244 research outputs found

    HEURISTICS USED BY HUMANS WITH PREFRONTAL CORTEX DAMAGE: TOWARD AN EMPIRICAL MODEL OF PHINEAS GAGE

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    In many research contexts it is necessary to group experimental subjects into behavioral “types.” Usually, this is done by pre-specifying a set of candidate decision-making heuristics and then assigning each subject to the heuristic that best describes his/her behavior. Such approaches might not perform well when used to explain the behavior of subjects with prefrontal cortex damage. The reason is that introspection is typically used to generate the candidate heuristic set, but this procedure is likely to fail when applied to the decision-making strategies of subjects with brain damage. This research uses the type classification approach introduced by Houser, Keane and McCabe (2002) to investigate the heuristics used by subjects in the gambling experiment (Bechara, Damasio, Damasio and Anderson, 1994). An advantage of our classification approach is that it does not require us to specify the nature of subjects’ heuristics in advance. Rather, both the number and nature of the heuristics used are discerned directly from the experimental data. Our sample includes normal subjects, as well as subjects with damage to the ventromedial (VM) area of the prefrontal cortex. Subjects are “clustered” according to similarities in their heuristic, and this clustering does not preclude some normal and VM subjects from using the same decision rule. Our results are consistent with what others have found in subsequent experimentation with VM patients.experiments, heuristics, neuroeconomics, behavioral economics

    The insula: a critical neural substrate for craving and drug seeking under conflict and risk

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    Drug addiction is characterized by the inability to control drug use when it results in negative consequences or conflicts with more adaptive goals. Our previous work showed that damage to the insula disrupted addiction to cigarette smoking-the first time that the insula was shown to be a critical neural substrate for addiction. Here, we review those findings, as well as more recent studies that corroborate and extend them, demonstrating the role of the insula in (1) incentive motivational processes that drive addictive behavior, (2) control processes that moderate or inhibit addictive behavior, and (3) interoceptive processes that represent bodily states associated with drug use. We then describe a theoretical framework that attempts to integrate these seemingly disparate findings. In this framework, the insula functions in the recall of interoceptive drug effects during craving and drug seeking under specific conditions where drug taking is perceived as risky and/or where there is conflict between drug taking and more adaptive goals. We describe this framework in an evolutionary context and discuss its implications for understanding the mechanisms of behavior change in addiction treatments

    The Cognitive Processes Underlying Affective Decision-Making Predicting Adolescent Smoking Behaviors in a Longitudinal Study

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    This study investigates the relationship between three different cognitive processes underlying the Iowa Gambling Task (IGT) and adolescent smoking behaviors in a longitudinal study. We conducted a longitudinal study of 181 Chinese adolescents in Chengdu City, China. The participants were followed from 10th to 11th grade. When they were in the 10th grade (Time 1), we tested these adolescents’ decision-making using the IGT and working memory capacity using the Self-ordered Pointing Test (SOPT). Self-report questionnaires were used to assess school academic performance and smoking behaviors. The same questionnaires were completed again at the 1-year follow-up (Time 2). The Expectancy-Valence (EV) Model was applied to distill the IGT performance into three different underlying psychological components: (i) a motivational component which indicates the subjective weight the adolescents assign to gains vs. losses; (ii) a learning-rate component which indicates the sensitivity to recent outcomes vs. past experiences; and (iii) a response component which indicates how consistent the adolescents are between learning and responding. The subjective weight to gains vs. losses at Time 1 significantly predicted current smokers and current smoking levels at Time 2, controlling for demographic variables and baseline smoking behaviors. Therefore, by decomposing the IGT into three different psychological components, we found that the motivational process of weight gain vs. losses may serve as a neuropsychological marker to predict adolescent smoking behaviors in a general youth population

    Decision-making in Adolescents: Performance under Different Conditions of Information and Alcohol Intoxication

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    El objetivo fue evaluar la toma de decisiones en adolescentes. Se utilizó la Iowa Gambling Task (IGT) y la Game of Dice Task (GDT). Se utilizó un diseño experimental con pre y postest donde se manipuló el tratamiento (intoxicado/no intoxicado) y la información recibida (verdadera/falsa). Se evaluaron 77 participantes voluntarios entre 18 y 25 años. Para analizar los datos se utilizaron ANOVAs. Se encontraron diferencias en hombres y mujeres en relación a las distintas puntuaciones de la IGT y GDT. Encontrar efectos relacionados al sexo de los participantes coincide con lo informado en algunos estudios. El mejor rendimiento de las mujeres en la GDT puede explicarse teniendo en cuenta que las funciones ejecutivas están implicadas, lo que daría ventaja a las mujeres. Finalmente, los resultados relacionados a la intoxicación podrían mostrar que el alcohol afecta la calidad de la toma de decisiones.The aim was to assess decision-making in adolescents. To this, we used the Iowa Gambling Task (IGT) and the Game of Dice Task (GDT). We used an experimental design with pre-post-test where we manipulated the treatment (Intoxicated/ Non Intoxicated) and the information received (True/False). 77 volunteers were evaluated between 18 and 25 years old. Data was analyzed using ANOVA. We found differences between men and women in different scores on the IGT and GDT. Sex-related effects of the participants agreed with other studies. The better performance of women on the GDT can be explained taking into account that executive functions are involved in task execution, at which women perform better. Finally, results related to intoxication suggest that alcohol affects the quality of decision making.Fil: Acuña, Hugo Ignacio. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Castillo, Daniela Susana. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bechara, Antoine. University of Southern California; Estados UnidosFil: Godoy, Juan Carlos. Universidad Nacional de Córdoba; Argentin

