Motor behavior reflects reduced hemispheric asymmetry in the psychosis risk period

Schizophr Res. 2016 Jan;170(1):137-42. doi: 10.1016/j.schres.2015.10.017. Epub 2015 Oct 20.


Background: A body of work focusing on brain connectivity, language dominance, and motor laterality research suggests that reduced hemispheric asymmetry is a core feature in schizophrenia. However, there is little consensus about whether reduced dominance is present in those at ultrahigh risk (UHR) for psychosis.

Methods: A total of 94 demonstrated right-handed neuroleptic free participants (38 UHR and 56 matched healthy controls) were assessed with structured clinical interviews and completed an innovative handwriting task using a digital tablet computer. A laterality quotient (LQ) was calculated using kinematic variables from the participant's left and right hands. A subset of the sample (26 UHR and 29 controls) returned after 12-months to complete clinical interviews in order to examine relationships between handwriting laterality and progression of psychosis risk symptoms.

Results: The UHR group showed decreased dextrality compared to healthy controls. At the 12-month follow-up, decreased dextrality accounted for 8% of the variance in worsened positive symptoms within the UHR group.

Conclusion: The current results suggest that disrupted cerebral dominance is also present in the ultrahigh risk period and that decreased dextrality may serve as a novel biomarker for the progression of psychosis risk.

Keywords: Cerebral dominance; Dextrality; Handwriting; Laterality; Psychosis; Ultrahigh risk.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Biomechanical Phenomena
  • Female
  • Follow-Up Studies
  • Functional Laterality*
  • Handwriting*
  • Humans
  • Interview, Psychological
  • Linear Models
  • Male
  • Motor Activity / physiology*
  • Psychotic Disorders / physiopathology*
  • Risk
  • Young Adult