Test-retest reliability of fMRI-measured brain activity during decision making under risk

Neural correlates of decision making under risk are being increasingly utilized as biomarkers of risk for substance abuse and other psychiatric disorders, treatment outcomes, and brain development. This research relies on the basic assumption that fMRI measures of decision making represent stable, trait-like individual differences. However, reliability needs to be established for each individual construct. Here we assessed long-term test-retest reliability (TRR) of regional brain activations related to decision making under risk using the Balloon Analogue Risk Taking task (BART) and identified regions with good TRRs and familial influences, an important prerequisite for the use of fMRI measures in genetic studies. A secondary goal was to examine the factors potentially affecting fMRI TRRs in one particular risk task, including the magnitude of neural activation, data analytical approaches, different methods of defining boundaries of a region, and participant motion. For the average BOLD response, reliabilities ranged across brain regions from poor to good (ICCs of 0 to 0.8, with a mean ICC of 0.17) and highest reliabilities were observed for parietal, occipital, and temporal regions. Among the regions that were of a priori theoretical importance due to their reported associations with decision making, the activation of left anterior insula and right caudate during the decision period showed the highest reliabilities (ICCs of 0.54 and 0.63, respectively). Among the regions with highest reliabilities, the right fusiform, right rostral anterior cingulate and left superior parietal regions also showed high familiality as indicated by intrapair monozygotic twin correlations (ranging from 0.66 to 0.69). Overall, regions identified by modeling the average BOLD response to a specific event type (rather than its modulation by a parametric regressor), regions including significantly activated vertices (compared to a whole parcel), and regions with greater magnitude of task-related activations showed greater reliabilities. Participant motion had a moderate negative effect on TRR. Regions activated during decision period rather than outcome period of risky decisions showed the greatest TRR and familiality. Regions with reliable activations can be utilized as neural markers of individual differences or endophenotypes in future clinical neuroscience and genetic studies of risk-taking

Risk-taking behaviour

The environment we interact with constantly confronts us with challenges that may cause us potential harm or provide a reward depending on our choices. The ability to evaluate and weigh the trade-off between a potential win and a harmful loss is called risk-taking ability. This Thesis aims to better clarify some of the many unknown aspects regarding this function. As an index of real-life risk-taking tendencies, we chose to use the Balloon Analogue Risk Task (BART). This Thesis is divided into two chapters. The first chapter describes the effects on risk-taking behaviour of 2 techniques of vestibular stimulation: Caloric Vestibular Stimulation (CVS) and Galvanic Vestibular Stimulation (GVS). More in detail, contrary to our predictions, results in Study 1 show how the CVS can selectively increase risk tendencies only for bodily-related stimuli, implying that the CVS is not sufficient to modify risk-taking behaviour as a whole, but a biologically salient and bodily-related stimulus is necessary to allow the effects of the CVS on the representation of the body to interfere with the decision regarding dangerous situations. As a continuation, Study 2 directly deals with the influence of the vestibular input on risk-taking. To assess that, the BART is administered to subjects undergoing GVS. A significant reduction of hazardous tendencies is reported during L-GVS when compared with the opposite polarity, highlighting the vestibular contribution to high cognitive functions, risk-taking in particular, with a polarity specific effect that mainly excites the activity of the right hemisphere. In continuity with the previous, chapter 2 shows the effects on risk-taking of more ecological and natural tools. More precisely, Study 3 reports our findings regarding short-term alterations of the gravitational signals to the brain and how they influenced the willingness to take risks. Our results demonstrated an effect of head orientation on risk propensity, where an upright head position showed behavioural patterns directed towards more conservative and less risky choices compared to a downward head position (i.e. “bed rest”). A coherent and well-integrated vestibular input to the brain is needed to properly cope with different environmental situations. Lastly, Study 4 displays an attempt to detect possible changes in risk-taking after the prolonged time spent in isolation during the Covid-19 lockdown. No significant modification in risk tendencies was found as the time spent in isolation increased. Together, these results highlight the importance of a preserved ability to judge risk situations and have the ability to cope with challenging environments. In particular, the understanding of the neurocognitive substrates underpinning this function is of primary importance in order to begin to sort out the many unknown sides of this topic.The environment we interact with constantly confronts us with challenges that may cause us potential harm or provide a reward depending on our choices. The ability to evaluate and weigh the trade-off between a potential win and a harmful loss is called risk-taking ability. This Thesis aims to better clarify some of the many unknown aspects regarding this function. As an index of real-life risk-taking tendencies, we chose to use the Balloon Analogue Risk Task (BART). This Thesis is divided into two chapters. The first chapter describes the effects on risk-taking behaviour of 2 techniques of vestibular stimulation: Caloric Vestibular Stimulation (CVS) and Galvanic Vestibular Stimulation (GVS). More in detail, contrary to our predictions, results in Study 1 show how the CVS can selectively increase risk tendencies only for bodily-related stimuli, implying that the CVS is not sufficient to modify risk-taking behaviour as a whole, but a biologically salient and bodily-related stimulus is necessary to allow the effects of the CVS on the representation of the body to interfere with the decision regarding dangerous situations. As a continuation, Study 2 directly deals with the influence of the vestibular input on risk-taking. To assess that, the BART is administered to subjects undergoing GVS. A significant reduction of hazardous tendencies is reported during L-GVS when compared with the opposite polarity, highlighting the vestibular contribution to high cognitive functions, risk-taking in particular, with a polarity specific effect that mainly excites the activity of the right hemisphere. In continuity with the previous, chapter 2 shows the effects on risk-taking of more ecological and natural tools. More precisely, Study 3 reports our findings regarding short-term alterations of the gravitational signals to the brain and how they influenced the willingness to take risks. Our results demonstrated an effect of head orientation on risk propensity, where an upright head position showed behavioural patterns directed towards more conservative and less risky choices compared to a downward head position (i.e. “bed rest”). A coherent and well-integrated vestibular input to the brain is needed to properly cope with different environmental situations. Lastly, Study 4 displays an attempt to detect possible changes in risk-taking after the prolonged time spent in isolation during the Covid-19 lockdown. No significant modification in risk tendencies was found as the time spent in isolation increased. Together, these results highlight the importance of a preserved ability to judge risk situations and have the ability to cope with challenging environments. In particular, the understanding of the neurocognitive substrates underpinning this function is of primary importance in order to begin to sort out the many unknown sides of this topic

