Trait Anticipatory Pleasure Predicts Effort Expenditure for Reward

Research in motivation and emotion has been increasingly influenced by the perspective that processes underpinning the motivated approach of rewarding goals are distinct from those underpinning enjoyment during reward consummation. This distinction recently inspired the construction of the Temporal Experience of Pleasure Scale (TEPS), a self-report measure that distinguishes trait anticipatory pleasure (pre-reward feelings of desire) from consummatory pleasure (feelings of enjoyment and gratification upon reward attainment). In a university community sample (N = 97), we examined the TEPS subscales as predictors of (1) the willingness to expend effort for monetary rewards, and (2) affective responses to a pleasant mood induction procedure. Results showed that both anticipatory pleasure and a well-known trait measure of reward motivation predicted effort-expenditure for rewards when the probability of being rewarded was relatively low. Against expectations, consummatory pleasure was unrelated to induced pleasant affect. Taken together, our findings provide support for the validity of the TEPS anticipatory pleasure scale, but not the consummatory pleasure scale.     

Altruism and Reward: Motivational Compatibility in Deceased Organ Donation

Acts of helping others are often based on mixed motivations. Based on this claim, it has been argued that the use of a financial reward to incentivize organ donation is compatible with promoting altruism in organ donation. In its report Human Bodies: Donation for Medicine and Research, the Nuffield Council on Bioethics uses this argument to justify its suggestion to pilot a funeral payment scheme to incentivize people to register for deceased organ donation in the UK. In this article, I cast a sceptical eye on the above Nuffield report's argument that its proposed funeral payment scheme would prompt deceased organ donations that remain altruistic (as defined by and valued the report). Specifically, I illustrate how this scheme may prompt various forms of mixed motivations which would not satisfy the report's definition of altruism. Insofar as the scheme produces an expectation of the reward, it stands diametrical to promoting an ‘altruistic perspective’. My minimal goal in this article is to argue that altruism is not motivationally compatible with reward as an incentive for donation. My broader goal is to argue that if a financial reward is used to incentivize organ donation, then we should recognize that the donation system is no longer aiming to promote altruism. Rewarded donation would not be altruistic but it may be ethical given a persistent organ shortage situation.     

Social Network Analysis Predicts Health Behaviours and Self-Reported Health in African Villages

The provision of healthcare in rural African communities is a highly complex and largely unsolved problem. Two main difficulties are the identification of individuals that are most likely affected by disease and the prediction of responses to health interventions. Social networks have been shown to capture health outcomes in a variety of contexts. Yet, it is an open question as to what extent social network analysis can identify and distinguish among households that are most likely to report poor health and those most likely to respond to positive behavioural influences. We use data from seven highly remote, post-conflict villages in Liberia and compare two prominent network measures: in-degree and betweenness. We define in-degree as the frequency in which members from one household are named by another household as a friends. Betweenness is defined as the proportion of shortest friendship paths between any two households in a network that traverses a particular household. We find that in-degree explains the number of ill family members, whereas betweenness explains engagement in preventative health. In-degree and betweenness independently explained self-reported health and behaviour, respectively. Further, we find that betweenness predicts susceptibility to, instead of influence over, good health behaviours. The results suggest that targeting households based on network measures rather than health status may be effective for promoting the uptake of health interventions in rural poor villages.     

Monetary Reward Modulates Task-Irrelevant Perceptual Learning for Invisible Stimuli

Task Irrelevant Perceptual Learning (TIPL) shows that the brain’s discriminative capacity can improve also for invisible and unattended visual stimuli. It has been hypothesized that this form of “unconscious” neural plasticity is mediated by an endogenous reward mechanism triggered by the correct task performance. Although this result has challenged the mandatory role of attention in perceptual learning, no direct evidence exists of the hypothesized link between target recognition, reward and TIPL. Here, we manipulated the reward value associated with a target to demonstrate the involvement of reinforcement mechanisms in sensory plasticity for invisible inputs. Participants were trained in a central task associated with either high or low monetary incentives, provided only at the end of the experiment, while subliminal stimuli were presented peripherally. Our results showed that high incentive-value targets induced a greater degree of perceptual improvement for the subliminal stimuli, supporting the role of reinforcement mechanisms in TIPL.     

