Neural correlates underlying impaired memory facilitation and suppression of negative material in depression

Abstract

Previous behavioral studies demonstrated that depressed individuals have difficulties in forgetting unwanted, especially negative, event. However, inconsistent results still exit and the neural mechanism of this phenomenon has not been investigated. This study examined the intentional memory facilitation/suppression of negative and neutral materials in depression using Think/No-Think paradigm. We found that compared with nondepressed group, depressed group recalled more negative items, irrespective of either "Think" or "No-Think" instructions. Accordingly, the frontal N2 (reflecting voluntary memory inhibition) and parietal late positive component (LPC) (reflecting conscious recollection) showed deflection for negative items in depressed compared with nondepressed participants. On the one hand, the reduced N2 for negative "No-Think" items indicated that depressed individuals have low motivation to suppress negative items so intentional forgetting is less successful for mood-congruent events. On the other hand, the enhanced LPC for negative "Think" items suggested that negative memories are excessively revisited by depressed participants (compared with nondepressed ones) due to their mood-congruent and intrusive nature. Thus we demonstrated that depressed individuals show behavioral and ERP deviations from healthy controls for both voluntary suppression and conscious retrieval of negative memory; the two abnormalities of memory control together contribute to the difficulties in forgetting negative material in depression.

The Think/No‐Think Alcohol Task: A New Paradigm for Assessing Memory Suppression in Alcohol‐Related Contexts

“…Thus, the lower LPP amplitude observed for No‐Think trials relative to Think trials may constitute an index of the reduction in the amount of conscious recollection. These findings converge with earlier ERP studies which have repeatedly reported a diminished parietal positivity in comparable time windows for No‐Think relative to Think material (Bergström et al., , 2009a; Cano and Knight, ; Chen et al., ; Depue et al., ; Mecklinger et al., ; Waldhauser et al., ; Zhang et al., ). In the same line, the lower LPP amplitude for suppressed alcohol‐related memories than for recalled nonalcohol‐related memories might be indicative of a decrement in the amount of conscious recollection devoted to alcohol relative to no‐alcohol material, which is also congruent with the behavioral evidence: Alcohol No‐Think items displayed lower recollection rates than No‐Alcohol Think items.…”

“…This positive wave, which arises approximately 400 to 800 ms after stimulus presentation, is largest over parietal scalp locations—often lateralized to the left hemisphere (Allan et al., ; Doidge et al., )—and has been interpreted as an index of successful recollection (Friedman and Johnson, ; Rugg and Curran, ; Wilding and Ranganath, ; Yonelinas, ). During the TNT task, this late parietal positivity (LPP) is typically smaller for No‐Think items than for Think items (Bergström et al., 2009b; Cano and Knight, ; Depue et al., ; Mecklinger et al., ; Zhang et al., ). The reduction in the LPP amplitude linked to the attempts of suppression is considered the ERP correlate of the attenuation of recollection‐related activity in the hippocampal‐parietal cortical network (Bergström et al., ; Chen et al., ; Mecklinger et al., ).…”

Memory suppression and its deficiency in psychological disorders: A focused meta-analysis

“…Moreover, we observed a numerically larger impairment for participants suffering from PTSD, GAD, or elevated anxiety. These data thus corroborate prior evidence from individual studies that had reported a negative association between SIF and trait anxiety (Benoit et al, 2016;Waldhauser et al, 2018), poor thought control ability (Catarino et al, 2015), depressed mood (Zhang et al, 2016), or rumination (Fawcett et al, 2015) 755…”

“…Second, we coded the valence of the stimulus material as either neutral, positive, negative, or mixed (i.e., when the only reported effect sizes were combined across different valence levels). When studies comprehensively reported SIF for different valence categories assigned to the same 255 participants (e.g., for neutral, negative, and positive memories in Marzi, Regina, & Righi, 2014;neutral and negative in Sacchett et al, 2017;Zhang, Xie, Liu, & Luo, 2016), we generally included the effect size related to neutral items. Only for one study (Dieler, Herrmann, & Fallgatter, 2014) did we code SIF for negative rather than neutral items, because its analysis of group differences (low vs. high anxiety) was based on 260 negative items only.…”

Reconsidering unconscious persistence: Suppressing unwanted memories reduces their indirect expression in later thoughts

“…First, growing evidence suggests that inhibitory processes engaged to suppress retrieval of unwanted memories reduce explicit memory for the suppressed events, contributing to a phenomenon known as suppression-induced forgetting ( Anderson & Green, 2001 ; see Anderson & Hanslmayr, 2014 for a review). Notably, difficulties in forgetting via retrieval suppression have been associated with worse mental health status: impaired suppression-induced forgetting has been found in individuals suffering from post-traumatic stress disorder ( Catarino, Kupper, Werner-Seidler, Dalgleish, & Anderson, 2015 ), high ruminators ( Fawcett et al, 2015 , Hertel et al, 2018 ), people with higher trait anxiety ( Marzi, Regina, & Righi, 2014 ; see also Benoit, Davies, & Anderson, 2016 ), and in participants suffering from depression ( Hertel and Gerstle, 2003 , Noreen and Ridout, 2016a , Noreen and Ridout, 2016b , Zhang et al, 2016 ). In contrast, better suppression-induced forgetting ability predicts reduced intrusiveness of a traumatic film over a one-week period ( Streb, Mecklinger, Anderson, Lass-Hennemann, & Michael, 2016 ) and also predicts reduced negative affect associated with suppressed content ( Gagnepain, Hulbert, & Anderson, 2017 ).…”