The neuromodulator dopamine is centrally involved in reward, approach behavior, exploration, and various aspects of cognition. Variations in dopaminergic function are assumed to be associated with variations in personality, but exactly which traits are influenced by dopamine remains an open question. This paper proposes a theory of the role of dopamine in personality that organizes and explains the diversity of findings, utilizing the division of the dopaminergic system into value coding and salience coding neurons (Bromberg-Martin, Matsumoto, and (...) Hikosaka, 2010). The value coding system is proposed to be related primarily to Extraversion and the salience coding system to Openness/Intellect. Global levels of dopamine influence the higher order personality factor, Plasticity, which comprises the shared variance of Extraversion and Openness/Intellect. All other traits related to dopamine are linked to Plasticity or its subtraits. The general function of dopamine is to promote exploration, by facilitating engagement with cues of specific reward (value) and cues of the reward value of information (salience). This theory constitutes an extension of the entropy model of uncertainty (EMU; Hirsh, Mar, & Peterson, 2012), enabling EMU to account for the fact that uncertainty is an innate incentive reward as well as an innate threat. The theory accounts for the association of dopamine with traits ranging from sensation and novelty seeking, to impulsivity and aggression, to achievement striving, creativity, and cognitive abilities, to the overinclusive thinking characteristic of schizotypy. (shrink)
Brain dopamine has long been known to be implicated in the domains of appetitive motivation and cognition. Recent work indicates that dopamine also plays a role in the interaction between appetitive motivation and cognition. Here we review this work. Animal work has revealed an arrangement of spiraling connections between the midbrain and the striatum that subserves a mechanism by which dopamine can direct information flow from ventromedial to more dorsal regions in the striatum. In line with current (...) knowledge about dopamine’s effects on cognition, we hypothesize that these striato-nigro-striatal connections provide the basis for functionally specific effects of appetitive motivation on cognition. One implication of this hypothesis is that appetitive motivation can induce cognitive improvement or impairment depending on task demands. (shrink)
The effects of striatal dopamine on behaviour have been widely investigated over the past decades, with “phasic” burst firings considered as the key expression of a reward prediction error responsible for reinforcement learning. Less well studied is tonic dopamine, where putative functions include the idea that it is a regulator of vigour, incentive salience, disposition to exert an effort and a modulator of approach strategies. We present a model combining tonic and phasic dopamine to show how different (...) outflows triggered by either intrinsically or extrinsically motivating stimuli dynamically affect the basal ganglia by impacting on a selection process this system performs on its cortical input. The model, which has been tested on the simulated humanoid robot iCub in the interaction with a mechatronic board, shows the putative functions ascribed to dopamine emerging from the combination of a standard computational mechanism coupled to a differential sensitivity to the presence of dopamine across the striatum. (shrink)
Gambling disorder sufferers prefer immediately larger rewards despite long term losses on the Iowa Gambling Task (IGT), and these impairments are associated with dopamine dysfunctions. Dopamine is a neurotransmitter linked with temporal and structural dysfunctions in substance use disorder, which has supported the idea of impaired decision-making and dopamine dysfunctions in gambling disorder. However, evidence from substance use disorders cannot be directly transferred to gambling disorder. This article focuses on three hypotheses of dopamine dysfunctions in gambling (...) disorder, which appear to be “fallacies”, i.e., have not been supported in a series of positron emission tomography (PET) studies. The first “fallacy” suggests that gambling disorder suffers, similar to substance use disorders, have lower dopamine receptor availability. No evidence supported this hypothesis. The second “fallacy” suggests that maladaptive decision-making in gambling disorder is associated with higher dopamine release during gambling. No evidence supported the hypothesis, and the literature on substance use disorders offers limited support for this hypothesis. The third “fallacy” suggests that maladaptive decision-making in gambling disorder is associated with higher dopamine release during winning. The evidence did not support this hypothesis either. Instead, dopaminergic coding of reward prediction and uncertainty might better account for dopamine dysfunctions in gambling disorder. Studies of reward prediction and reward uncertainty shows a sustained dopamine response towards stimuli with maximum uncertainty, which may explain the continued dopamine release and gambling despite losses in gambling disorder. The findings from the studies presented here are consistent with the notion of dopaminergic dysfunctions of reward prediction and reward uncertainty signals in gambling disorder. (shrink)
