Aversive States Research Articles

Mutations in the guanylate cyclase gcy-28 neuronally dissociate naïve attraction and memory retrieval.

The molecules and mechanisms that are involved in the acquisition, storage, and retrieval of memories in many organisms are unclear. To investigate these processes, we use the nematode worm Caenorhabditis elegans, which is attracted naïvely to the odorant benzaldehyde but learns to avoid it after paired exposure with starvation. Mutations in the receptor-like guanylate cyclase GCY-28 have previously been thought to result in a behavioral switch in the primary chemosensory neuron AWCON , from an attractive state to an aversive (already-learned) state. Here, we offer a different interpretation and show that GCY-28 functions in distinct neurons to modulate two independent processes: naïve attraction to AWCON -sensed odors in the AWCON neuron, and associative learning of benzaldehyde and starvation in the AIA interneurons. Consequently, mutants that lack gcy-28 do not approach AWCON -sensed odors and cannot associate benzaldehyde with starvation. We further show that this learning deficit lies in memory retrieval, not in its acquisition or storage, and that GCY-28 is required in AIA for sensory integration only when both AWC neurons (ON and OFF) are activated by chemical stimuli. Our results reveal a novel role of GCY-28 in the retrieval of associative memories and may have wide implications for the neural machineries of learning and memory in general.

Behavioural responses to unexpected changes in reward quality

Successive negative contrast (SNC) effects are changes in anticipatory or consummatory behaviour when animals unexpectedly receive a lower value reward than they have received previously. SNC effects are often assumed to reflect frustration and appear to be influenced by background affective state. However, alternative explanations of SNC, such as the functional-search hypothesis, do not necessarily imply an aversive affective state. We tested 18 dogs in a SNC paradigm using a patch foraging task. Dogs were tested in two conditions, once with the low value reward in all of five trials (unshifted) and once when reward value was altered between high and low (shifted). Following a reward downshift, subjects showed a SNC effect by switching significantly more often between patches compared to the unshifted condition. However, approach latency, foraging time and quantity consumed did not differ between conditions, suggesting non-affective functional search behaviour rather than frustration. There was no relationship between strength of SNC and anxiety-related behaviours as measured in a novel object test and a personality questionnaire (C-BARQ). However, associations with the C-BARQ scores for Trainability and Stranger directed aggression suggest a possible link with behavioural flexibility and coping style. While reward quality clearly affects incentive motivation, the relationship between SNC, frustration and background affective state requires further exploration.

Animal maltreatment from ancient times to the 21st century: Foundation for a call to action now

Animal maltreatment from ancient times to the 21st century: Foundation for a call to action now

Automated Depression Diagnosis Based on Deep Networks to Encode Facial Appearance and Dynamics

As a severe psychiatric disorder disease, depression is a state of low mood and aversion to activity, which prevents a person from functioning normally in both work and daily lives. The study on automated mental health assessment has been given increasing attentions in recent years. In this paper, we study the problem of automatic diagnosis of depression. A new approach to predict the Beck Depression Inventory II (BDI-II) values from video data is proposed based on the deep networks. The proposed framework is designed in a two stream manner, aiming at capturing both the facial appearance and dynamics. Further, we employ joint tuning layers that can implicitly integrate the appearance and dynamic information. Experiments are conducted on two depression databases, AVEC2013 and AVEC2014. The experimental results show that our proposed approach significantly improve the depression prediction performance, compared to other visual-based approaches.

Fear Extinction Requires Reward

Learning theorists long hypothesized that appetitive and aversive motivational states influence one another antagonistically. Here, Felsenberg etal. show that the activity of neurons in Drosophila known to be important in appetitive conditioning is necessary for the extinction of aversive conditioning, thereby uncovering biological evidence for this opponent-process.

Conditioned aversive responses produced by delayed, but not immediate, exposure to cocaine and morphine in male Sprague-Dawley rats.

