Similar to patients with orbitofrontal cortex lesions, substance dependent individuals (SDI) show... more Similar to patients with orbitofrontal cortex lesions, substance dependent individuals (SDI) show signs of impairments in decision-making, characterised by a tendency to choose the immediate reward at the expense of severe negative future consequences. The somatic-marker hypothesis proposes that decision-making depends in many important ways on neural substrates that regulate homeostasis, emotion and feeling. According to this model, there should be a link between abnormalities in experiencing emotions in SDI, and their severe impairments in decision-making in real-life. Growing evidence from neuroscientific studies suggests that core aspects of substance addiction may be explained in terms of abnormal emotional guidance of decision-making. Behavioural studies have revealed emotional processing and decision-making deficits in SDI. Combined neuropsychological and physiological assessment has demonstrated that the poorer decision-making of SDI is associated with altered reactions to r...
To review the studies on brain mechanisms in decision making within the framework of the somatic ... more To review the studies on brain mechanisms in decision making within the framework of the somatic marker hypothesis, and based on experiments employing the Iowa Gambling Task. An overview of the somatic marker hypothesis is presented together with the review of the main results obtained from research in brain damaged patients, and normal subjects with functional neuroimaging studies, that have led to the identification of the neural structures involved in decision making in humans. The main region involved in decision making is the ventromedial prefrontal cortex, that integrates sensory, mnesic and emotional information relevant to the task. Other structures intervening in the various relevant processes in decision making are the amygdala (processing and encoding of the emotional signal and its association with contextual stimuli) and the cingulate cortex (process monitoring and response inhibition, especially in situations of uncertainty). The prefrontal dorsolateral cortex would al...
Impairments in flexible goal-directed decisions, often examined by reversal learning, are associa... more Impairments in flexible goal-directed decisions, often examined by reversal learning, are associated with behavioral abnormalities characterized by impulsiveness and disinhibition. Although the lateral orbital frontal cortex (OFC) has been consistently implicated in reversal learning, it is still unclear whether this region is involved in negative feedback processing, behavioral control, or both, and whether reward and punishment might have different effects on lateral OFC involvement. Using a relatively large sample (N = 47), and a categorical learning task with either monetary reward or moderate electric shock as feedback, we found overlapping activations in the right lateral OFC (and adjacent insula) for reward and punishment reversal learning when comparing correct reversal trials with correct acquisition trials, whereas we found overlapping activations in the right dorsolateral prefrontal cortex (DLPFC) when negative feedback signaled contingency change. The right lateral OFC and DLPFC also showed greater sensitivity to punishment than did their left homologues, indicating an asymmetry in how punishment is processed. We propose that the right lateral OFC and anterior insula are important for transforming affective feedback to behavioral adjustment, whereas the right DLPFC is involved in higher level attention control. These results provide insight into the neural mechanisms of reversal learning and behavioral flexibility, which can be leveraged to understand risky behaviors among vulnerable populations.
Human decision making is dependent on not only the function of several brain regions but also the... more Human decision making is dependent on not only the function of several brain regions but also their synergistic interaction. The specific function of brain areas within the ventromedial prefrontal cortex has long been studied in an effort to understand choice evaluation and decision making. These data specifically focus on whole-brain functional interconnectivity using the principles of network science. The Iowa Gambling Task (IGT) was the first neuropsychological task used to model real-life decisions in a way that factors reward, punishment, and uncertainty. Clinically, it has been used to detect decision-making impairments characteristic of patients with prefrontal cortex lesions. Here, we used performance on repeated blocks of the IGT as a behavioral measure of advantageous and disadvantageous decision making in young and mature adults. Both adult groups performed poorly by predominately making disadvantageous selections in the beginning stages of the task. In later phases of th...
The long-term consequences of early prefrontal cortex lesions occurring before 16 months were inv... more The long-term consequences of early prefrontal cortex lesions occurring before 16 months were investigated in two adults. As is the case when such damage occurs in adulthood, the two early-onset patients had severely impaired social behavior despite normal basic cognitive abilities, and showed insensitivity to future consequences of decisions, defective autonomic responses to punishment contingencies and failure to respond to behavioral interventions. Unlike adult-onset patients, however, the two patients had defective social and moral reasoning, suggesting that the acquisition of complex social conventions and moral rules had been impaired. Thus early-onset prefrontal damage resulted in a syndrome resembling psychopathy.
