Activation In Reward Regions Research Articles

Appetitive conditioning with pornographic stimuli elicits stronger activation in reward regions than monetary and gaming-related stimuli.

Appetitive conditioning plays an important role in the development and maintenance of pornography-use and gaming disorders. It is assumed that primary and secondary reinforcers are involved in these processes. Despite the common use of pornography and gaming in the general population appetitive conditioning processes in this context are still not well studied. This study aims to compare appetitive conditioning processes using primary (pornographic) and secondary (monetary and gaming-related) rewards as unconditioned stimuli (UCS) in the general population. Additionally, it investigates the conditioning processes with gaming-related stimuli as this type of UCS was not used in previous studies. Thirty-one subjects participated in a differential conditioning procedure in which four geometric symbols were paired with either pornographic, monetary, or gaming-related rewards or with nothing to become conditioned stimuli (CS + porn, CS + game, CS + money, and CS-) in an functional magnetic resonance imaging study. We observed elevated arousal and valence ratings as well as skin conductance responses for each CS+ condition compared to the CS-. On the neural level, we found activations during the presentation of the CS + porn in the bilateral nucleus accumbens, right medial orbitofrontal cortex, and the right ventral anterior cingulate cortex compared to the CS-, but no significant activations during CS + money and CS + game compared to the CS-. These results indicate that different processes emerge depending on whether primary and secondary rewards are presented separately or together in the same experimental paradigm. Additionally, monetary and gaming-related stimuli seem to have a lower appetitive value than pornographic rewards.

Transdiagnostic Mood, Anxiety, and Trauma Symptom Factors in Alcohol Use Disorder: Neural Correlates Across 3 Brain Networks

BackgroundAlcohol use disorder (AUD) is associated with high rates of trauma, mood, and anxiety disorders. Across these diagnoses, individual symptoms substantially overlap, highlighting the need for a transdiagnostic approach. Furthermore, there is limited research on how transdiagnostic psychopathology impacts the neural correlates of AUD. Thus, we aimed to identify symptom factors spanning diagnoses and examine how they relate to the neurocircuitry of addiction. MethodsEighty-six veterans with AUD completed self-report measures and reward, incentive salience, and cognitive control functional magnetic resonance imaging tasks. Factor analysis was performed on self-reported trauma, depression, anxiety, and stress symptoms to obtain transdiagnostic symptom compositions. Neural correlates of a priori–defined regions of interest in the 3 networks were assessed. Independent sample t tests were used to compare the same nodes by DSM-5 diagnosis. ResultsFour symptom factors were identified: Trauma distress, Negative affect, Hyperarousal, and Somatic anxiety. Trauma distress score was associated with increased cognitive control activity during response inhibition (dorsal anterior cingulate cortex). Negative affect was related to lower activation in reward regions (right caudate) but higher activation in cognitive control regions during response inhibition (left dorsolateral prefrontal cortex). Hyperarousal was related to lower reward activity during monetary reward anticipation (left caudate, right caudate). Somatic anxiety was not significantly associated with brain activation. No difference in neural activity was found by posttraumatic stress disorder, major depressive disorder, or generalized anxiety disorder diagnosis. ConclusionsThese hypothesis-generating findings offer transdiagnostic symptom factors that are differentially associated with neural function and could guide us toward a brain-based classification of psychiatric dysfunction in AUD. Results warrant further investigation of transdiagnostic approaches in addiction.

The Neural Processes in Food Decision-making and their Effect on Daily Diet Management in Successful and Unsuccessful Restrained Eaters

This study aimed to explore the neural mechanisms underlying food decision making in unsuccessful restrained eaters (US-REs) and successful restrained eaters (S-REs). During a functional magnetic resonance imaging scan, participants were required to choose between pairs of high- and low-calorie foods under the following conditions: the congruent condition (choose between high- and low-calorie foods with the same level of tastiness) and incongruent condition (choose between high-calorie foods tastier than the corresponding low-calorie foods). Subsequently, the participants’ diets were monitored for one week. The behavioral results showed that US-REs (n = 28) chose more high-calorie foods than S-REs (n = 26); in contrast, S-REs spent more time in choosing for the incongruent than the congruent condition. The fMRI results found that US-REs exhibited more activity in reward regions (caudate and thalamus) than S-REs in the congruent condition. In the incongruent condition, S-REs showed stronger functional connectivity between the conflict-monitoring region (anterior cingulate cortex) and inhibitory-control regions (inferior frontal gyrus [IFG] and medial frontal gyrus) than US-REs. In both the conditions, increased activation of the insula, putamen, middle frontal gyrus, and IFG could predict increased food intake among US-REs in the following week. Furthermore, in both the conditions, increased IFG activation could predict decreased food cravings among S-REs during the following week. Our results suggest that US-REs have a strong reward response to food. Compared to US-REs, S-REs are more guided more by the goal of weight control, and exhibit strong functional connections between the conflict-monitoring and inhibitory-control regions. Therefore, eating enjoyment and weight-control goals influence restrained eating in daily life.

