Just do it: A neuropsychological theory of agency, cognition, mood, and dopamine.

Agency is the sense that one has control over one's own actions and the consequences of those actions. Despite the critical role that agency plays in the human condition, little is known about its neural basis. A novel theory proposes that increases in agency disinhibit the dopamine system and thereby increase the number of tonically active dopamine neurons in the ventral tegmental area. The theory, called ADDS (Agency Disinhibits the Dopamine System), proposes a specific neural network that mediates these effects. ADDS accurately predicts a variety of relevant neuroscience results, and makes many novel predictions, including that increases in an agency will (a) increase motivation, (b) improve executive function, (c) facilitate procedural learning, but only in the presence of immediate trial-by-trial feedback, (d) have little or no effect on learning-related effects of stimulus repetition or on standard eyeblink conditioning, (e) facilitate the development of automatic behaviors, but have little or no effect on the production of behaviors that are already automatized, (f) amplify the cognitive benefits of positive mood, and (g) reduce pain. The implications of this new theory are considered for several purely psychological theories that assign prominent roles to agency, including self-efficacy theory, hope theory, and goal-focused positive psychotherapy. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Dissociable feedback valence effects on frontal midline theta during reward gain versus threat avoidance learning.

While frontal midline theta (FMθ) has been associated with threat processing, with cognitive control in the context of anxiety, and with reinforcement learning, most reinforcement learning studies on FMθ have used reward rather than threat-related stimuli as reinforcer. Accordingly, the role of FMθ in threat-related reinforcement learning is largely unknown. Here, n = 23 human participants underwent one reward-, and one punishment-, based reversal learning task, which differed only with regard to the kind of reinforcers that feedback was tied to (i.e., monetary gain vs. loud noise burst, respectively). In addition to single-trial EEG, we assessed single-trial feedback expectations based on both a reinforcement learning computational model and trial-by-trial subjective feedback expectation ratings. While participants' performance and feedback expectations were comparable between the reward and punishment tasks, FMθ was more reliably amplified to negative vs. positive feedback in the reward vs. punishment task. Regressions with feedback valence, computationally derived, and self-reported expectations as predictors and FMθ as criterion further revealed that trial-by-trial variations in FMθ specifically relate to reward-related feedback-valence and not to threat-related feedback or to violated expectations/prediction errors. These findings suggest that FMθ as measured in reinforcement learning tasks may be less sensitive to the processing of events with direct relevance for fear and anxiety.

Extraversion and reward-processing: Consolidating evidence from an electroencephalographic index of reward-prediction-error.

Trait extraversion has been theorized to emerge from functioning of the dopaminergic reward system. Recent evidence for this view shows that extraversion modulates the scalp-recorded Reward Positivity, a putative marker of dopaminergic signaling of reward-prediction-error. We attempt to replicate this association amid several improvements on previous studies in this area, including an adequately-powered sample (N = 100) and thorough examination of convergent-divergent validity. Participants completed a passive associative learning task presenting rewards and non-rewards that were either predictable or unexpected. Frequentist and Bayesian analyses confirmed that the scalp recorded Reward Positivity (i.e., the Feedback-Related-Negativity contrasting unpredicted rewards and unpredicted non-rewards) was significantly associated with three measures of extraversion and unrelated to other basic traits from the Big Five personality model. Narrower sub-traits of extraversion showed similar, though weaker associations with the Reward Positivity. These findings consolidate previous evidence linking extraversion with a putative marker of dopaminergic reward-processing.

The effects of social anxiety on emotional face discrimination and its modulation by mouth salience.

People high in social anxiety experience fear of social situations due to the likelihood of social evaluation. Whereas happy faces are generally processed very quickly, this effect is impaired by high social anxiety. Mouth regions are implicated during emotional face processing, therefore differences in mouth salience might affect how social anxiety relates to emotional face discrimination. We designed an emotional facial expression recognition task to reveal how varying levels of sub-clinical social anxiety (measured by questionnaire) related to the discrimination of happy and fearful faces, and of happy and angry faces. We also categorised the facial expressions by the salience of the mouth region (i.e. high [open mouth] vs. low [closed mouth]). In a sample of 90 participants higher social anxiety (relative to lower social anxiety) was associated with a reduced happy face reaction time advantage. However, this effect was mainly driven by the faces with less salient closed mouths. Our results are consistent with theories of anxiety that incorporate an oversensitive valence evaluation system.

