Characterization of the decision-making deficit of patients with ventromedial prefrontal cortex lesions

Abstract

On a gambling task that models real-life decisions, patients with bilateral lesions of the ventromedial prefrontal cortex (VM) opt for choices that yield high immediate gains in spite of higher future losses. In this study, we addressed three possibilities that may account for this behaviour: (i) hypersensitivity to reward; (ii) insensitivity to punishment; and (iii) insensitivity to future consequences, such that behaviour is always guided by immediate prospects. For this purpose, we designed a variant of the original gambling task in which the advantageous decks yielded high immediate punishment but even higher future reward. The disadvantageous decks yielded low immediate punishment but even lower future reward. We measured the skin conductance responses (SCRs) of subjects after they had received a reward or punishment. Patients with VM lesions opted for the disadvantageous decks in both the original and variant versions of the gambling task. The SCRs of VM lesion patients after they had received a reward or punishment were not significantly different from those of controls. In a second experiment, we investigated whether increasing the delayed punishment in the disadvantageous decks of the original task or decreasing the delayed reward in the disadvantageous decks of the variant task would shift the behaviour of VM lesion patients towards an advantageous strategy. Both manipulations failed to shift the behaviour of VM lesion patients away from the disadvantageous decks. These results suggest that patients with VM lesions are insensitive to future consequences, positive or negative, and are primarily guided by immediate prospects. This 'myopia for the future' in VM lesion patients persists in the face of severe adverse consequences, i.e. rising future punishment or declining future reward.

Orbitofrontal cortex dysfunction in abstinent cocaine abusers performing a decision-making task

“…It appears that individuals with right OFC dysfunction, which include cocaine abusers, may not make associations between present emotions and past negative experiences, despite knowing the adverse consequences (Bechara, 2000b). Therefore, understanding the roles of the OFC and DLPFC in relation to substance abuse could facilitate the development of more appropriately targeted prevention and treatment programs for those who suffer from addiction.…”

“…Lesion studies show that the OFC plays an important role in the ability to perform well on this task (Bechara et al, 2000b). The Iowa Gambling Task measures the participant's ability to choose between high gains with a risk of extremely high losses, and low gains with a risk of smaller losses.…”

To discard or not to discard: the neural basis of hoarding symptoms in obsessive-compulsive disorder

“…Both lesion and neuroimaging studies suggest that the VMPFC, amygdala and nucleus accumbens are part of a neural network that is crucial for advantageous decisionmaking. [38][39][40][41][42][43] The current psychological model of compulsive hoarding emphasizes information processing deficits including decision-making. 1 Indeed, deciding what to keep and what to discard can be an extremely difficult task for these patients.…”

Risky decisions and response reversal: is there evidence of orbitofrontal cortex dysfunction in psychopathic individuals?

“…Two studies have found psychopathic adults to perform similarly to comparison groups on the gambling task [60,12]. However, the studies contained significant procedural differences from those presented by Bechara et al [8]. Furthermore, in a recent study using identical instructions to those of Bechara et al [6], Blair et al found that the performance of boys with psychopathic tendencies on the gambling task was impaired relative to a comparison group [14].…”