Neural processing of emotional facial and semantic expressions in euthymic bipolar disorder (BD) and its association with theory of mind (ToM).
BACKGROUND
Adults with bipolar disorder (BD) have cognitive impairments that affect face processing and social cognition. However, it remains unknown whether these deficits in euthymic BD have impaired brain markers of emotional processing.


RESULTS
We recruited twenty six participants, 13 controls subjects with an equal number of euthymic BD participants. We used an event-related potential (ERP) assessment of a dual valence task (DVT), in which faces (angry and happy), words (pleasant and unpleasant), and face-word simultaneous combinations are presented to test the effects of the stimulus type (face vs word) and valence (positive vs. negative). All participants received clinical, neuropsychological and social cognition evaluations. ERP analysis revealed that both groups showed N170 modulation of stimulus type effects (face > word). BD patients exhibited reduced and enhanced N170 to facial and semantic valence, respectively. The neural source estimation of N170 was a posterior section of the fusiform gyrus (FG), including the face fusiform area (FFA). Neural generators of N170 for faces (FG and FFA) were reduced in BD. In these patients, N170 modulation was associated with social cognition (theory of mind).


CONCLUSIONS
This is the first report of euthymic BD exhibiting abnormal N170 emotional discrimination associated with theory of mind impairments.
Laboratory of Experimental Psychology and Neuroscience, Institute of Cognitive Neurology and Institute of Neuroscience, Favaloro University, Buenos Aires, Argentina. aibanez@ineco.org.ar
Agustin
A
Ibanez
Hugo
H
Urquina
Agustín
A
Petroni
Sandra
S
Baez
Vladimir
V
Lopez
Micaela
M
do Nascimento
Eduar
E
Herrera
Raphael
R
Guex
Esteban
E
Hurtado
Alejandro
A
Blenkmann
Leandro
L
Beltrachini
Carlos
C
Gelormini
Mariano
M
Sigman
Alicia
A
Lischinsky
Teresa
T
Torralva
Fernando
F
Torrente
Marcelo
M
Cetkovich
Facundo
F
Manes
D000161:Acoustic Stimulation; D000328:Adult; D001519:Behavior / Q000502:physiology; D001714:Bipolar Disorder / Q000503:physiopathology*; D004644:Emotions / Q000502:physiology*; D005071:Evoked Potentials; D005149:Facial Expression; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D021641:Recognition, Psychology / Q000502:physiology; D012660:Semantics; D056345:Theory of Mind / Q000502:physiology*