Independent neural computation of value from other people's confidence

Expectation of reward can be shaped by the observation of actions and expressions of other people in one's environment. A person's apparent confidence in the likely reward of an action, for instance, makes qualities of their evidence, not observed directly, socially accessible. This strategy is computationally distinguished from associative learning methods that rely on direct observation, by its use of inference from indirect evidence. In twenty-three healthy human subjects, we isolated effects of first-hand experience, other people's choices, and the mediating effect of their confidence, on decision-making and neural correlates of value within ventromedial prefrontal cortex (vmPFC). Value derived from first hand experience and other people's choices (regardless of confidence) were indiscriminately represented across vmPFC. However, value computed from agent choices weighted by their associated confidence was represented with specificity for ventromedial area 10. This pattern corresponds to shifts of connectivity and overlapping cognitive processes along a posterior-anterior vmPFC axis. Task behavior and self-reported self-reliance for decision-making in other social contexts correlated. The tendency to conform in other social contexts corresponded to increased activation in cortical regions previously shown to respond to social conflict in proportion to subsequent conformity (Campbell-Meiklejohn et al., 2010). The tendency to self-monitor predicted a selectively enhanced response to accordance with others in the right temporoparietal junction (rTPJ). The findings anatomically decompose vmPFC value representations according to computational requirements and provide biological insight into the social transmission of preference and reassurance gained from the confidence of others. Significance Statement: Decades of research have provided evidence that the ventromedial prefrontal cortex (vmPFC) signals the satisfaction we expect from imminent actions. However, we have a surprisingly modest understanding of the organization of value across this substantial and varied region. This study finds that using cues of the reliability of other peoples'; knowledge to enhance expectation of personal success generates value correlates that are anatomically distinct from those concurrently computed from direct, personal experience. This suggests that representation of decision values in vmPFC is suborganized according to the underlying computation, consistent with what we know about the anatomical heterogeneity of the region. These results also provide insight into the observational learning process by which someone else's confidence can sway and reassure our choices

In for a penny, in for a pound: methylphenidate reduces the inhibitory effect of high stakes on persistent risky choice

Methylphenidate (MPH) is a stimulant that increases extracellular levels of dopamine and noradrenaline. It can diminish risky decision-making tendencies in certain clinical populations. MPH is also used, without license, by healthy adults, but the impact on their decision-making is not well established. Previous work has found that dopamine receptor activity of healthy adults can modulate the influence of stake magnitude on decisions to persistently gamble after incurring a loss. In this study, we tested for modulation of this effect by MPH in 40 healthy human adults. In a double-blind experiment, 20 subjects received 20 mg of MPH, while 20 matched controls received a placebo. All were provided with 30 rounds of opportunities to accept an incurred loss from their assets or opt for a "double-or-nothing" gamble that would either avoid or double it. Rounds began with a variable loss that would double with every failed gamble until it was accepted, recovered, or reached a specified maximum. Probability of recovery on any gamble was low and ambiguous. Subjects receiving placebo gambled less as the magnitude of the stake was raised and as the magnitude of accumulated loss escalated over the course of the task. In contrast, subjects treated with MPH gambled at a consistent rate, well above chance, across all stakes and trials. Trait reward responsiveness also reduced the impact of high stakes. The findings suggest that elevated catecholamine activity by MPH can disrupt inhibitory influences on persistent risky choice in healthy adults

Enhanced automatic action imitation and intact imitation- inhibition in schizophrenia

Imitation plays a key role in social learning and in facilitating social interactions and likely constitutes a basic building block of social cognition that supports higher-level social abilities. Recent findings suggest that patients with schizophrenia have imitation impairments that could contribute to the social impairments associated with the disorder. However, extant studies have specifically assessed voluntary imitation or automatic imitation of emotional stimuli without controlling for potential confounders. The imitation impairments seen might therefore be secondary to other cognitive, motoric or emotional deficits associated with the disorder. To overcome this issue, we used an automatic imitation paradigm with nonemotional stimuli to assess automatic imitation and the top-down modulation of imitation where participants were required to lift one of two fingers according to a number shown on the screen whilst observing the same or the other finger movement. In addition, we used a control task with a visual cue in place of a moving finger, to isolate the effect of observing finger movement from other visual cueing effects. Data from 33 patients (31 medicated) and 40 matched healthy controls were analyzed. Patients displayed enhanced imitation and intact top-down modulation of imitation. The enhanced imitation seen in patients may have been medication induced as larger effects were seen in patients receiving higher antipsychotic doses. In sum, we did not find an imitation impairment in schizophrenia. The results suggest that previous findings of impaired imitation in schizophrenia might have been due to other cognitive, motoric and/or emotional deficits

Hyper- and hypo-mentalizing in patients with first-episode schizophrenia: fMRI and behavioural studies

Background: Historically, research investigating neural correlates of mentalizing deficits in schizophrenia has focused on patients who have been ill for several years with lengthy exposure to medication. Little is known about the neural and behavioural presentations of theory-of-mind deficits in schizophrenia, shortly after the first episode of psychosis. Methods: We investigated social cognition in seventeen recently diagnosed first-episode schizophrenia (FES) patients with little or no exposure to antipsychotic medication and 1:1 matched healthy controls. We recorded behavioural and neural responses to the Animated Triangles Task (ATT), which is a non-verbal validated mentalizing task that measures the ascription of intentionality to the movements of objects. Results: FES patients under-interpreted social cues and over-interpreted non-social cues. These effects were influenced by current intelligence (IQ). Control group and FES neural responses replicated earlier findings in healthy adults. However, a region of anterior medial prefrontal cortex (amPFC) of FES patients showed a different response pattern to that of controls. Unlike healthy controls, patients increased activity in this social cognition region while studying ‘random’ movements of shapes, as compared to the study of movements normally interpreted as ‘intentional’. Conclusions: Mentalizing deficits in FES consists of hypo- and hyper-mentalizing. The neural pattern of FES patients is consistent with deficits in the ability to switch off mentalizing processes in potentially social contexts, instead increasing them when intentionality is not forthcoming. Overall, results demonstrate complexities of theory of mind deficits in schizophrenia that should be considered when offering social cognitive training programs

