To trust or not to trust: the dynamics of social interaction in psychosis

Understanding the mechanisms underlying cognitive control in psychosis

BACKGROUND

Cognitive control (CC) involves a top-down mechanism to flexibly respond to complex stimuli and is impaired in schizophrenia.

METHODS

This study investigated the impact of increasing complexity of CC processing in 140 subjects with psychosis and 39 healthy adults, with assessments of behavioral performance, neural regions of interest and symptom severity.

RESULTS

The lowest level of CC (Stroop task) was impaired in all patients; the intermediate level of CC (Faces task) with explicit emotional information was most impaired in patients with first episode psychosis. Patients showed activation of distinct neural CC and reward networks, but iterative learning based on the higher-order of CC during the trust game, was most impaired in chronic schizophrenia. Subjects with first episode psychosis, and patients with lower symptom load, demonstrate flexibility of the CC network to facilitate learning, which appeared compromised in the more chronic stages of schizophrenia.

CONCLUSION

These data suggest optimal windows for opportunities to introduce therapeutic interventions to improve CC.

Trust of patients and families in mental healthcare providers and institutions: a cross-cultural study in Chennai, India, and Montreal, Canada

PURPOSE

Cross-cultural psychosis research has typically focused on a limited number of outcomes (generally symptom-related). It is unknown if the purported superior outcomes for psychosis in some low- and middle-income countries extend to fundamental treatment processes like trust. Addressing this gap, we studied two similar first-episode psychosis programs in Montreal, Canada, and Chennai, India. We hypothesized higher trust in healthcare institutions and providers among patients and families in Chennai at baseline and over follow-up.

METHODS

Upon treatment entry and at months 3, 12 and 24, trust in healthcare providers was measured using the Wake Forest Trust scale and trust in the healthcare and mental healthcare systems using two single items. Nonparametric tests were performed to compare trust levels across sites and mixed-effects linear regression models to investigate predictors of trust in healthcare providers.

RESULTS

The study included 333 patients (Montreal = 165, Chennai = 168) and 324 family members (Montreal = 128, Chennai = 168). Across all timepoints, Chennai patients and families had higher trust in healthcare providers and the healthcare and mental healthcare systems. The effect of site on trust in healthcare providers was significant after controlling for sociodemographic characteristics known to impact trust. Patients' trust in doctors increased over follow-up.

CONCLUSION

This study uniquely focuses on trust as an outcome in psychosis, via a comparative longitudinal analysis of different trust dimensions and predictors, across two geographical settings. The consistent differences in trust levels between sites may be attributable to local cultural values and institutional structures and processes and underpin cross-cultural variations in treatment engagement and outcomes.

Trust and psychosis: a systematic review and meta-analysis

BACKGROUND

Impaired trust in other humans is commonly seen in psychosis and it leads to poor societal functioning. However, examining trust behavior in an experimental setting is challenging. Investigators have used the trust game, a neuro-economic game to assess trust behavior in psychosis. However, the findings are inconsistent. Hence, we systematically reviewed the existing literature and conducted a meta-analysis to examine trust behavior in patients with psychosis, their relatives, and those at high risk for psychosis.

METHODS

We searched electronic databases for studies that have examined trust game in patients with psychosis, published up to November 2021. The primary outcome measure was the baseline trust in a trust game by patients and controls. The meta-analysis was performed if at least three data sets of control and patient groups were available for that measure/design. We conducted meta-analyses with a random-effects model. The results were described narratively wherever meta-analysis was not possible due to paucity of studies.

RESULTS

The searches across the databases including cross-references yielded 465 publications of which 10 studies were included in the final analysis. Baseline trust in the trust game was significantly lower in patients with psychosis compared to controls (SMD 0.39, 95% CI -0.14 to 0.64, p -0.002). However, a similar decrease in baseline trust was not present in relatives of patients (SMD 0.08, 95% CI -0.20 to 0.36, p -0.58).

CONCLUSIONS

The current meta-analysis suggests significant trust deficits in patients with psychosis. Future studies with a bigger sample size are required to understand the nature of trust deficits and factors affecting this impairment.

Language skills and interpersonal trust in adolescents with and without mental illness

PURPOSE

The primary aim was to compare adolescents with mental illness and non-clinical adolescents on vocabulary, social problem-solving, trust in parents, attachment and mentalisation. A secondary aim was to investigate whether adolescents' language skills were associated with trust in parents.

METHOD

Seventy-eight adolescents (16-18 years) participated in this cross-sectional quantitative study: a clinical sample (n = 28, M = 16.7 years, 19F) recruited from a mental health service and a non-clinical sample (n = 50, M = 17.0 years, 28F). Standardised language measures and self-report measures of trust in parents; communication quality; attachment; and mentalisation were used. Primary and secondary aims were addressed through independent samples t-tests and Pearson's correlation analyses, respectively.

RESULT

Adolescents experiencing mental illness reported significantly poorer vocabulary, less trust in mother/father, greater attachment anxiety/avoidance, and poorer reflective functioning, than non-clinical adolescents. Expressive vocabulary of clinical (but not non-clinical) adolescents significantly negatively correlated with trust in mother (but not father).

CONCLUSION

Results highlight a role for speech-language pathologists (SLPs) in supporting communication needs of adolescents with mental illness. SLPs should consider trust by: i) understanding adolescents with mental illness may have difficulty trusting them potentially impacting therapeutic engagement; and ii) delivering services in ways that might build trust, such as involving adolescents in treatment planning.

Blocking D2/D3 dopamine receptors in male participants increases volatility of beliefs when learning to trust others

The ability to learn about other people is crucial for human social functioning. Dopamine has been proposed to regulate the precision of beliefs, but direct behavioural evidence of this is lacking. In this study, we investigate how a high dose of the D2/D3 dopamine receptor antagonist sulpiride impacts learning about other people's prosocial attitudes in a repeated Trust game. Using a Bayesian model of belief updating, we show that in a sample of 76 male participants sulpiride increases the volatility of beliefs, which leads to higher precision weights on prediction errors. This effect is driven by participants with genetically conferred higher dopamine availability (Taq1a polymorphism) and remains even after controlling for working memory performance. Higher precision weights are reflected in higher reciprocal behaviour in the repeated Trust game but not in single-round Trust games. Our data provide evidence that the D2 receptors are pivotal in regulating prediction error-driven belief updating in a social context.

How social information impacts action in rodents and humans: the role of the prefrontal cortex and its connections

Day-to-day choices often involve social information and can be influenced by prior social experience. When making a decision in a social context, a subject might need to: 1) recognize the other individual or individuals, 2) infer their intentions and emotions, and 3) weigh the values of all outcomes, social and non-social, prior to selecting an action. These elements of social information processing all rely, to some extent, on the medial prefrontal cortex (mPFC). Patients with neuropsychiatric disorders often have disruptions in prefrontal cortical function, likely contributing to deficits in social reasoning and decision making. To better understand these deficits, researchers have turned to rodents, which have revealed prefrontal cortical mechanisms for contending with the complex information processing demands inherent to making decisions in social contexts. Here, we first review literature regarding social decision making, and the information processing underlying it, in humans and patient populations. We then turn to research in rodents, discussing current procedures for studying social decision making, and underlying neural correlates.

