Autobiographical Memory: Individual Differences and Assessment of the Subjective State of Mental Time Travel
Brian Levine
University of Toronto

Autobiographical memory concerns memory for facts and events about one’s own life. Patient research has demonstrated that damage to the brain’s medial temporal lobe systems can selectively affect event memory, particularly the subjective re-experiencing or “mental time travel” to past events. More recently, we have studied individual differences in autobiographical memory (i.e., trait mnemonics) among healthy adults. These differences are defined at their extremes by those with highly superior autobiographical memory (HSAM), who can recall copious details from past experiences (even everyday ones) and those with severely deficient autobiographical memory (SDAM) who lack detailed recollection of even significant life events. We propose that HSAM/SDAM reflect developmental syndromes akin to developmental topographical disorientation, face blindness, synesthesia, and the closely related condition, aphantasia.

The subjective nature of mental time travel necessitates novel instrumentation that indirectly assesses this construct from different approaches. The Autobiographical Interview involves classifying details from transcribed verbal free recall with the assumption that “internal” (episodic) details reflect richness of re-experiencing, whereas “external” (non-episodic) details are inversely related to cognitive control over autobiographical retrieval. The Survey of Autobiographical Memory (SAM) is a self-report measure developed to assess trait mnemonics along the normal spectrum of remote episodic, semantic, and spatial memory abilities as well as future imagining. The staged event method creates a standardized but naturalistic event (e.g., a museum tour) that can be subjected to more traditional measures from the memory literature, such as recognition.

I will present data from each of these measures touching upon the effects of individual differences in trait mnemonics on occupation selection and cognitive aging, intrinsic medial temporal – cortical functional connectivity, and the fractionation of different measures of item and contextual recall in relation to sleep consolidation.