Smartphone-Based Neuropsychological Assessment in Parkinson's Disease: Feasibility, Validity, and Contextually Driven Variability in Cognition

Abstract

Objectives: The prevalence of neurodegenerative disorders demands methods of accessible assessment that reliably captures cognition in daily life contexts. We investigated the feasibility of smartphone cognitive assessment in people with Parkinson's disease (PD), who may have cognitive impairment in addition to motor-related problems that limit attending in-person clinics. We examined how daily-life factors predicted smartphone cognitive performance and examined the convergent validity of smartphone assessment with traditional neuropsychological tests.

Methods: Twenty-seven nondemented individuals with mild-moderate PD attended one in-lab session and responded to smartphone notifications over 10 days. The smartphone app queried participants 5x/day about their location, mood, alertness, exercise, and medication state and administered mobile games of working memory and executive function.

Results: Response rate to prompts was high, demonstrating feasibility of the approach. Between-subject reliability was high on both cognitive games. Within-subject variability was higher for working memory than executive function. Strong convergent validity was seen between traditional tests and smartphone working memory but not executive function, reflecting the latter's ceiling effects. Participants performed better on mobile working memory tasks when at home and after recent exercise. Less self-reported daytime sleepiness and lower PD symptom burden predicted a stronger association between later time of day and higher smartphone test performance.

Conclusions: These findings support feasibility and validity of repeat smartphone assessments of cognition and provide preliminary evidence of the effects of context on cognitive variability in PD. Further development of this accessible assessment method could increase sensitivity and specificity regarding daily cognitive dysfunction for PD and other clinical populations.

Keywords: Cognition; Ecological sampling method; Mobile phone; Parkinson’s disease; Precision medicine; Smartphone.

Fig. 1.

mindLAMP App Assessments. (a) Location & Social Context Survey: Indication of type of current location and social context. (b) Mood & Alertness Survey: five questions including rating happiness, sadness, anxiety, alertness, and level of motivation to try one’s hardest on subsequent cognitive games. (c) Backwards Spatial Span Test: four increasingly challenging trials of a task requiring one to tap the sequences of boxes that appeared on the screen during that trial but in reverse order. (d) Trails-B Test: four increasingly lengthy trials of a task requiring one to tap numbers and letters on the screen in a sequential and alternating manner.

Fig. 2.

Summary of Smartphone Survey Responses.

Fig. 3.

Examples of Between-Person Variability in the Association Between Time of Day and Smartphone Trails-B Accuracy.