Modeling dopaminergic and other processes involved in learning from reward prediction error: contributions from an individual differences perspective.

Phasic firing changes of midbrain dopamine neurons have been widely characterized as reflecting a reward prediction error (RPE). Major personality traits (e.g., extraversion) have been linked to inter-individual variations in dopaminergic neurotransmission. Consistent with these two claims, recent research (Smillie et al., 2011; Cooper et al., 2014) found that extraverts exhibited larger RPEs than introverts, as reflected in feedback related negativity (FRN) effects in EEG recordings. Using an established, biologically-localized RPE computational model, we successfully simulated dopaminergic cell firing changes which are thought to modulate the FRN. We introduced simulated individual differences into the model: parameters were systematically varied, with stable values for each simulated individual. We explored whether a model parameter might be responsible for the observed covariance between extraversion and the FRN changes in real data, and argued that a parameter is a plausible source of such covariance if parameter variance, across simulated individuals, correlated almost perfectly with the size of the simulated dopaminergic FRN modulation, and created as much variance as possible in this simulated output. Several model parameters met these criteria, while others did not. In particular, variations in the strength of connections carrying excitatory reward drive inputs to midbrain dopaminergic cells were considered plausible candidates, along with variations in a parameter which scales the effects of dopamine cell firing bursts on synaptic modification in ventral striatum. We suggest possible neurotransmitter mechanisms underpinning these model parameters. Finally, the limitations and possible extensions of our general approach are discussed.

Individual differences in reward prediction error: contrasting relations between feedback-related negativity and trait measures of reward sensitivity, impulsivity and extraversion.

Medial-frontal negativity occurring ∼200-300 ms post-stimulus in response to motivationally salient stimuli, usually referred to as feedback-related negativity (FRN), appears to be at least partly modulated by dopaminergic-based reward prediction error (RPE) signaling. Previous research (e.g., Smillie et al., 2011) has shown that higher scores on a putatively dopaminergic-based personality trait, extraversion, were associated with a more pronounced difference wave contrasting unpredicted non-reward and unpredicted reward trials on an associative learning task. In the current study, we sought to extend this research by comparing how trait measures of reward sensitivity, impulsivity and extraversion related to the FRN using the same associative learning task. A sample of healthy adults (N = 38) completed a battery of personality questionnaires, before completing the associative learning task while EEG was recorded. As expected, FRN was most negative following unpredicted non-reward. A difference wave contrasting unpredicted non-reward and unpredicted reward trials was calculated. Extraversion, but not measures of impulsivity, had a significant association with this difference wave. Further, the difference wave was significantly related to a measure of anticipatory pleasure, but not consummatory pleasure. These findings provide support for the existing evidence suggesting that variation in dopaminergic functioning in brain "reward" pathways may partially underpin associations between the FRN and trait measures of extraversion and anticipatory pleasure.

Measuring belief in conspiracy theories: the generic conspiracist beliefs scale.

The psychology of conspiracy theory beliefs is not yet well understood, although research indicates that there are stable individual differences in conspiracist ideation - individuals' general tendency to engage with conspiracy theories. Researchers have created several short self-report measures of conspiracist ideation. These measures largely consist of items referring to an assortment of prominent conspiracy theories regarding specific real-world events. However, these instruments have not been psychometrically validated, and this assessment approach suffers from practical and theoretical limitations. Therefore, we present the Generic Conspiracist Beliefs (GCB) scale: a novel measure of individual differences in generic conspiracist ideation. The scale was developed and validated across four studies. In Study 1, exploratory factor analysis of a novel 75-item measure of non-event-based conspiracist beliefs identified five conspiracist facets. The 15-item GCB scale was developed to sample from each of these themes. Studies 2, 3, and 4 examined the structure and validity of the GCB, demonstrating internal reliability, content, criterion-related, convergent and discriminant validity, and good test-retest reliability. In sum, this research indicates that the GCB is a psychometrically sound and practically useful measure of conspiracist ideation, and the findings add to our theoretical understanding of conspiracist ideation as a monological belief system unpinned by a relatively small number of generic assumptions about the typicality of conspiratorial activity in the world.