Distinguishing Oneself from Others: Spontaneous Perspective- Taking in First Episode Schizophrenia and its relation to Mentalizing and Psychotic Symptoms

Characteristic symptoms of schizophrenia such as thought broadcasting, verbal hallucinations and delusions of being controlled suggest a failure in distinguishing between oneself and others. In addition, patients frequently experience mentalizing deficits, which could be related to such a failure. Here we investigated the tendency to distinguish self and other with a visual perspective-taking task that measures to what extent individuals spontaneously take another’s perspective when having to process their own (altercentric intrusion) or vice versa (egocentric intrusion). This was done in 22 patients with first episode schizophrenia and 23 matched healthy controls. We assessed whether patients displayed altered altercentric or egocentric intrusion and whether such alterations are related to mentalizing deficits – as measured with the Animated Triangles Task (ATT) and The Awareness of Social Inference Task (TASIT) – and/or specific psychotic symptoms, suggestive of problems with self-other distinction. The results showed that patients display similar egocentric intrusion and increased altercentric intrusion compared to controls. Degree of altercentric intrusion was associated with severity of delusions and hallucinations that have been tied to problems with self-other distinction but not with unrelated delusions and hallucinations or negative symptom severity. Higher altercentric intrusion was also associated with better TASIT performance in both patients and controls; suggesting that it may also be beneficial. In conclusion, patients display difficulties inhibiting representations of the other when having to process self-relevant information. A failure to control or distinguish the two representations could give rise to the experience that others have access to and control of your thoughts and actions

Cross-cultural comparison of theory of mind deficits in patients with schizophrenia from China and Denmark: different aspects of ToM show different results

Introduction: Theory of mind (ToM) has been established as one of the most investigated and pronounced social cognitive deficits in schizophrenia. Yet, knowledge on whether measures of ToM can be used and compared across cultures is sparse. In this study, we used two simple, non-verbal ToM tests in patients with schizophrenia and non-clinical controls from China and Denmark to investigate whether culture has an impact on ToM performance. Methods: Sixty-six patients with schizophrenia (35 Chinese) and 67 matched non-clinical controls (38 Chinese) from China and Denmark were tested with Brunes Picture Sequencing Task and Animated Triangles Task. We compared three models for each outcome variable in order to investigate which model best fitted the data: the first model included group (controls, patients) as a predictor variable, the second included group and nationality (Chinese, Danish), and the third included both predictors and their interaction. Results: On most ToM subtests, culture seemed to play a role. Only performance on Brune's 1st order ToM were best described as similar in both countries. The second model had the best fit for most of the subtests indicating that the difference between patients and controls in China and Denmark, respectively, is similar. Conclusions: Caution to cultural differences should be taken when comparing ToM in Asian and Western patients with schizophrenia as well as healthy individuals

Vocal patterns in schizophrenia: toward a cumulative approach

Voice atypicalities are a characteristic feature of schizophrenia, often associated with core negative symptoms. A recent meta-analysis identified atypicalities in pitch, speech rate, and pauses. However, heterogeneity across studies was large and replications almost nonexistent. Further, it is not clear whether vocal patterns are directly related to the mechanisms underlying the disorder and could therefore be found across languages, or not. In this study we implemented a more rigorously cumulative scientific approach by collecting and analyzing a large cross-linguistic corpus of voice recordings. We critically employed meta-analytic priors to systematically assess the replicability of previous findings, and modeled between-participants variability and cross-linguistic differences. We replicate previous meta-analytic findings across all languages for reduced pitch variability, while increased pause duration and lower speech rate results were replicated only in some languages. Most atypical voice patterns, thus, seem not to be distinctive of schizophrenia in general, but more specifically situated in linguistic/cultural differences

Serotoninergic effects on judgments and social learning of trustworthiness

RATIONALE Certain disorders, such as depression and anxiety, to which serotonin dysfunction is historically associated, are also associated with lower assessments of other people's trustworthiness. Serotonergic changes are known to alter cognitive responses to threatening stimuli. This effect may manifest socially as reduced apparent trustworthiness of others. Trustworthiness judgments can emerge from either direct observation or references provided by third parties. OBJECTIVE We assessed whether explicit judgments of trustworthiness and social influences on those judgments are altered by changes within serotonergic systems. METHODS We implemented a double-blind between-subject design where 20 healthy female volunteers received a single dose of the selective serotonin reuptake inhibitor (SSRI) citalopram (2 × 20 mg), while 20 control subjects (matched on age, intelligence, and years of education) received a placebo. Subjects performed a face-rating task assessing how trustworthy they found 153 unfamiliar others (targets). After each rating, the subjects were told how other subjects, on average, rated the same target. The subjects then performed 30 min of distractor tasks before, unexpectedly, being asked to rate all 153 faces again, in a random order. RESULTS Compared to subjects receiving a placebo, subjects receiving citalopram rated targets as less trustworthy. They also conformed more to opinions of others, when others rated targets to be even less trustworthy than subjects had initially indicated. The two effects were independent of negative effects of citalopram on subjective state. CONCLUSIONS This is evidence that serotonin systems can mediate explicit assessment and social learning of the trustworthiness of others