Social interaction, psychotic disorders and inflammation: A triangle of interest

Social interaction difficulties are a hallmark of psychotic disorders, which in some cases can be definitely traced back to autoimmunological causes. Interestingly, systemic and intrathecal inflammation have been shown to significantly influence social processing by increasing sensitivity to threatening social stimuli, which bears some resemblance to psychosis. In this article, we review evidence for the involvement of systemic and intrathecal inflammatory processes in psychotic disorders and how this might help to explain some of the social impairments associated with this group of disorders. Vice versa, we also discuss evidence for the immunomodulatory function of social interactions and their potential role for therapeutic interventions in psychotic disorders.

Paranoid thinking and perceived competitive intention

Paranoid thinking, that others are hostile, can be seen even in the general population. Paranoia is considered the expectation that others are competitors who aim to maximize the differences in payoffs rather than maximize their own payoffs. This study examined whether paranoia reflects the irrational belief that others have a competitive intention and is associated with avoiding perceived competition. We recruited 884 US residents via the Internet and conducted a modified Dictator Game, in which monetary allocation was carried out between the Dictator and the Recipient. The Dictator chooses either fair or competitive allocation while selecting the competitive allocation is irrelevant to increasing the Dictator's payoffs. The Recipient decides whether to accept the Dictator's decision or receive sure but low rewards. We found that Recipients with high-level paranoid thinking expected their opponent to select competitive allocation more than those with low levels, even when selecting it was costly for Dictators. Paranoid thinking was not associated with selecting sure rewards or competitive allocations. The results suggest that paranoia reflects the belief that others have a competitive intention but is not related to avoidance behavior against perceived threats and unilateral attacks.

Neuroimaging oxytocin modulation of social reward learning in schizophrenia

BACKGROUND

Conventional pharmacological approaches have limited effectiveness for schizophrenia. There is interest in the application of oxytocin, which is involved in social cognition. Clinical trials have yielded mixed results, with a gap in understanding neural mechanisms.

AIMS

To evaluate the behavioural impact of oxytocin administration on a social learning task in individuals with schizophrenia, and elucidate any differential neural activity produced.

METHOD

We recruited 20 clinically stable right-handed men diagnosed with schizophrenia or schizoaffective disorder. In a double-blind cross-over randomised controlled study, 40 IU of oxytocin or placebo were administered before functional magnetic resonance imaging of participants playing a multi-round economic exchange game of trust. Participants had the role of investors (investment trials) receiving repayment on their investments (repayment trials), playing one session against a computer and a second against a player believed to be human.

RESULTS

During investment trials, oxytocin increased neural signalling in the right lateral parietal cortex for both human and computer player trials, and attenuated signalling in the right insula for human player trials. For repayment trials, oxytocin elicited signal increases in left insula and left ventral caudate, and a signal decrease in right amygdala during the human player trials; conversely it resulted in right dorsal caudate activation during the computer player trials. We did not find a significant change in behavioural performance associated with oxytocin administration, or any associations with symptoms.

CONCLUSIONS

During a social learning task oxytocin modulates cortical and limbic substrates of the reward-processing network. These perturbations can be putatively linked to the pathoaetiology of schizophrenia.

A Model of Trust

Trust is central to a large variety of social interactions. Different research fields have empirically and theoretically investigated trust, observing trusting behaviors in different situations and pinpointing their different components and constituents. However, a unifying, computational formalization of those diverse components and constituents of trust is still lacking. Previous work has mainly used computational models borrowed from other fields and developed for other purposes to explain trusting behaviors in empirical paradigms. Here, I computationally formalize verbal models of trust in a simple model (i.e., vulnerability model) that combines current and prospective action values with beliefs and expectancies about a partner’s behavior. By using the classic investment game (IG)—an economic game thought to capture some important features of trusting behaviors in social interactions—I show how variations of a single parameter of the vulnerability model generates behaviors that can be interpreted as different “trust attitudes”. I then show how these behavioral patterns change as a function of an individual’s loss aversion and expectations of the partner’s behavior. I finally show how the vulnerability model can be easily extended in a novel IG paradigm to investigate inferences on different traits of a partner. In particular, I will focus on benevolence and competence—two character traits that have previously been described as determinants of trustworthiness impressions central to trust. The vulnerability model can be employed as is or as a utility function within more complex Bayesian frameworks to fit participants’ behavior in different social environments where actions are associated with subjective values and weighted by individual beliefs about others’ behaviors. Hence, the vulnerability model provides an important building block for future theoretical and empirical work across a variety of research fields.

Associations of interpersonal trust with juvenile offending/conduct disorder, callous-unemotional traits, and criminal recidivism

Interpersonal trust has been described as a core dimension of cooperative, mutually beneficial interpersonal relationships but it is unclear if it is related to antisocial behaviours in youth. The present study aimed at analysing a subsample of male juveniles who committed serious violent offenses and met criteria of conduct disorder (JO/CD), and a subsample of healthy controls (HC) using a series of trust games (TGs). Twenty-four male JO/CD and 24 age matched male HC performed a series of eight one-shot TGs against different unknown human respectively computer opponents. Mixed model analyses found a non-significant trend that JO/CD invested less points than HC during TGs. In the subsample of JO/CD, the overall investment in TGs was found to be negatively associated with self-reported uncaring behaviours and officially reported general re-offenses. Our findings suggest some indication of an impaired ability of JO/CD to initiate mutually trusting relationships to others that should be addressed in further research. Trust is a promising factor to predict general criminal recidivism and can be a target for treatment of juveniles who committed violent offenses, for example through the building of stable relationships to care givers. This study encourages future studies to investigate the effects of trust-increasing psychosocial interventions.

A Computational Model of Non-optimal Suspiciousness in the Minnesota Trust Game

This study modelled spite sensitivity, the worry that others are willing to incur a loss to hurt you, which is thought to undergird suspiciousness and persecutory ideation. Two samples performed a parametric, non-iterative trust game known as the Minnesota Trust Game (MTG). The MTG distinguishes suspicious decision-making from otherwise rational mistrust by incentivizing the player to trust in certain situations but not others. In Sample 1, 243 undergraduates who completed the MTG showed less trust as the amount of money they could lose increased. However, only for choices where partners had a financial disincentive to betray the player was variation in the willingness to trust associated with suspicious beliefs. We modified the Fehr-Schmidt (1999) inequity aversion model, which compares unequal outcomes in social decision-making tasks, to include the possibility for spite sensitivity. An anticipated partner's dislike of advantageous inequity (i.e., guilt) parameter included negative values, with negative guilt indicating spite. We hypothesized that the anticipated guilt parameter would be strongly related to suspicious beliefs. Our modification of the Fehr-Schmidt model improved estimation of MTG behavior. Furthermore, the estimation of partner's spite-guilt was highly correlated with choices associated with beliefs in persecution. We replicated our findings in a second sample. This parameter was weakly correlated with a self-reported measure of persecutory ideation in Sample 2. The "Suspiciousness" condition, unique to the MTG, can be modeled to isolate spite sensitivity, suggesting differentiation from inequity aversion or risk aversion. The MTG offers promise for future studies to quantify persecutory beliefs in clinical populations.