    Theta-burst stimulation and frontotemporal regulation of cardiovascular autonomic outputs : the role of state anxiety

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    Dysregulation of autonomic cardiovascular homeostasis is an important cardiological and neurological risk factor. Cortical regions including the prefrontal and insular cortices exert tonic control over cardiovascular autonomic functions. Transcranial Magnetic Stimulation (TMS) may be a suitable approach for studying top-down control of visceromotor processes. However, there is inconsistent evidence as to whether TMS can modify cardiovascular autonomic states. One reason for the inconsistency may arise from the lack of studies accounting for the acute affective states of participants with respect to the stimulation procedures. To gain more insights into these processes, we evaluated the effects of intermittent and continuous theta-burst stimulation (TBS) to the right frontotemporal cortex on state anxiety and cardiovascular responses in a preliminary study. State anxiety significantly increased for both intermittent and continuous TBS relative to sham. Intermittent TBS also significantly increased heart-rate variability (HRV) at natural and slow-paced breathing rates. The effect of intermittent TBS on vagally-mediated HRV was attenuated after accounting for stimulation-induced anxiety, suggesting that increased HRV after stimulation may reflect a response to a transient stressor (i.e., the stimulation itself), rather than TBS effects on visceromotor networks. In contrast, continuous TBS increased pulse transit time latency across breathing rates, an effect that was enhanced after accounting for state anxiety. TMS is a promising approach to study cortical involvement in cardiovascular autonomic regulation. The findings show that TBS induces effects on visceromotor networks, and that analysis of state covariates such as anxiety can be important for increasing the precision of these estimates. Future non-invasive brain stimulation studies of top-down neurocardiac regulation should account for the potential influence of non-specific arousal or anxiety responses to stimulation

    Damage to Ventromedial Prefrontal Cortex Impairs Judgment of Harmful Intent

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    SummaryMoral judgments, whether delivered in ordinary experience or in the courtroom, depend on our ability to infer intentions. We forgive unintentional or accidental harms and condemn failed attempts to harm. Prior work demonstrates that patients with damage to the ventromedial prefrontal cortex (VMPC) deliver abnormal judgments in response to moral dilemmas and that these patients are especially impaired in triggering emotional responses to inferred or abstract events (e.g., intentions), as opposed to real or actual outcomes. We therefore predicted that VMPC patients would deliver abnormal moral judgments of harmful intentions in the absence of harmful outcomes, as in failed attempts to harm. This prediction was confirmed in the current study: VMPC patients judged attempted harms, including attempted murder, as more morally permissible relative to controls. These results highlight the critical role of the VMPC in processing harmful intent for moral judgment

    Increased ventral anterior insular connectivity to sports betting availability indexes problem gambling

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    With the advent of digital technologies, online sports betting is spurring a fast-growing expansion. In this study, we examined how sports betting availability modulates the brain connectivity of frequent sports bettors with [problem bettors (PB)] or without [non-problem bettors (NPB)] problematic sports betting. We conducted functional connectivity analyses centred on the ventral anterior insular cortex (vAI), a brain region playing a key role in the dynamic interplay between reward-based processes. We re-analysed a dataset on sports betting availability undertaken in PB (n = 30) and NPB (n = 35). Across all participants, we observed that sports betting availability elicited positive vAI coupling with extended clusters of brain activation (encompassing the putamen, cerebellum, occipital, temporal, precentral and central operculum regions) and negative vAI coupling with the orbitofrontal cortex. Between-group analyses showed increased positive vAI coupling in the PB group, as compared with the NPB group, in the left lateral occipital cortex, extending to the left inferior frontal gyrus, the anterior cingulate gyrus and the right frontal pole. Taken together, these results are in line with the central assumptions of triadic models of addictions, which posit that the insular cortex plays a pivotal role in promoting the drive and motivation to get a reward by ‘hijacking’ goal-oriented processes toward addiction-related cues. Taken together, these findings showed that vAI functional connectivity is sensitive not only to gambling availability but also to the status of problematic sport betting