Aspects of cognitive functioning in schizotypy and schizophrenia: evidence for a continuum model.

This research consisted of two studies, the fundamental aim of which was to delineate the pattern of relationships between measures of cognitive task performance and both symptom subtypes in schizophrenia and their corresponding schizotypal personality traits in healthy individuals. Study 1 compared these relationships in healthy individuals using the Schizotypal Personality Questionnaire (SPQ) and Study 2 assessed the relationships between symptomatology assessed using the Scale for the Assessment of Positive Symptoms and Scale for the Assessment of Negative Symptoms (SAPS/SANS) and cognitive task performance in a group of patients with schizophrenia. The contribution of fluid intelligence to task performance was also examined. In Study 1 high levels of negative schizotypy were associated with reduced verbal fluency, and high levels of disorganised schizotypy were associated with reduced negative priming in the healthy participants. In Study 2, closely corresponding relationships between symptom measures and these tasks were found in the patients with schizophrenia. The associations between the symptom and cognitive measures were independent of the effects of fluid IQ on performance.

A facial expression for anxiety.

Anxiety and fear are often confounded in discussions of human emotions. However, studies of rodent defensive reactions under naturalistic conditions suggest anxiety is functionally distinct from fear. Unambiguous threats, such as predators, elicit flight from rodents (if an escape-route is available), whereas ambiguous threats (e.g., the odor of a predator) elicit risk assessment behavior, which is associated with anxiety as it is preferentially modulated by anti-anxiety drugs. However, without human evidence, it would be premature to assume that rodent-based psychological models are valid for humans. We tested the human validity of the risk assessment explanation for anxiety by presenting 8 volunteers with emotive scenarios and asking them to pose facial expressions. Photographs and videos of these expressions were shown to 40 participants who matched them to the scenarios and labeled each expression. Scenarios describing ambiguous threats were preferentially matched to the facial expression posed in response to the same scenario type. This expression consisted of two plausible environmental-scanning behaviors (eye darts and head swivels) and was labeled as anxiety, not fear. The facial expression elicited by unambiguous threat scenarios was labeled as fear. The emotion labels generated were then presented to another 18 participants who matched them back to photographs of the facial expressions. This back-matching of labels to faces also linked anxiety to the environmental-scanning face rather than fear face. Results therefore suggest that anxiety produces a distinct facial expression and that it has adaptive value in situations that are ambiguously threatening, supporting a functional, risk-assessing explanation for human anxiety.

Individual differences in reward-prediction-error: extraversion and feedback-related negativity.

Medial frontal scalp-recorded negativity occurring ∼200-300 ms post-stimulus [known as feedback-related negativity (FRN)] is attenuated following unpredicted reward and potentiated following unpredicted non-reward. This encourages the view that FRN may partly reflect dopaminergic 'reward-prediction-error' signalling. We examined the influence of a putatively dopamine-based personality trait, extraversion (N = 30), and a dopamine-related gene polymorphism, DRD2/ANKK1 (N = 24), on FRN during an associative reward-learning paradigm. FRN was most negative following unpredicted non-reward and least-negative following unpredicted reward. A difference wave contrasting these conditions was significantly more pronounced for extraverted participants than for introverts, with a similar but non-significant trend for participants carrying at least one copy of the A1 allele of the DRD2/ANKK1 gene compared with those without the allele. Extraversion was also significantly higher in A1 allele carriers. Results have broad relevance to neuroscience and personality research concerning reward processing and dopamine function.

Individual differences in cognitive-flexibility: the influence of spontaneous eyeblink rate, trait psychoticism and working memory on attentional set-shifting.

