Local contextual processing in major depressive disorder.
OBJECTIVE
The study investigated local contextual processing in patients with major depressive disorder (MDD). This was defined as the ability to utilize predictive contextual information to facilitate detection of predictable versus random targets.


METHODS
We recorded EEG in 15 MDD patients and 14 age-matched controls. Recording blocks consisted of targets preceded by randomized sequences of standards and by sequences of standards that included a predictive sequence signaling the occurrence of a subsequent target event.


RESULTS
Both MDD patients and age-matched controls demonstrated a significant reaction time (RT) and P3b latency differences between predicted and random targets. However, patients demonstrated a specific prolongation of these measures during processing of predicted targets, as well as an attenuation of P3b amplitudes for the predictive sequence. In addition, patients target N1 amplitudes were attenuated compared with controls.


CONCLUSIONS
MDD patients were able to utilize predictive context in order to facilitate processing of deterministic targets, however, this ability was limited compared to controls, as demonstrated by context-dependent P3b deficits.


CONCLUSIONS
These findings suggest that patients with major depression have altered processing of local contextual processing.
Department of Psychology, University of A Coruña, La Coruña, Spain. Electronic address: nfogelson@udc.es.
Noa
N
Fogelson
Institute for Psychiatric Studies, Sha'ar Menashe Mental Health Center, Hadera, Israel; B Rappaport Faculty of Medicine, Technion, Haifa, Israel.
Avi
A
Peled
Department of Psychiatry, Rambam Medical Center, Technion, Haifa, Israel; B Rappaport Faculty of Medicine, Technion, Haifa, Israel.
Sarah
S
Marmor
Department of Physical Education, University of A Coruña, La Coruña, Spain.
Miguel
M
Fernandez-del-Olmo
Department of Psychiatry, Rambam Medical Center, Technion, Haifa, Israel; B Rappaport Faculty of Medicine, Technion, Haifa, Israel.
Ehud
E
Klein
D000293:Adolescent; D000328:Adult; D032882:Comprehension; D003865:Major Depressive Disorder / Q000503:physiopathology* / Q000523:psychology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D011930:Reaction Time / Q000502:physiology
Context; EEG; Major depression; N1; P3b