Rc. Gur et al., EFFECTS OF EMOTIONAL DISCRIMINATION TASKS ON CEREBRAL BLOOD-FLOW - REGIONAL ACTIVATION AND ITS RELATION TO PERFORMANCE, Brain and cognition, 25(2), 1994, pp. 271-286
Facial discrimination tasks were applied as activation probes during p
hysiologic neuroimaging (''neurobehavioral probes''). The stimuli pict
ured professional actors and actresses, posing degrees of happy and sa
d emotion. Cortical cerebral blood flow (CBF) was determined using the
Xenon-133 inhalation method during resting baseline, two emotional (h
appy from neutral and sad from neutral faces) and one nonemotional dis
crimination task (age). The three tasks produced CBF increase over bas
eline, which was greater in the right hemisphere (Task x Hemisphere in
teraction, p = .0001). There were regionally specific effects (Task x
Region x Hemisphere interaction, p = .022). Relative to the age discri
mination task, both emotion discrimination tasks were associated with
greater right parietal activation. In addition, the happy discriminati
on task induced greater left frontal activation relative to the sad di
scrimination task. While overall magnitude of CBF increase did not sho
w regionally specific correlations with performance, laterality did sh
ow such specificity. Sad discrimination performance correlated with gr
eater right parietal activation, while performance on the happy discri
mination task correlated with left frontal activation. Age discriminat
ion performance correlated with higher activated right temporal CBF. T
hese results support the hypothesis of right hemispheric involvement i
n facial processing and further suggest regionally specific hemispheri
c participation in happy and sad emotional discrimination. The study u
nderscores the utility of performance measures for understanding the b
ehavioral significance of activation effects in physiologic neuroimagi
ng studies. (C) 1994 Academic Press, Inc.