Time estimation and episodic memory following traumatic brain injury.

The ability to accurately estimate the passage of time plays an important role in helping to structure daily activities. In this study, we used a prospective verbal time estimation paradigm to investigate time perception in 27 moderate to severe traumatic brain injury (TBI) participants and 27 controls. Verbal time estimations were made for filled intervals both within (i.e., <30 s) and beyond the time frame of working memory. We found that the TBI participants exhibited normal or near-normal estimates of time passage for duration up to 25 s. In contrast, for durations that exceeded working memory, the TBI group perceived less time as having passed than actually had passed as the TBI group significantly underestimated time when compared to controls. This pattern of data was interpreted as being due to episodic memory dysfunction.