Consummatory Reward Research Articles

Differentiating anticipatory and consummatory reward processing in problematic pornography use: An event-related potential analysis of reward dynamics

Problematic pornography use (PPU) is characterized by compulsive and uncontrolled pornography consumption due to a disordered reward processing system. Past studies have shown that reward involves multiple stages, but the connection between these specific stages and PPU remains unclear. In this research, an electrophysiological incentive delay task (IDT) was employed, using both erotic and monetary incentives as rewards, to decompose the distinct phases of both anticipatory and consummatory aspects of reward processing. ERP components linked to reward anticipation (cue-P3 and contingent negative variation, CNV), as well as reward feedback (reward positivity; RewP and feedback-P3; fb-P3), were investigated in a group of 31 individuals with PPU and 33 control participants. In contrast to the control group, who reacted faster to monetary cues, individuals with PPU responded more quickly to erotic cues. RT differences between erotic and monetary cues correlated with CNV amplitudes during anticipation, although no significant CNV differences across groups. In the consummatory phase, controls had higher RewP for large-monetary than large-erotic rewards, not seen in the PPU group. Conversely, the PPU group had increased fb-P3 for large-erotic over large-monetary rewards, a trend absents in controls. Our findings indicate an imbalanced sensitivity in PPU to erotic versus non-erotic rewards, evident in both the anticipatory and consummatory aspects of reward processing. This imbalance could lead to a preference for erotic rewards, possibly fostering addictive sexual behaviors.

Trait dimensions of anticipatory and consummatory reward relate differently to self-injurious thoughts and behaviors in a community adult sample

BackgroundSelf-injurious thoughts and behaviors (SITBs) are a major problem worldwide and continue to be a serious public health concern. Research investigating risk factors for suicide has shown that reward processes, such as the inability to feel pleasure, may confer risk for SITBs. However, less work has examined how different dimensions of trait reward relate to SITBs. Accordingly, the present study investigated the unique and interactive effects of trait anticipatory and consummatory reward for explaining SITBs. Methods260 community adults ages 18–55 (M/SD = 32.79/10.54, females = 49.6 %, males = 50.4 %) completed an interview, neuropsychological tests, and questionnaires. We used hierarchical multivariate multiple regression analysis to assess cross-sectional associations between trait anticipatory and consummatory reward and different types of SITBs [self-injurious thoughts, nonsuicidal self-injury (NSSI), and suicide attempts] from the Risky, Impulsive, and Self-destructive Behavior Questionnaire. ResultsThe unique variance associated with anticipatory and consummatory reward were differentially related to self-injurious thoughts but unrelated to self-injurious behaviors (NSSI/suicide attempts). The interaction of anticipatory and consummatory reward was associated with self-injurious behavior, such that the inability to experience both anticipatory and consummatory reward was associated with higher frequency of NSSI. LimitationsLimitations of the study include its cross-sectional nature and reliance on self-reported measures. ConclusionsLow anticipatory reward and high consummatory reward may confer risk for self-injurious thoughts. Low levels of both trait anticipatory and consummatory reward may confer risk for NSSI. Findings suggest reward sensitivity may be an understudied risk factor for a range of SITBs.

Negative emotion reduces the discriminability ofreward outcomes inthe ventromedial prefrontal cortex.

Reward and emotion are tightly intertwined, so there is a growing interest in mapping their interactions. However, our knowledge of these interactions in the human brain, especially during the consummatory phase of reward is limited. To address this critical gap, we conducted a functional magnetic resonance imaging study to investigate the effects of negative emotion on reward outcome processing. We employed a novel design where emotional valence (negative or neutral) indicated the type of outcome (reward or no-reward) in a choice task. We focused our functional magnetic resonance imaging analysis on the ventro-medial prefrontal cortex (vmPFC), ventral striatum and amygdala, which were frequently implicated in reward outcome processing. In these regions of interest, we performed multi-voxel pattern analysis to specifically probe how negative emotion modulates reward outcome processing. In vmPFC, using decoding analysis, we found evidence consistent with the reduced discriminability of multi-variate activity patterns of reward vs no-reward outcomes when signaled by a negative relative to a neutral image, suggesting an emotional modulation of reward processing along the plausible common value/valence dimension. These findings advance our limited understanding of the basic brain mechanisms underlying the influence of negative emotion on consummatory reward processing, with potential implications for mental disorders, particularly anxiety and depression.