Individual differences in psychophysiological function have been shown to influence the balance between flexibility and distractibility during attentional set-shifting [e.g., Dreisbach et al. (2005). Dopamine and cognitive control: The influence of spontaneous eyeblink rate and dopamine gene polymorphisms on perseveration and distractibility. Behavioral Neuroscience, 119(2), 483-490]. Here we replicate both the facilitatory and detrimental influence of spontaneous eyeblink rate upon switch costs across the two distinct conditions of a set-shifting task. We extend this by presenting additional, putatively dopamine related, individual differences that also influence attentional control. Whereas trait psychoticism showed a pattern of effects opposite to that of eyeblink rate, greater working memory served to decrease switch costs across both conditions. These results highlight the need for further exploration of the role of dopaminergic neurotransmission and component processes involved in such attentional paradigms, and illustrates the importance of considering individual differences in cognitive control.

Do measures of schizotypal personality provide non-clinical analogues of schizophrenic symptomatology?

This study tested the assumption that measures of schizotypal personality provide non-clinical analogues of the heterogeneous symptomatology found in the schizophrenic disorder. The Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE) was administered to schizophrenic patients and healthy controls, and measures of symptomatology from the Scale for the Assessment of Positive Symptoms (SAPS) and the Scale for the Assessment of Negative Symptoms (SANS) were assessed in the patient group. Schizophrenic patients scored significantly higher than controls on O-LIFE measures of positive, negative and disorganised schizotypy, while no difference in Impulsive Nonconformity was observed. In the patient group, SAPS positive symptomatology was significantly correlated with O-LIFE positive schizotypy (Unusual Experiences) and Cognitive Disorganisation. However, there was no significant relationship between SAPS/SANS disorganisation and O-LIFE Cognitive Disorganisation, or between the SANS negative factor score and O-LIFE Introvertive Anhedonia. The results suggest that the O-LIFE is a valid tool for assessing schizotypal personality in both schizophrenic patients and healthy controls. However, while the O-LIFE measure of positive schizotypy may correspond with SAPS/SANS positive schizophrenic symptomatology, the negative and disorganised subscales may not be analogous to their SAPS/SANS counterparts. There is also evidence to question the acceptability of Impulsive Nonconformity as a true schizophrenia-like construct.

Variation in DRD2 dopamine gene predicts Extraverted personality.

Quantitative geneticists estimate the heritability of Extraverted personality to be around 40-60%. Theory and research which links Extraversion with variation in dopaminergic function suggests that dopaminergic genes should be a start-point for molecular genetic investigations of this trait. Recent endeavours in this area have met with some encouragement but also setbacks. In this study, we investigate the relationship between Extraversion and the DRD2 TaqIA/ANKK1 polymorphism in 224 university students. Presence of at least one copy of the A1 allele was associated with significantly higher Extraversion. The robustness of this finding was confirmed through bootstrap analysis. Findings are discussed in relation to the broader literature, in particular, methodological issues which may have obscured this finding in previous research.

A note on DeCaro, Thomas, and Beilock (2008): further data demonstrate complexities in the assessment of information-integration category learning.

DeCaro et al. [DeCaro, M. S., Thomas, R. D., & Beilock, S. L. (2008). Individual differences in category learning: Sometimes less working memory capacity is better than more. Cognition, 107(1), 284-294] explored how individual differences in working memory capacity differentially mediate the learning of distinct category structures. Specifically, their results showed that greater working memory capacity facilitates the learning of novel category structures that are verbalisable and discoverable through logical reasoning processes. Conversely, however, greater working memory was shown to impede the learning of novel category structures thought to be non-verbalisable, inaccessible to conscious reasoning and discoverable only through implicit (procedural) learning of appropriate stimulus-category responses. The present paper calls into question the specific nature of the category learning tasks used, in particular their ability to discriminate between different modes of category learning.

Associations between schizotypal personality traits and the facilitation and inhibition of the speed of contextually cued responses.

