Tendency to overestimate the explicit time interval in relation to aging and cognitive decline

Age-related deficits in explicit time perception has been reported by some studies. However, the findings are inconsistent about the preference of older adults to over/underestimate the observed interval as well as the relationship between the time estimation and the participant´s cognitive status. In this study, we used a verbal estimation task for the rotation time of a virtual building (40 seconds) to assess the explicit interval timing of participants. The performance of a cohort of 250 cognitively-healthy adults and 10 Alzheimer´s patients was analyzed in relation to their age and cognitive scale, measured by Montreal Cognitive Assessment (MoCA) score. The participants´ performances were evaluated based on three measurements: Coefficient of variation (CV) for measuring stability, Absolute Error (AE) for measuring accuracy and Directional Error (DE) for measuring the degree of over/under-estimation. A significant difference was observed between the participants who overestimated the interval and those who underestimated it in terms of age, cognitive status and Absolute Error. We also found a significant effect of time estimation, with underestimation by cognitively healthy participants to mild over-estimation by 70+ year old and low-MoCA (MoCA score <; 26) participants as well as severe overestimation by Alzheimer´s disease patients. The result of regression analysis for predicting MoCA score based on the dependent variables (AE, DE and CV) support the superiority of Directional Error to Absolute Error and Coefficient of Variation that are commonly used in the time perception studies.