List of abstract

NemoImage

13, Number

6, 2001, Part 2 of 2 Parts 1 D E ,I;L”

EMOTION

& COGNITION

Schizophrenic patients show increased amygdala activation during facial recognition: a fMRI study Hirotaka Kosaka*t, Masao Omorit, Tetsuhito Muratat, Tetsuya IidakaS, Hiroki YamadaO, Tomohii Okadaq, Norihiro Sadato’, Harumi Itoh&!, Yoshiharu Yonekura*, Yuji Wadat *Department of Biological Imaging Research Center, Fukui Medical University j-Department of Neuropsychiatry, Fukui Medical University *Department of Human Information Processing School of Informutics and Sciences, Nagoya University $Department of Radiology, Fukui Medical University ‘Department of Cerebral Research, National Institute for Physiological Sciences, Okazaki Intioduction Recent neuroimaging studies have reported that amygdala was activated during emotional face perception, and patients with arnygdala damage are poor in recognition of facial emotion. Schizophrenic patients are often impaired in recognizing facial and/or emotional expression, and their anatomical abnormalities in amygdala have been reported. These impairments may be related to the misinterpretation of social interactions or to flat affect, which are attributed to the dysfunction of the amygdala. To investigate the differential response of amygdala during facial recognition between schizophrenics and normal controls, we utilized functional magnetic resonance imaging (fMR1). Subjects

and Methods

The schizophrenic group consisted of 12 medicated patients (6 men and 6 women; mean age, 26.0 years). Twelve age- and sex-matched healthy volunteers were recruited as controls. Emotional intensity judgment consisted of 6 rest and 6 task periods; each period was 24 s long, alternative rest and task. During one task period, subjects were asked to view a happy and neutral faces simultaneously presented every 3 seconds and to judge which face has emotional valence (Positive face discrimination). In the other task period, an angry or disgusting face and neutral face were presented (Negative face discrimination). During rest periods, the subjects were instructed to compare the size of two rectangles placed side-by-side. A time course series of 100 volumes was acquired using T2*-weighted, gradient echo, EPI sequences with a 1.5 Tesla MR imager (Signa Horizon, General Electric, Milwaukee, Wise., USA) and a standard birdcage head coil. Each volume consisted of 12 coronal slices, with a slice thickness of 4 mm, with a 1 mm gap, to cover the amygdala. The tune interval between two successive acquisitions of the same image was 3000 ms, echo time was 40 ms, and flip angle was 90 degrees. Statistical analysis of the data was conducted at two levels with SPM99. First, task-related activation was evaluated on an individual basis. Then, the individual summary data were incorporated into a second level analysis of group effects Results Between two groups, there was no significant performance difference in either positive discrimination tasks. Positive face discrimination activated the bilateral amygdalae of schizophrenic group showed more prominent activation than the control group in the right activated the bilateral amygdala of the schizophrenic group whereas the right amygdala significant group difference. There was no significant correlation between the task-related neuroleptic dosage in the schizophrenics.

or negative face discrimination, or size both controls and schizophrenics. The amygdala. Negative face discrimination only in the control group. There was no signal change of the amygdala and daily

Comments Exaggerated amygdala activation during input containing emotional valence.

emotional

intensity

judgment

s431

in schizophrenics

may reflect

impaired

gating

of sensory