Anterior cingulate metabolism correlates with stroop errors in paranoid schizophrenia patients.
Using [O-15]-H(2)O PET Carter et al. (1997) reported that medicated patients with schizophrenia performing computerized single trial Stroop (1935) showed a reduction in the anterior cingulate activation response to the more attention demanding, incongruent Stroop condition. In that study, both patients and controls also showed a direct correlation between anterior cingulate activation and errors committed during incongruent trials of the task. In this study we follow up with an examination of paranoid schizophrenia outpatients and controls with very high resolution positron emission tomography (PET) and the longer half-life tracer [F-18]-fluorinated deoxyglucose (FDG) (Valk et al. 1990). All subjects (10 controls and 9 paranoid schizophrenia patients) were studied with FDG-PET while performing a computerized trial-by-trial version of the Stroop task during the uptake phase of the tracer (Carter et al. 1992).


RESULTS
As in previous studies using the single trial Stroop, patients were able to perform the task but made more color-naming errors during incongruent trials than controls. The patients in the present study showed a trend towards increased metabolic activity in the right anterior cingulate cortex. In the patient group, but not in controls, the anterior cingulate glucose metabolic rate correlated positively with the total incongruent trial errors.


CONCLUSIONS
These results are consistent with the hypothesis that the anterior cingulate plays a performance-monitoring role during human cognition. This study does not rule out a reduction in error sensitivity in this region of the brain in schizophrenia, as other studies have suggested, however the data show that in unmedicated patients with the paranoid subtype this function is preserved to some extent.
Nordahl
T E
TE
Center for Functional Imaging, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720, USA. tenordahl@ucdavis.edu
Carter
C S
CS
Salo
R E
RE
Kraft
L
L
Baldo
J
J
Salamat
S
S
Robertson
L
L
Kusubov
N
N
D000328:Adult; D001931:Brain Mapping / Q000379:methods; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D007839:Functional Laterality / Q000502:physiology*; D005947:Glucose / Q000378:metabolism; D006179:Gyrus Cinguli / Q000473:pathology* / Q000503:physiopathology*; D006624:Hippocampus / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012563:Schizophrenia, Paranoid / Q000473:pathology* / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D014055:Tomography, Emission-Computed
D019788:Fluorodeoxyglucose F18; D005947:Glucose