Neural abnormalities of reward processing in adolescents with bipolar disorders: An ERP study

Adolescent onset is common in bipolar disorders (BDs) and is associated with a worse illness course in adulthood. A model of BDs suggests that a dysregulated behavioral approach system (BAS), a neural system that mobilizes reward-seeking behavior, is at the root of BDs. Normative adolescence is often accompanied by dynamic changes to neural structures underlying the BAS and related cognitive processes. It is possible that adolescent-onset BDs is associated with abnormal BAS neurodevelopment. Consistently, the present study is the first to compare specific BAS-relevant anticipatory and consummatory reward processes as indexed by event-related potentials (ERPs) in adolescents with BDs and typically developing peers. Using a sample of 43 adolescents with BDs and 56 without psychopathology, we analyzed N1 and P3 responses to anticipatory cues and feedback-related negativity (FRN) and P3 responses to feedback stimuli during a monetary incentive delay (MID) task. Hierarchical linear models examined relationships between ERP amplitudes and diagnostic group, MID condition, sex, and age. During anticipation phase, adolescent boys with BDs exhibited significantly larger N1 amplitudes in loss than even or gain trials. During feedback phase, compared to their healthy peers, adolescents with BDs had smaller FRN amplitudes across all conditions. Additional effects involving age, sex and trial type were observed. The findings indicate subtle, non-ubiquitous BAS-relevant neural abnormalities involving early attentional processes during reward anticipation and reward learning following feedback in adolescents with BDs. Adolescents with BDs did not show overall hypersensitive neural responses to monetary reward anticipation or feedback observed in adults with BDs.

Aberrant reward dynamics in depression with anticipatory anhedonia

ObjectivePrevious studies have shown that anticipatory anhedonia is linked to abnormal reward processing. The present study aimed to explore the underlying neural mechanism of the influence of anticipatory anhedonia symptoms on reward processing. MethodsElectrophysiological activities in the anticipatory and consummatory phase were recorded during the Monetary Incentive Delay (MID) task in 24 depressed high anticipatory anhedonia (HAA) patients, 25 depressed low anticipatory anhedonia (LAA) patients, and 29 healthy controls (HC). ResultsWe suggested a significant condition × group interaction effect on feedback-related negativity (FRN) amplitudes during the consummatory phase, a smaller FRN in reward cue trails compared with neutral cue trail was revealed in the HC and LAA group, but such reward-related effect was not found in the HAA group. In addition, we found significant correlations between FRN, fb-P3 and cue-N1, cue-N2 in the HC group, besides, significant correlations between FRN, fb-P3 and cue-P2 was also revealed in the HC and LAA group. However, no significant correlation was found in HAA patients. ConclusionsOur results suggest that the link between the anticipatory and consummatory phase was interrupted in depressed HAA patients, which may be driven by the aberrant consummatory reward processing. SignificanceThe current study is the first one to demonstrate the influence of anticipatory anhedonia symptom on the association between anticipatory and consummatory phase of reward process.

Deficits in consummatory reward relate to severity of cocaine use

Background and aimsIdentifying modifiable neuropsychological factors associated with more severe CUD could improve CUD treatment. Impairments in processing of non-drug rewards may be one such factor. This study assessed the relationship between reward functioning and cocaine use severity using multi-modal measures of three distinct reward functions: consummatory reward (pleasure or “liking”); motivational reward (“wanting”) and reward learning. MethodsFifty-three adults with at least moderate CUD completed self-report and behavioral measures of consummatory reward, motivational reward and reward learning, and a composite cocaine use severity measure including quantity, frequency and life impacts of cocaine use. We conducted parallel Frequentist and Bayesian multiple regressions with measures of reward functioning as predictors of cocaine use severity. ResultsLess self-reported ability to experience pleasure, a hypothesized measure of consummatory reward, significantly predicted greater severity after adjustment for covariates and multiple hypothesis testing, β = 0.39, t(38) = 2.86, p = 0.007. Bayesian analyses confirmed a highly likely association between severity and ability to experience pleasure, and provided moderate evidence for associations with willingness to exert effort and reward learning. ConclusionsOur results suggest that less experience of subjective pleasure is related to greater cocaine use severity. This cross-sectional study cannot establish whether differences in consummatory reward are pre-existing, a result of CUD, or both. However, these results suggest interventions focused on increasing subjective pleasure, such as mindful “savoring”, should be investigated for CUD.