This essay selectively reviews, from an historical and philosophical perspective, the dopamine (DA) hypothesis of schizophrenia (DHS; Table 1 lists the abbreviations used in this essay). Our goal is not to adjudicate the validity of the theory—although we arrive at a generally skeptical conclusion—but to focus on the process whereby the DHS has evolved over time and been evaluated. Since its inception, the DHS has been the most prominent etiologic theory in psychiatry and is still referred to widely in (...) current textbooks (e.g., Buchanan and Carpenter, Jr. 2005, 1336; Cohen 2003, 225; Gazzaniga 2004, 1257;Kandel et al. 2000, 1200). Understanding its origins and evolution should help to clarify the nature of modern .. (shrink)
We are gratified at the largely positive comments on our essay on the dopamine hypothesis of schizophrenia (DHS) by these two distinguished commentators from the fields of biological psychiatry (Dr. Tamminga) and the philosophy of psychiatry (Dr. Murphy). There is little that they have said with which we disagree. Rather, we want to expand briefly on their commentaries.We found Dr. Tamminga's reactions to be particularly fascinating because she has been an "insider" to the story of the DHS as it (...) has unfolded. She provides substantial insight into the "extra-scientific" reasons for the persistence of the DHS despite its poor empirical record.She validates our impression that the DHS was in its first years of .. (shrink)
Kendler and Schaffner have written an exemplary case study of the rise of the dopamine hypothesis and, if not its fall, at least its stagnation and transmutation. They bring out well both the state of the science and the opportunities offered by the theory to consider some famous philosophical theories of scientific progress. So well, in fact, have they done this, that I do not have a lot to say about it. I will just mention one or two points (...) that I found interesting, and then say a little about what looks to me like an omission from the story that the two Kens recount.One point they raise is the importance of competitor theories: now, there is supposed to be an old story about a quack who was apprehended during .. (shrink)
Depue & Collins propose that extraversion should be separated from the impulsivity-constraint dimension of personality, and that the VTA dopamine system is the primary engine of extraversion. Although their focus is on personality traits, it may be useful to consider the evidence on psychological state changes, related both to affective arousal and to drug effects. This evidence shows that there are inherent relations between extraversion and impulsivity-constraint, and that there are influences of dopamine on impulsivity-constraint that are not (...) consistent with the Depue & Collins model. Increased positive affect leads to increased extraversion, and this is associated with more impulsivity and less constraint. The evidence on drug effects shows that greater dopaminergic control is associated with more constraint, and with anxiety and vigilance rather than positive affect. (shrink)
Disruptions in dopamine transmission within the basal ganglia (BG) produce deficits in voluntary actions, that is, in the interface between cortically-generated goal representation and BG-mediated response selection. Under conditions of dopamine loss in humans and other animals, responses are impaired when they require internal generation, but are relatively intact when elicited by external stimuli.
Interpreting VTA dopamine activity as a facilitator of affective engagement fits Depue & Collins's agency dimension of extraverted personality and also Watson's and Tellegen's (1985) engagement dimension of state mood. Serotonin, by turning down the gain on dopaminergic affective engagement, would permit already prepotent responses or habits to prevail against the behavior-switching incentive-simulation-driven temptations of the moment facilitated by fickle VTA DA. Intelligent switching between openly responsive affective engagement and constraint by long-term plans, goals, or values presumably involves environment-sensitive (...) balancing of these neuromodulators, such as socially dominant primates may show. (shrink)
Despite general agreement that altered reward sensitivity is involved in attention-deficit/hyperactivity disorder (ADHD), a wide range of different alterations has been proposed. We cite work showing abnormal sensitivity to delay of reward, together with abnormal sensitivity to individual instances of reward. We argue that at the cellular level these behavioural characteristics might indicate that dopamine timing is off in children with ADHD.
