Examining the bidirectional longitudinal associations between body mass index and episodic memory following bariatric surgery.

BACKGROUND: The relationship between obesity and episodic memory (i.e., conscious memory for specific events) is hypothesized to be bidirectional. Indeed, studies have shown that metabolic and bariatric surgery (MBS) is associated with episodic memory improvement, and better memory is associated with better postsurgical weight-loss outcomes. However, direct tests of the hypothesized bidirectional association between episodic memory and body mass index (BMI) in MBS are lacking, as few studies have employed repeated, prospective assessments of memory in conjunction with bidirectional modeling techniques. OBJECTIVES: The present study used latent change score analysis to examine the bidirectional longitudinal associations between episodic memory and BMI in the 2 years following MBS. SETTING: University hospital; public practice. METHODS: Episodic memory function and BMI were assessed in adults prior to MBS, and at 1, 6, 12, 18, and 24-months postsurgery. RESULTS: A total of 124 participants (41% lost at 2-year follow-up) showed, on average, favorable weight-loss and episodic memory outcomes following MBS. Crucially, presurgery episodic memory predicted initial change in BMI at 1-month postsurgery, and postsurgery episodic memory at 1- and 6-months predicted change in BMI at 6- and 12-months postsurgery. No evidence was found for pre- and postsurgery BMI predicting changes in episodic memory. CONCLUSIONS: Results supported a unidirectional prospective relationship between episodic memory and weight change following MBS, such that better memory pre- and postsurgery predicted improved weight-loss outcomes. These findings highlight the likely importance of episodic memory function for weight change and support the potential benefit of targeting memory processes to improve weight-loss outcomes.

Behaviourally assessed negative urgency is uniquely associated with binge-eating frequency.

OBJECTIVE: Binge eating appears to be associated with impulsivity, especially in response to negative affect (i.e., negative urgency). However, negative urgency is typically assessed via self-report, which captures only some aspects of urgency and may be subject to bias. Few studies have examined impulsivity following experimental manipulations of affect in binge-eating samples. METHOD: In the present study, individuals who engage in regular binge eating completed a behavioural impulsivity (go/no-go) task with high- and low-calorie food stimuli, once following negative affect induction and once following neutral affect induction. RESULTS: Greater behavioural impulsivity to high-calorie food cues while in a negative (and not a neutral) affective state was associated with more frequent binge-eating behaviour. Further, this behavioural measure of negative urgency uniquely accounted for variance in binge-eating frequency when controlling for self-reported negative urgency, suggesting that behavioural measures may be a useful complement to self-report measures. DISCUSSION: These findings provide novel and compelling evidence for the relationship between negative urgency and binge eating, highlighting negative urgency as a potentially important target for intervention.

An examination of state and trait urgency in individuals with binge-eating disorder.

OBJECTIVE: Negative urgency (i.e., acting rashly when experiencing negative affect; NU), is a theorised maintenance factor in binge-eating type eating disorders. This study examined the association between trait NU and eating disorder severity, momentary changes in state NU surrounding episodes of binge eating, and the momentary mechanistic link between affect, rash action, and binge-eating risk. METHODS: Participants were 112 individuals with binge-eating disorder (BED). Baseline measures included the UPPS-P Impulsive Behaviour Scale to assess trait NU and the Eating Disorders Examination to assess binge-eating frequency and global eating disorder severity. Ecological momentary assessment captured real-time data on binge eating, negative affect, and state NU. RESULTS: Multiple regression analysis revealed a strong association between trait NU and eating disorder severity. Generalised estimating equations showed that state NU increased before and decreased after binge-eating episodes, and that this pattern was not moderated by trait-level NU. Finally, a multilevel structural equation model indicated that increases in rash action mediated the momentary relationship between states of high negative affect and episodes of binge eating. CONCLUSION: These findings underscore the importance of both trait and state NU in binge-eating type eating disorders, and suggest NU as a potential key target for intervention.

Changes in evening-shifted loss of control eating severity following treatment for binge-eating disorder.

