The mission of our research is to find out the neural mechanisms of information processing associated with human cognitive, affective, and social functions through psychiatric disorders.

To achieve the mission, we are currently conducting several neuropsychological research in humans, in which various approaches are utilized such as;

• Measuring behaviors (brain functions): Questionnaire surveys, Psychological tasks, Eye-tracking, Vital signs (e.g., heart rate, GSK, respiration, body temperature)

• Measuring brain activities: fNIRS, fMRI, EEG

• Manipulating brain activities: Non-invasive brain stimulation (e.g., TMS, tDCS), Pharmacological manipulations (e.g., Acute tyrosine/phenylalanine depletion, Acute tryptophane depletion)

• Exploring biological mechanisms and biomarkers: HPLC, ELISA, Genome-wide methylation analysis

Keywords: Addiction; Schizophrenia Spectrum Disorder; Autism Spectrum Disorder; Sociality; Cognitive Bias; Social Bias; Judgment/Decision Making; Dopamine; Serotonin; Neuroplasticity; Neurodevelopment

• Research to find out what brain dysfunction and behavioral abnormalities are associated with addiction (particularly behavioral addiction, such as Kleptomania, Paraphilia, Internet, Gaming, Smartphone, Gambling, and Eating disorder).

• Research to find out what neural mechanisms produce social biases (systematic tendencies of social behaviors that humans exhibit at interacting with others, including bullying and discrimination) and their relationships with psychiatric disorders, such as addiction, schizophrenia spectrum disorder, and autism spectrum disorder.

• Research to find out how social environments affect brain development in humans.

Human Studies

• Recognition of social rank is stronger in children with autism spectrum disorder (but, the way to recognize it is different from normal children).
  Sci Rep, 9: 15657 (2019)

• A part of cognitive dysfunction observed in children with autism spectrum disorder is actually caused by stress, not disorder itself.
  Neuroscience, 343: 229-239 (2017)

• Behavioral addicts, who compulsively seek and cannot stop inappropriate behaviors (sometimes associated with crimes, such as stealing goods and molesting), are unable to accurately estimate probabilities and exhibit a problem on self-recognition bias.
  Int J Neuropsychopharmacol, 23: 662-672 (2020)

• Behavioral addiction involves physiological alterations that are overlapping with those observed in drug addiction.
  Sci Rep, 10: 11760 (2020)

Animal Studies

• Autism spectrum disorder may be adaptive behavioral phenotypes against over-populated social environments.
  Sci Rep, 8: 3497 (2018)

• Dopamine is an important neurotransmitter that determines social hierarchy, which is under trade-off with cognitive functions and higher social ranks in non-human primates and rodents.
  Front Neurosci, 9: 219 (2015)
  Int J Neuropsychopharmacol, 20: 324-335 (2017)
  Sci Rep, 7: 43348 (2017)

• Prenatal stress induces neurodevelopmental changes, but such changes may be adaptive against expected postnatal environments (but if postnatal environments is not something expected, it results in maladaptive, and considered as deficits).
  Neural Plast, 2015: 291476 (2015)
  Physiol Behav, 165: 146-153 (2016)