To determine the conditions under which tastes paired with delayed access to experimenter-delivered cocaine and morphine elicit a conditionally aversive affective state. The potential of saccharin paired with immediate access to cocaine (5, 10, 20mg/kg, sc and ip) and delayed (30 and 10min) access to cocaine (20mg/kg, scand ip) and morphine (10mg/kg, sc) to elicit a pattern of aversive responding in the taste reactivity test (Grill and Norgren 1978a) was evaluated. Cocaine-induced aversions were compared with those produced by a moderate dose of LiCl (50mg/kg). Finally, as an independent measure of cocaine withdrawal, the potential of exposure to saccharin paired with delayed access to cocaine to produce anxiogenic-like responding in the Light-Dark Emersion test was evaluated. Immediate access to cocaine did not produce conditioned aversion at any dose. Delayed (30 or 10min) access to sc cocaine (20mg/kg) produced robust conditioned aversion and delayed access to ip cocaine (20mg/kg; 30min) and to sc morphine (10mg/kg; 10min) produced weaker conditioned aversion. Yawning emerged as a potential withdrawal response in rats conditioned with delayed (30 min) access to 20mg/kg, sc, cocaine. Contextual cues did not produce conditioned aversion when paired with delayed access to sc cocaine (20mg/kg). Finally, exposure to saccharin paired with delayed access to cocaine produced anxiogenic-like responding in the Light-Dark Emersion test. Our results support the contention that a conditioned aversive state develops when a taste cue comes to predict the delayed availability of drugs of abuse.

Associations Between Past-Month Pain and Distress Intolerance Among Daily Cigarette Smokers

A growing body of research indicates that pain is associated with the maintenance of tobacco smoking. Distress intolerance (DI) may play an important role in the link between pain and smoking. The goal of this study was to examine the association between past-month pain status and DI among a sample of daily cigarette smokers. It was hypothesized that smokers who reported past-month pain (vs. those reporting no past-month pain) would have higher perceived DI (i.e., lower scores on the Distress Tolerance Scale [DTS]) and higher physical DI (i.e., shorter persistence during the Breath-Holding Duration Task), and would report greater subjective distress and physical sensations during the breath-holding task. Participants (N = 126) were daily smokers (56.3% male) who attended a baseline session for a larger experimental study on smoking behavior. Participants self-reported the presence and severity of past-month pain and completed two breath-holding duration trials approximately 15 minutes after smoking. Data were cross-sectional in nature. Smokers with past-month pain had lower scores on the DTS relative to smokers without pain. No differences in breath-holding duration were observed. In addition, smokers with past-month pain, relative to those without, reported greater subjective distress and physical sensations during the initial, but not second, breath-holding trial. This is the first study to show that smokers with co-occurring pain may harbor beliefs about their inability to tolerate aversive psychological states, and are more emotionally reactive to physiological provocation (breath-holding task), than smokers without co-occurring pain. DI among smokers with pain may represent one mechanism by which pain contributes to the maintenance of smoking behavior.

An exploration of the aversive properties of 2-deoxy-D-glucose in rats.

Hypoglycemia can alter arousal and negatively impactmood. This study tests the hypothesis that acute drops in glucose metabolism cause an aversive state mediated by monoamine activity. In experiment 1, male Sprague-Dawley rats were either food deprived (FD) or pre-fed (PF) and tested on conditioned place avoidance (CPA; biased place conditioning design; 3 pairings drug/vehicle, each 30min-long) induced by the glucose antimetabolite 2-deoxy-D-glucose (2-DG; 0, 300 or 500mg/kg, SC). Locomotion and blood glucose were also assessed. Experiment 2 examined whether clonidine (noradrenergic α2 agonist, 0, 10 or 40μg/kg, SC) or bupropion (monoamine reuptake blocker, 0, 10 or 30mg/kg, SC) could alter CPA induced by 500mg/kg 2-DG. In experiment 3, blood corticosterone (CORT) was measured in response to 500mg/kg 2-DG, alone or in combination with 40μg/kg clonidine or 30mg/kg bupropion. Finally, experiment 4 controlled for possible place conditioning induced by 10 or 40μg/kg clonidine, or 10 or 30mg/kg bupropion injected without 2-DG. It was found that 2-DG increased blood glucose and produced a robust CPA. The feeding status of the animals modulated these effects, including CORT levels. Both clonidine and bupropion attenuated the effects of 2-DG on CPA and CORT, but only bupropion reversed suppression of locomotion. Taken together, these results in rats suggest that impaired glucose metabolism can negatively impact arousal and mood via effects on HPA and monoamine systems.