Data from further human experiments touch four open questions in the target article. (1) Extinction of reward acquisition postulated by Depue & Collins's model could not be confirmed if correlating craving for, liking of, and satisfaction from smoking. (2) Intraindividual correspondence between responsivity to dopamine agonists and antagonists could likewise not be confirmed. (3) Nicotine craving and drug-induced hormone responses were not substantially correlated. (4) Low serotonin can be the cause and not just the moderator of dopaminergic sensitivity, and (...) personality correlates of low dopamine/low MAO (aggressive impulsive traits) can hardly be related to the positive emotion associated with dopaminergic activity. (shrink)
Sensitivity to incentive motivation has a formative influence on extraversion. Mesoamygdaloid dopamine (DA) activity may, at one level, act as a micro-gate permitting an incentive to influence behavioral organization – “Go/No-Go” in this scheme. Data on function elsewhere in the mesocorticolimbic DA system are taken to support this particular function. At another level of analysis, the data in Depue & Collins's review, along with those on the rest of the ventral tegmental area (VTA) system, may fit better with a (...) “switching” function in information processing. This link is supported by correlations between measures of extraversion, learned inattention, and overall DA activity. The point is extended to the novelty-seeking feature of the extraverted personality. (shrink)
In psychiatry, pharmacological drugs play an important experimental role in attempts to identify the neurobiological causes of mental disorders. Besides being developed in applied contexts as potential treatments for patients with mental disorders, pharmacological drugs play a crucial role in research contexts as experimental instruments that facilitate the formulation and revision of neurobiological theories of psychopathology. This paper examines the various epistemic functions that pharmacological drugs serve in the discovery, refinement, testing, and elaboration of neurobiological theories of mental disorders. I (...) articulate this thesis with reference to the history of antipsychotic drugs and the evolution of the dopamine hypothesis of schizophrenia in the second half of the twentieth century. I argue that interventions with psychiatric patients through the medium of antipsychotic drugs provide researchers with information and evidence about the neurobiological causes of schizophrenia. This analysis highlights the importance of pharmacological drugs as research tools in the generation of psychiatric knowledge and the dynamic relationship between practical and theoretical contexts in psychiatry. (shrink)
Because little is known about the human trait of affiliation, we provide a novel neurobehavioral model of affiliative bonding. Discussion is organized around processes of reward and memory formation that occur during approach and consummatory phases of affiliation. Appetitive and consummatory reward processes are mediated independently by the activity of the ventral tegmental area (VTA) dopamine (DA)–nucleus accumbens shell (NAS) pathway and the central corticolimbic projections of the u-opiate system of the medial basal arcuate nucleus, respectively, although these two (...) projection systems functionally interact across time. We next explicate the manner in which DA and glutamate interact in both the VTA and NAS to form incentive-encoded contextual memory ensembles that are predictive of reward derived from affiliative objects. Affiliative stimuli, in particular, are incorporated within contextual ensembles predictive of affiliative reward via: (a) the binding of affiliative stimuli in the rostral circuit of the medial extended amygdala and subsequent transmission to the NAS shell; (b) affiliative stimulus-induced opiate potentiation of DA processes in the VTA and NAS; and (c) permissive or facilitatory effects of gonadal steroids, oxytocin (in interaction with DA), and vasopressin on (i) sensory, perceptual, and attentional processing of affiliative stimuli and (ii) formation of social memories. Among these various processes, we propose that the capacity to experience affiliative reward via opiate functioning has a disproportionate weight in determining individual differences in affiliation. We delineate sources of these individual differences, and provide the first human data that support an association between opiate functioning and variation in trait affiliation. Key Words: affiliation corticolimbic-striatal networks; appetitive and consummatory reward; dopamine; oxytocin; personality; social bonds; social memory; u-opiates. (shrink)
