Wednesday, May 05, 2010

Our brain as a cognitive miser - where decision costs are registered.

McGuire1 and Botvinick show that lateral prefrontal cortex (LPFC) is where the costs of cognitively demanding decisions are reflected. From their introduction:

...decision-makers balance a motive to maximize gains with a motive to minimize decision costs. The concept of decision costs helps explain such behavioral phenomena as effort-accuracy tradeoffs, reliance on fast and frugal heuristics, failure to consider all available alternatives, effort discounting, the use of stereotypes, and salutary effects of monetary incentives. Amplified decision costs might play a role in clinical depression and chronic fatigue syndrome. This idea is related to the view that decision-making consumes a limited resource, and, more generally, that humans act as cognitive misers.
Their abstract: (Experiment 1 elicited repeated self-reports of experienced decision costs, measured in terms of participants’ rated desire to avoid the task. Experiment 2 sought to confirm the relevance of LPFC to the evaluation of decision costs, with costs measured directly in terms of observed avoidance behavior.)
Human choice behavior takes account of internal decision costs: people show a tendency to avoid making decisions in ways that are computationally demanding and subjectively effortful. Here, we investigate neural processes underlying the registration of decision costs. We report two functional MRI experiments that implicate lateral prefrontal cortex (LPFC) in this function. In Experiment 1, LPFC activity correlated positively with a self-report measure of costs as this measure varied over blocks of simple decisions. In Experiment 2, LPFC activity also correlated with individual differences in effort-based choice, taking on higher levels in subjects with a strong tendency to avoid cognitively demanding decisions. These relationships persisted even when effects of reaction time and error were partialled out, linking LPFC activity to subjectively experienced costs and not merely to response accuracy or time on task. In contrast to LPFC, dorsomedial frontal cortex—an area widely implicated in performance monitoring—showed no relationship to decision costs independent of overt performance. Previous work has implicated LPFC in executive control. Our results thus imply that costs may be registered based on the degree to which control mechanisms are recruited during decision-making.

1 comment:

Matthias Weinberger said...

Would be interesting to see how people with different IQ's handle it (or if there's a difference in how much activity shows up in the scanner).
Some people thrive on challenges - others don't. ;-)

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