Cognitive function and mood at high altitude following acclimatization and use of supplemental oxygen and adaptive servoventilation sleep treatments.

Impairments in cognitive function, mood, and sleep quality occur following ascent to high altitude. Low oxygen (hypoxia) and poor sleep quality are both linked to impaired cognitive performance, but their independent contributions at high altitude remain unknown. Adaptive servoventilation (ASV) improves sleep quality by stabilizing breathing and preventing central apneas without supplemental oxygen. We compared the efficacy of ASV and supplemental oxygen sleep treatments for improving daytime cognitive function and mood in high-altitude visitors (N = 18) during acclimatization to 3,800 m. Each night, subjects were randomly provided with ASV, supplemental oxygen (SpO2 > 95%), or no treatment. Each morning subjects completed a series of cognitive function tests and questionnaires to assess mood and multiple aspects of cognitive performance. We found that both ASV and supplemental oxygen (O2) improved daytime feelings of confusion (ASV: p < 0.01; O2: p < 0.05) and fatigue (ASV: p < 0.01; O2: p < 0.01) but did not improve other measures of cognitive performance at high altitude. However, performance improved on the trail making tests (TMT) A and B (p < 0.001), the balloon analog risk test (p < 0.0001), and the psychomotor vigilance test (p < 0.01) over the course of three days at altitude after controlling for effects of sleep treatments. Compared to sea level, subjects reported higher levels of confusion (p < 0.01) and performed worse on the TMT A (p < 0.05) and the emotion recognition test (p < 0.05) on nights when they received no treatment at high altitude. These results suggest that stabilizing breathing (ASV) or increasing oxygenation (supplemental oxygen) during sleep can reduce feelings of fatigue and confusion, but that daytime hypoxia may play a larger role in other cognitive impairments reported at high altitude. Furthermore, this study provides evidence that some aspects of cognition (executive control, risk inhibition, sustained attention) improve with acclimatization

A Test of the Psychometric Characteristics of the BIS-Brief Among Three Groups of Youth

The current study empirically investigates the relationships between the Dark Triad personality traits and cyber-aggression among adolescents (14–18 year old). The sample consisted of 324 participants aged 14–18 (M = 16.05, SD = 1.31). Participants completed the Short Dark Triad (SD3) as a measure of the Dark Triad personality traits, the Facebook Intensity Scale and a scale to measure cyber-aggression. Structural equation modelling was applied to investigate the relationships. Results show that only Facebook intensity and psychopathy significantly predict cyber-aggression, when controlling for age and gender. Findings are discussed regarding the potential importance to further study Dark Triad traits, and psychopathy in particular, in the context of adolescent cyber-aggression