The topics treated in The brain and emotion include the definition, nature, and functions of emotion (Ch. 3); the neural bases of emotion (Ch. 4); reward, punishment, and emotion in brain design (Ch. 10); a theory of consciousness and its application to understanding emotion and pleasure (Ch. 9); and neural networks and emotion-related learning (Appendix). The approach is that emotions can be considered as states elicited by reinforcers (rewards and punishers). This approach helps with understanding the functions of emotion, with (...) classifying different emotions, and in understanding what information-processing systems in the brain are involved in emotion, and how they are involved. The hypothesis is developed that brains are designed around reward-and punishment-evaluation systems, because this is the way that genes can build a complex system that will produce appropriate but flexible behavior to increase fitness (Ch. 10). By specifying goals rather than particular behavioral patterns of responses, genes leave much more open the possible behavioral strategies that might be required to increase fitness. The importance of reward and punishment systems in brain design also provides a basis for understanding the brain mechanisms of motivation, as described in Chapters 2 for appetite and feeding, 5 for brain-stimulation reward, 6 for addiction, 7 for thirst, and 8 for sexual behavior. Key Words: amygdala; brain evolution; consciousness; dopamine; emotion; hunger; orbitofrontal cortex; punishment; reward; taste. (shrink)
There is growing evidence that dopamine replacement therapy (DRT) used to treat Parkinson’s Disease can cause compulsive behaviours and impulse control disorders (ICDs), such as pathological gambling, compulsive buying and hypersexuality. Like more familiar drug-based forms of addiction, these iatrogenic disorders can cause significant harm and distress for sufferers and their families. In some cases, people treated with DRT have lost their homes and businesses, or have been prosecuted for criminal sexual behaviours. In this article we first examine the (...) evidence that these disorders are caused by DRT. If it is accepted that DRT cause compulsive or addictive behaviours in a significant minority of individuals, then the following ethical and clinical questions arise: Under what circumstances is it ethical to prescribe a medication that may induce harmful compulsive behaviours? Are individuals treated with DRT morally responsible and hence culpable for harmful or criminal behaviour related to their medication? We conclude with some observations of the relevance of DRT-induced ICDs for our understanding of addiction and identify some promising directions for future research and ethical analysis. (shrink)
Depue & Collins's general idea of a functional relationship between DA activity and extraversion is an important step toward an integrative biological model of personality. However, focusing primarily on incentive motivation and variations in VTA DA activity as basic behavioral and biological components underlying extraversion appears too limited. Existing data suggest that responsivity to changes in DA activity is higher in introverts than in extraverts. This may reflect a general, extraversion- related characteristic of the entire dopaminergic network in the brain.
Whether or not trait affiliation correlates with human behaviour needs investigating. One should be careful generalizing neuropsychological mechanisms for affiliation, and generalizing an analysis based on one or two neuropsychological mechanisms and mostly studies on rodents, to complex human social interactions. Serotonin is an example of a neurotransmitter playing an important role in cooperation and interacting with the dopaminergic system.
