The perception of emotion-free faces in schizophrenia: a magneto-encephalography study.
OBJECTIVE
To analyze how patients suffering from schizophrenia perceive faces of unknown individuals that show no actual emotions in order to investigate the attribution of meanings to a relatively non-significant but complex sensory experience.


METHODS
Analysis of baseline and poststimulation magneto-encephalographic recordings. The stimuli consisted of four pictures with neutral emotional expression of male and female faces of Spanish individuals unknown to research subjects.


METHODS
Twelve right-handed patients suffering from schizophrenia (DSM IV-TR criteria), age 18-65, with active delusional activity (SAPS score in delusions above 39) and 15 right-handed sex- and age-matched control subjects.


RESULTS
Compared to controls patients have a significant higher activity of both hemispheres (0-700 ms) being the activity in the right hemisphere (RH) higher than in the left hemisphere (LH). Patients also have a higher activity on the middle fusiform gyrus (BA 37) in the LH (200-300 ms), on the superior temporal areas (BA 22, 41 and 42) in both hemispheres (100-700 ms) and on the temporal pole (BA 38) in the RH (300-400 ms) and a lower activity in the LH of the latter.


CONCLUSIONS
The areas that are more activated in our study are those involved in the process of thinking, in attributing meanings to perceptions and in activities such as theory of mind, which are essential for social interaction. The anterior temporal areas less activated indicate a reduced semantic memory for faces that could explain the social withdrawal of schizophrenia. These alterations are suggestive of a dysfunction of left hemisphere neuronal networks.
López-Ibor
Juan J
JJ
The Institute of Psychiatry and Mental Health, San Carlos University Hospital, Department of Psychiatry and Medical Psychology, Complutense University, Madrid, Spain. jli@lopez-ibor.com
López-Ibor
María-Inés
MI
Méndez
María-Andreína
MA
Morón
María-Dolores
MD
Ortiz-Terán
Laura
L
Fernandez
Alberto
A
Diaz-Marsá
Marina
M
Ortiz
Tomás
T
D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001921:Brain / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000503:physiopathology; D035061:Control Groups; D004644:Emotions / Q000502:physiology*; D005149:Facial Expression; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D015225:Magnetoencephalography / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012559:Schizophrenia / Q000175:diagnosis* / Q000503:physiopathology; D012565:Schizophrenic Psychology; D012938:Social Perception; D014796:Visual Perception