Social isolation and psychosis: an investigation of social interactions and paranoia in daily life

Social isolation has been suggested to foster paranoia. Here we investigate whether social company (i.e., being alone vs. not) and its nature (i.e., stranger/distant vs. familiar other) affects paranoia differently depending on psychosis risk. Social interactions and paranoid thinking in daily life were investigated in 29 patients with clinically stable non-affective psychotic disorders, 20 first-degree relatives, and 26 controls (n = 75), using the experience sampling method (ESM). ESM was completed up to ten times daily for 1 week. Patients experienced marginally greater paranoia than relatives [b = 0.47, p = 0.08, 95% CI (- 0.06, 1.0)] and significantly greater paranoia than controls [b = 0.55, p = 0.03, 95% CI (0.5, 1.0)], but controls and relatives did not differ [b = 0.07, p = 0.78, 95% CI (- 0.47, 0.61)]. Patients were more often alone [68.5% vs. 44.8% and 56.2%, respectively, p = 0.057] and experienced greater paranoia when alone than when in company [b = 0.11, p = 0.016, 95% CI (0.02, 0.19)]. In relatives this was reversed [b = - 0.17, p < 0.001, 95% CI (- 0.28, - 0.07)] and in controls non-significant [b = - 0.02, p = 0.67, 95% CI (- 0.09, 0.06)]. The time-lagged association between being in social company and subsequent paranoia was non-significant and paranoia did not predict the likelihood of being in social company over time (both p's = 0.68). All groups experienced greater paranoia in company of strangers/distant others than familiar others [X2(2) = 4.56, p = 0.03] and being with familiar others was associated with lower paranoia over time [X2(2) = 4.9, p = 0.03]. Patients are frequently alone. Importantly, social company appears to limit their paranoia, particularly when being with familiar people. The findings stress the importance of interventions that foster social engagement and ties with family and friends.

Neural, behavioural and real-life correlates of social context sensitivity and social reward learning during interpersonal interactions in the schizophrenia spectrum

OBJECTIVE

Recent findings suggest that diminished processing of positive contextual information about others during interactions may contribute to social impairment in the schizophrenia spectrum. This could be due to general social context processing deficits or specific biases against positive information. We studied the impact of positive and negative social contextual information during social interactions using functional neuroimaging and probed whether these neural mechanisms were associated with real-life social functioning in schizophrenia spectrum disorders.

METHODS

Patients with a schizophrenia spectrum disorder (N = 23) and controls disorder (N = 25) played three multi-round trust games during functional magnetic resonance imaging scanning, with no, positive and negative information about the counterpart's trustworthiness, while all counterparts were programmed to behave trustworthy. The main outcome variable was the height of the shared amount in the trust game, i.e. investment, representing an indication of trust. The first investment in the game was considered to be basic trust, since no behavioural feedback was given yet. We performed region-of-interest analyses and examined the association with real-life social functioning using the experience sampling method.

RESULTS

Social contextual information had no effect on patients' first investments, whereas controls made the lowest investment after negative and the highest investments after positive contextual information was provided. Over trials, patients decreased investments, suggesting reduced social reward learning, whereas controls increased investments in response to behavioural feedback in the negative context. Patients engaged the dorsolateral prefrontal cortex less than controls during context presentation and showed reduced activity within the caudate during repayments. In patients, lower investments were associated with more time spent alone and social exclusion and lower caudate activation was marginally significantly associated with higher perceived social exclusion.

CONCLUSION

The failure to adapt trust to positive and negative social contexts suggests that patients have a general insensitivity to prior social information, indicating top-down processing impairments. In addition, patients show reduced sensitivity to social reward, i.e. bottom-up processing deficits. Moreover, lower trust and lower neural activation were related to lower real-life social functioning. Together, these findings indicate that improving trust and social interactions in schizophrenia spectrum needs a multi-faceted approach that targets both mechanisms.

Anhedonia in Schizophrenia

Anhedonia has long been considered a cardinal symptom of schizophrenia. This symptom is strongly associated with poor functional outcome, and limited treatment options are available. While originally conceptualized as an inability to experience pleasure, recent work has consistently shown that individuals with schizophrenia have an intact capacity to experience pleasure in-the-moment. Adjacent work in basic affective neuroscience has broadened the conceptualization of anhedonia to include not only the capacity to experience pleasure but highlights important temporal affective dynamics and decision-making processes that go awry in schizophrenia. Here we detail these mechanisms for emotional and motivational impairment in people with schizophrenia including: (1) initial response to reward; (2) reward anticipation; (3) reward learning; (4) effort-cost decision-making; (5) working memory and cognitive control. We will review studies that utilized various types of rewards (e.g., monetary, social), in order to draw conclusions regarding whether findings vary by reward type. We will then discuss how modern assessment methods may best incorporate each of the mechanisms, to provide a more fine-grained understanding of anhedonia in individuals with schizophrenia. We will close by providing a discussion of relevant future directions.

Integration of social status and trust through interpersonal brain synchronization

Trust can be a dynamic social process, during which the social identity of the interacting agents (e.g., an investor and a trustee) can bias trust outcomes. Here, we investigated how social status modulates trust and the neural mechanisms underlying this process. An investor and a trustee performed a 10-round repeated trust game while their brain activity was being simultaneously recorded using functional near-infrared spectroscopy. The social status (either high or low) of both investors and trustees was manipulated via a math competition task. The behavioral results showed that in the initial round, individuals invested more in low-status partners. However, the investment ratio increased faster as the number of rounds increased during trust interaction when individuals were paired with a high-status partner. This increasing trend was particularly prominent in the low (investor)-high (trustee) status group. Moreover, the low-high group showed increased investor-trustee brain synchronization in the right temporoparietal junction as the number of rounds increased, while brain activation in the right dorsolateral prefrontal cortex of the investor decreased as the number of rounds increased. Both interpersonal brain synchronization and brain activation predicted investment performance at the early stage; furthermore, two-brain data provided earlier predictions than did single-brain data. These effects were detectable in the investment phase in the low-high group only; no comparable effects were observed in the repayment phase or other groups. Overall, this study demonstrated a multi-brain mechanism for the integration of social status and trust.

Affective temperaments of Lebanese patients with schizophrenia: comparison by gender and severity of psychosis

Objectives

Our aim in this study was to identify affective temperament differences utilizing the TEMPS-A in a large sample size of Lebanese patients with schizophrenia and compare them to healthy controls. Gender differences, demographic factors and degree of psychotic symptoms were also considered. A cross‐sectional study was conducted at the Psychiatric Hospital of the Cross (PHC) from March to June 2019. Two-hundred fifty chronic patients with schizophrenia were compared to 250 healthy controls randomly chosen from the general population.

Results

Patients with schizophrenia significantly had higher mean depressive, cyclothymic, irritable and anxious temperament scores compared to healthy controls. Healthy controls significantly had a higher mean hyperthymic temperament score compared to patients with schizophrenia. In the group of patients with schizophrenia exclusively, females scored higher in terms of depressive, cyclothymic and anxious temperaments compared to males. In the group of healthy controls, males scored higher in terms of hyperthymic and irritable temperaments compared to females, whereas a higher mean depressive and anxious temperament scores were significantly found in females compared to males. In addition, higher PANSS total scores, as well as higher positive, negative and general subscales scores were significantly associated with higher depressive, cyclothymic, irritable and anxious temperament scores.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-021-05854-8.

