A midline dissociation between error-processing and response-conflict monitoring.
Midline brain activation subsequent to errors has been proposed to reflect error detection and, alternatively, conflict-monitoring processes. Adjudicating between these alternatives is challenging as both predict high activation on error trials. In an effort to resolve these interpretations, subjects completed a GO/NOGO task in which errors of commission were frequent and response conflict was independently varied by manipulating response speeds. A mixed-block and event-related fMRI design identified task-related, tonic activation and event-related activations for correct and incorrect trials. The anterior cingulate was the only area with error-related activation that was not modulated by the conflict manipulation and hence is implicated in specific error-related processes. Conversely, activation in the pre-SMA was not specific to errors but was sensitive to the conflict manipulation. A significant region by conflict interaction for tonic activation supported a functional dissociation between these two midline areas. Finally, an intermediate, caudal cingulate area was implicated in both error processing and conflict monitoring. The results suggest that these two action-monitoring processes are distinct and dissociable and are localised along the midline.
Garavan
H
H
Department of Psychology and Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland. Hugh.Garavan@tcd.ie
Ross
T J
TJ
Kaufman
J
J
Stein
E A
EA
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000502:physiology*; D003220:Conflict, Psychological; D005071:Evoked Potentials; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007266:Inhibition, Psychological; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance / Q000502:physiology*