Span of temporal continuity as a measure of personal and present existence

Abstract

Severely impaired memory deprives amnesics of a sense of personal continuity in their daily lives, yet there are no tests that accurately measure this impairment (see Lezak, 1995). Several neuropsychological tasks have been developed to document the severity of memory loss in terms of memory span, such as the Brown–Peterson Technique (Peterson & Peterson, 1959), but the ecological validity of such tasks as measures of personal or temporal continuity is not obvious (see Heinrichs, 1990). Instead they measure memory in terms of how much information could be held in working or short-term memory, not memory span in the sense of continuity. To develop a new measure of amnesia with greater relation to everyday function, we had to examine the integrity of memory function in terms of temporal continuity in a way that would engage the patient in everyday behavior, such as informal conversation, and still allow memory function to be quantifiable. Thus, we set out to create a bedside task that could measure the span in which the patient with amnesia experiences temporal continuity. We call this measure the “span of temporal continuity,” or “personal and present span of existence.”