Reconsolidation impairment of reward memory by stimulating stress response.

Abstract

Research in memory reconsolidation has raised hope for new treatment options of persistent psychiatric disorders like substance dependence and post-traumatic stress disorder (PTSD). While animal research showed successful memory modification by interfering with reconsolidation, human research requires less invasive techniques. In our pilot study, we aimed to reduce appetitive memory reconsolidation of a newly acquired reward memory by exerting a stressor. Thirty healthy participants were randomly assigned to two groups performing a monetary reward paradigm at a personal computer. Day 1 was considered to allow for memory acquisition; on day 2, the experimental group was exposed to a frightening stimulus in the reconsolidation window; and day 3 again served to determine reward memory effects. Measures of reward memory were reaction times to reward announcing stimuli (ie, showing instrumental behavior), actual reward gained, and electrodermal response as a measure for reward anticipation. We found significantly smaller reaction time improvements to reward stimuli over time in the experimental group, as well as reduced achievements in monetary reward. Electrodermal response to reward announcing stimuli was lower in the experimental group after intervention, whereas it was higher in the untreated group. Thus, we argue in favor of the reconsolidation hypothesis, assuming our intervention had successfully interfered with the reconsolidation process. This points towards future treatment options that interfere with an addiction memory.