Rhythmic Entrainment and Alertness in Lewy Body Dementia

This study will examine how people with dementia with Lewy bodies (DLB) or mild cognitive impairment with Lewy bodies respond to rhythmic auditory cues, and whether changes in alertness affect ability to synchronize movements to a rhythm. Participants will complete a single study visit that includes finger-tapping tasks performed with and without rhythmic auditory cues at different tempos. Brain activity will be recorded using electroencephalography (EEG), and tapping performance will be measured. Participants and the participant's study partners will also provide repeated ratings of alertness during the visit. The study aims to identify brain and behavioral measures of rhythmic synchronization and determine whether these measures change depending on a participant's level of alertness. The findings will help guide the development of future rhythm-based interventions for people with DLB.

Inclusion Criteria: * Age 18 years or older * Diagnosis of probable dementia with Lewy bodies (DLB) or mild cognitive impairment with Lewy bodies (MCI-LB) based on established clinical diagnostic criteria * Fluent in English * Able to attend with a study partner who can complete care-partner-reported cognitive fluctuation measures * Clinical Dementia Rating (CDR) global score of 0.5-1.0 * Adequate upper-limb motor function, defined as Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III finger-tapping item (3.4) score ≤2 on at least one hand and ability to sustain rhythmic tapping for at least 10 seconds at approximately 1-3 Hz during a brief practice trial * Adequate hearing, corrected if necessary, to perceive rhythmic auditory cues * Stable on all medications for at least 30 days before enrollment Exclusion Criteria: * Age younger than 18 years * CDR global score ≥2.0 * Severe upper-limb impairment, defined as MDS-UPDRS Part III finger-tapping item (3.4) score ≥3 in the dominant hand, or inability to produce more than 10 consecutive taps at ≥1 Hz despite instruction/practice * Other neurological, musculoskeletal, or sensory conditions that preclude safe or reliable task participation