Development of a Novel Multimodal Social Reward Task for Neurobiological Adult and Late-life Depression Studies

Exposure to social rewards protects against depression. Positive social interactions elicit activation in reward regions, which are hypoactive in depression especially in late life. Psychotherapy can increase engagement in social interactions and in turn increase activity in the reward system. We developed a paradigm to assess changes in social reward processing using EEG and MRI during psychotherapy for late life depression.

The longitudinal stability of fMRI activation during reward processing in adolescents and young adults

BackgroundThe use of functional neuroimaging has been an extremely fruitful avenue for investigating the neural basis of human reward function. This approach has included identification of potential neurobiological mechanisms of psychiatric disease and examination of environmental, experiential, and biological factors that may contribute to disease risk via effects on the reward system. However, a central and largely unexamined assumption of much of this research is that neural reward function is an individual difference characteristic that is relatively stable and trait-like over time. MethodsIn two independent samples of adolescents and young adults studied longitudinally (Ns = 145 & 139, 100% female and 100% male, ages 15–21 and 20–22, 2–4 scans and 2 scans respectively), we tested within-person stability of reward-task BOLD activation, with a median of 1 and 2 years between scans. We examined multiple commonly used contrasts of active states and baseline in both the anticipation and feedback phases of a card-guessing reward task. We examined the effects of cortical parcellation resolution, contrast, network (reward regions and resting-state networks), region-size, and activation strength and variability on the stability of reward-related activation. ResultsIn both samples, contrasts of an active state relative to a baseline were more stable (ICC: intra-class correlation; e.g., Win>Baseline; mean ICC = 0.13 – 0.33) than contrasts of two active states (e.g., Win>Loss; mean ICC = 0.048 – 0.05). Additionally, activation in reward regions was less stable than in many non-task networks (e.g., dorsal attention), and activation in regions with greater between-subject variability showed higher stability in both samples. ConclusionsThese results show that some contrasts from functional neuroimaging activation during a card guessing reward task have partially trait-like properties in adolescent and young adult samples over 1–2 years. Notably, results suggest that contrasts intended to map cognitive function and show robust group-level effects (i.e. Win > Loss) may be less effective in studies of individual differences and disease risk. The robustness of group-level activation should be weighed against other factors when selecting regions of interest in individual difference fMRI studies.

Neural Indicators Of Food Cue Reactivity, Regulation, And Valuation And Their Associations With Body Composition And Daily Eating Behavior.

Exposure to food cues activates the brain's reward system and undermines efforts to regulate impulses to eat. During explicit regulation, lateral prefrontal cortex activates and modulates activity in reward regions and decreases food cravings. However, it is unclear the extent to which between-person differences in recruitment of regions associated with reward processing, subjective valuation, and regulation during food cue exposure-absent instructions to regulate-predict body composition and daily eating behaviors. In this preregistered study, we pooled data from five fMRI samples (N = 262) to examine whether regions associated with reward, valuation, and regulation, as well as whole-brain pattern expression indexing these processes, were recruited during food cue exposure and associated with body composition and real-world eating behavior. Regression models for a single a priori analytic path indicated that univariate and multivariate measures of reward and valuation were associated with individual differences in BMI and enactment of daily food cravings. Specification curve analyses further revealed reliable associations between univariate and multivariate neural indicators of reactivity, regulation, and valuation, and all outcomes. These findings highlight the utility of these methods to elucidate brain-behavior associations and suggest that multiple processes are implicated in proximal and distal markers of eating behavior.

