The technique uses transcranial direct current stimulation (tDCS), in which weak electrical currents are applied to the scalp using electrodes, reports the New Scientist.
The method can temporarily increase or decrease activity in a specific brain region and has already been shown to boost verbal and motor skills in volunteers.
Richard Chi of University of Sydney, and colleagues showed 36 volunteers a dozen “study” slides covered with shapes that varied in their number, arrangement, colour and size (see “Brain games”).
The volunteers were then shown five “test” slides – two with patterns that appeared in the study slides, two with completely new patterns and one whose pattern looked similar to that on a study slide.
Participants were asked to identify which of the test slides they had already seen, first performing the task without any brain stimulation.
Subjects then repeated the experiment 12 times, with one group receiving so-called anodal tDCS (which boosts activity) on their right ATL and cathodal tDCS (which inhibits activity) on their left.
A second group received the opposite stimulation and a third group received a placebo treatment, which did not stimulate either side of the brain.
Those in the first group more than doubled their scores after receiving tDCS, experiencing a 110 per cent improvement in visual memory. Participants in the second and third groups showed no overall improvement in performance.