Mounting evidence links the enjoyment of music to brain areas implicated in emotion and the dopaminergic reward system. In particular, dopamine release in the ventral striatum seems to play a major role in the rewarding aspect of music listening. Striatal dopamine also influences reinforcement learning, such that subjects with greater dopamine efficacy learn better to approach rewards while those with lesser dopamine efficacy learn better to avoid punishments. In this study, we explored the practical implications of (...) musical pleasure through its ability to facilitate reinforcement learning via non-pharmacological dopamine elicitation. Subjects from a wide variety of musical backgrounds chose a pleasurable and a neutral piece of music from an experimenter-compiled database, and then listened to one or both of these pieces (according to pseudo-random group assignment) as they performed a reinforcement learning task dependent on dopamine transmission. We assessed musical backgrounds as well as typical listening patterns with the new Helsinki Inventory of Music and Affective Behaviors (HIMAB), and separately investigated behavior for the training and test phases of the learning task. Subjects with more musical experience trained better with neutral music and tested better with pleasurable music, while those with less musical experience exhibited the opposite effect. HIMAB results regarding listening behaviors and subjective music ratings indicate that these effects arose from different listening styles: namely, more affective listening in non-musicians and more analytical listening in musicians. In conclusion, musical pleasure was able to influence task performance, and the shape of this effect depended on group and individual factors. These findings have implications in affective neuroscience, neuroaesthetics, learning, and music therapy. (shrink)
A great variety of medical conditions are subject to the placebo effect. Although there is mounting evidence to suggest that the placebo effect is related to the expectation of clinical benefit, little is still known about the biochemical bases underlying placebo responses. Positron emission tomography studies have recently shown that the placebo effect in Parkinson’s disease, pain, and depression is related to the activation of the limbic circuitry. The observation that placebo administration induces the release of dopamine in the (...) ventral striatum of patients with Parkinson’s disease suggests a link between the placebo effect and reward mechanisms. In addition to Parkinson’s disease, the placebo-reward model may also apply to other disorders. However, the relative contribution of the different neurotransmitters and neuropeptides that are known to be involved in modulating the activity of the limbic system may be disease-specific. Thus, while the placebo-induced clinical benefit observed in Parkinson’s disease would mostly reflect the release of dopamine in the dorsal striatum, the activation of opioid and serotonin pathways could be particularly implicated in mediating placebo responses encountered in pain and depression, respectively. (shrink)
New findings point to a role for mesolimbic DA circuits in the generation of dreaming. We disagree with Solms about these structures having an exclusive role in generating dreams. We review data suggesting that dreaming can be interrupted at different levels of processing and that anterior-subcortical lesions associated with dream cessation are unlikely to produce selective hypodopaminergic dynamic impairments. [Hobson et al.; Nielsen; Solms].
Two strains of male mice have bred over fortygenerations, starting with the work of RobertCairns and his colleagues, one strain with ahigh level of intra-species aggression, theother a low level of aggression. Thehigh-aggression mice tend to establishdominance hierarchies and particularly fight inthe presence of female mice. Thelow-aggression mice tend, in groups of theirown, to have a high degree of low-intensity,peaceful social contact, and to be more timidin initiating action than the high-aggressionmice. Biochemical differences have beenobserved between the two strains, and (...) confirmedby the present data: the high-aggression micehave greater dopamine concentrations (in thecaudate nucleus and nucleus accumbens), lowerlevels of the stress hormone corticosterone,and higher levels of testosterone than thelow-aggression mice. The current experimentswere designed to answer questions about theflexibility of adaptive behaviors:specifically, what is the effect of early dailymaternal separation on adult stress response ineach strain? What are the behavioral andhormonal mechanisms by which, as has beenobserved, low-aggression mice achieve adominant status when brought into situationswhere they compete for territory withhigh-aggression mice? Finally, what are thesocial and neurochemical mechanisms by whichhigh-aggression mice can develop low-aggressionbehavior if brought out of isolation and intogroups?Maternal separation was found to lead todecreases in stress levels, as measured bycorticosterone, in the low-aggression but notthe