Adaptive decision making, ecological validity, and the frontal lobes.

Existing neuropsychological procedures assess veridical, but not adaptive, decision making, which are based on different mechanisms. This severely curtails the tests' ecological validity, because most real-life decision making situations are adaptive, rather than veridical. Veridical decision making entails finding the correct response intrinsic to external situations and is actor-independent. Adaptive decision making is actor-centered and priority-based. Prefrontal cortex is critical for adaptive decision making. Innovative actor-centered decision-making tasks are required to better understand frontal lobe functions. We have designed a prototype for such procedures, the Cognitive Bias Task (CBT). CBT elicited strong gender and hemispheric differences in the effects of focal frontal lesions, which are more robust than those elicited with veridical tasks, such as the Wisconsin Card Sorting Test.