Perceptual and physiological dysfunction in depression.
P300 responses to emotive words of different hedonic tones were assessed in depressed patients (unipolar major), patients recovered from the same type of depression and normal controls. Depressed patients showed a smaller amplitude of P300 in response to negatively toned words than to positive words; normal controls showed the opposite pattern and recovered patients showed a pattern of response which resembled that of depressed patients. The experimental trials comparing responses to negative and positive stimuli in relation to neutral words showed significant differences for negative as compared with neutral stimuli, but not for positive as compared with neutral stimuli. Latencies of P300 did not differentiate depressed patients from normal controls. The results are discussed within the context of the 'expectancy' theory of information processing.
Blackburn
I M
IM
MRC Brain Metabolism Unit, Royal Edinburgh Hospital.
Roxborough
H M
HM
Muir
W J
WJ
Glabus
M
M
Blackwood
D H
DH
D000328:Adult; D000339:Affect / Q000502:physiology; D001143:Arousal / Q000502:physiology; D001288:Attention / Q000502:physiology; D002540:Cerebral Cortex / Q000503:physiopathology; D003866:Depressive Disorder / Q000503:physiopathology / Q000523:psychology*; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010556:Personality Tests; D011930:Reaction Time / Q000502:physiology; D011932:Reading; D012660:Semantics; D012815:Signal Processing, Computer-Assisted