high-aggression, mice – presumably becauseof the surplus of maternal care the pupsreceive on returning to the nest. When alow-aggression mouse became dominant and ahigh-aggression mouse became submissive, theirusual pattern of corticosterone andtestosterone levels was found to be reversed. The change to low-aggression behavior inhigh-aggression mice switching from anisolation condition to a group condition, wasmediated by a decrease in D 1 dopaminereceptor densities.These results, like the ones on which theybuild, argue for substantial developmentalinfluences in expressions of the genesinfluencing aggressive or cooperative behavior. In this approach to evolution, epigenesis istreated not as a set of traits and behaviorspredetermined by the genome, but as a set ofprobabilistic tendencies toward certain traitsand behaviors. (shrink)
Patients with schizophrenia have an impairment in the inhibition of reflexive saccades, as a consequence of a functional impairment of the prefrontal cortex, which has not yet been encapsulated in terms of a formal model. A number of novel and testable hypotheses can be generated from the framework proposed by Findlay & Walker that will stimulate further research. Their framework therefore marks an important step in the development of a comprehensive functional model of saccadic eye movements. Further advances will be (...) assisted by (1) a recognition of important distinctions in the executive control of volitional saccades and (2) addressing the capacity for cross-model integration of spatial information in the generation of the spatial properties of saccadic eye movements. (shrink)
One of the most prominent paradigms in neuroeconomics is the Ultimatum Game (UG) that provides a framework for the study of pro-social behavior in two players interacting anonymously with each other: Player 1 has to split an endowment with player 2. Player 2 can either accept or reject the offer from player 1. If player 2 accepts the offer then the money is split as proposed by player 1. In case of rejection both players get nothing. Until now only one (...) twin study investigated the heritability of the behavior in the UG. Results indicated a strong heritability for the decision behavior of player 2 whereas no genetic influence on player 1 behavior could be detected. Further studies are mandatory to validate these heritability estimates. However, a first candidate polymorphism, the DRD4 exon III, constituting the biological basis of the heritability in the responder behavior has already been identified in a Chinese sample (Zhong et al., 2010). Until now genetic studies in Caucasians on the UG are lacking. The present study wants to fill this gap by investigating the UG in a healthy German sample. Moreover, we intend to find candidate genes that are associated with the first-mover-behavior. In a sample of N=130 healthy participants an online version of the UG was conducted and polymorphisms of the dopamine D2 receptor gene (DRD2) and the DRD4 exon III VNTR were genotyped. We could confirm the DRD4 exon III effect on the responder behavior and the absence of an effect on the proposer behavior reported before. In line with Zhong et al. (2010) carriers of the 4/4 genotype showed a significant higher minimal acceptable offer (p=0.023) than subjects with any other genotype. Furthermore, a DRD2-haplotype-block containing the single nucleotide polymorphisms rs1800497 and rs2283265 was significantly associated with the amount player1 offered (p=.005) but not with the decision of player 2. Results support the importance of the dopaminergic system for pro-social behavior. (shrink)
Maximizing gains during probabilistic reinforcement learning requires the updating of choice–outcome expectations at the time when the feedback about a specific choice or action is given. Extant theories and evidence suggest that dopaminergic modulation plays a crucial role in reinforcement learning and the updating of choice–outcome expectations. Furthermore, recently a positive component of the event-related potential (ERP) about 200 msec (P2) after feedback has been suggested to reflect such updating. The efficacy of dopaminergic modulation changes across the life span. However, (...) to date investigations of age-related differences in feedback-related P2 during reinforcement learning are still scarce. The present study thus aims to investigate whether individual differences in the feedback-related P2 would be associated with polymorphic variations in a dopamine relevant gene PPP1R1B (also known as DARPP-32) and whether the genetic effect may differ between age groups. We observed larger P2 amplitudes in individuals carrying the genotype associated with higher dopamine receptor efficacy, i.e., A allele homozygotes of a single nucleotide polymorphism (rs907094) of the PPP1R1B gene. Moreover, this effect was more pronounced in children and older adults in comparison to adolescents and younger adults. Together, our findings indicate that polymorphic variations in a dopamine relevant gene are associated with individual differences in brain-evoked potentials of outcome updating and hint at the possibility that genotype effects on neurocognitive phenotypes may vary as a function of brain maturation and aging. (shrink)