Conjecturing Harmful Intent and Preemptive Strike in Paranoia

Paranoia depicts a belief of others having harmful intent. Research using economic games has exhibited the correlation between paranoia and the propensity to characterize ambiguous intentions as harmful. Using a non-clinical sample recruited online from the United States (N=290), we examined whether paranoid thoughts influence aggressive behavior against the subjective perception of harmful intent. We conducted a preemptive strike game wherein aggressive behavior was assumed to be guided by the fear of an opponent. The outcomes indicate that (1) individuals with high paranoia assume harmful intent of an opponent more than those with low paranoia (2) conjecturing an opponent's harmful intent predicted an increase in the probability of a preemptive strike, and (3) paranoia did not have a statistically significant effect on encouraging a preemptive strike. Additionally, the exploratory analysis revealed that paranoia was related to participant's aggressiveness and with suppositions of other's self-interests and competitiveness. This study presents empirical evidence that paranoia is related to the perception of social threats in an uncertain situation. We discuss the possibility that paranoid ideation can promote or inhibit a preemptive strike.

Exploring the association between social behaviour, trust, and its neural correlates in first episode psychosis patients and in individuals at clinical high risk for psychosis

OBJECTIVES

Psychosis is characterized by paranoid delusions, social withdrawal, and distrust towards others. Trust is essential for successful social interactions. It remains unknown which aspects of social functioning are associated with reduced trust in psychosis. Therefore, we investigated the association between social behaviour, trust, and its neural correlates in a group of individuals with psychotic symptoms (PS-group), consisting of first episode psychosis patients combined with individuals at clinical high risk.

METHODS

We compared 24 PS individuals and 25 healthy controls. Affect and social withdrawal were assessed using the Experience Sampling Method. Trust was measured during functional magnetic resonance imaging (fMRI) scanning, using a trust game with a cooperative and unfair counterpart.

RESULTS

The PS-group showed lower baseline trust compared to controls and reported less positive and more negative general affect. Social withdrawal did not differ between the groups. Social withdrawal and social reactivity in affect (i.e., changes in affect when with others compared to when alone) were not associated with trust. On the neural level, in controls but not in the PS-group, social withdrawal was associated with caudate activation during interactions with an unfair partner. An increase in positive social reactivity, was associated with reduced insula activation in the whole sample.

CONCLUSIONS

Social withdrawal and social reactivity were not associated with reduced initial trust in the PS-group. Like controls, the PS-group showed a positive response in affect when with others, suggesting a decrease in emotional distress. Supporting patients to keep engaging in social interactions, may alleviate their emotional distress.

PRACTITIONER POINTS

Individuals with psychotic symptoms show reduced initial trust towards unknown others. Trust in others is not associated with social withdrawal and reported affect when with others, nor when alone. Like controls, individuals with psychotic symptoms showed reduced negative affect and increased positive affect when with others compared to when alone. We emphasize to support individuals with psychotic symptoms to keep engaging in social interactions, given it may reduce social withdrawal and alleviate their emotional distress.

Decision-making ability, psychopathology, and brain connectivity

Decision-making is a cognitive process of central importance for the quality of our lives. Here, we ask whether a common factor underpins our diverse decision-making abilities. We obtained 32 decision-making measures from 830 young people and identified a common factor that we call "decision acuity," which was distinct from IQ and reflected a generic decision-making ability. Decision acuity was decreased in those with aberrant thinking and low general social functioning. Crucially, decision acuity and IQ had dissociable brain signatures, in terms of their associated neural networks of resting-state functional connectivity. Decision acuity was reliably measured, and its relationship with functional connectivity was also stable when measured in the same individuals 18 months later. Thus, our behavioral and brain data identify a new cognitive construct that underpins decision-making ability across multiple domains. This construct may be important for understanding mental health, particularly regarding poor social function and aberrant thought patterns.

Individuals with schizophrenia display behaviour inconsistent with learned social impressions during a gambling task

Many studies of social perception and judgement have required individuals to make evaluations of social parameters based on static presentations of social stimuli. In the current study, we assessed whether individuals with a schizophrenia spectrum disorder and community controls differed in their judgements of others based on a series of computerized encounters designed to simulate impression formation over time. Twenty-eight community controls and 29 individuals with a schizophrenia spectrum disorder completed 25 gambling interactions with three different computer partners. After interacting with each partner, subjects rated how much they liked, trusted, and would like to play again with each partner. Results indicated that while individuals with schizophrenia rated the three partners differently (evaluating partners who returned more money higher than partners who returned less money), they did not adjust their gambling strategies with the different partners. Community controls adjusted the amount of money they gambled with the different partners, gambling more with partners that returned more money and gambling less with partners who returned less money, despite not rating the neutral and positive partners significantly differently from one another. These results suggest differences in behavioural strategies and social evaluation practices between community controls and individuals with schizophrenia. PRACTITIONER POINTS: Schizophrenia (SZ) and community control (CC) participants evaluate virtual partners on a gambling task in accordance with their behaviour (e.g., positive > neutral > negative in terms of trustworthiness, how much they liked them, and the likelihood that they would play with that individual again). Individuals with schizophrenia gambled equally with neutral, negative, and positive partner. Individuals with schizophrenia demonstrate an intact ability to form social impressions based on others' behaviour. However, subsequent behaviour does not parallel the formed impression (i.e., changing their gambling amount so that they are betting less money with a virtual partner they know is untrustworthy).

The neurochemistry of social reward during development: What have we learned from rodent models?

Social rewards are fundamental to survival and overall health. Several studies suggest that adequate social stimuli during early life are critical for developing appropriate socioemotional and cognitive skills, whereas adverse social experiences negatively affect the proper development of brain and behavior, by increasing the susceptibility to develop neuropsychiatric conditions. Therefore, a better understanding of the neural mechanisms underlying social interactions, and their rewarding components in particular, is an important challenge of current neuroscience research. In this context, preclinical research has a crucial role: Animal models allow to investigate the neurobiological aspects of social reward in order to shed light on possible neurochemical alterations causing aberrant social reward processing in neuropsychiatric diseases, and they allow to test the validity and safety of innovative therapeutic strategies. Here, we discuss preclinical research that has investigated the rewarding properties of two forms of social interaction that occur in different phases of the lifespan of mammals, that is, mother-infant interaction and social interactions with peers, by focusing on the main neurotransmitter systems mediating their rewarding components. Together, the research performed so far helped to elucidate the mechanisms of social reward and its psychobiological components throughout development, thus increasing our understanding of the neurobiological substrates sustaining social functioning in health conditions and social dysfunction in major psychiatric disorders.

Plasma acetylcholine and nicotinic acid are correlated with focused preference for photographed females in depressed males: an economic game study

Interpersonal difficulties are often observed in major depressive disorder (MDD), while the underlying psychological and biological mechanisms have not yet been elucidated. In the present case–control study, a PC-based trust game was conducted for 38 drug-free MDD patients and 38 healthy controls (HC). In the trust game, participants invested money in a partner (trusting behaviors), and also rated each partner’s attractiveness (preference for others). In addition, blood biomarkers including metabolites were measured. Both MDD and HC males exhibited more trusting behaviors compared to females. MDD males’ preference for ordinary-attractive partners (lay-person photographs) was lower than HC males, whereas their preference for high-attractive females (fashion-model photographs) was similar levels to HC males. This tendency in MDD males could reflect a “focused (narrowed) preference for females”. As for blood biomarker analysis, the levels of 37 metabolites including acetylcholine, AMP, GMP, nicotinic acid and tryptophan were significantly different between two groups. Interestingly, among male participants, acetylcholine and nicotinic acid were negatively correlated with the level of focused preference for photographed females. In sum, we have revealed some behavioral, psychological and biological traits of trusting behaviors and preference for others especially in MDD males. Larger studies should be conducted to validate our preliminary findings.

