Compromised frontocerebellar circuitry contributes to nonplanning impulsivity in recovering alcoholics.
BACKGROUND
Degradation of frontocerebellar circuitry is a principal neural mechanism of alcoholism-related executive dysfunctions affecting impulse control and cognitive planning.


OBJECTIVE
We tested the hypothesis that alcoholic patients would demonstrate compromised dorsal anterior cingulate cortex (dACC) -cerebellar functional connectivity when adjusting their strategies to accommodate uncertain conditions and would recruit compensatory brain regions to overcome ineffective response patterns.


METHODS
Twenty-six alcoholics and 26 healthy participants underwent functional MRI in two sequential runs while performing a decision-making task. The first run required a response regardless of level of ambiguity of the stimuli; the second run allowed a PASS option (i.e., no response choice), which was useful on ambiguous trials.


RESULTS
Healthy controls demonstrated strong synchronous activity between the dACC and cerebellum while planning and executing a behavioral strategy. By contrast, alcoholics showed synchronous activity between the dACC and the premotor cortex, perhaps enabling successful compensation for accuracy and reaction time in certain conditions; however, a negative outcome of this strategy was rigidity in modifying response strategy to accommodate uncertain conditions. Compared with the alcoholic group, the control group had lower nonplanning impulsiveness, which correlated with using the option PASS to respond in uncertain conditions.


CONCLUSIONS
These findings suggest that compromised dACC-cerebellar functional circuitry contributes to recruitment of an alternative network-dACC-premotor cortex- to perform well under low-risk, unambiguous conditions. This compensatory network, however, was inadequate to enable the alcoholics to avert making poor choices in planning and executing an effective behavioral strategy in high-risk, uncertain conditions.
Department of Psychiatry, Yonsei University College of Medicine, Seoul, South Korea, 120-752.
Young-Chul
YC
Jung
Tilman
T
Schulte
Eva M
EM
Müller-Oehring
Kee
K
Namkoong
Adolf
A
Pfefferbaum
Edith V
EV
Sullivan
D000328:Adult; D057229:Alcoholics; D000437:Alcoholism / Q000503:physiopathology* / Q000523:psychology; D001931:Brain Mapping; D002531:Cerebellum / Q000503:physiopathology*; D003657:Decision Making / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006801:Humans; D007175:Impulsive Behavior / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology*; D011930:Reaction Time / Q000502:physiology