Phase Synchronization Index of Vestibular System Activity in Schizophrenia

  • S. Haghgooie
  • B. J. Lithgow
  • C. Gurvich
  • J. Kulkarni
Part of the IFMBE Proceedings book series (IFMBE, volume 23)


Schizophrenia is a severe mental illness associated with multiple neuropathological and neurochemical abnormalities. The aim of this study is to examine if patients with schizophrenia exhibit any abnormality in the level of functional connectivity between the neuronal centers responsible for the processing of vestibular information in the left and right side of the head. Signals were recorded simultaneously in response to tilt stimuli by a special hydraulic chair via a pair of electrodes inserted in the left and right ear canals to rest on tympanic membrane. Using the complex Morlet wavelet transform, we compared instantaneous phase synchronization indices on a set of recordings collected from a group of control subjects (n=24) against schizophrenia group (n=11). Our results show differences between groups in the level and duration of synchrony mostly during dynamic rather than static phases of the tilts. Larger study sample is required to verify these findings.


Schizophrenia vestibular system phase synchronization complex Morlet wavelet 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Abi-Dargham, A., Do we still believe in the dopamine hypothesis? New data bring new evidence. Int J Neuropsychopharmacol, 2004. 7 Suppl 1: p. S1–5.CrossRefGoogle Scholar
  2. 2.
    Barmack, N.H., Central vestibular system: vestibular nuclei and posterior cerebellum. Brain Res Bull, 2003. 60(5–6): p. 511–41.CrossRefGoogle Scholar
  3. 3.
    Picard, H., et al., The Role of the Cerebellum in Schizophrenia: an Update of Clinical, Cognitive, and Functional Evidences. Schizophrenia Bulletin, 2007.Google Scholar
  4. 4.
    Balaban, C.D. and au]J.F. Thayer, Neurological bases for balanceanxiety links. J Anxiety Disord, 2001. 15(1–2): p. 53–79.CrossRefGoogle Scholar
  5. 5.
    Rosenblum, M.G., A.S. Pikovsky, and J. Kurths, Phase Synchronization of Chaotic Oscillators. Physical Review Letters, 1996. 76(11): p. 1804–1807.CrossRefGoogle Scholar
  6. 6.
    Mima, T., et al., Transient Interhemispheric Neuronal Synchrony Correlates with Object Recognition. Journal of Neuroscience, 2001. 2(11): p. 3942.Google Scholar
  7. 7.
    van Leeuwen, C., Task, Intention, Context, Globality, Ambiguity: More of the Same. Ambiguity in Mind and Nature: Multistable Cognitive Phenomena, 1995: p. 85.Google Scholar
  8. 8.
    Lithgow, B.J., A neural event proces. (WO 2006/024102, priority date 1st September 2004), (Inventor) Patent.Google Scholar
  9. 9.
    Ferraro, J.A., Clinical Electrocochleography: Overview of Theories, Techniques and Applications. 2000, Hearing and Speech Department, University of Kansas, Medical Center.Google Scholar
  10. 10.
    Tass, P., et al., Detection of n: m Phase Locking from Noisy Data: Application to Magnetoencephalography. Physical Review Letters, 1998. 81(15): p. 3291–3294.CrossRefGoogle Scholar
  11. 11.
    Rosenblum, M.G. and au]A.S. Pikovsky, Detecting direction of coupling in interacting oscillators. Physical Review E, 2001. 64(4): p. 45202.CrossRefGoogle Scholar

Copyright information

© International Federation of Medical and Biological Engineering 2009

Authors and Affiliations

  • S. Haghgooie
    • 1
  • B. J. Lithgow
    • 1
  • C. Gurvich
    • 2
  • J. Kulkarni
    • 2
  1. 1.Diagnostic and Neurosignal Processing GroupMonash UniversityMelbourneAustralia
  2. 2.Alfred Psychiatry Research CentreThe Alfred HospitalMelbourneAustralia

Personalised recommendations