Ecology of cooperation: The influence of fasting and satiety on interpersonal trust

The willingness to cooperate in social interaction often depends on factors such as trustworthiness, reciprocity, and gender, but perhaps also on situational factors such as satiety. Here, we examined Trust Game performance before (fasting condition) and after ingestion of a high-caloric drink (satiety condition) of 37 psychologically healthy male subjects who played the game against individuals of both sexes differing in facial attractiveness. Participants invested significantly fewer money units (MUs) in the fasting condition compared to the satiated condition. Female opposing players received more MUs than males and attractive players more than less attractive ones. Time to arrive at a decision was shorter in the satiated condition than in the fasting condition. These findings indicate that satiety affects social cooperation and suggests that physical needs are prioritized over social cooperation.

Social reward, punishment, and prosociality in paranoia

Paranoia is the exaggerated belief that harm will occur and is intended by others. Although commonly framed in terms of attributing malicious intent to others, recent work has explored how paranoia also affects social decision-making, using economic games. Previous work found that paranoia is associated with decreased cooperation and increased punishment in the Dictator Game (where cooperating and punishing involve paying a cost to respectively increase or decrease a partner's income). These findings suggest that paranoia might be associated with variation in subjective reward from positive and/or negative social decision-making, a possibility we explore using a preregistered experiment with U.S.-based participants (n = 2,004). Paranoia was associated with increased self-reported enjoyment of negative social interactions and decreased self-reported enjoyment of prosocial interactions. More paranoid participants attributed stronger harmful intent to a partner. Harmful intent attributions and the enjoyment of negative social interactions positively predicted the tendency to pay to punish the partner. Cooperation was positively associated with the tendency to enjoy prosocial interactions and increased with participant age. There was no main effect of paranoia on tendency to cooperate in this setting. We discuss these findings in light of previous research. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Derationalizing Delusions

Because of the traditional conceptualization of delusion as “irrational belief,” cognitive models of delusions largely focus on impairments to domain-general reasoning. Nevertheless, current rationality-impairment models do not account for the fact that (a) equivalently irrational beliefs can be induced through adaptive social cognitive processes, reflecting social integration rather than impairment; (b) delusions are overwhelmingly socially themed; and (c) delusions show a reduced sensitivity to social context both in terms of how they are shaped and how they are communicated. Consequently, we argue that models of delusions need to include alteration to coalitional cognition—processes involved in affiliation, group perception, and the strategic management of relationships. This approach has the advantage of better accounting for both content (social themes) and form (fixity) of delusion. It is also supported by the established role of mesolimbic dopamine in both delusions and social organization and the ongoing reconceptualization of belief as serving a social organizational function.

The role of cortisol in trust behavior: Results from an experimental study on healthy controls and patients with juvenile myoclonic epilepsy

Trust is one of the foundations of human society and pervades all aspects of human live. Research on humans focused primarily on identifying the biological basis of trust behavior in healthy subjects, and this evidence hints to certain brain areas, hormones, and genetic factors to be fundamentally involved. The contribution of cortisol in trust has not yet elicited much attention in research, especially when specifically examined at basal cortisol levels. Trust has been previously studied in some neurological diseases but not in patients with epilepsy, and the influence of hormones on trust in these diseases remains yet unknown. Against this background, we designed an experimental study with a group of patients with juvenile myoclonic epilepsy and a group of healthy controls to compare trust behavior and plasma cortisol levels between the two groups. This economic game is frequently used in research to operationalize trust behavior. All participants further underwent neuropsychological assessment. Our results showed that there was no significant difference in trust behavior during the trust game, but a trend toward lower trust in patients. Furthermore, there was a significant difference in cortisol levels between groups with lower levels in patients. Interestingly, cortisol levels correlated with trust only in the patient group, but not in the control group. Future studies should specifically differentiate the effect of induced cortisol increases (e.g., acute stress) versus the effect of basal cortisol levels reflecting homeostasis or chronic stress on trust behavior and leverage the potential of comparison between patients and healthy controls.

"To co-operate or not?" Risky co-operative behavior in Schizophrenia and the effect of vasopressin

Risky co-operation is when an individual chooses to co-operate in a social situation despite the possibility of the partner refusing to co-operate. Although this is a deviation from rational behavior, it may have helped humans in societal adaptation. Risky co-operation holds significance in social functioning. However, the status of risky cooperative behavior in schizophrenia, a disorder with impaired social cognition, is yet to be investigated. Moreover, the underlying neurobiology is unexplored. 27 individuals with schizophrenia and 30 healthy volunteers performed an iterative stag hunt game, an ecologically valid, neuroeconomics game to measure risky cooperative behavior. The patients and healthy volunteers were matched on age and sex. An independent group of patients (n = 30) later performed the stag hunt game with intranasal vasopressin or saline in a counterbalanced crossover study design. Patients with schizophrenia, compared to healthy controls, switched from high-risk situations to a low-risk situation at lower payoff, suggesting impaired co-operation in a risky situation. Group differences were significant even after controlling for general risk- taking tendency and subjective mood state. In part-II of the study, there was no statistically significant difference in risky co-operative behavior with vasopressin. The results suggest impaired risky co-operative behavior in schizophrenia, which could influence the functional outcome. The study also provides a testable, ecologically valid paradigm for risky co-operative behavior in schizophrenia. Though single dose vasopressin did not influence the risky co-operative behavior, long term study with repeated administration is needed for a definitive conclusion.

Terminology and assessment tools of psychosis: A systematic narrative review

AIM

Phenomena within the psychosis continuum that varies in frequency/duration/intensity have been increasingly identified. Different terms describe these phenomena, however there is no standardization within the terminology. This review evaluated the definitions and assessment tools of seven terms - (i) 'psychotic experiences'; (ii) 'psychotic-like experiences'; (iii) 'psychotic-like symptoms'; (iv) 'attenuated psychotic symptoms'; (v) 'prodromal psychotic symptoms'; (vi) 'psychotic symptomatology'; and (vii) 'psychotic symptoms'.

METHODS

EMBASE, MEDLINE, and CINAHL were searched during February-March 2019. Inclusion criteria included 1989-2019, full text, human, and English. Papers with no explicit definition or assessment tool, duplicates, conference abstracts, systematic reviews, meta-analyses, or no access were excluded.

RESULTS

A total of 2238 papers were identified and of these, 627 were included. Definitions and assessment tools varied, but some trends were found. Psychotic experiences and psychotic-like experiences were transient and mild, found in the general population and those at-risk. Psychotic-like symptoms were subthreshold and among at-risk populations and non-psychotic mental disorders. Attenuated psychotic symptoms were subthreshold but associated with distress, risk, and help-seeking. Prodromal psychotic symptoms referred to the prodrome of psychotic disorders. Psychotic symptomatology included delusions and hallucinations within psychotic disorders. Psychotic symptoms was the broadest term, encompassing a range of populations but most commonly involving hallucinations, delusions, thought disorder, and disorganization.

DISCUSSION

A model for conceptualizing the required terms is proposed and future directions needed to advance this field of research are discussed.