Neural reward response to substance-free activity images in opiate use disorder patients with depressive symptoms

BackgroundDeficits in the ability to experience reward from natural, substance-free activities and stimuli is a common mechanism contributing to both opiate use disorder and depressive symptoms, and is a target of behavioral-focused treatments for substance use and depression. Although the neural response to monetary, positive affect-eliciting and social images has been investigated, the neural response to images representing substance-free activity engagement remains untested. The current study tested the neural response to anticipation and receipt of substance-free activity engagement images and monetary reward in opiate use disorder patients with elevated depressive symptoms compared to healthy controls. MethodsSixteen male opiate use disorder detoxification patients with elevated depressive symptoms (Beck Depression Inventory (BDI-II) ≥ 14) (OUDD Mage = 32.19 years, SD = 8.17 years) and seventeen male healthy controls (BDI-II < 14) (HC: Mage = 26.82 years, SD = 5.29 years) completed the Monetary Incentive Delay (MID) and newly developed Activity Incentive Delay (AID) tasks. Within- and between-group whole-brain contrasts tested activation during anticipation ([reward]-[non-reward]) and receipt ([win]-[non-win]) of substance-free activity image, monetary, and substance-free activity relative to monetary (AID-MID), reward. ResultsOUDD demonstrated significantly lower activation in reward regions during anticipation and significantly greater activation during receipt of substance-free activity image reward compared to HC. OUDD demonstrated significantly lower activation during anticipation of substance-free activity reward relative to monetary reward, compared to HC. ConclusionsThe observed reduction in frontostriatal response to reward anticipation of substance-free activity engagement images in OUDD, yet increased neural response to reward receipt, supports theory linking reductions in reward processing with deficits in motivation for substance-free activity engagement.

Calcium/calmodulin-stimulated adenylyl cyclases 1 and 8 regulate reward-related brain activity and ethanol consumption

Evidence suggests a predictive link between elevated basal activity within reward-related networks (e.g., cortico-basal ganglia-thalamic networks) and vulnerability for alcoholism. Both calcium channel function and cyclic adenosine monophosphate (cAMP)/protein kinase A-mediated signaling are critical modulators of reward neurocircuitry and reward-related behaviors. Calcium/calmodulin-stimulated adenylyl cyclases (AC) 1 and 8 are sensitive to activity-dependent increases in intracellular calcium and catalyze cAMP production. Therefore, we hypothesized AC1 and 8 regulate brain activity in reward regions of the cortico-basal ganglia-thalamic circuit and that this regulatory influence predicts voluntary ethanol drinking responses. This hypothesis was evaluated by manganese-enhanced magnetic resonance imaging and chronic, intermittent ethanol access procedures. Ethanol-naïve mice with genetic deletion of both AC1 and 8 (DKO mice) exhibited bilateral reductions in baseline activity within cortico-basal ganglia-thalamic regions associated with reward processing compared to wild-type controls (WT, C57BL/6 mice). Significant activity changes were not evident in regions either outside of the cortico-basal ganglia-thalamic network or within the network that are not associated with reward processing. Parallel studies demonstrated that reward network hypoactivity in DKO mice predicted a significant attenuation in consumption and preference levels to escalating ethanol concentrations (12, 20 and 30%) compared to WT mice, an effect that was maintained over extended access (14 sessions) to 20% ethanol. Summarizing, these data support a contribution of AC1 and 8 in cortico-basal ganglia-thalamic activity and the predictive value of this regulatory influence on ethanol drinking behavior, which merits the future evaluation of calcium-stimulated ACs in the neural processes that engender vulnerability to maladaptive alcohol drinking.

A pathway linking reward circuitry, impulsive sensation-seeking and risky decision-making in young adults: identifying neural markers for new interventions

High trait impulsive sensation seeking (ISS) is common in 18–25-year olds, and is associated with risky decision-making and deleterious outcomes. We examined relationships among: activity in reward regions previously associated with ISS during an ISS-relevant context, uncertain reward expectancy (RE), using fMRI; ISS impulsivity and sensation-seeking subcomponents; and risky decision-making in 100, transdiagnostically recruited 18–25-year olds. ISS, anhedonia, anxiety, depression and mania were measured using self-report scales; clinician-administered scales also assessed the latter four. A post-scan risky decision-making task measured ‘risky’ (possible win/loss/mixed/neutral) fMRI-task versus ‘sure thing’ stimuli. ‘Bias’ reflected risky over safe choices. Uncertain RE-related activity in left ventrolateral prefrontal cortex and bilateral ventral striatum was positively associated with an ISS composite score, comprising impulsivity and sensation-seeking–fun-seeking subcomponents (ISSc; P⩽0.001). Bias positively associated with sensation seeking–experience seeking (ES; P=0.003). This relationship was moderated by ISSc (P=0.009): it was evident only in high ISSc individuals. Whole-brain analyses showed a positive relationship between: uncertain RE-related left ventrolateral prefrontal cortical activity and ISSc; uncertain RE-related visual attention and motor preparation neural network activity and ES; and uncertain RE-related dorsal anterior cingulate cortical activity and bias, specifically in high ISSc participants (all ps<0.05, peak-level, family-wise error corrected). We identify an indirect pathway linking greater levels of uncertain RE-related activity in reward, visual attention and motor networks with greater risky decision-making, via positive relationships with impulsivity, fun seeking and ES. These objective neural markers of high ISS can guide new treatment developments for young adults with high levels of this debilitating personality trait.

