Electrophysiological evidence of abnormal activation of the cerebral network of involuntary attention in alcoholism.
OBJECTIVE
Increased distractibility is a common impairment in alcoholism, but objective evidence has remained elusive. Here, a task designed to investigate with event-related brain potentials (ERPs) the neural mechanism underlying distraction was used to show abnormal involuntary orienting of attention in chronic alcoholism.


METHODS
Fifteen alcoholics and 17 matched healthy controls were instructed to ignore auditory stimuli while concentrating in the discrimination of immediately following visual stimuli. The auditory sequences contained repetitive standard tones occasionally replaced by deviant tones of slightly higher frequency, or by complex novel sounds.


RESULTS
Deviant tones and novel sounds distracted visual performance, i.e. increased reaction time to visual stimuli, similarly in patients and controls. Compared to controls, however, alcoholics showed ERP abnormalities, i.e. enhanced P3a amplitudes over the left frontal region, and a positive posterior deflection instead of the frontally distributed reorienting negativity (RON).


CONCLUSIONS
The enhanced P3a to novelty and subsequent positive wave instead of RON in alcoholics suggests encoding into working memory of task-irrelevant auditory events and provides neurophysiological markers of impaired involuntary attention mechanisms in chronic alcoholism.
Polo
Maria Dolores
MD
Neurodynamics Laboratory, Department of Psychiatry and Clinical Psychobiology, University of Barcelona, P. Vall d'Hebron 171, 08035, Barcelona, Spain.
Escera
Carles
C
Yago
Elena
E
Alho
Kimmo
K
Gual
Antoni
A
Grau
Carles
C
D000161:Acoustic Stimulation; D000328:Adult; D000437:Alcoholism / Q000503:physiopathology*; D001307:Auditory Perception; D001921:Brain / Q000503:physiopathology*; D016022:Case-Control Studies; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D011597:Psychomotor Performance; D013647:Task Performance and Analysis; D014796:Visual Perception