Evaluation of adaption skills in older adults using behavioural and EEG repeated measurements during a visual oddball object detection task

Abstract

AbstractBackgroundAdaptation to new demands is a fundamental skill that relies on the neuroplasticity of the brain. The breadth of this adaptation (an aspect of cognitive function) is reduced with ageing and is further perturbed with amnesic mild cognitive impairment. Perturbed adaptation skills could be a potential marker of early cognitive deficits, which is key for early diagnosis. Here we aim to investigate behavioural and neurophysiological adaptation to a gamified tablet‐based version of the visual oddball paradigm in older adults across 12 weeks.Method89 neurotypical older adults (mean age: 58.7 years, SD: 8.89; mean MoCA score: 27.1, SD: 1.8; 77.5% female) were asked to perform a gamified 2‐stimulus visual oddball paradigm 5 times a week during a 3‐month period, while neurophysiology was recorded with a 16‐channel EEG headset designed for unsupervised use in the home. A session event‐related potential (ERP) was calculated per channel, which was then downsampled into 8‐ms bins. To assess the effect of session on the ERP signal and on the average reaction time (RT), we statistically tested two mixed effects models (per channel‐temporal bin): i) a reference model, with covariates and subject as a random effect; and ii) an across‐sessions model, with Session added as a fixed effect to the reference model.ResultBehaviourally, RTs to Target stimulus were significantly faster across sessions. RTs in the first session and the rate of improvement between the 1st and 2nd sessions were modulated by the MoCA score. In response to the Target stimulus, there were amplitude increases with session overlapping the P300 component on frontal channels (FCz, Fpz), and on parietal channels (CPz, Cz, P3, P4). In response to the Non Target stimulus, there was a higher amplitude with Session in FC3 between 209.9‐242 ms, and in Fpz between 482.6‐514.7 ms.ConclusionA gamified visual oddball task is sensitive to MoCA score categorization at baseline and early stages of adaptation in neurotypical subjects. Potential neurophysiological adaptation, accompanying the behavioural adaptation, is suggested by EEG P300 amplitudes that increase across sessions.