Neural Correlates of the False Consensus Effect: Evidence for Motivated Projection and Regulatory Restraint.

The false consensus effect (FCE), the tendency to project our attitudes and opinions on to others, is a pervasive bias in social reasoning with a range of ramifications for individuals and society. Research in social psychology has suggested that numerous factors (anchoring and adjustment, accessibility, motivated projection, etc.) may contribute to the FCE. In this study, we examine the neural correlates of the FCE and provide evidence that motivated projection plays a significant role. Activity in reward regions (ventromedial pFC and bilateral nucleus accumbens) during consensus estimation was positively associated with bias, whereas activity in right ventrolateral pFC (implicated in emotion regulation) was inversely associated with bias. Activity in reward and regulatory regions accounted for half of the total variation in consensus bias across participants (R2 = .503). This research complements models of the FCE in social psychology, providing a glimpse into the neural mechanisms underlying this important phenomenon.

On Weight and Waiting: Delay Discounting in Anorexia Nervosa Pretreatment and Posttreatment

BackgroundIndividuals with anorexia nervosa (AN) override the drive to eat, forgoing immediate rewards in favor of longer-term goals. We examined delay discounting and its neural correlates in AN before and after treatment to test a potential mechanism of illness persistence. MethodsInpatients with AN (n = 59) and healthy control subjects (HC, n = 39) performed a delay discounting task at two time points. A subset (n = 30 AN, n = 22 HC) participated in functional magnetic resonance imaging scanning during the task. The task consisted of a range of monetary choices with variable delay times, yielding individual discount rates—the rate by which money loses value over time. ResultsBefore treatment, the AN group showed a preference for delayed over earlier rewards (i.e., less steep discount rates) compared with HC; after weight restoration, AN did not differ from HC. Underweight AN showed slower response times for earlier versus delayed choices; this reversed with treatment. Underweight AN showed abnormal neural activity in striatum and dorsal anterior cingulate; normalization of behavior was associated with increased activation in reward regions (striatum and dorsal anterior cingulate) and decision-making regions (dorsolateral prefrontal cortex and parietal cortex). ConclusionsThe undernourished state of AN may amplify the tendency to forgo immediate rewards in favor of longer-term goals. The results suggest that behavior that looks phenotypically like excessive self-control does not correspond with enhanced prefrontal recruitment. Rather, the results point to alterations in cingulostriatal circuitry that offer new insights on the potential role of abnormalities in decision-making neural systems in the perpetuation of AN.

Multilocus Genetic Composite Reflecting Dopamine Signaling Capacity Predicts Reward Circuitry Responsivity

The objective of the study was to test the hypotheses that humans with genotypes putatively associated with low dopamine (DA) signaling capacity, including the TaqIA A1 allele, DRD2-141C Ins/Ins genotype, DRD4 7-repeat or longer allele, DAT1 10-repeat allele, and the Met/Met COMT genotype, and with a greater number of these genotypes per a multilocus composite, show less responsivity of reward regions that primarily rely on DA signaling. Functional magnetic resonance imaging (fMRI) paradigms were used to investigate activation in response to receipt and anticipated receipt of palatable food and monetary reward. DNA was extracted from saliva using standard methods. Participants were 160 adolescents (mean age = 15.3 years, SD = 1.07 years; mean body mass index = 20.8, SD = 1.9). The main outcome was blood oxygenation level-dependent activation in the fMRI paradigms. Data confirmed that these fMRI paradigms activated reward, attention, somatosensory, and gustatory regions. Individuals with, versus without, these five genotypes did not show less activation of DA-based reward regions, but those with the Met/Met versus the Val/Val COMT genotype showed less middle temporal gyrus activation and those with the DRD4-L versus the DRD4-S genotype showed less middle occipital gyrus activation in response to monetary reward. Critically, the multilocus composite score revealed that those with a greater number of these genotypes showed less activation in reward regions, including the putamen, caudate, and insula, in response to monetary reward. The results suggest that the multilocus genetic composite is a more sensitive index of vulnerability for low reward region responsivity than individual genotypes.

