Researchers have successfully improved the visual perception of a group of healthy individuals by using a non-invasive technique called transcranial magnetic stimulation (TMS). The study, led by Antoni Valero-Cabré from the Centre de Recherche de l’Institut du Cerveau et de la Moelle Epinière (CNRS / Inserm / UPMC), is published in the journal PLoS ONE.

The researchers used TMS to send magnetic pulses to a region of the right cerebral hemisphere in the brain known as the frontal eye field. These magnetic pulses activate the cortical neurons located within the range of the magnetic field, which modifies their activity in a painless and temporary manner.

According to the authors, findings from this study could lead to the development of new rehabilitation techniques for certain visual disorders and could also help enhance the performance of individuals whose tasks require extremely high precision.

In the study, healthy participants were asked to watch a screen and try and distinguish a very low contrast target for just 30ms. In some of the tests, the researchers used TMS on participants for between 80 and 140ms before the target appeared on the screen. The team found that TMS increased the visual sensitivity of participants by around 12%, and that more subjects were able to distinguish the target when TMS was applied.

In a second experiment, a brief visual cue indicating the spot where the target could appear was shown to the participants. The researchers found that their visual sensitivity only improved when the cue indicated the correct location of the target.

According to the authors, TMS can improve cerebral functions, such as conscious vision, and could also be tested for the rehabilitation of individuals with retinal disorders, and for patients with cortical damage.

Results from the second experiment indicate that rehabilitation based on TMS and visual cues could be more effective than stimulation alone. The team plans to research this in more detail by using repetitive TMS, which, in this case, could make it possible to obtain long-lasting modification of cerebral activity.

The authors state that, in the future, TMS could be used to enhance the the attentional abilities of individuals performing tasks that require good visual skills.

Written by Grace Rattue