Hedonic Overeating–Questionnaire: Exploring interactive effects between wanting, liking, and dyscontrol on body mass index

The Hedonic Overeating–Questionnaire is a brief self-report measure for the trait assessment of liking (pleasure to eat; consummatory reward component), wanting (food craving; anticipatory reward component), and dyscontrol (loss of control over eating). In the original validation study, higher scores on each of the three subscales related to higher body mass index (BMI). However, theories on food reward and self-regulation suggest that overeating and obesity may also result from interactions between these aspects. Therefore, we reanalyzed the data of the original, cross-sectional study (N = 2504, 53% female) and explored whether liking, wanting, and dyscontrol scores interactively predicted BMI. Indeed, there was a significant interaction effect Wanting × Dyscontrol on BMI such that higher dyscontrol scores related to higher BMI, particularly at high wanting scores. The other two-way interactions and the three-way interaction were not significant. Results do not support certain theories on food reward (e.g., the incentive-sensitization theory of addiction and its application to obesity), which would suggest an interactive effect between liking and wanting on BMI. However, they do support dual systems models of self-regulation that suggest that overeating and obesity result from an interplay of strong bottom-up impulses (here: wanting) and weak top-down control (here: dyscontrol).

Parsing within & between-person dynamics of therapy homework completion and clinical symptoms in two cognitive behavioral treatments for adults with anhedonia

ObjectiveHomework is a key theoretical component of cognitive-behavioral therapies, however, the effects of homework on clinical outcomes have largely been evaluated between-persons rather than within-persons. MethodsThe effects of homework completion on treatment response were examined in a randomized trial comparing Behavioral Activation Treatment for Anhedonia (BATA, n = 38), a novel psychotherapy, to Mindfulness-Based Cognitive Therapy (MBCT, n=35). The primary endpoint was consummatory reward sensitivity, measured weekly by the Snaith Hamilton Pleasure Scale (SHAPS), up to 15 weeks. Multilevel models evaluated change in SHAPS scores over time and the effects of clinician-reported and participant-reported homework. ResultsBATA and MBCT resulted in significant, equivalent reductions in SHAPS scores. Unexpectedly, participants who completed greater mean total amounts of homework did not improve at a faster rate (i.e., no between-person effect). However, sessions with greater than average participant-reported homework completion were associated with greater than average reductions in SHAPS scores (i.e., a within-person effect). For clinician-reported homework, this effect was only evident within the BATA condition. ConclusionThis study shows psychotherapy homework completion relates to symptomatic improvement in cognitive-behavioral treatments for anhedonia when session-to-session changes are examined within-person. On the contrary, we found no evidence that total homework completion predicted greater improvements between-person. When possible, psychotherapy researchers should evaluate their constructs of interest across multiple sessions (not just pre/post) to allow more direct tests of hypotheses predicted by theoretical models of individual change processes.

Frustrative nonreward and the basal ganglia: Chemogenetic inhibition and excitation of the nucleus accumbens and globus pallidus externus during reward downshift

Frustrative nonreward contributes to anxiety disorders and addiction, and is included in the Research Domain Criteria initiative as a relevant endophenotype. These experiments explored the role of the basal ganglia in consummatory reward downshift (cRD) using inhibitory and excitatory DREADDs (designer receptors exclusively activated by designer drugs) infused in either the nucleus accumbens (NAc) or one of its downstream targets, the globus pallidus externus (GPe). NAc inhibition did not disrupt consummatory suppression during a 32-to-2% (Experiment 1) or 8-to-2% sucrose downshift (Experiment 2). However, NAc excitation enhanced consummatory suppression during a 32-to-2% sucrose downshift (Experiment 1). GPe inhibition caused a trend toward increased consummatory suppression after a 32-to-2% sucrose downshift, whereas GPe excitation eliminated consummatory suppression after an 8-to-2% sucrose downshift (Experiment 3). Chemogenetic manipulations of NAc and GPe had no detectable effects on open field activity. The effects of DREADD activation via clozapine N-oxide (CNO) administration were compared to controls that carried the DREADDs, but received vehicle injections. There was no evidence that CNO or vehicle injections in virus vector control (VVC) animals affected cRD or OF activity after either CNO or vehicle injections. NAc and GPe excitation led to opposite results in the cRD task, providing evidence that the basal ganglia circuit has a function in frustrative nonreward in the absence of detectable motor effects.

