title: 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.
authors.affiliation: Division Neuropsychology, Institute of Psychology, University of Zurich Zurich, Switzerland ; University Clinics for Child and Adolescent Psychiatry, University of Zurich Zurich, Switzerland ; Neuroscience Center Zurich, University of Zurich and ETH Zurich Zurich, Switzerland.
authors.forename: Tobias U
authors.initials: TU
authors.lastname: Hauser
authors.forename: Stephanie
authors.initials: S
authors.lastname: Rotzer
authors.forename: Roland H
authors.initials: RH
authors.lastname: Grabner
authors.forename: Susan
authors.initials: S
authors.lastname: Mérillat
authors.forename: Lutz
authors.initials: L
authors.lastname: Jäncke
keywords: mathematics; mental arithmetic; number comparison; numerical magnitude processing; subtraction; transcranial Direct Current Stimulation (tDCS)