BACKGROUND: Loss of control eating is more likely to occur in the evening and is uniquely associated with distress. No studies have examined the effect of treatment on within-day timing of loss of control eating severity. We examined whether time of day differentially predicted loss of control eating severity at baseline (i.e. pretreatment), end-of-treatment, and 6-month follow-up for individuals with binge-eating disorder (BED), hypothesizing that loss of control eating severity would increase throughout the day pretreatment and that this pattern would be less pronounced following treatment. We explored differential treatment effects of cognitive-behavioral guided self-help (CBTgsh) and Integrative Cognitive-Affective Therapy (ICAT). METHODS: Individuals with BED (N = 112) were randomized to receive CBTgsh or ICAT and completed a 1-week ecological momentary assessment protocol at baseline, end-of-treatment, and 6-month follow-up to assess loss of control eating severity. We used multilevel models to assess within-day slope trajectories of loss of control eating severity across assessment periods and treatment type. RESULTS: Within-day increases in loss of control eating severity were reduced at end-of-treatment and 6-month follow-up relative to baseline. Evening acceleration of loss of control eating severity was greater at 6-month follow-up relative to end-of-treatment. Within-day increases in loss of control severity did not differ between treatments at end-of-treatment; however, evening loss of control severity intensified for individuals who received CBTgsh relative to those who received ICAT at 6-month follow-up. CONCLUSIONS: Findings suggest that treatment reduces evening-shifted loss of control eating severity, and that this effect may be more durable following ICAT relative to CBTgsh.

Prospective associations between cognitive flexibility and eating disorder symptoms in anorexia nervosa and bulimia nervosa.

This study investigated concurrent and prospective associations between measures of reversal learning and attentional set-shifting and eating disorder symptoms at baseline, 3 months, and 6 months among individuals with anorexia nervosa restricting subtype (AN-R, n = 26), AN binge eating/purging subtype (AN-BP, n = 22), bulimia nervosa (BN, n = 35), and healthy controls (n = 27), and explored whether these associations differed by diagnosis. At baseline, participants completed diagnostic interviews, height/weight measurements, and measures of set-shifting (the Intradimensional/Extradimensional shift task) and reversal learning (a probabilistic reversal learning task). At 3- and 6-month follow-up, participants with eating disorders completed assessments of weight and eating disorder symptoms. A one-way analysis of variance found no evidence that baseline reversal learning and attentional set-shifting differed across diagnostic groups. Multilevel modeling analyses indicated that perseverative errors (an index of reversal learning) predicted an increase in purging over time for individuals with AN-BP and BN. Set-shifting errors differentially predicted frequency of loss of control eating for individuals with AN-BP and BN; however, set-shifting was not related to loss of control eating when examined separately in AN-BP and BN. These findings suggest that disentangling facets of cognitive flexibility may help understand change in eating disorder symptoms.

Neurocognitive reward processes measured via event-related potentials are associated with binge-eating disorder diagnosis and ecologically-assessed behavior.

Altered reward processing has been implicated in the onset and maintenance of binge-eating disorder (BED). However, it is unclear which precise neurocognitive reward processes may contribute to BED. In the present study, 40 individuals with BED and 40 age-, sex-, and BMI-matched controls completed a reward (incentive delay) task while their neural activity was recorded using electroencephalography (EEG). Individuals with BED also completed a 10-day ecological momentary assessment (EMA) protocol assessing binge-eating behavior in the natural environment. Event-related potential (ERP) analysis of the EEG indicated that individuals with BED had stronger anticipatory (CNV) and outcome-related (RewP) neural reward activity to food and monetary rewards, compared to controls. However, within the BED group, greater frequency of binge eating during the EMA protocol was associated with stronger anticipatory (CNV) but weaker outcome-related (RewP) neural reward activity. These associations within the BED group were unique to food, and not monetary, rewards. Although preliminary, these results suggest that both anticipatory ("wanting") and outcome ("liking") reward processes may be generally amplified in BED. However, they also suggest that among individuals with BED, disorder severity may be associated with increased anticipatory reward processes ("wanting"), but relatively decreased reward-outcome processing ("liking"), of food rewards specifically.

Evaluating dietary restriction as a maintaining factor in binge-eating disorder.

OBJECTIVE: Prominent theories of binge-eating (BE) maintenance highlight dietary restriction as a key precipitant of BE episodes. Consequently, treatment approaches for eating disorders (including binge-eating disorder; BED) seek to reduce dietary restriction in order to improve BE symptoms. The present study tested the hypothesis that dietary restriction promotes BE among 112 individuals with BED. METHODS: Participants completed a 7-day ecological momentary assessment (EMA) protocol before and after completing 17 weeks of either Integrative Cognitive-Affective Therapy or guided self-help cognitive behavioral therapy. Analyses examined whether dietary restriction on 1 day of the baseline EMA protocol predicted risk for BE later that same day, and on the following day. Changes in dietary restriction over the course of treatment were also evaluated as a predictor of change in BE from pre-treatment to post-treatment. Baseline dietary restraint was examined as a moderator of the above associations. RESULTS: Dietary restriction did not predict BE later the same day, and changes in restriction were not related to changes in BE across treatment, regardless of baseline dietary restraint levels. Restriction on 1 day did predict increased BE risk on the following day for individuals with higher levels of dietary restraint, but not those with lower levels. DISCUSSION: These findings challenge the assumption that dietary restriction maintains BE among all individuals with BED. Rather, results suggest that dietary restriction may be largely unrelated to BE maintenance in this population, and that reducing dietary restriction generally does not have the intended effect on BE frequency.

