Demographic data for participants included in analyses of RP and CNV task.

CAG, cytosine-adenine-guanine; CAG-index, [CAGn(# of CAG repeats)– 35.5]multiplied by age; probability of onset in 5-years; DBS, Disease Burden Score (CAG-35.5)*age; UHDRS, motor subscale score, Unified Huntington’s Disease Rating Scale (pre-HD, UHDRS <5; symp-HD, UHDRS ≥5); IQ (NART: National Adult Reading Test 2nd Edition); BDI-II, Beck Depression Inventory—second edition; Trails B, Trail Making Test Two-Target-Switch; HVLT, Hopkins Verbal Learning Test. Independent samples t-test for differences between groups; * p < .05, ** p < .01; a significantly different from controls, b significantly different from pre-HD. Standard deviations (SD) provided in parentheses.