Sensorimotor laterality in schizophrenia: which features transcend cultural influences?

Area of Science:

• Neuroscience
• Psychiatry
• Human lateralization

Background:

• Schizophrenia is a complex mental disorder with potential links to altered brain lateralization.
• Previous research on sensorimotor lateralization in schizophrenia has yielded mixed results, potentially due to cultural influences or methodological variations.

Purpose of the Study:

• To investigate differences in motor laterality and eye dominance between Nigerian individuals with schizophrenia and healthy controls.
• To explore the utility of cross-dominance as a potential indicator of sensorimotor lateralization in schizophrenia.

Main Methods:

• A battery of performance tests was administered to assess handedness, foot dominance, and eye dominance.
• Participants included Nigerian individuals diagnosed with schizophrenia and a matched group of normal controls.
• Statistical analyses were performed to compare lateralization patterns between the groups.

Main Results:

• No significant differences were found in overall handedness, foot dominance, or eye dominance between schizophrenic and control groups.
• Cross-dominance, defined as full left eye dominance combined with full right handedness, significantly differentiated individuals with schizophrenia from controls.
• This pattern of cross-dominance also differentiated paranoid from nonparanoid subtypes of schizophrenia.

Conclusions:

• Cross-dominance emerged as a significant distinguishing feature between Nigerian schizophrenics and controls.
• This specific lateralization pattern may serve as a more reliable measure of sensorimotor lateralization in schizophrenia.
• The findings suggest that cross-dominance might be less susceptible to cultural masking compared to other lateralization measures.