Cognitive dissonance resolution depends on episodic memory

Abstract

The notion that past choices affect preferences is one of the most influential concepts of social psychology since its first report in the 50 s, and its theorization within the cognitive dissonance framework. In the free-choice paradigm (FCP) after choosing between two similarly rated items, subjects reevaluate chosen items as more attractive and rejected items as less attractive. However the relations prevailing between episodic memory and choice-induced preference change (CIPC) remain highly debated: is this phenomenon dependent or independent from memory of past choices? We solve this theoretical debate by demonstrating that CIPC occurs exclusively for items which were correctly remembered as chosen or rejected during the choice stage. We used a combination of fMRI and intra-cranial electrophysiological recordings to reveal a modulation of left hippocampus activity, a hub of episodic memory retrieval, immediately before the occurrence of CIPC during item reevaluation. Finally, we show that contrarily to a previous influential report flawed by a statistical artifact, this phenomenon is absent in amnesic patients for forgotten items. These results demonstrate the dependence of cognitive dissonance on conscious episodic memory. This link between current preferences and previous choices suggests a homeostatic function of this regulative process, aiming at preserving subjective coherence.

How Decisions and the Desire for Coherency Shape Subjective Preferences Over Time

“…The objective of decision making is therefore to reduce the error between one's past choices and present preferences; we refer to this general mechanism as coherency maximization. Consistent with patterns of repeatpurchasing observed in supermarket consumers 24 and studies of choice-induced preference change [11][12][13][14][15][16][17][18][19][20][21][22][23] , coherency maximization boosts the likelihood of past choices being repeated by shifting preferences towards the chosen item and away from rejected alternatives. As was shown in a simple simulation, this mechanism can elicit strong subjective preferences in the absence of extrinsic feedback.…”

“…As well as facilitating the inference of preferences, past choices also shape them. This has been demonstrated in studies of free choice, which show that after freely choosing an option, people tend to increase their subjective preference for it [11][12][13][14][15][16][17][18][19][20][21][22][23][24] . In the original free-choice paradigm, Brehm 11 asked participants to rate a set of items (e.g.…”

“…Studies of free choice imply that people refer to past acceptances and rejections to infer what they like and dislike 17,19,[22][23][24]28 . Yet, we know that people can also infer the value of things they've never tried.…”

Inducing preference reversals in aesthetic choices for paintings: Introducing the contrast paradigm

“…More recently, choice-induced preference changes have been reported using a paradigm that incorporates two consecutive rating opportunities for the same items, to control for artifacts caused by regression toward the mean [ 41 – 43 ]. Using this paradigm, Salti et al [ 43 ] first had participants rate their desire to visit each of a set of vacation destinations (rating opportunity 1).…”

“…Memory for previous judgments has been shown to moderate these preference changes. For example, participants who forget their initial choice are significantly less likely to exhibit the expected spread of alternatives across ratings [ 41 , 43 ]. The authors of these studies propose that forgetting one’s initial choices eliminates the possibility of experiencing cognitive dissonance later on, such that participants no longer feel pressured to strengthen their initial judgments by increasing their second ratings.…”