    Versão em português do Iowa Gambling Test: adaptação transcultural e validade discriminate

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    OBJECTIVE: The Iowa Gambling Task is a neuropsychological task developed in English, most widely used to assess decision-making. The aim of this work was to adapt the Iowa Gambling Task to Brazilian Portuguese, compare it with the original version and assess its validity. METHOD: We assessed 75 Brazilian adults divided into three groups: 1) 25 healthy volunteers holding the Proficiency Certificate in English tested using the English version of the Iowa Gambling Task; 2) 25 healthy volunteers who did not speak or read English tested using the Iowa Gambling Task-Portuguese; 3) 25 Attention Deficit Hyperactivity Disorder subjects tested with the Iowa Gambling Task-Portuguese. RESULTS: No difference between groups 1 and 2 was observed. Nonetheless, we found significant differences between Attention Deficit Hyperactivity Disorder subjects and the other 2 groups on blocks 3, 4, 5, and on net score. CONCLUSION: Our results are similar to those previously described in the literature concerning adults without neuropsychiatric diseases. Since those two versions were equivalent and Attention Deficit Hyperactivity Disorder subjects performed significantly worse than healthy volunteers we can conclude that the adaptation of the Iowa Gambling Task to Brazilian Portuguese is valid and can be used for research purposes in the Brazilian context.OBJETIVO: Iowa Gambling Task é uma tarefa neuropsicológica originalmente desenvolvida em inglês, mais usada no mundo para avaliar o processo de tomada de decisões. Este estudo pretendeu adaptar o Iowa Gambling Task para o português, comparar a versão adaptada com a versão original em inglês e avaliar sua validade discriminante. MÉTODO: Foram investigados 75 adultos brasileiros divididos em três grupos: 1) 25 voluntários sadios proficientes em inglês, avaliados com a versão original em inglês; 2) 25 voluntários sadios não-proficientes em inglês avaliados com o Iowa Gambling Task-português; 3) 25 adultos com Transtorno do Déficit de Atenção e Hiperatividade (avaliados com o Iowa Gambling Task-português. RESULTADOS: Não houve diferenças entre os grupos 1 e 2. No entanto, encontramos diferenças entre os adultos com Transtorno do Déficit de Atenção e Hiperatividade e os outros dois grupos nos blocos 3, 4, 5 e no netscore. CONCLUSÃO: Nossos resultados são semelhantes aos descritos na literatura. Considerando que as duas versões se mostraram equivalentes e os sujeitos com Transtorno do Déficit de Atenção e Hiperatividade desempenharam significativamente pior do que os controles, podemos concluir que a adaptação do Iowa Gambling Task para o português praticado no Brasil é válida e pode ser aplicada no contexto brasileiro

    Personality, executive control, and neurobiological characteristics associated with different forms of risky driving

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    Background: Road crashes represent a huge burden on global health. Some drivers are prone to repeated episodes of risky driving (RD) and are over-represented in crashes and related morbidity. However, their characteristics are heterogeneous, hampering development of targeted intervention strategies. This study hypothesized that distinct personality, cognitive, and neurobiological processes are associated with the type of RD behaviours these drivers predominantly engage in. Methods: Four age-matched groups of adult (19-39 years) males were recruited: 1) driving while impaired recidivists (DWI, n = 36); 2) non-alcohol reckless drivers (SPEED, n = 28); 3) drivers with a mixed RD profile (MIXED, n = 27); and 4) low-risk control drivers (CTL, n = 47). Their sociodemographic, criminal history, driving behaviour (by questionnaire and simulation performance), personality (Big Five traits, impulsivity, reward sensitivity), cognitive (disinhibition, decision making, behavioural risk taking), and neurobiological (cortisol stress response) characteristics were gathered and contrasted. Results: Compared to controls, group SPEED showed greater sensation seeking, disinhibition, disadvantageous decision making, and risk taking. Group MIXED exhibited more substance misuse, and antisocial, sensation seeking and reward sensitive personality features. Group DWI showed greater disinhibition and more severe alcohol misuse, and compared to the other RD groups, the lowest level of risk taking when sober. All RD groups exhibited less cortisol increase in response to stress compared to controls. Discussion: Each RD group exhibited a distinct personality and cognitive profile, which was consistent with stimulation seeking in group SPEED, fearlessness in group MIXED, and poor behavioural regulation associated with alcohol in group DWI. As these group differences were uniformly accompanied by blunted cortisol stress responses, they may reflect the disparate behavioural consequences of dysregulation of the stress system. In sum, RD preference appears to be a useful marker for clarifying explanatory pathways to risky driving, and for research into developing more personalized prevention efforts
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