Electrotactile Frequency, Amplitude, and Temporal Gap Discrimination in Young Adults, Older Adults, and Stroke Survivors

The purpose of this study is to evaluate and compare sensory discrimination ability for electrotactile stimulation among young adults, older adults, and patients with stroke. Participants will receive non-invasive electrotactile stimulation through electrodes attached to the skin of the upper limb, such as the fingertip, palm, elbow, or shoulder, depending on the stimulation condition. The study will assess discrimination thresholds for changes in stimulation frequency and amplitude, as well as temporal resolution using a gap-in-noise detection task. Task accuracy and reaction time will also be evaluated. In selected experimental conditions, electroencephalography (EEG) will be recorded non-invasively from the scalp during electrotactile stimulation to investigate neural responses associated with electrotactile sensory processing. The results are expected to provide foundational data for sensory assessment, electrotactile feedback design, and sensory-based rehabilitation technologies for older adults and patients with stroke.