Psychopathic Traits in College Students: Electrodermal Reactivity, Anxiety, Disinhibition, Risk-Taking, and Executive Functioning

A robust finding is that psychopaths exhibit electrodermal hyporeactivity in the presence of stimuli that elicit anxiety in non-psychopathic samples. This finding has been associated with decreased anxiety, although recent research suggests the relationship between psychopathic traits and electrodermal hyporeactivity may be related to other correlates of psychopathy (i.e. decreased inhibitory control, risk-taking, and executive functioning deficits). The present study was a preliminary examination to assess electrodermal reactivity, disinhibition, risk-taking, and executive functioning in a sample of undergraduate students with varying degrees of psychopathic characteristics. Results generally did not support hypothesized relationships between psychopathic traits, physiological responsivity, and executive functioning deficits. Specifically, higher self reported psychopathy scores were not predictive of depressed skin conductance responses to unpleasant images nor was psychopathy related to executive functioning deficits. However, consistent with hypotheses, Self-Report Psychopathy -II factor 2 scores (antisocial behaviors) were significantly related to both self-reported impulsivity and a behavioral measure of risk-taking. Implications and suggestions for future research are discussed

Assessing Factors of Physical Risk-Taking in a Novel Behavioral Measure

Risk taking is a complex heterogeneous construct that has proven difficult to assess, especially when using behavioral tasks. A new measure, the Assessment of Physical Risk Taking (APRT) is presented as a comprehensive assessment of several factors of risk. Specifically, the measure seeks to examine the effects of several decision-making elements (e.g., probability of success and failure, magnitude of reward and punishment) of different types of physically risky behaviors and produce a variety of different outcome scores. Participants (N = 256) completed APRT in a laboratory setting, with half being assigned to an enforced Delay condition. Main effects, two-way interactions among five within-subject factors, and interactions between the within-subject factors and Delay were estimated for four APRT outcome scores using Generalized Estimating Equations. Results indicated that Injury Magnitude and Injury Probability exerted much stronger effects than any of the other independent variables. The implications of these results are discussed in the context of the future of behavioral risk-taking tasks and studies

The Balloon Analogue Risk Task and Behavioral Correlates in Pigeons

Individuals experience risk ubiquitously, but measuring risk taking is difficult. The balloon analogue risk task (BART) was developed in order to assess risk taking through having subjects press a key that accrues reward but also risk losing all reward with each press. In humans, greater responding in this task is associated with other maladaptive risk taking behaviors. The present research modeled this relationship in pigeons due to their previously shown propensity towards risk taking behavior. Experiment 1 used an unsignaled balloon task in which losing could only occur after 5 pecks. Results showed below optimal performance with greater pecks associated with faster acquisition of risk taking in the suboptimal choice task and evidence of modulation by delay discounting measures. Experiment 2 signaled the number of pecks with colors and tested multiple hoppers as a reinforcement modality to increase performance. Results showed only signaling the number of pecks improved performance and was related to performance in the high risk BART task. Both the low and high risk variants were associated with slower suboptimal choice acquisition and again had evidence of modulation by delay discounting measures. Potential shared underlying mechanisms are discussed

Intranasal Oxytocin Modulates Decision-Making Depending on Outcome Predictability-A Randomized Within-Subject Controlled Trial in Healthy Males.

Oxytocin (OT) has been extensively studied with regard to its socio-cognitive and -behavioral effects. Its potential as a therapeutic agent is being discussed for a range of neuropsychiatric conditions. However, there is limited evidence of its effects on non-social cognition in general and decision-making in particular, despite the importance of these functions in neuropsychiatry. Using a crossover/within-subject, blinded, randomized design, we investigated for the first time if intranasal OT (24 IU) affects decision-making differently depending on outcome predictability/ambiguity in healthy males. The Iowa Gambling Task (IGT) and the Cambridge Risk Task (CRT) were used to assess decision-making under low outcome predictability/high ambiguity and under high outcome probability/low ambiguity, respectively. After administration of OT, subjects performed worse and exhibited riskier performance in the IGT (low outcome predictability/high ambiguity), whereas they made borderline-significant less risky decisions in the CRT (high outcome probability/low ambiguity) as compared to the control condition. Decision-making in healthy males may therefore be influenced by OT and adjusted as a function of contextual information, with implications for clinical trials investigating OT in neuropsychiatric conditions