This study measured schizotypal personality traits in a sample of 33 healthy participants using the Oxford-Liverpool Inventory of Feelings and Experiences. These traits were correlated with measures of inhibition and facilitation of response times (RTs) within a cued letter-comparison task. It was expected that scores on a measure of positive schizotypy, reflecting unrealistically distorted perceptions and beliefs, would be negatively associated with inhibition of RTs to targets that were unexpected in the context of the preceding letter cue. No specific predictions were made for the facilitation of RTs to targets expected in the context of the cues. The predicted negative association for positive schizotypy and inhibition of RTs was confirmed. There was no significant association between positive schizotypy and facilitation of RTs; however, there was an unpredicted finding that facilitation of RTs was increased in individuals with higher levels of disorganized schizotypy. The findings for positive schizotypy were consistent with Hemsley's model, in that high positive schizotypy results from a weakening of contextually elicited inhibitory processes, and is associated with altered functioning of a monitoring system. The normal functioning of the monitoring system is to generate mismatch signals that interrupt information processing when a contextually unexpected stimulus occurs.

The new reinforcement sensitivity theory: implications for personality measurement.

In this article, we review recent modifications to Jeffrey Gray's (1973, 1991) reinforcement sensitivity theory (RST), and attempt to draw implications for psychometric measurement of personality traits. First, we consider Gray and McNaughton's (2000) functional revisions to the biobehavioral systems of RST. Second, we evaluate recent clarifications relating to interdependent effects that these systems may have on behavior, in addition to or in place of separable effects (e.g., Corr, 2001; Pickering, 1997). Finally, we consider ambiguities regarding the exact trait dimension to which Gray's "reward system" corresponds. From this review, we suggest that future work is needed to distinguish psychometric measures of (a) fear from anxiety and (b) reward-reactivity from trait impulsivity. We also suggest, on the basis of interdependent system views of RST and associated exploration using formal models, that traits that are based upon RST are likely to have substantial intercorrelations. Finally, we advise that more substantive work is required to define relevant constructs and behaviors in RST before we can be confident in our psychometric measures of them.

Disrupting feedback processing interferes with rule-based but not information-integration category learning.

The effect of a sequentially presented memory scanning task on rule-based and information-integration category learning was investigated. On each trial in the short feedback-processing time condition, memory scanning immediately followed categorization. On each trial in the long feedback-processing time condition, categorization was followed by a 2.5-sec delay and then memory scanning. In the control condition, no memory scanning was required. Rule-based category learning was significantly worse in the short feedback-processing time condition than in the long feedback-processing time condition or control condition, whereas information-integration category learning was equivalent across conditions. In the rule-based condition, a smaller proportion of observers learned the task in the short feedback-processing time condition, and those who learned took longer to reach the performance criterion than did those in the long feedback-processing time or control condition. No differences were observed in the information integration task. These results provide support for a multiple-systems approach to category learning and argue against the validity of single-system approaches.

The partial reinforcement extinction effect in humans: effects of schizophrenia, schizotypy and low doses of amphetamine.

The partial reinforcement extinction effect (PREE) was studied in human subjects. It has been suggested that the PREE depends on neural mechanisms critical to the cognitive dysfunction which underlines acute schizophrenia. We therefore predicted that the PREE should be reduced, through decreased resistance to extinction in the partial reinforcement (PR) condition, in various types of individual: (a) healthy volunteers given low doses of oral amphetamine; (b) those in the acute (but not chronic) phase of a schizophrenic illness and; (c) healthy volunteers with high scores on personality measures of schizotypy. Despite obtaining robust demonstrations of PREE in all experiments, none of these predictions were confirmed. A single, low dose, of amphetamine had no effect on either continuous reinforcement (CR) or partial reinforcement (PR). Acute and chronic schizophrenic patients showed a reduced PREE compared to controls. However this was due to increased resistance to extinction in the CR groups. Finally, high schizotypy scores were associated with greater PREE, attributable to both decreased extinction in the CR condition and increased extinction in the PR condition. The results of these experiments on human PREE provide no support that PREE is a valid paradigm with which to explore the cognitive dysfunction underlying schizophrenia.