Consummatory successive negative contrast in rats: Assessment through orofacial taste reactivity responses

Rats exposed to a downshift from a large reward (32% sucrose) to a small reward (4% sucrose) show an abrupt and transient reduction in consumption in comparison with animals that are always exposed to the small reward. This effect is called consummatory Successive Negative Contrast (cSNC) and involves negative affective consequences that lead to an aversive emotional, cognitive and behavioral state of frustration. There are few previous works that have investigated the hedonic alterations that undergo an unexpected incentive devaluation. The hedonic impact of fluids can be reliably assessed by examining the orofacial reactions of acceptance and rejection in the taste reactivity (TR) test. This study addressed in male adult Wistar rats the hedonic impact of incentive devaluation in an adapted cSNC protocol. Specifically, the orofacial responses to a sucrose solution infused into the oral cavity were measured. It was observed that animals exposed to reward devaluation, from a 32% to a 4% sucrose solution, showed a decrease in the duration of appetitive responses (tongue protrusions, mouth movements, paw licks) as compared with subjects which only experienced the low concentration of sucrose. The results are consistent with the hypothesis that incentive devaluation in a cSNC not only results in reduced intake, but also in a reduction in the hedonic value or palatability of the devalued reward.

A Stress-Coping Model of Problem Online Video Game Use

It is argued that problem video game use (PVGU) has similarities with behavioral addictions such as problem gambling. Unlike other addictions, the predictors of online PVGU have not been studied extensively. We applied a stress-coping model, previously developed for electronic gambling addiction, to PVGU. In this model, stressors lead to excessive behavior via maladaptive coping strategies involving the behavior. Video game players (N = 2261) completed an online questionnaire about their gaming habits, and self-report measures of depression, loneliness, social anxiety, and escapism and social interaction motives for gaming. Consistent with the stress-coping model, depression, loneliness, and social anxiety predicted levels of PVGU, these effects being partially mediated by escapism and social interaction motives for gaming. The pattern of mediation differed by gamers’ preferred game genre in a way that suggested “First Person Shooter” games provide an escape from aversive states, while, in addition to providing escape, massively multiplayer online role playing games, which emphasize collaborative play, may also be supplementing or substituting for face-to-face social interactions.

Effects of acute morphine withdrawal on ultrasonic vocalizations in adult rats: unchanged 50-kHz call rate and altered subtype profile.

Adult rat 22- and 50-kHz ultrasonic vocalizations (USVs) are commonly considered as indices of negative and positive affect, respectively. More specifically, we have proposed that positive affective states are revealed by a predominance of trill over flat 50-kHz call subtypes. However, the 50-kHz call subtypes emitted during aversive drug states remain largely uninvestigated. To determine whether acute morphine withdrawal affects 50-kHz call rates or alters the relative prevalence of trill and flat calls. In experiment 1, adult male rats were given saline or morphine (6mg/kg SC), then acutely challenged 4h later with saline or naloxone (1mg/kg SC), and recorded 10-30min post-injection. In experiments 2 and 3, rats received saline or morphine (6mg/kg), followed 4h later by acute saline or naloxone (0.1mg/kg) challenge; USVs were subsequently recorded during 30-min place conditioning sessions. Naloxone (0.1mg/kg) produced a strong conditioned place aversion only after acute morphine pretreatment, consistent with antagonist-precipitated morphine withdrawal. The morphine-naloxone combination decreased the relative prevalence of trills and promoted flat calls. Naloxone given alone (0.1 and 1mg/kg) inhibited trill calls but did not significantly alter the prevalence of flat calls, whereas morphine given alone (4h pre-session) was largely without effect. Fifty-kHz call rates were inhibited by naloxone given alone, but otherwise unaffected. Twenty-two-kHz calls were sparse. The 50-kHz call subtype shift seen during antagonist-precipitated morphine withdrawal was opposite in direction to that previously associated with rewards, and hence may reveal negative affect.