Initial D2 Dopamine Receptor Sensitivity Predicts Cocaine Sensitivity and Reward in Rats

The activation of dopamine receptors within the mesolimbic dopamine system is known to be involved in the initiation and maintenance of cocaine use. Expression of the D₂ dopamine receptor subtype has been implicated as both a predisposing factor and consequence of chronic cocaine use. It is unclear whether there is a predictive relationship between D₂ dopamine receptor function and cocaine sensitivity that would enable cocaine abuse. Therefore, we exploited individual differences in behavioral responses to D₂ dopamine receptor stimulation to test its relationship with cocaine-mediated behaviors. Outbred, male Sprague-Dawley rats were initially characterized by their locomotor responsiveness to the D₂ dopamine receptor agonist, quinpirole, in a within-session ascending dose-response regimen (0, 0.1, 0.3 & 1.0 mg/kg, sc). Rats were classified as high or low quinpirole responders (HD₂ and LD₂, respectively) by a median split of their quinpirole-induced locomotor activity. Rats were subsequently tested for differences in the psychostimulant effects of cocaine by measuring changes in cocaine-induced locomotor activity (5 and 15 mg/kg, ip). Rats were also tested for differences in the development of conditioned place preference to a low dose of cocaine (7.5 mg/kg, ip) that does not reliably produce a cocaine conditioned place preference. Finally, rats were tested for acquisition of cocaine self-administration and maintenance responding on fixed ratio 1 and 5 schedules of reinforcement, respectively. Results demonstrate that HD₂ rats have enhanced sensitivity to the locomotor stimulating properties of cocaine, display greater cocaine conditioned place preference, and self-administer more cocaine compared to LD₂ animals. These findings suggest that individual differences in D₂ dopamine receptor sensitivity may be predictive of cocaine sensitivity and reward.     

Between Difference and Belonging: Configuring Self and Others in Inpatient Treatment for Eating Disorders

Dedicated inpatient care for eating disorders has profound impact on patients'' embodied practices and lived realities. Analyses of inpatients'' accounts have shown that participants endorse complex and conflicting attitudes toward their experiences in eating disorders wards, yet the apparent ambivalence that characterizes inpatient experiences has not been subject to critical examination. This paper examines the narrated experiences of 13 participants (12 women and one man; age 18–38 years at first interview) with past or present anorexia nervosa, bulimia nervosa, or eating disorder not otherwise specified, who had been hospitalized in an inpatient eating disorders ward for adults in central Israel. The interviews, which took place in 2005–2006, and again in 2011, were part of a larger longitudinal study exploring the subjective experiences of eating disorders and recovery among Israeli adults. Employing qualitative analysis, this study finds that the participants'' accounts were concerned with dynamics of difference and belonging, as they played out in various aspects of inpatient care, including diagnosis, treatment, relationships with fellow patients and staff, and everyday life in hospital. Notably, participants simultaneously defined themselves as connected to, but also distinct from, the eating disordered others who formed their reference group at the ward. Through negotiating a protectively ambivalent positioning, participants recognized their eating disordered identities and connected with others on the ward, while also asserting their non-disordered individuality and distancing themselves from the potential dangers posed by ‘excessive’ belonging. The paper suggests that this ambivalent positioning can usefully be understood through the anthropological concept of liminality: being both a part of and apart from one''s community.     

Common Neural Mechanisms Underlying Reversal Learning by Reward and Punishment

Impairments in flexible goal-directed decisions, often examined by reversal learning, are associated with behavioral abnormalities characterized by impulsiveness and disinhibition. Although the lateral orbital frontal cortex (OFC) has been consistently implicated in reversal learning, it is still unclear whether this region is involved in negative feedback processing, behavioral control, or both, and whether reward and punishment might have different effects on lateral OFC involvement. Using a relatively large sample (N = 47), and a categorical learning task with either monetary reward or moderate electric shock as feedback, we found overlapping activations in the right lateral OFC (and adjacent insula) for reward and punishment reversal learning when comparing correct reversal trials with correct acquisition trials, whereas we found overlapping activations in the right dorsolateral prefrontal cortex (DLPFC) when negative feedback signaled contingency change. The right lateral OFC and DLPFC also showed greater sensitivity to punishment than did their left homologues, indicating an asymmetry in how punishment is processed. We propose that the right lateral OFC and anterior insula are important for transforming affective feedback to behavioral adjustment, whereas the right DLPFC is involved in higher level attention control. These results provide insight into the neural mechanisms of reversal learning and behavioral flexibility, which can be leveraged to understand risky behaviors among vulnerable populations.     

