|M.Sc Student||Taly Bonder|
|Subject||The joint effects of spatial precueing and transcranial|
direct current stimulation on visual acuity
|Department||Department of Industrial Engineering and Management||Supervisors||Professor Emeritus Gopher Daniel|
|Full Thesis text|
The present study examines the mutual influence of cortical neuroenhancement and allocation of spatial attention on perception. Specifically, it is directed to explore the effects of Transcranial Direct Current Stimulation (tDCS) on visual acuity in Landolt gap task, with and without preceding cues. Replicating the methods of Yeshurun and Carrasco (1999) and Montagna, Pestilli and Carrasco (2009) we reproduced the effects of cuing on performance, generating significant attentional benefits and costs to performance at congruent and incongruent cued locations respectively. Anodal tDCS, applied to posterior occipital area for fifteen minutes, improved performance during stimulation. Reaction time was lower, and response sensitivity higher in the tDCS Stimulation group, compared to Sham control group. Additionally, tDCS interacted significantly with the effect of spatial cuing, in post-stimulation test trials. Reaction time was lower in congruent trials (benefit) and higher in incongruent trials (cost) in Stimulation group compared to Sham control group. These changes in cost and benefit in Stimulation group were expressed in a similar fashion, suggesting that anodal tDCS influenced the process of overall attention orienting. These findings indicate a magnification of attention modulation by cues through external enhancement of striate cortex. It is hypothesized that neuromodulation of visual cortex during manipulation of attention, may affect its connections with functionally connected areas, resulting in improvement of attention allocation.