The neural mechanisms of social reward in early psychosis

In chronic psychosis, reduced trust is associated with a neural insensitivity to social reward and reduced theory of mind (ToM). Here we investigate whether these mechanisms could underlie emerging social impairments in early psychosis. Twenty-two participants with early psychosis and 25 controls (male, 13–19 years) participated in two interactive trust games against a cooperative and unfair partner. Region of interest neuroimaging analyses included right caudate, medial prefrontal cortex (mPFC) and right temporoparietal junction (rTPJ), involved in reward and ToM processing. Both groups showed similar levels of trust (i.e. investments). However, individuals with psychosis failed to activate the caudate differentially in response to cooperation and unfairness while making decisions to trust. During cooperative returns, patients showed reduced and controls increased caudate activation. Patients demonstrated greater rTPJ activation than controls, possibly pointing towards compensatory mechanisms. Effects were associated with Wechsler Abbreviated Scale of Intelligence vocabulary scores. No group differences emerged in mPFC activation. Early psychosis is associated with an aberrant neural sensitivity to social reward. This could foster reduced social motivation and social isolation. Absent behavioural differences in early, relative to chronic psychosis could indicate that trust is achieved through increased compensatory demand on ToM.

Victory is its own reward: oxytocin increases costly competitive behavior in schizophrenia

BACKGROUND

Aberrant sensitivity to social reward may be an important contributor to abnormal social behavior that is a core feature of schizophrenia. The neuropeptide oxytocin impacts the salience of social information across species, but its effect on social reward in schizophrenia is unknown.

METHODS

We used a competitive economic game and computational modeling to examine behavioral dynamics and oxytocin effects on sensitivity to social reward among 39 men with schizophrenia and 54 matched healthy controls. In a randomized, double-blind study, participants received one dose of oxytocin (40 IU) or placebo and completed a 35-trial Auction Game that quantifies preferences for monetary v. social reward. We analyzed bidding behavior using multilevel linear mixed models and reinforcement learning models.

RESULTS

Bidding was motivated by preferences for both monetary and social reward in both groups, but bidding dynamics differed: patients initially overbid less compared to controls, and across trials, controls decreased their bids while patients did not. Oxytocin administration was associated with sustained overbidding across trials, particularly in patients. This drug effect was driven by a stronger preference for winning the auction, regardless of monetary consequences. Learning rate and response variability did not differ between groups or drug condition, suggesting that differences in bidding derive primarily from differences in the subjective value of social rewards.

CONCLUSIONS

Our findings suggest that schizophrenia is associated with diminished motivation for social reward that may be increased by oxytocin administration.

Trust and the city: Linking urban upbringing to neural mechanisms of trust in psychosis

OBJECTIVE

Elevated prevalence of non-affective psychotic disorders is often found in densely populated areas. This functional magnetic resonance imaging study investigates if reduced trust, a component of impaired social functioning in patients with psychotic disorder, is associated with urban upbringing.

METHODS

In total, 39 patients (22 first episode and 17 clinical high risk) and 30 healthy controls, aged 16-29, performed two multi-round trust games, with a cooperative and unfair partner during functional magnetic resonance imaging scanning. Baseline trust was operationalized as the first investment made, and changes of trust as changes in investments made over the 20 trials during the games. Urban exposure during upbringing (0-15 years) was defined as higher urban (≥2500 inhabitants/km²) or lower urban (<2500 inhabitants/km²).

RESULTS

Patients displayed lower baseline trust (first investment) than controls, regardless of urbanicity exposure. During cooperative interactions, lower-urban patients showed increasing investments. In addition, during cooperative interactions, group-by-developmental urbanicity interactions were found in the right and left amygdalae, although for the latter only at trend level. Higher urbanicity was associated with decreased activation of the left amygdala in patients and controls during investments and with increased activation of the right and left amygdalae in patients only, during repayments. During unfair interactions, no associations of urbanicity with behavior or brain activation were found.

CONCLUSION

Urban upbringing was unrelated to baseline trust. Associations with urbanicity were stronger for patients compared to controls, suggesting greater susceptibility to urbanicity effects during the developmental period. Higher-urban patients failed to compensate for the initial distrust specifically during repeated cooperative interactions. This finding highlights potential implications for social functioning. Urban upbringing was linked to differential amygdala activation, suggesting altered mechanisms of feedback learning, but this was not associated with trust game behavior.

Social and non-social reward learning reduced and related to a familial vulnerability in schizophrenia spectrum disorders

Patients with a disorder in the schizophrenia spectrum (SZ) demonstrate impairments in reward learning. A reduced sensitivity to social reward may impede social beyond non-social reward learning mechanisms. The aim of the current study was to investigate social and non-social reward learning in SZ by means of two interactive game-theoretical investment paradigms. Unaffected first-degree relatives of patients were included to examine whether (social) reward-learning impairments are part of a familial vulnerability of SZ. We included 50 patients with a SZ disorder, 20 unaffected first-degree relatives of patients and 49 healthy controls. The trust game (social) and the lottery game (non-social) were used, consisting of 20 game trials each. The game paradigms were programmed to increase the likelihood of higher repayments in response to increased investments. Multilevel regression analyses were used to examine learning over trials in both contexts. The results showed that controls learned equally well in social and non-social contexts, as reflected in an increase of investments over game rounds in both paradigms. In contrast, patients and relatives showed reduced reward learning, regardless of its social or non-social nature, reflected by flatter or decreasing slopes over game rounds in both paradigms. The findings suggest that patients and relatives have a general reduced sensitivity to reward, which appears to reflect a familial vulnerability rather than illness related mechanisms. Results indicate that reward learning may be an important marker for the familial risk to SZ.

A review of neuroeconomic gameplay in psychiatric disorders

Abnormalities in social interaction are a common feature of several psychiatric disorders, aligning with the recent move towards using Research Domain Criteria (RDoC) to describe disorders in terms of observable behaviours rather than using specific diagnoses. Neuroeconomic games are an effective measure of social decision-making that can be adapted for use in neuroimaging, allowing investigation of the biological basis for behaviour. This review summarises findings of neuroeconomic gameplay studies in Axis 1 psychiatric disorders and advocates the use of these games as measures of the RDoC Affiliation and Attachment, Reward Responsiveness, Reward Learning and Reward Valuation constructs. Although research on neuroeconomic gameplay is in its infancy, consistencies have been observed across disorders, particularly in terms of impaired integration of social and cognitive information, avoidance of negative social interactions and reduced reward sensitivity, as well as a reduction in activity in brain regions associated with processing and responding to social information.

Appearance-based trust processing in schizophrenia

OBJECTIVES

Schizophrenia is characterized by impaired social interactions and altered trust. In the general population, trust is often based on facial appearance, with limited validity but enormous social consequences. The aim was to examine trust processing in schizophrenia and specifically to examine how people with schizophrenia use facial appearance as well as actual partner fairness to guide trusting decisions.

DESIGN

An experimental economic game study.

METHODS

Here, we tested how patients with schizophrenia and control participants (each N = 24) use facial trustworthiness appearance and partner fairness behaviour to guide decisions in a multi-round Trust Game. In the Trust Game, participants lent money to 'partners' whose facial appearance was either untrustworthy or trustworthy, and who either played fairly or unfairly. Clinical symptoms were measured as well as explicit trustworthiness impressions.

RESULTS

Overall, the patients with schizophrenia showed unimpaired explicit facial trustworthiness impressions and unimpaired facial appearance biases in the Trust Game. Crucially, patients and controls significantly differed so that the patients with schizophrenia did not learn to discriminate in the Trust Game based on actual partner fairness, unlike control participants.

