013;Mayseless and Shamay-Tsoory 2015;Podda et al 2016;Brunoni and Vanderhasselt 2014;Cappelletti et al 2013).…”