Brain dysfunctions during facial discrimination in schizophrenia: Selective association to affect decoding
ABSTRACT Schizophrenia patients exhibit impaired facial affect perception, yet the exact nature of this impairment remains unclear. We investigated neural activity related to processing facial emotional and non-emotional information and complex images in 12 schizophrenia patients and 15 healthy controls using functional magnetic resonance imaging. All subjects performed a facial information processing task with three conditions: matching facial emotion, matching facial identity, and matching complex visual patterns. Patients and controls showed comparable behavioral performance in all task conditions. The neural activation patterns in schizophrenia patients and healthy controls were distinctly different while processing affect-related facial information but not other non-emotional facial features. During emotion matching, orbital frontal cortex and left amydala activations were found in controls but not in patients. When comparing emotion versus identity matching, controls activated the fusiform and middle temporal gyri, left superior temporal gyrus, and right inferior and middle frontal gyrus, whereas schizophrenia patients only activated the middle and inferior frontal gyri, the frontal operculi and the right insular cortex. Our findings suggest that schizophrenia patients and healthy controls may utilize different neural networks when processing facial emotional information.
SourceAvailable from: Thomas W Weickert[Show abstract] [Hide abstract]
ABSTRACT: Background: Schizophrenia is characterized by deficits in executive control and impairments in emotion processing. This study assessed the nature and extent of potential alterations in the neural substrates supporting the interaction between cognitive control mechanisms and emotion attribution processes in people with schizophrenia. Methods: Functional magnetic resonance imaging was performed during a verbal emotional go/no-go task. People with schizophrenia and healthy controls responded to word stimuli of a prespecified emotional valence (positive, negative or neutral) while inhibiting responses to stimuli of a different valence. Results: We enrolled 20 people with schizophrenia and 23 controls in the study. Healthy controls activated an extensive dorsal prefrontal-parietal network while inhibiting responses to negative words compared to neutral words, but showed deactivation of the midcingulate cortex while inhibiting responses to positive words compared to neutral words. People with schizophrenia failed to activate this network during response inhibition to negative words, whereas during response inhibition to positive words they did not deactivate the cingulate, but showed increased responsivity in the frontal cortex. Limitations: Sample heterogeneity is characteristic of studies of schizophrenia and may have contributed to more variable neural responses in the patient sample despite the care taken to control for potentially confounding variables. Conclusion: Our results showed that schizophrenia is associated with aberrant modulation of neural responses during the interaction between cognitive control and emotion processing. Failure of the frontal circuitry to regulate goal-directed behaviour based on emotion attributions may contribute to deficits in psychosocial functioning in daily life.Journal of psychiatry & neuroscience: JPN 05/2012; 37(6):379-88. DOI:10.1503/jpn.110088 · 7.49 Impact Factor
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ABSTRACT: Effective integration of visual information is necessary to utilize abstract thinking, but patients with schizophrenia have slow eye movement and usually explore limited visual information. This study examines the relationship between abstract thinking ability and the pattern of eye gaze in patients with schizophrenia using a novel theme identification task. Twenty patients with schizophrenia and 22 healthy controls completed the theme identification task, in which subjects selected which word, out of a set of provided words, best described the theme of a picture. Eye gaze while performing the task was recorded by the eye tracker. Patients exhibited a significantly lower correct rate for theme identification and lesser fixation and saccade counts than controls. The correct rate was significantly correlated with the fixation count in patients, but not in controls. Patients with schizophrenia showed impaired abstract thinking and decreased quality of gaze, which were positively associated with each other. Theme identification and eye gaze appear to be useful as tools for the objective measurement of abstract thinking in patients with schizophrenia.Behavioral and Brain Functions 04/2014; 10(1):13. DOI:10.1186/1744-9081-10-13 · 2.00 Impact Factor
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ABSTRACT: Experimental changes in resting cerebral blood flow (CBF) affect task-related blood oxygenation level dependent (BOLD) responses. Since patients with schizophrenia have been shown to have abnormal resting CBF, we sought to determine whether differences between patients and healthy controls in resting CBF contribute to group differences in BOLD response. BOLD images were acquired in nineteen patients and twenty healthy controls looking at photographs of faces, and resting CBF was measured by arterial spinning labeling. Resting CBF was then used to adjust group differences in task-related BOLD signal increases in linear models. Patients had different resting CBF from healthy controls in right basal ganglion and bilateral thalami. Associations between resting CBF and delta BOLD were evident in bilateral prefrontal areas, visual processing areas and right fusiform gyrus. Other areas showed significant three-way interactions among group, delta BOLD and resting CBF. Incorporating resting CBF when modeling group differences in BOLD responses identified areas of group differences in task-related delta BOLD response that were not evident in simple group contrasts. These were in right inferior frontal cortex, left insula, left middle frontal cortex and bilateral frontal poles. Adjusting for inter-group differences in resting CBF altered inter-group differences in task-related BOLD response in some areas, suggesting that assessing resting CBF in task-related BOLD studies could increase sensitivity and validity. In multiple regions, the relationship between resting CBF and task-related signal increases in BOLD differed between patients and controls, providing new evidence of possible metabolic and/or vascular pathology.Schizophrenia Research 07/2012; 140(1-3):143-8. DOI:10.1016/j.schres.2012.06.028 · 4.43 Impact Factor