Reward activity in satiated overweight women is decreased during unbiased viewing but increased when imagining taste: an event-related fMRI study

The aim of this functional magnetic resonance imaging (fMRI) study was to investigate reward-related brain activity in satiated overweight and healthy-weight participants in response to high-calorie palatable food pictures, when viewing the pictures without prior instructions (called unbiased viewing) versus imagining the taste of the shown pictures (called taste imagination). We predicted that neural activation in brain reward regions would be greater in overweight participants than in healthy-weight ones and that this difference between groups would be strongest during unbiased viewing. Neural activation was measured using fMRI in 14 overweight (mean body mass index (BMI): 29.8 kg m(-2)) and 15 healthy-weight (mean BMI: 21.1 kg m(-2)) participants who were satiated, in response to palatable and unpalatable high-calorie and low-calorie food pictures, presented in an event-related design during two conditions: unbiased viewing (no prior instructions) versus taste imagination. A group × condition interaction was found in 14 brain regions involved in food reward processing during the presentation of high-calorie palatable food stimuli. During the taste imagination condition, neural activation in these regions was greater in the overweight participants than in the healthy-weight ones. Contrary to our expectations, the opposite pattern was observed during unbiased viewing: activation in reward regions in the overweight participants was reduced compared with the healthy-weight ones. In all brain reward regions except for the left amygdala, the group × condition interaction was specific to high-calorie palatable food stimuli. Greater reward activity in the overweight participants compared with the control group when imagining taste may represent an increased reward response induced by high-calorie palatable food. During unbiased viewing, reduced reward activation in the overweight participants compared with those with a healthy weight may reflect avoidance of high-calorie palatable food stimuli. Taken together, this pattern of activation may reflect ambivalence in the overweight group between desire for (in the taste imagination condition) and avoidance of (in the unbiased viewing condition) high-calorie palatable food stimuli.

Female emotional eaters show abnormalities in consummatory and anticipatory food reward: A functional magnetic resonance imaging study

To test the hypothesis that emotional eaters show greater neural activation in response to food intake and anticipated food intake than nonemotional eaters and whether these differences are amplified during a negative versus neutral mood state. Female emotional eaters and nonemotional eaters (N = 21) underwent functional magnetic resonance imaging (fMRI) during receipt and anticipated receipt of chocolate milkshake and a tasteless control solution while in a negative and neutral mood. Emotional eaters showed greater activation in the parahippocampal gyrus and anterior cingulate (ACC) in response to anticipated receipt of milkshake and greater activation in the pallidum, thalamus, and ACC in response to receipt of milkshake during a negative relative to a neutral mood. In contrast, nonemotional eaters showed decreased activation in reward regions during a negative versus a neutral mood. Results suggest that emotional eating is related to increased anticipatory and consummatory food reward, but only during negative mood.

Fairness and Cooperation Are Rewarding

To motivate their consumers or employees, corporations often offer monetary incentives, such as cash-back deals or salary bonuses. However, human behavior is not solely driven by material outcome; fairness and equity matter as well. In a recent neuroimaging study, fair offers led to higher happiness ratings and increased activity in several reward regions of the brain compared with unfair offers of equal monetary value. Other neuroimaging studies have similarly shown activation in reward regions in response to cooperative partners or cooperative play. Here, we review these findings and discuss the implications for organizational settings.

Predictability Modulates Human Brain Response to Reward

Certain classes of stimuli, such as food and drugs, are highly effective in activating reward regions. We show in humans that activity in these regions can be modulated by the predictability of the sequenced delivery of two mildly pleasurable stimuli, orally delivered fruit juice and water. Using functional magnetic resonance imaging, the activity for rewarding stimuli in both the nucleus accumbens and medial orbitofrontal cortex was greatest when the stimuli were unpredictable. Moreover, the subjects' stated preference for either juice or water was not directly correlated with activity in reward regions but instead was correlated with activity in sensorimotor cortex. For pleasurable stimuli, these findings suggest that predictability modulates the response of human reward regions, and subjective preference can be dissociated from this response.