Back to the future: Progressing memory research in eating disorders.

OBJECTIVE: Human behaviors, thoughts, and emotions are guided by memories of the past. Thus, there can be little doubt that memory plays a fundamental role in the behaviors (e.g., binging), thoughts (e.g., body-image concerns), and emotions (e.g., guilt) that characterize eating disorders (EDs). Although a growing body of research has begun to investigate the role of memory in EDs, this literature is limited in numerous ways and has yet to be integrated into an overarching framework. METHODS: In the present article, we provide an operational framework for characterizing different domains of memory, briefly review existing ED memory research within this framework, and highlight crucial gaps in the literature. RESULTS: We distinguish between three domains of memory-episodic, procedural, and working-which differ based on functional attributes and underlying neural systems. Most recent ED memory research has focused on procedural memory broadly defined (e.g., reinforcement learning), and findings within all three memory domains are highly mixed. Further, few studies have attempted to assess these different domains simultaneously, though most behavior is achieved through coordination and competition between memory systems. We, therefore, offer recommendations for how to move ED research forward within each domain of memory and how to study the interactions between memory systems, using illustrative examples from other areas of basic and clinical research. DISCUSSION: A stronger and more integrated understanding of the mechanisms that connect memory of past experiences to present ED behavior may yield more comprehensive theoretical models of EDs that guide novel treatment approaches. PUBLIC SIGNIFICANCE: Memories of previous eating-related experiences may contribute to the onset and maintenance of eating disorders (EDs). However, research on the role of memory in EDs is limited, and distinct domains of ED memory research are rarely connected. We, therefore, offer a framework for organizing, progressing, and integrating ED memory research, to provide a better foundation for improving ED treatment and intervention going forward.

Examining the role of craving in affect regulation models of binge eating: Evidence from an ecological momentary assessment study.

Affect regulation models hypothesize that aversive affective states drive binge-eating behavior, which serves to regulate unpleasant emotions. Research using ecological momentary assessment (EMA) demonstrates that increases in guilt most strongly predict subsequent binge-eating episodes, raising the question: why would individuals with binge-eating pathology engage in a binge-eating episode when they feel guilty? Food craving is a robust predictor of binge eating and is commonly associated with subsequent feelings of guilt. The current study used EMA to test the hypothesis that food craving may promote increased feelings of guilt, which then predict an increased risk of binge eating within a sample of 109 individuals with binge-eating disorder. Multilevel mediation models indicated that increased momentary craving at Time 1 directly predicted a greater likelihood of binge eating at Time 2, and craving also indirectly predicted binge eating at Time 2 through momentary increases in guilt at Time 2. In other words, experiencing food craving at one time point was related to an increased likelihood of binge eating at the next time point, and a portion of this influence was attributable to increasing feelings of guilt. These results challenge simple affect regulation models of binge eating, suggesting that food-related anticipatory reward processes (i.e., craving) may be the primary driver of binge-eating risk and account for the increases in guilt commonly observed prior to binge-eating episodes. Although experimental studies are needed to confirm this possibility, these results suggest the importance of addressing food cravings within interventions for binge-eating disorder. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Pre-associative item encoding influences associative memory: Behavioral and ERP evidence.

It is unknown whether the manner with which an item is encoded in isolation, immediately before it is encoded into an inter-inter association, influences associative memory. We therefore presented the items of to-be-encoded associative pairings sequentially and manipulated how each first item of a pair was encoded (before associative encoding could begin). Furthermore, we recorded ERPs during memory encoding to investigate the neurocognitive processes that might relate pre-associative item encoding to subsequent associative memory performance. Behaviorally, we found that pre-associative item elaboration (vs. no elaboration) led to a memory tradeoff-enhanced item memory relative to impaired associative memory. This tradeoff likely reflected that item elaboration reduced cognitive resources for ensuing associative encoding, indexed by a reduced P300 and frontal slow wave at the time of associative encoding. However, frontal slow wave subsequent memory effects measured during pre-associative item encoding revealed that, for a given item, greater semantic elaboration was related to better item and associative memory while greater visual elaboration was related to better item and worse associative memory. Thus, there are likely two opposing ways in which pre-associative item encoding can influence associative memory: (1) by depleting encoding resources to impair associative memory and (2) by scaffolding inter-item associations to enhance associative memory. When item encoding occurs immediately before associative encoding, it appears that the temporary depletion of encoding resources is more important in determining later memory performance. Future research should compare the independent effects of resource depletion and encoding strategy during pre-associative item encoding.