Activation of 5-HT1B receptors in the Lateral Habenula attenuates the anxiogenic effects of cocaine

Recent work has implicated the Lateral Habenula (LHb) in the production of anxiogenic and aversive states. It is innervated by all the major monoamine neurotransmitter systems and has projections that have been shown to modulate the activity of both dopaminergic and serotonergic brain regions. Cocaine is a stimulant drug of abuse that potentiates neurotransmission in these monoamine systems and recent research suggests that the drug’s behavioral effects may be related in part to its actions within the LHb. The present research was therefore devised to test the hypothesis that alterations in serotonin (5-HT) function within the LHb can affect the behavioral response to cocaine. Male rats were fitted with intracranial guide cannula and trained to traverse a straight alleyway once a day for a 1 mg/kg i.v. injection of cocaine. Intra-LHb pretreatment with the 5-HT1B agonist CP 94,253 (0, 0.1, or 0.25 μg/side) attenuated the development of approach/avoidance “retreat” behaviors known to be a consequence of cocaine’s dual rewarding (approach) and anxiogenic (avoidance) properties. This effect was reversed by co-administration of a selective 5-HT1B antagonist, NAS-181 (0.1 μg/side), demonstrating drug specificity at the 5-HT1B receptor. These data suggest that 5-HT1B signaling within the LHb contributes to the anxiogenic effects of cocaine.

Monoacylglycerol Lipase Inhibitors Reverse Paclitaxel-Induced Nociceptive Behavior and Proinflammatory Markers in a Mouse Model of Chemotherapy-Induced Neuropathy.

Although paclitaxel effectively treats various cancers, its debilitating peripheral neuropathic pain side effects often persist long after treatment has ended. Therefore, a compelling need exists for the identification of novel pharmacologic strategies to mitigate this condition. As inhibitors of monoacylglycerol lipase (MAGL), the primary hydrolytic enzyme of the endogenous cannabinoid, 2-arachidonyolglycerol, produces antinociceptive effects in numerous rodent models of pain, we investigated whether inhibitors of this enzyme (i.e., JZL184 and MJN110) would reverse paclitaxel-induced mechanical allodynia in mice. These drugs dose dependently reversed allodynia with respective ED50 values (95% confidence limit) of 8.4 (5.2-13.6) and 1.8 (1.0-3.3) mg/kg. Complementary genetic and pharmacologic approaches revealed that the antiallodynic effects of each drug require both cannabinoid receptors, CB1 and CB2 MJN110 reduced paclitaxel-mediated increased expression of monocyte chemoattractant protein-1 (MCP-1, CCL2) and phospho-p38 MAPK in dorsal root ganglia as well as MCP-1 in spinal dorsal horn. Whereas the antinociceptive effects of high dose JZL184 (40 mg/kg) underwent tolerance following 6 days of repeated dosing, repeated administration of a threshold dose (i.e., 4 mg/kg) completely reversed paclitaxel-induced allodynia. In addition, we found that the administration of MJN110 to control mice lacked intrinsic rewarding effects in the conditioned place preference (CPP) paradigm. However, it produced a CPP in paclitaxel-treated animals, suggesting a reduced paclitaxel-induced aversive state. Importantly, JZL184 did not alter the antiproliferative and apoptotic effects of paclitaxel in A549 and H460 non-small cell lung cancer cells. Taken together, these data indicate that MAGL inhibitors reverse paclitaxel-induced neuropathic pain without interfering with chemotherapeutic efficacy.

Perceived Threat and Internet Use Predict Intentions to Get Bowel Cancer Screening (Colonoscopy): Longitudinal Questionnaire Study.

BackgroundMany people use the Internet for health-related information search, which is known to help regulate their emotional state. However, not much is known yet about how Web-based information search together with negative emotional states (ie, threat of cancer diagnosis) relate to preventive medical treatment decisions (ie, colonoscopy intentions).ObjectiveThe aim of this study was to investigate how frequency of health-related Internet use together with perceived threat of a possible (bowel) cancer diagnosis influences intentions to get a colonoscopy. Previous research has shown that people who experience threat preferentially process positive information in an attempt to downregulate the aversive emotional state. The Internet can facilitate this regulatory strategy through allowing self-directed, unrestricted, and thus biased information search. In the context of threat regarding a possible bowel cancer diagnosis, feelings of threat can still be effectively reduced through cancer screening (ie, colonoscopy). We, therefore, predict that in that particular context, feelings of threat should be related to stronger colonoscopy intentions, and that this relationship should be enhanced for people who use the Internet often.MethodsA longitudinal questionnaire study was conducted among healthy participants who were approaching or just entering the bowel cancer risk group (aged 45-55 years). Perceived threat of a possible (bowel) cancer diagnosis, frequency of health-related Internet use, and intentions to have a colonoscopy were assessed at 2 time points (6-month time lag between the 2 measurement points T1 and T2). Multiple regression analyses were conducted to test whether threat and Internet use at T1 together predicted colonoscopy intentions at T2.ResultsIn line with our predictions, we found that the threat of a possible (bowel) cancer diagnosis interacted with the frequency of Internet use (both T1) to predict colonoscopy intentions (T2; B=.23, standard error [SE]=0.09, P=.01). For people who used the Internet relatively often (+1 SD), the positive relationship between threat and colonoscopy intentions was significantly stronger (B=.56, SE=0.15, P<.001) compared with participants who used the Internet less often (−1 SD; B=.17, SE=0.09, P=.07). This relationship was unique to Web-based (vs other types of) information search and independent of risk factors (eg, body mass index [BMI] and smoking).ConclusionsThe results of this study suggest that health-related Internet use can facilitate emotion-regulatory processes. People who feel threatened by a possible (bowel) cancer diagnosis reported stronger colonoscopy intentions, especially when they used the Internet often. We propose that this is because people who experience threat are more likely to search for and process information that allows them to downregulate their aversive emotional state. In the present case of (bowel) cancer prevention, the most effective way to reduce threat is to get screened.

