Top-down and bottom-up deficits in conflict adaptation after frontal lobe damage

Abstract

The ability to adaptively control our responses to conflicting information is crucial if we are to respond in a flexible manner to the environment. The “conflict monitoring model” proposes that the prefrontal cortex is responsible of reactive adjustments in cognitive control. We present neuropsychological data contrasting the performance of patients with prefrontal lesions with the one exhibited by patients with lesions outside the frontal lobe and nonlesioned participants, on the processes involved in the dynamic adaptation to conflicting stimulus information. Relative to both lesioned and nonlesioned control groups, prefrontal patients were impaired in adapting to conflict when all features of the conflicting stimuli and their associated responses changed on consecutive trials. However, the prefrontal patients also showed an unusually large conflict adaptation effect when the stimuli and/or response features repeated across trials. We conclude that prefrontal cortex is relevant both for genuine “top-down” conflict monitoring and for regulating the influence of “bottom-up” responses based on the integration of stimulus features across trials.

Keywords:

• Cognitive control
• Conflict monitoring
• Frontal lobes
• Brain lesion
• Stroop

This research was supported by the Spanish Ministerio de Educación y Cultura with a postdoctoral grant (EX2004–0709) and a research grant (PSI2008–04223PSIC) to the first author and by grants from the Medical Research Council and the Stroke Association (UK) to the third author. We thank all the patients for their participation.