UC Irvine

Many studies have provided evidence that the medial temporal lobes of the brain are involved in memory for everyday life experiences (episodic memory). Episodic memory has several components: the event itself (what), where the event took place, and when the event took place. The goal of this dissertation was to understand how the brain supports memory for when events occur (temporal memory). We showed participants an episode of Curb Your Enthusiasm inside of the MRI scanner, to monitor task-related changes in relevant brain regions. Then, we tested participants’ memory for when events in the episode occurred. We found that a network of brain regions, including the hippocampus, lateral entorhinal cortex (LEC), and perirhinal cortex (PRC) were preferentially activated when participants were closest to the correct answer. This suggests that memory for time may have different neurobiological correlates than memory for spatial information. Cortical regions, such as medial prefrontal cortex, angular gyrus, and posterior cingulate cortex were also activated when participants responded most precisely, indicating that they may also support temporal memory precision. We found no evidence that scene changes (event boundaries) had an effect on temporal memory performance in this task. A cluster in the superior temporal gyrus was preferentially activated at event boundaries while participants watched the episode, which could reflect changes occurring at boundaries, music during the episode, or both. We also tested older adults on this task and their performance correlated with a neuropsychological test of memory involving remembering words over a delay. Future studies of memory for time involving more naturalistic stimuli will provide additional information on brain-behavior relationships critical for remembering when events occurred.