How gut hormones shape reward: A systematic review of the role of ghrelin and GLP-1 in human fMRI

The gastrointestinal hormones ghrelin and glucagon-like peptide-1 (GLP-1) have opposite secretion patterns, as well as opposite effects on metabolism and food intake. Beyond their role in energy homeostasis, gastrointestinal hormones have also been suggested to modulate the reward system. However, the potential of ghrelin and GLP-1 to modulate reward responses in humans has not been systematically reviewed before. To evaluate the convergence of published results, we first conduct a multi-level kernel density meta-analysis of studies reporting a positive association of ghrelin (Ncomb = 353, 18 contrasts) and a negative association of GLP-1 (Ncomb = 258, 12 contrasts) and reward responses measured using task functional magnetic resonance imaging (fMRI). Second, we complement the meta-analysis using a systematic literature review, focusing on distinct reward phases and applications in clinical populations that may account for variability across studies. In line with preclinical research, we find that ghrelin increases reward responses across studies in key nodes of the motivational circuit, such as the nucleus accumbens, pallidum, putamen, substantia nigra, ventral tegmental area, and the dorsal mid insula. In contrast, for GLP-1, we did not find sufficient convergence in support of reduced reward responses. Instead, our systematic review identifies potential differences of GLP-1 on anticipatory versus consummatory reward responses. Based on a systematic synthesis of available findings, we conclude that there is considerable support for the neuromodulatory potential of gut-based circulating peptides on reward responses. To unlock their potential for clinical applications, it may be useful for future studies to move beyond anticipated rewards to cover other reward facets.

Neural deficits in anticipatory and consummatory reward processing are uniquely associated with current depressive symptoms during adolescence.

Deficits within the consummatory phase of reward processing are associated with increased depression symptoms and risk; however, few studies have also examined other aspects of reward processing in relation to depression. In the current study, a community sample of 121 adolescents (Mage =13.1, Min=11.14; Max=15.12; 54% male) completed self-report questionnaires to assess depressive symptoms and the monetary incentive delay (MID) task while EEG was recorded. Results indicated that a reduced cue-P300 as well as a reduced reward positivity (RewP) and feedback negativity (FN) to gain and loss feedback, respectively, were associated with increased depressive symptoms; on the other hand, SPN and feedback P300 were unrelated to depressive symptoms. An exploratory multiple regression analysis revealed that a reduced money cue-P300, a reduced RewP, and a reduced (i.e., less negative) FN, all explained unique variance in depressive symptoms. The current study demonstrates that reduced cue-P300, RewP, and FN amplitudes may reflect distinct deficits in reward processing among adolescents with increased depressive symptoms. Notably, this study is one of the first to leverage the MID task in adolescents in relation to depressive symptoms, allowing for a more in-depth view of the individual differences in reward processing among adolescents with increased depressive symptomatology.

Associations between valued living and responsiveness to daily rewards

Valued living, or the extent to which one's behaviors are congruent with one's values, has been identified as a key target within acceptance-based and CBT treatments. Valued living has been associated with reduced symptom severity and better treatment outcomes. However, the mechanisms underlying these relationships are unclear. Theory suggests that valued living may increase reward salience and/or responsiveness to rewards. However, this remains largely untested. This study is the first to explore associations between valued living and reward responsiveness during both the anticipatory and consummatory phases of reward processing. In addition, this study explored whether valued living in specific domains was associated with reward responsivity in the same or dissimilar domains. A sample of 258 college students completed baseline questionnaires and a 7-day daily diary paradigm assessing reward responsivity to naturally occurring reinforcers. Significant global associations were found among valued living and both anticipatory and consummatory reward responsivity. Valued living across interpersonal, self-care, and educational/work domains was largely predictive of both anticipatory and consummatory reward responsivity in corresponding and distinct domains. Reward responsiveness in the educational/work domain demonstrated the weakest associations with valued living. Findings suggest relationships between valued living and increased reward responsiveness, highlighting a potential mechanism of action contributing to enhanced clinical outcomes and supporting the clinical utility of values-work.