Substance dependent individuals (SDI) often exhibit decision-making deficits; however, it remains... more Substance dependent individuals (SDI) often exhibit decision-making deficits; however, it remains unclear whether the nature of the underlying decision-making processes is the same in users of different classes of drugs and whether these deficits persist after discontinuation of drug use. We used computational modeling to address these questions in a unique sample of relatively "pure" amphetamine-dependent (N = 38) and heroin-dependent individuals (N = 43) who were currently in protracted abstinence, and in 48 healthy controls (HC). A Bayesian model comparison technique, a simulation method, and parameter recovery tests were used to compare three cognitive models: (1) Prospect Valence Learning with decay reinforcement learning rule (PVL-DecayRI), (2) PVL with delta learning rule (PVL-Delta), and (3) Value-Plus-Perseverance (VPP) model based on Win-Stay-Lose-Switch (WSLS) strategy. The model comparison results indicated that the VPP model, a hybrid model of reinforcement le...
The Journal of neuroscience : the official journal of the Society for Neuroscience, 1998
We tested the hypothesis that cognitive functions related to working memory (assessed with delay ... more We tested the hypothesis that cognitive functions related to working memory (assessed with delay tasks) are distinct from those related to decision making (assessed with a gambling task), and that working memory and decision making depend in part on separate anatomical substrates. Normal controls (n = 21), subjects with lesions in the ventromedial (VM) (n = 9) or dorsolateral/high mesial (DL/M) prefrontal cortices (n = 10), performed on (1) modified delay tasks that assess working memory and (2) a gambling task designed to measure decision making. VM subjects with more anterior lesions (n = 4) performed defectively on the gambling but not the delay task. VM subjects with more posterior lesions (n = 5) were impaired on both tasks. Right DL/M subjects were impaired on the delay task but not the gambling task. Left DL/M subjects were not impaired on either task. The findings reveal a cognitive and anatomic double dissociation between deficits in decision making (anterior VM) and workin...
Rationale: Illicit drug use can increase driver crash risk due to loss of control over vehicle tr... more Rationale: Illicit drug use can increase driver crash risk due to loss of control over vehicle trajectory. This study asks, does recreational use of ±3,4-Methylenedioxymethamphetamine (MDMA; ecstasy) and tetrahydrocannabinol (THC; marijuana) impair cognitive processes that help direct our safe movement through the world? Objective: This study assesses the residual effects of combined MDMA/THC use, and of THC use alone, upon perceived trajectory of travel. Methods: Perception of selfmotion, or heading, from optical flow patterns was assessed using stimuli comprising random dot ground planes presented at three different densities and eight heading angles (1, 2, 4 and 8°to the left or right). On each trial, subjects reported if direction of travel was to the left or the right. Results: Results showed impairments in both drug groups, with the MDMA/THC group performing the worst. Conclusions: The finding that these psychoactive agents adversely affect heading perception, even in recently abstinent users, raises potential concerns about MDMA use and driving ability.
Using a novel quantitative model of repeated choice behavior, we investigated the cognitive proce... more Using a novel quantitative model of repeated choice behavior, we investigated the cognitive processes of criminal offenders incarcerated for various crimes. Eighty-one criminals, including violent offenders, drug and sex offenders, drivers operating a vehicle while impaired (OWI) and eighteen matched controls were tested. The results were also contrasted to those obtained from neurological patients with focal brain lesions in the orbitofrontal cortex, and from drug abusers. Participants performed the computerized version of the Iowa Gambling Task , and the results were decomposed into specific component processes using the Expectancy Valence model . The findings indicated that whereas all criminal groups tended to select disadvantageously, the cognitive profiles exhibited by different groups were considerably different. Certain subpopulations, most significantly drug and sex offenders, overweighted potential gains compared to losses, similar to chronic cocaine abusers. In contrast, assault/murder criminals tended to make less consistent choices and to focus on immediate outcomes, and in these respects were more similar to patients with orbitofrontal damage. The current cognitive model provides a novel way for building a bridge between cognitive neuroscience and complex human behaviors.
Disadvantageous decision-making has been reported in patients who had attempted suicide and may r... more Disadvantageous decision-making has been reported in patients who had attempted suicide and may represent a cognitive risk factor for suicide. Making decisions necessitates both implicit/associative and explicit/analytic processes. Here, we explored explicit mechanisms, and hypothesized that suicide attempters fail to use explicit understanding to make favorable choices. The Iowa Gambling Task (IGT) was used to assess decision-making in 151 non-depressed patients with a history of mood disorder and suicidal act, 81 nondepressed patients with a history of mood disorders but no suicidal act, and 144 healthy individuals. After performing the task, we assessed the explicit understanding of the participants of the contingencies in the task, i.e. which options yielded higher gain or loss. Correct explicit understanding was reported less often in suicide attempters and affective controls than in healthy controls (45.7% and 42.0% vs. 66.0%). Moreover, understanding was associated with better performance in healthy and affective controls, but not in suicide attempters, with no between-group difference among those who did not reach understanding. Patients with histories of suicide attempt, therefore, show a disconnection between what they "know" and what they "do", possibly reflecting underlying impairments in implicit associative processes. These cognitive alterations should be addressed in preventative interventions targeting suicide.