Being Moved by the Self and Others: Influence of Empathy on Self-Motion Perception

Background

The observation of conspecifics influences our bodily perceptions and actions: Contagious yawning, contagious itching, or empathy for pain, are all examples of mechanisms based on resonance between our own body and others. While there is evidence for the involvement of the mirror neuron system in the processing of motor, auditory and tactile information, it has not yet been associated with the perception of self-motion.

Methodology/Principal Findings

We investigated whether viewing our own body, the body of another, and an object in motion influences self-motion perception. We found a visual-vestibular congruency effect for self-motion perception when observing self and object motion, and a reduction in this effect when observing someone else''s body motion. The congruency effect was correlated with empathy scores, revealing the importance of empathy in mirroring mechanisms.

Conclusions/Significance

The data show that vestibular perception is modulated by agent-specific mirroring mechanisms. The observation of conspecifics in motion is an essential component of social life, and self-motion perception is crucial for the distinction between the self and the other. Finally, our results hint at the presence of a “vestibular mirror neuron system”.     

Psychological and Evolutionary Evidence for Altruism

Sober and Wilson have recentlyclaimed that evolutionary theory can do whatneither philosophy nor experimental psychologyhave been able to, namely, ``break the deadlock'in the egoism vs. altruism debate with anargument based on the reliability of altruisticmotivation. I analyze both their reliabilityargument and the experimental evidence ofsocial psychology in favor of altruism in termsof the folk-psychological ``laws' and inferencepatterns underlying them, and conclude thatthey both rely on the same patterns. I exposethe confusions that have led Sober and Wilsonto defend a reliability argument whilerejecting the experimental evidence of socialpsychology.     

Coexistence of Reward and Unsupervised Learning During the Operant Conditioning of Neural Firing Rates

A fundamental goal of neuroscience is to understand how cognitive processes, such as operant conditioning, are performed by the brain. Typical and well studied examples of operant conditioning, in which the firing rates of individual cortical neurons in monkeys are increased using rewards, provide an opportunity for insight into this. Studies of reward-modulated spike-timing-dependent plasticity (RSTDP), and of other models such as R-max, have reproduced this learning behavior, but they have assumed that no unsupervised learning is present (i.e., no learning occurs without, or independent of, rewards). We show that these models cannot elicit firing rate reinforcement while exhibiting both reward learning and ongoing, stable unsupervised learning. To fix this issue, we propose a new RSTDP model of synaptic plasticity based upon the observed effects that dopamine has on long-term potentiation and depression (LTP and LTD). We show, both analytically and through simulations, that our new model can exhibit unsupervised learning and lead to firing rate reinforcement. This requires that the strengthening of LTP by the reward signal is greater than the strengthening of LTD and that the reinforced neuron exhibits irregular firing. We show the robustness of our findings to spike-timing correlations, to the synaptic weight dependence that is assumed, and to changes in the mean reward. We also consider our model in the differential reinforcement of two nearby neurons. Our model aligns more strongly with experimental studies than previous models and makes testable predictions for future experiments.     

Resting-State fMRI Activity Predicts Unsupervised Learning and Memory in an Immersive Virtual Reality Environment

In the real world, learning often proceeds in an unsupervised manner without explicit instructions or feedback. In this study, we employed an experimental paradigm in which subjects explored an immersive virtual reality environment on each of two days. On day 1, subjects implicitly learned the location of 39 objects in an unsupervised fashion. On day 2, the locations of some of the objects were changed, and object location recall performance was assessed and found to vary across subjects. As prior work had shown that functional magnetic resonance imaging (fMRI) measures of resting-state brain activity can predict various measures of brain performance across individuals, we examined whether resting-state fMRI measures could be used to predict object location recall performance. We found a significant correlation between performance and the variability of the resting-state fMRI signal in the basal ganglia, hippocampus, amygdala, thalamus, insula, and regions in the frontal and temporal lobes, regions important for spatial exploration, learning, memory, and decision making. In addition, performance was significantly correlated with resting-state fMRI connectivity between the left caudate and the right fusiform gyrus, lateral occipital complex, and superior temporal gyrus. Given the basal ganglia''s role in exploration, these findings suggest that tighter integration of the brain systems responsible for exploration and visuospatial processing may be critical for learning in a complex environment.     

