Multimodal Investigation of Neural Plasticity

The goal of this study is to learn important information about the effects of weak electrical stimulation (known as high-definition transcranial direct current stimulation or HD-tDCS) on brain functioning in those with mild cognitive impairment (MCI). The findings will help determine how stimulation affects brain's activity and metabolism (in particular, the neurotransmitter glutamate). Ultimately, this information may help develop new treatments for those with Alzheimer's disease. The study will use different forms of brain imaging to see whether stimulation changes how the brain responds during a memory task. Functional magnetic resonance spectroscopy (fMRS), functional magnetic resonance imaging (fMRI), and functional near-infrared spectroscopy (fNIRS) will be used. The study also uses cognitive tests and questionnaires.