The Effect of Transcranial Direct Current Stimulation on Visual Attention in Mild Cognitive Impairment

Investigator will investigate the long‐term effects of 10 active tDCS consecutive sessions using an optimized stimulation protocol as compared to a placebo stimulation on visual attention in the MCI‐AD. A two‐parallel‐group, randomized, placebo‐controlled design will be used. In addition, the cognitive transfer of tDCS will be evaluated. Repeated tDCS sessions will be performed in 10 consecutive sessions (2 weeks: Monday to Friday) over one preselected ROI together with ongoing visual attention training. During the stimulation, investigator will use the visual matching task. Before the repeated stimulation sessions, participants will undergo the neurocognitive examination. Behavioral examinations of the trained and untrained tasks (i.e. the transfer tasks) will be performed to assess the baseline performance. MRI protocol consisting of T1, T2, FLAIR, and fMRI during the task performance (visual matching task), resting state fMRI, and DTI sequences will be acquired before and after the whole 10‐day stimulation protocol in order to search for active vs. placebo tDCS‐induced changes in brain activation and resting state functional and structural connectivity and to identify neural correlates of behavioral changes. Behavioral assessment of the trained task and the transfer task will be repeated immediately after and again at a one‐month follow‐up visit after the end of the last stimulation session