Reward-based decision-learning refers to the process of learning to select those actions that lead to rewards while avoiding actions that lead to punishments. This process, known to rely on dopaminergic activity in striatal brain regions, is compromised in Parkinson’s disease (PD). We hypothesized that such decision-learning deficits are alleviated by induced positive affect, which is thought to incur transient boosts in midbrain and striatal dopaminergic activity. Computational measures of probabilistic reward-based decision-learning were determined for 51 patients diagnosed with PD. Previous (...) work has shown these measures to rely on the nucleus caudatus (outcome evaluation during the early phases of learning) and the putamen (reward prediction during later phases of learning). We observed that induced positive affect facilitated learning, through its effects on reward prediction rather than outcome evaluation. Viewing a few minutes of comedy clips served to remedy dopamine-related problems in putamen-based frontostriatal circuitry and, consequently, in learning to predict which actions will yield reward. (shrink)
Implicit motives like the need for power (nPower) scale affective responses to need-specific rewards or punishments and thereby influence activity in motivational-brain structures. In this paper, we review evidence specifically supporting a role of the striatum in nPower. Individual differences in nPower predict (a) enhanced implicit learning accuracy, but not speed, on serial-response tasks that are reinforced by power-related incentives (e.g., winning or losing a contest; dominant or submissive emotional expressions) in behavioral studies and (b) activation of the anterior caudate (...) in response to dominant emotional expressions in brain imaging research. We interpret these findings on the basis of Hikosaka, Nakamura, Sakai, and Nakahara's (2002; Current Opinion in Neurobiology, 12(2), 217-222) model of central mechanisms of motor skill learning. The model assigns a critical role to the dorsoanterior striatum in dopamine-driven learning of spatial stimulus sequences. Based on this model, we suggest that the dorsoanterior striatum is the locus of nPower-dependent reinforcement. However, given the centrality of this structure in a wide range of motivational pursuits, we also propose that activity in the dorsoanterior striatum may not only reflect individual differences in nPower, but also in other implicit motives, like the need for achievement or the need for affiliation, provided that the proper incentives for these motives are present during reinforcement learning. We discuss evidence in support of such a general role of the dorsoanterior striatum in implicit motivation. (shrink)
Psychoneural reductionists sometimes claim that sufficient amounts of lower-level explanatory achievement preclude further contributions from higher-level psychological research. Ostensibly, with nothing left to do, the effect of such preclusion on psychological explanation is extinction. Reductionist arguments for preclusion have recently involved a reorientation within the philosophical foundations of neuroscience---namely, away from the philosophical foundations and toward the neuroscience. In this chapter, I review a successful reductive explanation of an aspect of reward function in terms of dopaminergic operations of the mesocorticolimbic (...) system in order to demonstrate why preclusion/extinction claims are dubious. (shrink)
Schizophrenia, like other pathological conditions of mental life, has not been systematically included in the general study of consciousness. By focusing on aspects of chronic schizophrenia, we attempt to remedy this omission. Basic components of Husserl’s phenomenology (intentionality, synthesis, constitution, epoche, and unbuilding) are explicated and then employed in an account of chronic schizophrenia. In schizophrenic experience, basic constituents of reality are lost and the subject must try to explicitly re-constitute them. “Automatic mental life” is weakened such that much of (...) the world that is normally taken-for-granted cannot continue to be so. The subject must actively re-lay the ontological foundations of reality. (shrink)
The question of domain-specific versus domain-general processing is an ongoing source of inquiry surrounding cognitive control. Using a comparative evolutionary approach, Stout (2010) proposed two components of cognitive control: coordinating hierarchical action plans and social cognition. This article reports additional molecular and experimental evidence supporting a domain-general attentional process coordinating hierarchical action plans, with the earliest such control processing originating in the capacity of dynamic foraging behaviors—predating the vertebrate-invertebrate divergence (c. 700 million years ago). Further discussion addresses evidence required for (...) additional, domain-specific, cognitive control processes, noting that proposed social processes may simply provide emotionally valenced representational information to the above hierarchical process. (shrink)
