Constructive memory: past and future

Abstract

Human memory is not a literal reproduction of the past, but instead relies on constructive processes that are sometimes prone to error and distortion. Understanding of constructive memory has accelerated during recent years as a result of research that has linked together its cognitive and neural bases. This article focuses on three aspects of constructive memory that have been the target of recent research: (i) the idea that certain kinds of memory distortions reflect the operation of adaptive cognitive processes that contribute to the efficient functioning of memory; (ii) the role of a constructive memory system in imagining or simulating possible future events; and (iii) differences between true and false memories that have been revealed by functional neuroimaging techniques. The article delineates the theoretical implications of relevant research, and also considers some clinical and applied implications.

Keywords: episodic memory; episodic simulation; false memory; future thinking; hippocampus; memory distortion; neuroimaging.

Figure 1.. Regions of a core network engaged by imagining future events. In a recent study described in the text, participants imagined future events including person, place, and object details that were taken from actual memories. On control trials, participants created a “size sentence,” ordering three objects by physical size. The contrast of future events relative to control trials revealed significant activation of a core network identified in other similar studies, including bilateral medial parietal and prefrontal cortices (right and middle) and bilateral medial temporal lobes and left lateral temporal cortex (left). Adapted from ref 87: Martin VC, Schacter DL, Corballis MC, Addis DR. A role for the hippocampus in encoding simulations of future events. Proc Natl Acad Sci U S A. 2011;108:13858-13863. Copyright© National Academy of Sciences 2011.

Figure 2.. Hippocampal responses to encoding. In the same study described in Figure 1, approximately 10 minutes after imagining future events comprised of person, place, and object details, participants were given a cued recall test in which two details from the simulation were provided, and they were asked to recall the third detail. A subsequent memory analysis revealed clusters in anterior and posterior right hippocampus that showed significantly greater activity during encoding for those simulations in which details were subsequently remembered vs those in which details were subsequently forgotten. Adapted from ref 87: Martin VC, Schacter DL, Corballis MC, Addis DR. A role for the hippocampus in encoding simulations of future events. Proc Natl Acad Sci U S A. 2011;108:13858-13863. Copyright© National Academy of Sciences 2011.