Effort and Appetitive Responding in Depression: Examining Deficits in Motivational and Consummatory Stages of Reward Processing Using the Effort-Doors Task

BackgroundReward sensitivity is a dimensional construct central to understanding the nature of depression. Psychophysiological research on this construct has primarily focused on the reward positivity, an event-related potential (ERP) that indexes consummatory reward sensitivity. This study extended prior research by focusing on ERPs that index the motivational component of reward. MethodsA novel effort-for-reward task was used to elicit motivational and consummatory ERPs. Groups consisting of 34 participants with depression and 32 participants without depression were compared across a range of reward-related ERPs. ResultsParticipants with depression exhibited reduced responsivity to effort completion cues following high effort expenditure, reduced anticipation of rewards after low effort expenditure (i.e., the stimulus preceding negativity), and reduced reward positivity following high effort expenditure. ERPs occurring prior to reward receipt accounted for unique variance in depression status and differentiated between subgroups of depressed individuals. ConclusionsFindings support the utility of leveraging multiple ERPs that index separate reward processing deficits to better characterize depression and depressive subtypes.

Electroconvulsive therapy effects on anhedonia and reward circuitry anatomy: A dimensional structural neuroimaging approach

BackgroundAnhedonia is a core symptom of major depressive disorder (MDD) resulting from maladaptive reward processing. Electroconvulsive therapy (ECT) is an effective treatment for patients with MDD. No previous neuroimaging studies have taken a dimensional approach to assess whether ECT-induced volume changes are specifically related to improvements in anhedonia and positive valence emotional constructs. We aimed to assess the relationship between ECT-induced brain volumetric changes and improvement in anhedonia and reward processing in patients with MDD. MethodsWe evaluated 15 patients with MDD before and after ECT. We used magnetic resonance imaging, clinical scales (i.e., Quick Inventory of Depressive Symptomatology for syndromal depression severity and Snaith-Hamilton Pleasure Scale for anhedonia) and the Temporal Experience of Pleasure Scale for anticipatory and consummatory experiences of pleasure. We identified 5 regions of interest within the reward circuit and a 6th control region relevant for MDD but not core to the reward system (Brodmann Area 25). ResultsAnhedonia, anticipatory and consummatory reward processing improved after ECT. Volume increases within the right reward system separated anhedonia responders and non-responders. Improvement in anticipatory (but not consummatory) reward correlated with increases in volume in hippocampus, amygdala, ventral tegmental area and nucleus accumbens. LimitationsWe evaluated a modest sample size of patients with concurrent pharmacological treatment using a subjective psychometric assessment. ConclusionsWe highlight the importance of a dimensional and circuit-based approach to understanding target engagement and the mechanism of action of ECT, with the goal to define symptom- and circuit-specific response biomarkers for device neuromodulation therapies.

Does Bypass of the Proximal Small Intestine Impact Food Intake, Preference, and Taste Function in Humans? An Experimental Medicine Study Using the Duodenal-Jejunal Bypass Liner.

The duodenal-jejunal bypass liner (Endobarrier) is an endoscopic treatment for obesity and type 2 diabetes mellitus (T2DM). It creates exclusion of the proximal small intestine similar to that after Roux-en-Y Gastric Bypass (RYGB) surgery. The objective of this study was to employ a reductionist approach to determine whether bypass of the proximal intestine is the component conferring the effects of RYGB on food intake and sweet taste preference using the Endobarrier as a research tool. A nested mechanistic study within a large randomised controlled trial compared the impact of lifestyle modification with vs. without Endobarrier insertion in patients with obesity and T2DM. Forty-seven participants were randomised and assessed at several timepoints using direct and indirect assessments of food intake, food preference and taste function. Patients within the Endobarrier group lost numerically more weight compared to the control group. Using food diaries, our results demonstrated similar reductions of food intake in both groups. There were no significant differences in food preference and sensory, appetitive reward, or consummatory reward domain of sweet taste function between groups or changes within groups. In conclusion, the superior weight loss seen in patients with obesity and T2DM who underwent the Endobarrier insertion was not due to a reduction in energy intake or change in food preferences.