Jouissance is a Lacanian concept, infamous for being impervious to understanding and which expresses the paradoxical satisfaction that a subject may derive from his symptom. On the basis of Freud’s “experience of satisfaction” we have proposed a first working definition of jouissance as the (benefit gained from) the motor tension underlying the action which was [once] adequate in bringing relief to the drive and, on the basis of their striking reciprocal resonances, we have proposed that central dopaminergic systems could embody (...) the physiological architecture of Freud’s concept of the drive. We have then distinguished two constitutive axes to jouissance: one concerns the subject’s body and the other the subject’s history. Four distinctive aspects of these axes are discussed both from a metapsychological and from a neuroscience point of view. We conclude that jouissance could be described as an accumulation of body tension, fuelling for action, but continuously balancing between reward and anxiety, and both marking the physiology of the body with the history of its commemoration and arising from this inscription as a constant push to act and to repeat. Moroever, it seems that the mesolimbic accumbens dopaminergic pathway is a reasonable candidate for its underlying physiological architecture. (shrink)
It is becoming increasingly appreciated that affective influences can contribute strongly to goal-oriented cognition and behaviour. However, much work is still needed to properly characterize these influences and the mechanisms by which they contribute to cognitive processing. An important question concerns the nature of emotional manipulations (i.e., direct induction of affectively-valenced subjective experience) versus motivational manipulations (e.g., delivery of performance-contingent rewards and punishments) and their impact on cognitive control. Empirical evidence suggests that both kinds of manipulations can influence cognitive control (...) in a systematic fashion, but investigations of both have largely been conducted independently of one another. Likewise, some theoretical accounts suggest that emotion and motivation may modulate cognitive control via common neural mechanisms, while others suggest the possibility of dissociable influences. Here, we provide an analysis and synthesis of these various accounts, suggesting potentially fruitful new research directions to test competing hypotheses. (shrink)
Attention deficit hyperactivity disorder is a developmental disorder with an age onset prior to 7 years. Children with ADHD have significantly lower ability to focus and sustain attention and also score higher on impulsivity and hyperactivity. Stimulants, such as methylphenidate, have remained the mainstay of ADHD treatment for decades with evidence supporting their use. However, recent years have seen emergence of newer drugs and drug delivery systems, like osmotic release oral systems and transdermal patches, to mention a few. The use (...) of nonstimulant drugs like atomoxetine and various other drugs, such as a-agonists, and a few antidepressants, being used in an off-label manner, have added to the pharmacotherapy of ADHD. This review discusses current trends in drug therapy of ADHD and highlights the promise pharmacogenomics may hold in the future. (shrink)
Prominent computational models describe a neural mechanism for learning from reward prediction errors, and it has been suggested that variations in this mechanism are reflected in personality factors such as trait extraversion. However, although trait extraversion has been linked to improved reward learning, it is not yet known whether this relationship is selective for the particular computational strategy associated with error-driven learning, known as model-free reinforcement learning, versus another strategy, model-based learning, which the brain is also known to employ. In (...) the present study we test this relationship by examining whether humans’ scores on an extraversion scale predict individual differences in the balance between model-based and model-free learning strategies in a sequentially structured decision task designed to distinguish between them. In previous studies with this task, participants have shown a combination of both types of learning, but with substantial individual variation in the balance between them. In the current study, extraversion predicted worse behavior across both sorts of learning. However, the hypothesis that extraverts would be selectively better at model-free reinforcement learning held up among a subset of the more engaged participants, and overall, higher task engagement was associated with a more selective pattern by which extraversion predicted better model-free learning. The findings indicate a relationship between a broad personality orientation and detailed computational learning mechanisms. Results like those in the present study suggest an intriguing and rich relationship between core neuro-computational mechanisms and broader life orientations and outcomes. (shrink)