Forgetting Unwanted Memories: Active Forgetting and Implications for the Development of Psychological Disorders

Abstract

Intrusive memories are a common feature of many psychopathologies, and suppression-induced forgetting of unwanted memories appears as a critical ability to preserve mental health. In recent years, biological and cognitive studies converged in revealing that forgetting is due to active processes. Recent neurobiological studies provide evidence on the active role of main neurotransmitter systems in forgetting, suggesting that the brain actively works to suppress retrieval of unwanted memories. On the cognitive side, there is evidence that voluntary and involuntary processes (here termed “intentional” and “incidental” forgetting, respectively) contribute to active forgetting. In intentional forgetting, an inhibitory control mechanism suppresses awareness of unwanted memories at encoding or retrieval. In incidental forgetting, retrieval practice of some memories involuntarily suppresses the retrieval of other related memories. In this review we describe recent findings on deficits in active forgetting observed in psychopathologies, like post-traumatic stress disorder, depression, schizophrenia, and obsessive-compulsive disorder. Moreover, we report studies in which the role of neurotransmitter systems, known to be involved in the pathogenesis of mental disorders, has been investigated in active forgetting paradigms. The possibility that biological and cognitive mechanisms of active forgetting could be considered as hallmarks of the early onset of psychopathologies is also discussed.

To deliberate, remember; to anticipate, forget: Cognitive deliberation profiles underpinning active forgetting-dependent everyday-like memory performance in young and aged mice

“…Recent studies in rodents and humans have demonstrated that such memory selection processes do not consist simply in activation of the appropriate memory item but also require the concomitant inhibition of inappropriate but related mnemonic content which may be evoked by the global or local environment and thereby intrude into conscious attention, competing with and perturbing accurate local action choice (M. C. Anderson & Hulbert, 2021;Brewin & Smart, 2005;Wimber et al, 2015). The literature refers to such inhibition of interference as adaptive, directed, or active forgetting (M. C. Anderson & Hulbert, 2021;Tanaka et al, 2019;Costanzi et al, 2021), where this term is to be understood in the organizational and attentional sense of 'Forget about that for a moment' rather than as total erasure of a memory episode. This organizational conception of memory function fits with classical theories and computational models conceiving of cognitive consciousness as a global workspace (GW) of limited capacity (Baars, 1988(Baars, , 1997(Baars, , 2002Dehaene et al, 2003;Dehaene & Changeux, 2011; for a novel distributed neuronal version of the global workspace, or GNW, see Mashour et al, 2020).…”

“…Our starting point interpretation is that EdM errors increase as a function of trial difficulty primarily as a result of the repeated instances of inhibitory active-and retrieval-induced forgetting (Bekinschtein et al, 2018;Tanaka et al, 2019;Costanzi et al, 2021;M. C. Anderson & Hulbert, 2021; M. C. Anderson et al, 1994) entailed by the continuous mnemonic retrieval and organization the EdM protocol was designed to elicit (Al Abed et al, 2016).…”

Acute stress impairs intentional memory suppression through aberrant prefrontal cortex activation in high trait ruminators

“…Moreover, research has shown dynamic interaction between the prefrontal cortex and the temporal gyrus during the process of memory suppression ( Depue et al, 2007 ). Specifically, an increase in brain activation in the DLPFC was found to be accompanied by decreased activity in the hippocampus during memory suppression ( Costanzi et al, 2021 ). These findings indicate that brain regions including the DLPFC, the temporal gyrus and hippocampus play an important roles during memory suppression.…”

Forgetting generates a novel state that is reactivatable

“…Meanwhile, the rate of forgetting is integral to its function. Excessively persistent memories due to slow forgetting, especially those of aversive experience, may be associated with mental health issues in posttraumatic stress disorder ( 8 ). In addition, mutants of several autism-risk genes in Drosophila displayed reduced behavioral flexibility associated with impaired forgetting ( 3 , 9 ).…”