Rates of Perceived Cognitive Exertion are Elevated in Older Adults with Mild Cognitive Impairment during Rhythmic Motor-Cognitive Tasks

Research Objectives The Borg Rate of Perceived Exertion (RPE) measures an individual's self-perceived physical exertion. We developed an analogous 10-point category cognitive scale to estimate participants’ rates of perceived cognitive exertion (RPCE). We evaluated and compared RPCE, RPE, and heart rate (HR) in older adults with and without Mild Cognitive Impairment (MCI) during rhythm-based motor-cognitive tasks. Design Data were collected during motor-cognitive treatments in a randomized controlled trial. Setting Participants attended three, 1h group rhythmic-dance classes in a dedicated movement space. Participants Older adults with (MCI, n = 10, 7F/3M) and without (OA, n = 14, 10F/4M) MCI participated from a volunteer sample (Enrolled/ Contacted: 10/∼46 MCI, 14/∼250 OA). MCI participants had previous MCI diagnosis per Alzheimer ’s disease Neuroimaging Initiative criteria. Participants were age-matched (MCI: 74.4±3.8y, OA: 70.2±6.05y; p = 0.067). Interventions Participants were administered motor-cognitive therapy using novel Rhythmic Movement Sequences (RMS): a library of complex, multi-step movements with dance/ music elements to simultaneously challenge motor and cognitive function. Main Outcome Measures We collected participants’ RPCE, RPE, and HR during each RMS class at pre-class, post warm-up, halfway, and post-class timepoints. We evaluated association between these metrics via Spearman's Rank correlations, and group effects on timepoint metrics via independent t-tests. Results MCI consistently reported elevated RPCE relative to OA throughout classes (all p < 0.03), despite no baseline differences (p = 0.068). MCI exhibited elevated RPE scores only at post warm-up (p = 0.029) and class end (p = 0.020). RPE and RPCE at pre-class were strongly correlated (r = 0.744, p < 0.001). RPE and HR were surprisingly weakly correlated (r = 0.143, p = 0.047). RPCE and HR were not correlated (p = 0.744). Conclusions Our proposed RPCE captured elevated perceived cognitive effort in participants with MCI. We recommend the RPCE scale be used in addition to Borg RPE during exercise-based treatments that induce high motor and cognitive engagement in populations with cognitive deficits. Author(s) Disclosures All authors have no conflicts of interest to declare.