Presenters: Eden Harder, Nicholas Samaha, Jocelyn Lopez, Poster Presentation
Research Title: Visual Neural and Behavioral Response to tDCS
Faculty Co-Advisors: Susanne Jaeggi, Ramesh Srinivasan [Cognitive Science]
Mentor: Jacky Au
Transcranial direct current stimulation (tDCS) is widely thought to operate by modulating the excitability of target neurons through a selective, subthreshold depolarization or hyperpolarization of neuronal membranes. However, evidence has been accumulating that there may be downstream effects on memory consolidation, which may not appear until hours or days after the initial stimulation. For example, ongoing research in our lab has found that EEG activity, as measured through steady state visual evoked potentials (SSVEP), increases as a function of tDCS, but this effect is not apparent immediately after stimulation but manifests approximately one day later. In this study, SSVEPs were measured concurrently with a working memory task, but no behavioral improvements were detected. However, despite applying the electrodes over the parietal cortex, a region known to be important for working memory function, results indicated that the cortical region that exhibited the strongest tDCS-related increase was actually centered over the occipital lobe instead, a brain area that is largely responsible for integrating visual stimuli. The goal of the current study, therefore, aims to replicate the effect of tDCS on the SSVEP response and demonstrate the behavioral relevance of this enhancement by concurrently training subjects on a visual perceptual learning task that taxes the occipital cortex. Data analysis is ongoing.