CONCLUSION

A failure to discriminate trust has important implications for everyday functioning in schizophrenia, as forming accurate trustworthiness beliefs is an essential social skill. Critically, without relying on more valid trust cues, people with schizophrenia may be especially susceptible to the misleading effect of appearance when making trusting decisions.

PRACTITIONER POINTS

Findings People with schizophrenia made very similar facial trustworthiness impressions to healthy controls and also used facial appearance to guide trust decisions similarly to controls. However, the patient group were less able to explicitly distinguish between fair and unfair partners based on their behaviour compared with the control group. Moreover, people with schizophrenia failed to use actual partner fairness to guide their financial decisions in the Trust Game, unlike controls, and this impairment was specific to a social task. People with schizophrenia may be particularly reliant on facial appearance when trusting others, as they may struggle to incorporate more valid trustworthiness information in their decision-making, such as actual partner fairness.

Paranoia and conspiracy: group cohesion increases harmful intent attribution in the Trust Game

Current theories argue that hyper-sensitisation of social threat perception is central to paranoia. Affected people often also report misperceptions of group cohesion (conspiracy) but little is known about the cognitive mechanisms underpinning this conspiracy thinking in live interactions. In a pre-registered experimental study, we used a large-scale game theory approach (N > 1,000) to test whether the social cohesion of an opposing group affects paranoid attributions in a mixed online and lab-based sample. Participants spanning the full population distribution of paranoia played as proposers in a modified Trust Game: they were allocated a bonus and chose how much money to send to a pair of responders which was quadrupled before reaching these responders. Responders decided how much to return to the proposers through the same process. Participants played in one of two conditions: against a cohesive group who communicated and arrived at a joint decision, or a non-cohesive group who made independent decisions. After the exchange, proposers rated the extent to which the responders’ decisions were driven by (i) self-interest and (ii) intent to harm. Although the true motives are ambiguous, cohesive responders were reliably rated by participants as being more strongly motivated by intent to harm, indicating that group cohesion affects social threat perception. Highly paranoid participants attributed harmful intent more strongly overall but were equally reactive to social cohesion as other participants. This suggests that paranoia involves a generally lowered threshold for social threat detection but with an intact sensitivity for cohesion-related group characteristics.

Paranoia and conspiracy: group cohesion increases harmful intent attribution in the Trust Game

Current theories argue that hyper-sensitisation of social threat perception is central to paranoia. Affected people often also report misperceptions of group cohesion (conspiracy) but little is known about the cognitive mechanisms underpinning this conspiracy thinking in live interactions. In a pre-registered experimental study, we used a large-scale game theory approach (N > 1,000) to test whether the social cohesion of an opposing group affects paranoid attributions in a mixed online and lab-based sample. Participants spanning the full population distribution of paranoia played as proposers in a modified Trust Game: they were allocated a bonus and chose how much money to send to a pair of responders which was quadrupled before reaching these responders. Responders decided how much to return to the proposers through the same process. Participants played in one of two conditions: against a cohesive group who communicated and arrived at a joint decision, or a non-cohesive group who made independent decisions. After the exchange, proposers rated the extent to which the responders' decisions were driven by (i) self-interest and (ii) intent to harm. Although the true motives are ambiguous, cohesive responders were reliably rated by participants as being more strongly motivated by intent to harm, indicating that group cohesion affects social threat perception. Highly paranoid participants attributed harmful intent more strongly overall but were equally reactive to social cohesion as other participants. This suggests that paranoia involves a generally lowered threshold for social threat detection but with an intact sensitivity for cohesion-related group characteristics.

Connectome-based model predicts individual differences in propensity to trust

Trust constitutes a fundamental basis of human society and plays a pivotal role in almost every aspect of human relationships. Although enormous interest exists in determining the neuropsychological underpinnings of a person's propensity to trust utilizing task-based fMRI; however, little progress has been made in predicting its variations by task-free fMRI based on whole-brain resting-state functional connectivity (RSFC). Here, we combined a one-shot trust game with a connectome-based predictive modeling approach to predict propensity to trust from whole-brain RSFC. We demonstrated that individual variations in the propensity to trust were primarily predicted by RSFC rooted in the functional integration of distributed key nodes-caudate, amygdala, lateral prefrontal cortex, temporal-parietal junction, and the temporal pole-which are part of domain-general large-scale networks essential for the motivational, affective, and cognitive aspects of trust. We showed, further, that the identified brain-behavior associations were only evident for trust but not altruistic preferences and that propensity to trust (and its underlying neural underpinnings) were modulated according to the extent to which a person emphasizes general social preferences (i.e., horizontal collectivism) rather than general risk preferences (i.e., trait impulsiveness). In conclusion, the employed data-driven approach enables to predict propensity to trust from RSFC and highlights its potential use as an objective neuromarker of trust impairment in mental disorders.

Learning to trust: social feedback normalizes trust behavior in first-episode psychosis and clinical high risk

BACKGROUND

Psychosis is characterized by problems in social functioning that exist well before illness onset, and in individuals at clinical high risk (CHR) for psychosis. Trust is an essential element for social interactions that is impaired in psychosis. In the trust game, chronic patients showed reduced baseline trust, impaired response to positive social feedback, and attenuated brain activation in reward and mentalizing areas. We investigated whether first-episode psychosis patients (FEP) and CHR show similar abnormalities in the neural and behavioral mechanisms underlying trust.

METHODS

Twenty-two FEP, 17 CHR, and 43 healthy controls performed two trust games, with a cooperative and an unfair partner in the fMRI scanner. Region of interest analyses were performed on mentalizing and reward processing areas, during the investment and outcome phases of the games.

RESULTS

Compared with healthy controls, FEP and CHR showed reduced baseline trust, but like controls, learned to trust in response to cooperative and unfair feedback. Symptom severity was not associated with baseline trust, however in FEP associated with reduced response to feedback. The only group differences in brain activation were that CHR recruited the temporo-parietal junction (TPJ) more than FEP and controls during investment in the unfair condition. This hyper-activation in CHR was associated with greater symptom severity.

CONCLUSIONS

Reduced baseline trust may be associated with risk for psychotic illness, or generally with poor mental health. Feedback learning is still intact in CHR and FEP, as opposed to chronic patients. CHR however show distinct neural activation patterns of hyper-activation of the TPJ.

When trust is lost: the impact of interpersonal trauma on social interactions

BACKGROUND

Trauma due to deliberate harm by others is known to increase the likelihood of developing Post-Traumatic Stress Disorder (PTSD). This is the first study investigating basic and dynamic trust in 'interpersonal' PTSD.

METHODS

Thirty-two participants with PTSD and 22 healthy controls played a novel multi-round version of a monetary investment protocol, the so-called 'Trust Game', a task from the behavioural economics literature, which is considered to involve trust and reciprocity. We used two 'Trust Games' including cooperative and unfair partners.

RESULTS

Findings showed an effect for lower basic investment in PTSD compared to healthy controls, that trended towards significance (p = 0.09). All participants showed behavioural flexibility and modified their trust based on behavioural cues from their cooperative and unfair game partners. However, participants with PTSD made significantly lower investments towards the cooperative partner than controls. Investments towards the unfair partner did not differ between groups. Higher trauma scores were associated with lower levels of trust-related investments towards the cooperative but not the unfair game partner.

