Age effects in time estimation: relationship to frontal brain morphometry

Compared with many other cognitive functions, relatively little is known about time representation in the brain. Recent work shows disrupted timing and time estimation in older adults, although it is unclear whether these effects are the result of normal aging or disease-related processes. The present study examined time estimation in persons across the adult lifespan who were free from significant medical or psychiatric history. Results showed older adults exhibited greater variability in time estimation, but no evidence for systematic acceleration or slowing emerged. This variability was correlated with performance on a variety of cognitive tests including attention, working memory and executive function. Although no relationship emerged between time estimation and EEG indices from central regions, multiple MRI indices were significantly correlated with time estimation. Stepwise regression showed volume of the supplementary motor area predicted variability in time estimation. These results indicate that healthy aging is associated with altered time estimation and suggest that changes in frontal brain regions mediate these effects.