“I Smoke Like This to Suppress These Issues That Are Flaws of My Character”: Challenges and Facilitators of Cessation Among Smokers With Bipolar Disorder

ABSTRACTObjective: Smokers with bipolar disorder (BD) have low rates of successful quitting, yet no prior studies have evaluated the process of quitting among these smokers in the context of a current quit attempt. To facilitate development of more effective interventions, we conducted a qualitative exploration of challenges and facilitators of quitting in an intervention study for smokers with BD. Methods: Participants were adult daily smokers with BD (n = 10) who completed a 10-week smoking cessation intervention consisting of Acceptance and Commitment Therapy (ACT) and nicotine patch. We administered semistructured interviews focused on the quitting process at the end of treatment and used inductive content analysis to extract themes. Results: Emergent themes representing challenges of quitting included social impediments, lack of awareness, avoidance, maladaptive beliefs, ambivalence, benefits of smoking, and difficulties with nicotine replacement. Themes representing change facilitators included positive treatment effects (ACT-specific, nonspecific, and nicotine patch-related), coping behaviors, reasons to quit, changes in self-perception, and social benefits. Conclusions: Results suggest a need for assistance with obtaining social support and handling social impediments, interrupting the automaticity of smoking, expanding the behavioral repertoire to handle aversive internal states that tend to be avoided by smoking, preventing maladaptive beliefs from interfering with quitting, taking meaningful action toward change while experiencing ambivalence, either replacing the benefits of smoking or accepting their loss, and troubleshooting difficulties with nicotine replacement. Findings regarding facilitators of quitting supported previous quantitative findings that the ACT intervention impacted theory-based targets and highlighted the importance of the counseling relationship.

Green tea and cocoa enhance cognition in Lymnaea

ABSTRACTA flavonoid, (-)-epicatechi (Epi), enhances long-term memory (LTM) formation in Lymnaea and reverses memory obstruction caused by stress. Many foods contain substantial amounts of Epi, (e.g. green tea and cocoa). In humans eating such foods may directly or indirectly enhance cognition. We directly test whether operant conditioning training Lymnaea in these natural foods result in the same effects as training snails in pure Epi. We found that exposure to products containing high concentrations of Epi (e.g. green tea and cocoa) during training enhanced memory formation and could even reverse a learning and memory deficit brought about by stress. Epi can be photo-inactivated by exposure to ultraviolet light. We found that following photo-inactivation of Epi, memory enhancement did not occur. Photo-inactivation of foods containing Epi (e,g. green tea) blocked their ability to enhance LTM. Our data are thus consistent with the hypothesis that dietary sources of Epi can have positive benefits on cognitive ability and be able to reverse memory aversive states.

Distress intolerance modulation of neurophysiological markers of cognitive control during a complex go/no-go task.