CONCLUSION

The association between reduced trust towards cooperative others in individuals who experienced interpersonal trauma could indicate acquired insensitivity to social rewards or inflexible negative beliefs about others as a sequel of the traumatic experience, which increases in a dose response relationship with the severity of the trauma. A specific focus on cooperation and trusting behaviour could provide a treatment target for future cognitive and pharmacological interventions.

Social Mindfulness and Psychosis: Neural Response to Socially Mindful Behavior in First-Episode Psychosis and Patients at Clinical High-Risk

Background: Psychosis is characterized by problems in social functioning and trust, the assumed glue to positive social relations. But what helps building trust? A prime candidate could be social mindfulness: the ability and willingness to see and consider another person’s needs and wishes during social decision making. We investigated whether first-episode psychosis patients (FEP) and patients at clinical high-risk (CHR) show reduced social mindfulness, and examined the underlying neural mechanisms.

Methods: Twenty FEP, 17 CHR and 46 healthy controls, aged 16–31, performed the social mindfulness task (SoMi) during fMRI scanning, spontaneously and after the instruction “to keep the other’s best interest in mind.” As first of two people, participants had to choose one out of four products, of which three were identical and one was unique, differing in a single aspect (e.g., color).

Results: FEP tended to choose the unique item (unmindful choice) more often than controls. After instruction, all groups significantly increased the number of mindful choices compared to the spontaneous condition. FEP showed reduced activation of the caudate and medial prefrontal cortex (mPFC) during mindful, and of the anterior cingulate cortex (ACC), mPFC, and left dorsolateral prefrontal cortex (dlPFC) during unmindful decisions. CHR showed reduced activation of the ACC compared to controls.

Discussion: FEP showed a trend toward more unmindful choices. A similar increase of mindful choices after instruction indicated the ability for social mindfulness when prompted. Results suggested reduced sensitivity to the rewarding aspects of social mindfulness in FEP, and reduced consideration for the other player. FEP (and CHR to a lesser extent) might perceive unmindful choices as less incongruent with the automatic mindful responses than controls. Reduced socially mindful behavior in FEP may hinder the building of trust and cooperative interactions.

An evolutionary perspective on paranoia

Paranoia is the most common symptom of psychosis but paranoid concerns occur throughout the general population. Here, we argue for an evolutionary approach to paranoia across the spectrum of severity that accounts for its complex social phenomenology - including the perception of conspiracy and selective identification of perceived persecutors - and considers how it can be understood in light of our evolved social cognition. We argue that the presence of coalitions and coordination between groups in competitive situations could favour psychological mechanisms that detect, anticipate and avoid social threats. Our hypothesis makes testable predictions about the environments in which paranoia should be most common as well as the developmental trajectory of paranoia across the lifespan. We suggest that paranoia should not solely be viewed as a pathological symptom of a mental disorder but also as a part of a normally-functioning human psychology.

Cooperation and sensitivity to social feedback during group interactions in schizophrenia

Patients with schizophrenia show reduced cooperation and less sensitivity to social cues in pairwise interactions, however, it remains unclear whether these mechanisms are also present in interactions within social groups. We used a public goods game to investigate cooperation and sensitivity to social feedback in group interactions in 27 patients with schizophrenia and 27 healthy controls. Participants played 40 trials in two conditions: 1) no fine (20 trials): participants had the choice of investing into the public good (i.e. cooperating) or not (i.e. defecting), 2) fine (20 trials): participants had the same choice but defectors could be punished by the other players. On the first trial, patients invested less in the public good than healthy controls. In the no fine condition, controls decreased their investments over time, but patients did not. The possibility of being fined for defecting and actually being fined led to significantly higher cooperation in both groups. This shows that the groups were equally sensitive to social enforcement and social feedback. Our findings suggest that patients tend to approach social group interactions with less cooperative behaviour, which could contribute to social dysfunction in daily-life. However, an intact sensitivity to social enforcement and feedback indicates that patients can adjust their behaviour accordingly in group interactions.

Experimentally induced social threat increases paranoid thinking

The ability to attribute intentions to others is a hallmark of human social cognition but is altered in paranoia. Paranoia is the most common positive symptom of psychosis but is also present to varying degrees in the general population. Epidemiological models suggest that psychosis risk is associated with low social rank and minority status, but the causal effects of status and group affiliation on paranoid thinking remain unclear. We examined whether relative social status and perceived group affiliation, respectively, affect live paranoid thinking using two large-N (N = 2030), pre-registered experiments. Interacting with someone from a higher social rank or a political out-group led to an increase in paranoid attributions of harmful intent for ambiguous actions. Pre-existing paranoia predicted a general increase in harmful intent attribution, but there was no interaction with either type of social threat: highly paranoid people showed the same magnitude of increase as non-paranoid people, although from a higher baseline. We conclude social threat in the form of low social status and out-group status affects paranoid attributions, but ongoing paranoia represents a lowered threshold for detecting social threat rather than an impaired reactivity to it.

Conflict and cooperation in paranoia: a large-scale behavioural experiment

BACKGROUND

Paranoia involves thoughts and beliefs about the harmful intent of others but the social consequences have been much less studied. We investigated whether paranoia predicts maladaptive social behaviour in terms of cooperative and punitive behaviour using experimental game theory paradigms, and examined whether reduced cooperation is best explained in terms of distrust as previous studies have claimed.

METHODS

We recruited a large population sample (N = 2132) online. All participants completed the Green et al. Paranoid Thoughts Scale and (i) a Dictator Game and (ii) an Ultimatum Game, the former with an option for costly punishment. Following distrust-based accounts, we predicted highly paranoid people would make higher offers when the outcome depended on receiving a positive response from their partner (Ultimatum Game) but no difference when the partner's response was irrelevant (Dictator Game). We also predicted paranoia would increase punitive responses. Predictions were pre-registered in advance of data collection. Data and materials are open access.

RESULTS

Highly paranoid participants actually made lower offers than non-paranoid participants both in the Dictator Game and in the Ultimatum Game. Paranoia positively predicted punitive responses.

CONCLUSIONS

These findings suggest that distrust is not the best explanation for reduced cooperation in paranoia and alternative explanations, such as increased self-interest, may apply. However, the tendency to attribute harmful intent to partners was important in motivating punitive responses. These results highlight differing motivations underlying adverse social behaviour in paranoia and suggest that accounts based solely on the presenting features of paranoia may need to be rethought.

Social motivation in people with recent-onset schizophrenia spectrum disorders

People with schizophrenia-spectrum disorders (SSD) often experience impairments in non-social motivation. In this study, we extended this line of investigation by examining specific components of social motivation and the extent to which these components work together in people with and without a recent-onset SSD. Sixty-four people with a recent-onset SSD and 26 controls completed a task that allowed us to examine changes in anticipated pleasure, decisions to trust, and effort expenditure over the course of repeated interactions with positive or negative outcomes. Compared to controls, we found that people in the SSD group placed less trust, tended to anticipate less pleasure, and expended less effort to increase the likelihood of future interactions with positive outcomes. Further, in the SSD group, effort expenditure was not associated with either anticipated pleasure or decisions to trust. While there were no group differences in anticipated pleasure or trust placed during interactions with negative outcomes, people in the SSD group expended less effort to decrease to the likelihood of future interactions. Taken together, our findings suggest that people with a recent-onset SSD may experience both impairment and disconnection between various components of social motivation for interactions with positive outcomes. Implications for interventions for social engagement in people with SSD are discussed.