Neuroimaging studies of emotional response in schizophrenia have mainly used visual (faces) paradigms and shown globally reduced brain activity. None of these studies have used an auditory paradigm. Our principal aim is to evaluate the emotional response of patients with schizophrenia to neutral and emotional words. An auditory emotional paradigm based on the most frequent words heard by psychotic patients with auditory hallucinations was designed. This paradigm was applied to evaluate cerebral activation with functional magnetic resonance imaging (fMRI) in 11 patients with schizophrenia with persistent hallucinations and 10 healthy subjects.We found a clear enhanced activity of the frontal lobe, temporal cortex, insula, cingulate, and amygdala (mainly right side) in patients when hearing emotional words in comparison with controls. Our findings are consistent with other studies suggesting a relevant role for emotional response in the pathogenesis and treatment of auditory hallucinations.
Keywords: Schizophrenia; Functional MRI; Salience; Emotional paradigm; Auditory hallucinations
Fig. 1. Activation maps in chronic schizophrenic patients with AH, under non-emotional content stimuli. Areas with functional response are mainly the middle right cingulum, left superior and middle temporal gyri and left precentral area (after P value correction, no suprathreshold voxels were found. Therefore, for illustrational purposes, a P<0.001>Fig. 2. Activation maps in schizophrenia patients with chronic auditory hallucinations under emotional auditory content. Note the larger activation clusters in the left middle and right superior temporal lobes, right insula and thalamus, and middle and superior frontal lobes (Table 1) (P<0.05,>
Maps of significant differences in BOLD signal in all schizophrenic patients and controls between emotional content stimuli and baseline, and also between nonemotional content stimuli and baseline, were then calculated (Figs. 1 and 2). Corrected values of P<0.05>
In regard to the questions asked immediately after MR data acquisition, results were as follows:
– Frequency of voices during the MR experiment:
none=0, some=4 (36.4%), often=4 (36.4%),
almost continuously=2 (18.2%), all the time=1
– Resemblance of voices to their own voices:
none=0, a little resemblance=5 (45.5%), some
resemblance=2 (18.2%), a lot of resemblance=4
– Level of anxiety: none=1 (9.1%), very little=2
(18.2%), slight anxiety=4 (36.4%), moderate
anxiety=3 (27.3%), severe anxiety=1 (9.1%).
– Level of anxiety: none=4 (40%), very little=3
(30%), slight anxiety=2 (20%), moderate anxiety=
1 (10%), severe anxiety=0.