Distress intolerance (DI), a trait-like individual difference reflective of the inability to endure aversive affective states, is relevant to multiple forms of psychopathology, but its relations to theoretically relevant neurobiological systems have received little attention. Altered cognitive control-related neurobiology has been theorized to underlie individual differences in DI, but little empirical work has been conducted. To test this hypothesis, baseline data from a large community sample with elevated high levels of emotional psychopathology and comorbidity was utilized (N = 256). Participants completed a complex go/no-go task while EEG was recorded, and P2, N2, and P3 amplitudes were measured. Based upon prior findings on the relations between these components and response inhibition, a core cognitive control function, we hypothesized that DI would predict reduced no-go N2 and P3 amplitude while controlling for current anxious/depressive symptom severity (i.e., negative affect). Peak amplitudes from the raw data and principal components analysis were used to quantify amplitude of ERP components. Partially consistent with predictions, high DI was independently associated with reduced no-go N2 peak amplitude in the raw ERP data, and was significantly related to a frontal positivity factor in the N2 time window across no-go and go trials. Contrary to predictions, no relations between DI and the P3 were found. Overall, results support the theorized relevance of cognitive control-linked neurobiology to individual differences in tolerance of distress over and above distress severity itself, and suggest specific relations between DI and alterations in early controlled attention/conflict-monitoring but not response inhibition or response inhibition-related sequelae. (PsycINFO Database Record

Hardcastle Takes a HIT! Commentary: Why Sprint Interval Training is Inappropriate for a Largely Sedentary population

Our previous paper prompted a lively debate concerning the A„žA„¸cA„‚cy of sprint interval training (SIT) [1,2]. For clarification SIT refers to protocols that involve supramaximal efforts (>100% maximal oxygen uptake) and high-intensity-intervaltraining (HIIT) involves ‘vigorous’ or ‘near-maximal’ efforts (target intensity: 80% to 100% peak heart-rate) [3]. In the current commentary, we return to the role of affect and perceived effort on exercise adherence raised in the recent commentary by Jung et al. [4]. We contend that the considerable anticipated effort required to participate in SIT and aversive psychological states experienced during such 'all out' supramaximal exercise may likely to damage adherence to such protocols.

Functional Principles of Posterior Septal Inputs to the Medial Habenula

SummaryThe medial habenula (MHb) is an epithalamic hub contributing to expression and extinction of aversive states by bridging forebrain areas and midbrain monoaminergic centers. Although contradictory information exists regarding their synaptic properties, the physiology of the excitatory inputs to the MHb from the posterior septum remains elusive. Here, combining optogenetics-based mapping with ex vivo and in vivo physiology, we examine the synaptic properties of posterior septal afferents to the MHb and how they influence behavior. We demonstrate that MHb cells receive sparse inputs producing purely glutamatergic responses via calcium-permeable α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), heterotrimeric GluN2A-GluN2B-GluN1 N-methyl-D-aspartate (NMDA) receptors, and inhibitory group II metabotropic glutamate receptors. We describe the complex integration dynamics of these components by MHb cells. Finally, we combine ex vivo data with realistic afferent firing patterns recorded in vivo to demonstrate that efficient optogenetic septal stimulation in the MHb induces anxiolysis and promotes locomotion, contributing long-awaited evidence in favor of the importance of this septo-habenular pathway.

Pavlovian Control of Escape and Avoidance.

To survive in complex environments, animals need to have mechanisms to select effective actions quickly, with minimal computational costs. As perhaps the computationally most parsimonious of these systems, Pavlovian control accomplishes this by hardwiring specific stereotyped responses to certain classes of stimuli. It is well documented that appetitive cues initiate a Pavlovian bias toward vigorous approach; however, Pavlovian responses to aversive stimuli are less well understood. Gaining a deeper understanding of aversive Pavlovian responses, such as active avoidance, is important given the critical role these behaviors play in several psychiatric conditions. The goal of the current study was to establish a behavioral and computational framework to examine aversive Pavlovian responses (activation vs. inhibition) depending on the proximity of an aversive state (escape vs. avoidance). We introduce a novel task in which participants are exposed to primary aversive (noise) stimuli and characterized behavior using a novel generative computational model. This model combines reinforcement learning and drift-diffusion models so as to capture effects of invigoration/inhibition in both explicit choice behavior as well as changes in RT. Choice and RT results both suggest that escape is associated with a bias for vigorous action, whereas avoidance is associated with behavioral inhibition. These results lay a foundation for future work seeking insights into typical and atypical aversive Pavlovian responses involved in psychiatric disorders, allowing us to quantify both implicit and explicit indices of vigorous choice behavior in the context of aversion.