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A mechanism of behavioral organization and its breakdown in psychiatric disorders: Towards a novel and objective diagnosis

Toru Nakamura (photo)

Toru Nakamura

Research Site Osaka University
Graduate School of Engineering Science
Project Professor


An alteration of spontaneous physical activity (locomotor activity) is one of the cardinal signs in psychiatric disorders, suggestive of a breakdown of dynamical systems organizing human behaviors. In this project, we therefore study dynamical properties of locomotor activity measured continuously in daily life and reveal an underlying principle governing behavioral organization. Furthermore, through the understanding of a mechanism of its breakdown in patients with psychiatric disorder (i.e. major depressive disorder, bipolar disorder, and schizophrenia), we develop a novel and objective diagnostic method for early detection of alterations in pathological states or pathogenesis of the disorders.


  1. J. Kim, T. Nakamura, Y. Yamamoto, “A Momentary Biomarker for Depressive Mood”, InSilico Pharmacology, 4:4-1-6, 2016.
  2. T. Nakamura, K. Kiyono, H. Wendt, P. Abry, Y. Yamamoto, “Multiscale Analysis of Intensive Longitudinal Biomedical Signals and its Clinical Applications”, Proceedings of the IEEE, 104(2), pp. 242-261, 2016.
  3. J. Kim, T. Nakamura, H. Kikuchi, K. Yoshiuchi, T. Sasaki, Y. Yamamoto, “Continuous estimation of depressive mood from spontaneous physical activity in major depressive disorder”, IEEE J Biomed Health Inform.,19(4), pp. 1347-55, 2015.
  4. J. Kim, T. Nakamura, H. Kikuchi, Y. Yamamoto, “Psychobehavioral Validity of Self-reported Symptoms Based on Spontaneous Physical Activity”, Conf Proc IEEE Eng Med Biol Soc. 2015, pp. 4021-4024.
  5. J. Kim, T. Nakamura, H Kikuchi, K. Yoshiuchi, Y. Yamamoto, “Co-variation of Depressive Mood and Spontaneous Physical Activity Evaluated by Ecological Momentary Assessment in Major Depressive Disorder”, Conf Proc IEEE Eng Med Biol Soc. 2014, pp. 6635-6638.