"Respect for the Rights of Others Is Peace": Learning Aggression versus Nonaggression among the Zapotec

This article examines differences in aggression between two Zapotec communities in Oaxaca, Mexico. An ethological study of three- to eight-year-old children (N = 48) reveals statistically significant intercommunity differences in children's serious and play aggression, corresponding to ethnographically observed intercommunity differences in adult behavior. The parallels between adult and children's conduct within the communities support the conclusion that different social learning environments contribute to the maintenance across generations of divergent ideologies, values, and patterns of social interaction related to violence or peacefulness. Social learning and socialization processes also can be viewed as interacting with economic, historical, and ideological influences. The findings suggest that studies of violence that neglect social learning influences may be providing only partial explanations.     

Differential Response of Hippocampal Subregions to Stress and Learning

The hippocampus has two functionally distinct subregions–the dorsal portion, primarily associated with spatial navigation, and the ventral portion, primarily associated with anxiety. In a prior study of chronic unpredictable stress (CUS) in rodents, we found that it selectively enhanced cellular plasticity in the dorsal hippocampal subregion while negatively impacting it in the ventral. In the present study, we determined whether this adaptive plasticity in the dorsal subregion would confer CUS rats an advantage in a spatial task–the radial arm water maze (RAWM). RAWM exposure is both stressful and requires spatial navigation, and therefore places demands simultaneously upon both hippocampal subregions. Therefore, we used Western blotting to investigate differential expression of plasticity-associated proteins (brain derived neurotrophic factor [BDNF], proBDNF and postsynaptic density-95 [PSD-95]) in the dorsal and ventral subregions following RAWM exposure. Lastly, we used unbiased stereology to compare the effects of CUS on proliferation, survival and neuronal differentiation of cells in the dorsal and ventral hippocampal subregions. We found that CUS and exposure to the RAWM both increased corticosterone, indicating that both are stressful; nevertheless, CUS animals had significantly better long-term spatial memory. We also observed a subregion-specific pattern of protein expression following RAWM, with proBDNF increased in the dorsal and decreased in the ventral subregion, while PSD-95 was selectively upregulated in the ventral. Finally, consistent with our previous study, we found that CUS most negatively affected neurogenesis in the ventral (compared to the dorsal) subregion. Taken together, our data support a dual role for the hippocampus in stressful experiences, with the more resilient dorsal portion undergoing adaptive plasticity (perhaps to facilitate escape from or neutralization of the stressor), and the ventral portion involved in affective responses.     

Resting Heart Rate Variability Predicts Safety Learning and Fear Extinction in an Interoceptive Fear Conditioning Paradigm

This study aimed to investigate whether interindividual differences in autonomic inhibitory control predict safety learning and fear extinction in an interoceptive fear conditioning paradigm. Data from a previously reported study (N = 40) were extended (N = 17) and re-analyzed to test whether healthy participants'' resting heart rate variability (HRV) - a proxy of cardiac vagal tone - predicts learning performance. The conditioned stimulus (CS) was a slight sensation of breathlessness induced by a flow resistor, the unconditioned stimulus (US) was an aversive short-lasting suffocation experience induced by a complete occlusion of the breathing circuitry. During acquisition, the paired group received 6 paired CS-US presentations; the control group received 6 explicitly unpaired CS-US presentations. In the extinction phase, both groups were exposed to 6 CS-only presentations. Measures included startle blink EMG, skin conductance responses (SCR) and US-expectancy ratings. Resting HRV significantly predicted the startle blink EMG learning curves both during acquisition and extinction. In the unpaired group, higher levels of HRV at rest predicted safety learning to the CS during acquisition. In the paired group, higher levels of HRV were associated with better extinction. Our findings suggest that the strength or integrity of prefrontal inhibitory mechanisms involved in safety- and extinction learning can be indexed by HRV at rest.     

Becoming a Spirit Medium: Initiatory Learning and the Self in the Vale do Amanhecer

Drawing on ethnographic data from the Brazilian mediumistic religion known as Vale do Amanhecer (Valley of the Dawn), this article addresses the learning process at the core of mediumistic development. The process of learning is here approached as a multi-layered experience, which is embodied, intuitive, performative, conceptual and inter-subjective. I will illustrate how the relationship between mediums and spirits is established in trance states through what Thomas Csordas calls a ‘multi-sensory imagery’. The discussion examines the concurrence of emotions, feelings, somatosensory experience and doctrinal discourses in developing mediumistic skills, which simultaneously engenders the attributes of extendability and multi-dimensionality that ground the notion of the self, informing the conceptualisation of trance.