Greeting conversations are essential tools for communicating socially with family, friends, and community. Attractiveness
is one of the favorable behaviors associated with social communication. A recent study showed that the roles of inferior
frontal gyrus (IFG) and superior temporal gyrus (STG) are essential for perceiving auditory attractiveness. However, to our
knowledge, no study has ever investigated the cerebral response to auditory attractiveness in schizophrenia. We aimed to
clarify the cerebral function underlying the perception of auditory attractiveness in schizophrenia patients. Cerebral activation
was examined in 18 schizophrenia patients and 18 controls when performing Favorability Judgment Task (FJT) and Gender
Differentiation Task (GDT) for pairs of greetings using event-related functional MRI. Full-factorial analysis revealed that the
main effect of task was associated with activation of left IFG and STG. The main effect of Group revealed less activation of left
STG in schizophrenia compared with controls, whereas significantly greater activation in schizophrenia than in controls was
revealed at left middle frontal gyrus (MFG), right temporo-parietal junction (TPJ), right occipital lobe, and right amygdala
(p<0.05, FDR-corrected). A significant positive correlation was observed at right TPJ and right MFG between cerebral activation
under FJT minus GDT contrast and the score of hallucinatory behavior on the Positive and Negative Symptom Scale. Findings
of hypoactivation in left STG could indicate brain dysfunction in accessing vocal attractiveness in schizophrenia, whereas
hyperactivation in right TPJ and MFG may reflect the process of mentalizing other person’s behavior by auditory hallucination
by abnormality of cognitive bias.
Michihiko Koeda is a senior assistant professor of the psychiatry department at Nippon Medical School, Tokyo, Japan. He completed his PhD at the Medical Research Institute of Tokyo Medical and Dental University. He was a visiting researcher at the University of Glasgow. He is continuing to investigate auditory brain function by the use of functional MRI to clarify the pathophysiology of psychiatric symptoms, and pharmacological and/or genetic effects.