Similar to patients with orbitofrontal cortex lesions, substance dependent individuals (SDI) show... more Similar to patients with orbitofrontal cortex lesions, substance dependent individuals (SDI) show signs of impairments in decision-making, characterised by a tendency to choose the immediate reward at the expense of severe negative future consequences. The somatic-marker hypothesis proposes that decision-making depends in many important ways on neural substrates that regulate homeostasis, emotion and feeling. According to this model, there should be a link between abnormalities in experiencing emotions in SDI, and their severe impairments in decision-making in real-life. Growing evidence from neuroscientific studies suggests that core aspects of substance addiction may be explained in terms of abnormal emotional guidance of decision-making. Behavioural studies have revealed emotional processing and decision-making deficits in SDI. Combined neuropsychological and physiological assessment has demonstrated that the poorer decision-making of SDI is associated with altered reactions to r...
To review the studies on brain mechanisms in decision making within the framework of the somatic ... more To review the studies on brain mechanisms in decision making within the framework of the somatic marker hypothesis, and based on experiments employing the Iowa Gambling Task. An overview of the somatic marker hypothesis is presented together with the review of the main results obtained from research in brain damaged patients, and normal subjects with functional neuroimaging studies, that have led to the identification of the neural structures involved in decision making in humans. The main region involved in decision making is the ventromedial prefrontal cortex, that integrates sensory, mnesic and emotional information relevant to the task. Other structures intervening in the various relevant processes in decision making are the amygdala (processing and encoding of the emotional signal and its association with contextual stimuli) and the cingulate cortex (process monitoring and response inhibition, especially in situations of uncertainty). The prefrontal dorsolateral cortex would al...
Impairments in flexible goal-directed decisions, often examined by reversal learning, are associa... more Impairments in flexible goal-directed decisions, often examined by reversal learning, are associated with behavioral abnormalities characterized by impulsiveness and disinhibition. Although the lateral orbital frontal cortex (OFC) has been consistently implicated in reversal learning, it is still unclear whether this region is involved in negative feedback processing, behavioral control, or both, and whether reward and punishment might have different effects on lateral OFC involvement. Using a relatively large sample (N = 47), and a categorical learning task with either monetary reward or moderate electric shock as feedback, we found overlapping activations in the right lateral OFC (and adjacent insula) for reward and punishment reversal learning when comparing correct reversal trials with correct acquisition trials, whereas we found overlapping activations in the right dorsolateral prefrontal cortex (DLPFC) when negative feedback signaled contingency change. The right lateral OFC and DLPFC also showed greater sensitivity to punishment than did their left homologues, indicating an asymmetry in how punishment is processed. We propose that the right lateral OFC and anterior insula are important for transforming affective feedback to behavioral adjustment, whereas the right DLPFC is involved in higher level attention control. These results provide insight into the neural mechanisms of reversal learning and behavioral flexibility, which can be leveraged to understand risky behaviors among vulnerable populations.
Human decision making is dependent on not only the function of several brain regions but also the... more Human decision making is dependent on not only the function of several brain regions but also their synergistic interaction. The specific function of brain areas within the ventromedial prefrontal cortex has long been studied in an effort to understand choice evaluation and decision making. These data specifically focus on whole-brain functional interconnectivity using the principles of network science. The Iowa Gambling Task (IGT) was the first neuropsychological task used to model real-life decisions in a way that factors reward, punishment, and uncertainty. Clinically, it has been used to detect decision-making impairments characteristic of patients with prefrontal cortex lesions. Here, we used performance on repeated blocks of the IGT as a behavioral measure of advantageous and disadvantageous decision making in young and mature adults. Both adult groups performed poorly by predominately making disadvantageous selections in the beginning stages of the task. In later phases of th...
The long-term consequences of early prefrontal cortex lesions occurring before 16 months were inv... more The long-term consequences of early prefrontal cortex lesions occurring before 16 months were investigated in two adults. As is the case when such damage occurs in adulthood, the two early-onset patients had severely impaired social behavior despite normal basic cognitive abilities, and showed insensitivity to future consequences of decisions, defective autonomic responses to punishment contingencies and failure to respond to behavioral interventions. Unlike adult-onset patients, however, the two patients had defective social and moral reasoning, suggesting that the acquisition of complex social conventions and moral rules had been impaired. Thus early-onset prefrontal damage resulted in a syndrome resembling psychopathy.
