The role of executive functions and cognitive estimation in decision-making: a study with patients with prefrontal cortex damage

Evidence remained conflicting regarding how the prefrontal cortex supported decision-making abilities, particularly in patients with focal prefrontal cortex lesions. While damage to this region was known to impair executive functioning, the precise contribution of such deficits to decision-making performance - especially under varying levels of uncertainty - remained debated. Moreover, cognitive estimation processes, which were associated with logical reasoning and prefrontal involvement, had rarely been examined in relation to decision-making tasks. To clarify these associations, we administered a cognitive estimation task and the Iowa Gambling Task (IGT), alongside a battery of executive function tests, to 30 patients with focal prefrontal damage and 30 matched control subjects. Our results indicated that patients showed consistent impairment across executive functions, cognitive estimation, and decision-making under risk. Furthermore, correlation and regression analyses revealed that performance on executive tasks and cognitive estimation predicted IGT outcomes, particularly under risk conditions. Finally, voxel-based lesion-symptom mapping identified a bilateral prefrontal network - spanning ventromedial, dorsomedial, and dorsolateral regions - associated with impaired IGT performance. These findings suggested that the multidimensional nature of the IGT was associated with complex executive and inferential reasoning demands and implicated diverse patterns of frontal dysfunction beyond the ventromedial prefrontal cortex.