Evidence from unilateral lesions of early uncompensable implementation of opposed response-biases in each hemisphere of the brain.
OBJECTIVE
The intact right hemisphere presents an omissive response-bias and the left hemisphere a commissive response-bias in adults. This research sought to determine whether these hemispherically lateralized response-biases manifest early developmental and uncompensable brain implementation.


METHODS
Sixteen teenager and adult participants with focal left hemisphere lesions and fourteen with focal right hemisphere lesions (all with childhood onset: M=13 year recovery period) and 14 normal control participants were recruited. A computerized multitask high order working memory procedure was designed to generate many errors of omission and of commission.


RESULTS
The expected double dissociation of response-bias distortion as a function of lesion side was significantly demonstrated on this task and was significantly frontal-lobe dependent.


CONCLUSIONS
The hemispheres of the brain have an opposed response bias that is robustly implemented in infancy through adulthood.
Département de Psychologie, Université du Québec à Montréal, Montréal, QC, Canada.
Anik
A
Guimond
Claude M J
CM
Braun
Sylvie
S
Daigneault
Josée
J
Delisle
Jean-Pierre
JP
Farmer
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D055815:Young Adult
Response-bias; early vulnerability; energetics; errors of commission; errors of omission; executive functions; frontal lobes; hemispheric specialization; multitasking