An EEG study on the effect of being overweight on anticipatory and consummatory reward in response to pleasant taste stimuli

Two-thirds of adults in the United Kingdom currently suffer from overweight or obesity, making it one of the biggest contributors to health problems. Within the framework of the incentive sensitisation theory, it has been hypothesised that overweight people experience heightened reward anticipation when encountering cues that signal food, such as pictures and smells of food, but that they experience less reward from consuming food compared to normal-weight people. There is, however, little evidence for this prediction. Few studies test both anticipation and consumption in the same study, and even fewer with electroencephalography (EEG). This study sought to address this gap in the literature by measuring scalp activity when overweight and normal-weight people encountered cues signalling the imminent arrival of pleasant and neutral taste stimuli, and when they received these stimuli. The behavioural data showed that there was a smaller difference in valence ratings between the pleasant and neutral taste in the overweight than normal-weight group, in accordance with our hypothesis. However, contrary to our hypothesis, the groups did not differ in their electrophysiological response to taste stimuli. Instead, there was a reduction in N1 amplitude to both taste and picture cues in overweight relative to normal-weight participants. This suggests that reduced attention to cues may be a crucial factor in risk of overweight.

Relationships Among Sleep Disturbance, Reward System Functioning, Anhedonia, and Depressive Symptoms

Recent models propose reward system dysfunction as a key mediator of the relationship between sleep and depression and anhedonia. This study explored interrelationships among sleep disturbance, depressive symptoms, anhedonia, and reward responsiveness. Two-hundred and sixty undergraduate students completed questionnaires and a daily diary paradigm assessing sleep, reward responsiveness, depression, anhedonia, and positive affect over 1 week. Baseline sleep disturbance was associated with depressive symptoms, anhedonia, and reward responsiveness. Daily diary sleep parameters showed differential associations with anticipatory versus consummatory reward responsiveness and positive affect. Poorer sleep quality, shorter sleep duration, and longer awakening after sleep onset predicted blunted anticipatory and consummatory reward responsiveness, while increased sleep onset latency and lower sleep efficiency predicted only decreased consummatory reward responsiveness. All sleep indices, except sleep onset latency, were associated with positive affect. Findings demonstrate unique associations between disparate sleep disturbance and reward responsiveness elements, highlighting new treatment mechanisms for anhedonia and depression.

The effort-doors task: Examining the temporal dynamics of effort-based reward processing using ERPs

Aberrant reward processing is a cardinal feature of various forms of psychopathology. However, recent research indicates that aberrant reward processing may manifest at temporally distinct substages and involve interdependent subcomponents of reward processing. To improve our understanding of both the temporal dynamics and distinct subcomponents of reward processing, we added an effort manipulation to the "doors" reward-task paradigm, to derive behavioral and event-related potential (ERP) measures of effort-based reward processing. Behavioral measures consisting of reaction time, response rate, and response rate change were used to index effort expenditure, and ERP measures were used to index attention allocated toward effort-completion cues, anticipation of reward, valuation of reward, and attention toward monetary feedback. Reduced response rate and slowing of response were evident during the high effort versus the low effort condition. ERP findings indicated increased attention to signals of high- compared to low-effort completion cues-as well as reduced anticipation of rewards, and reduced attention toward feedback information following high effort expenditure. Participants showing the most response-rate slowing evidenced the greatest reward devaluation following high versus low effort. Findings demonstrate that the addition of an effort expenditure manipulation to the doors reward paradigm produced reliable ERP and behavioral measures of effort-based reward processing, providing opportunities for future researchers to utilize the effort-doors task to parse the temporal dynamics of both anticipatory and consummatory reward processing components.