Substance dependent individuals (SDI) often exhibit decision-making deficits; however, it remains... more Substance dependent individuals (SDI) often exhibit decision-making deficits; however, it remains unclear whether the nature of the underlying decision-making processes is the same in users of different classes of drugs and whether these deficits persist after discontinuation of drug use. We used computational modeling to address these questions in a unique sample of relatively "pure" amphetamine-dependent (N = 38) and heroin-dependent individuals (N = 43) who were currently in protracted abstinence, and in 48 healthy controls (HC). A Bayesian model comparison technique, a simulation method, and parameter recovery tests were used to compare three cognitive models: (1) Prospect Valence Learning with decay reinforcement learning rule (PVL-DecayRI), (2) PVL with delta learning rule (PVL-Delta), and (3) Value-Plus-Perseverance (VPP) model based on Win-Stay-Lose-Switch (WSLS) strategy. The model comparison results indicated that the VPP model, a hybrid model of reinforcement le...
The Journal of neuroscience : the official journal of the Society for Neuroscience, 1998
We tested the hypothesis that cognitive functions related to working memory (assessed with delay ... more We tested the hypothesis that cognitive functions related to working memory (assessed with delay tasks) are distinct from those related to decision making (assessed with a gambling task), and that working memory and decision making depend in part on separate anatomical substrates. Normal controls (n = 21), subjects with lesions in the ventromedial (VM) (n = 9) or dorsolateral/high mesial (DL/M) prefrontal cortices (n = 10), performed on (1) modified delay tasks that assess working memory and (2) a gambling task designed to measure decision making. VM subjects with more anterior lesions (n = 4) performed defectively on the gambling but not the delay task. VM subjects with more posterior lesions (n = 5) were impaired on both tasks. Right DL/M subjects were impaired on the delay task but not the gambling task. Left DL/M subjects were not impaired on either task. The findings reveal a cognitive and anatomic double dissociation between deficits in decision making (anterior VM) and workin...
Rationale: Illicit drug use can increase driver crash risk due to loss of control over vehicle tr... more Rationale: Illicit drug use can increase driver crash risk due to loss of control over vehicle trajectory. This study asks, does recreational use of ±3,4-Methylenedioxymethamphetamine (MDMA; ecstasy) and tetrahydrocannabinol (THC; marijuana) impair cognitive processes that help direct our safe movement through the world? Objective: This study assesses the residual effects of combined MDMA/THC use, and of THC use alone, upon perceived trajectory of travel. Methods: Perception of selfmotion, or heading, from optical flow patterns was assessed using stimuli comprising random dot ground planes presented at three different densities and eight heading angles (1, 2, 4 and 8°to the left or right). On each trial, subjects reported if direction of travel was to the left or the right. Results: Results showed impairments in both drug groups, with the MDMA/THC group performing the worst. Conclusions: The finding that these psychoactive agents adversely affect heading perception, even in recently abstinent users, raises potential concerns about MDMA use and driving ability.
Using a novel quantitative model of repeated choice behavior, we investigated the cognitive proce... more Using a novel quantitative model of repeated choice behavior, we investigated the cognitive processes of criminal offenders incarcerated for various crimes. Eighty-one criminals, including violent offenders, drug and sex offenders, drivers operating a vehicle while impaired (OWI) and eighteen matched controls were tested. The results were also contrasted to those obtained from neurological patients with focal brain lesions in the orbitofrontal cortex, and from drug abusers. Participants performed the computerized version of the Iowa Gambling Task , and the results were decomposed into specific component processes using the Expectancy Valence model . The findings indicated that whereas all criminal groups tended to select disadvantageously, the cognitive profiles exhibited by different groups were considerably different. Certain subpopulations, most significantly drug and sex offenders, overweighted potential gains compared to losses, similar to chronic cocaine abusers. In contrast, assault/murder criminals tended to make less consistent choices and to focus on immediate outcomes, and in these respects were more similar to patients with orbitofrontal damage. The current cognitive model provides a novel way for building a bridge between cognitive neuroscience and complex human behaviors.
Disadvantageous decision-making has been reported in patients who had attempted suicide and may r... more Disadvantageous decision-making has been reported in patients who had attempted suicide and may represent a cognitive risk factor for suicide. Making decisions necessitates both implicit/associative and explicit/analytic processes. Here, we explored explicit mechanisms, and hypothesized that suicide attempters fail to use explicit understanding to make favorable choices. The Iowa Gambling Task (IGT) was used to assess decision-making in 151 non-depressed patients with a history of mood disorder and suicidal act, 81 nondepressed patients with a history of mood disorders but no suicidal act, and 144 healthy individuals. After performing the task, we assessed the explicit understanding of the participants of the contingencies in the task, i.e. which options yielded higher gain or loss. Correct explicit understanding was reported less often in suicide attempters and affective controls than in healthy controls (45.7% and 42.0% vs. 66.0%). Moreover, understanding was associated with better performance in healthy and affective controls, but not in suicide attempters, with no between-group difference among those who did not reach understanding. Patients with histories of suicide attempt, therefore, show a disconnection between what they "know" and what they "do", possibly reflecting underlying impairments in implicit associative processes. These cognitive alterations should be addressed in preventative interventions targeting suicide.
Uploads
Papers by A. Bechara