SAT-LB59 Functional MRI Study: Weight Loss Induced Changes in Taste Receipt-Induced Activation in the Striatum and Hypothalamus

Background: Reward behaviors including those related to eating are influenced by output from the ventral striatum (VS), dorsal striatal [caudate(Cau) and putamen(Put)]and hypothalamus (HTH). We hypothesized that weight loss would induce modifications in activation in these regions of interest (ROI) during a consummatory reward task. Methods: We recruited metabolic abnormal obese (MAO) from the VA St.Louis Health Care System and Washington University in St.Louis (WUSTL). MAO was screened for by fasting insulin and plasma glucose, 2 hour 75 gram OGTT, and hemoglobin A1c. MAO was defined as prediabetes by ADA criteria and/ or elevated HOMA-IR. Functional magnetic resonance imaging (fMRI) scanning sessions were completed at the WUSTL Center for Clinical Imaging Research. A rapid event-related design was used to randomly deliver taste of chocolate milk (choc) or tasteless water (wat). Each taste receipt was proceeded by a cue of corresponding image of chocolate milk or a glass of water. A total of 5 runs, each with 24 trials were completed. Imaging analyses included preprocessing with fMRIprep including censoring excessive motion ≥ 0.5mm. Single subject GLM analyses were completed in AFNI. ROIs were designated bilaterally (lt and rt) except for HTH. A canonical HRF was applied to the food cue event and the AFNI tent function over 9 TRs was applied to the taste receipt event. To evaluate for an effect of weight loss (WL) on food cue and taste receipt-induced activation, repeated measures ANOVA for each region was completed with condition (choc or wat) as a covariate. Also in the model for taste receipt, repetition time (TR) was included as a covariate. Results reported as F(sign.). Results: Ten participants achieved at least 7% WL, (range 7-15%), 44±8 years, BMI 38±4kg/m2, f/m 4/6, fasting pg 105±11, 2 hour OGTT pg 132 ±49 mg/dL, HOMA-IR 3.9±1.8. One participant fulfilled criteria for T2D. For taste receipt several significant effects were found for WL: Cau_lt WL 5.9(0.02) and WL*TR 4.9(0.03), Cau_rt WL 8.6(0.004) and WL*TR 8(0.005), Put_lt WL 8.5(0.004), HTH WL*condition 5.4(0.02) and a trend for WL 3.3(0.07). All other comparisons were non-significant including all in the VS and all for food cue. Conclusions: Moderate weight loss in MAO modified taste receipt-induced activation in the Cau, Put, and HTH but not in the VS.

Anhedonia and emotional numbing in treatment-seeking veterans: behavioural and electrophysiological responses to reward

ABSTRACTBackground: Anhedonia is a common symptom following exposure to traumatic stress and a feature of the PTSD diagnosis. In depression research, anhedonia has been linked to deficits in reward functioning, reflected in behavioural and neural responses. Such deficits following exposure to trauma, however, are not well understood.Objective: The current study aims to estimate the associations between anhedonia, PTSD symptom-clusters and behavioural and electrophysiological responses to reward.Methods: Participants (N = 61) were recruited among Danish treatment-seeking veterans at the Department of Military Psychology in the Danish Defence. Before entering treatment, participants were screened with symptom measurement instruments and participated in a joint behavioural-electrophysiological experiment. The experimental paradigm consisted of a signal-detection task aimed at assessing reward-driven learning. Simultaneous electrophysiological-recordings were analysed to evaluate neural responses upon receiving reward, as indicated by the Feedback-Related Negativity (FRN) component.Result: Anhedonia as conceptualized in depression correlated with behavioural learning (r = -0.28, p = .032). Neither anhedonia nor behavioural learning correlated with FRN. However, the anhedonia symptom cluster of PTSD did correlate with FRN (r = 0.29, p = .023). Extending upon this in an exploratory analysis, the specific PTSD-symptom emotional numbing was found to correlate moderately with FRN (r = 0.38, p = .003).Conclusion: The present data suggest that anhedonia in trauma-exposed individuals is related to the anticipatory aspect of reward, whereas the neural consummatory reward response seems unlinked. Interestingly, emotional numbing in the same population is related to the consummatory phase of reward, correlating with the FRN response. This suggests that anhedonia and emotional numbing in response to trauma might pertain to different phases of reward processing.