Pilot Study: The Role of the Hemispheric Lateralization in Mental Disorders by Use of the Limb (Eye, Hand, Foot) Dominance

Introduction: Based on the previous studies, we know that the hemispheric lateralization defects, increase the probability of psychological disorders. We also know that dominant limb is controlled by dominant hemisphere and limb preference is used as an indicator for hemisphere dominance. In this study we attempted to explore the hemispheric dominance by the use of three limbs (hand, foot and eye). Methods: We performed this survey on two samples, psychiatric patients compared with normal population. For this purpose, knowing that the organ dominance is stabilized in adolescence, and age has no effect on the people above 15, we used 48 high school girls and 65 boys as the final samples of normal population. The patient group included 57 male and 26 female who were chronic psychiatric patients. Results: The result shows that left-eye dominance is more in patients than the normal group(p=0.000) but the handedness and footedness differences are not significance. In psychotic, bipolar and depressive disorders, eye dominance had significant difference (P= 0.018). But this is not true about hand and foot dominance. Discussion: Our findings proved that generally in psychiatric patients, left-eye dominance is more common, left-eye dominance is also more in psychotic and depressive disorders. It is less common in bipolar disorders. Key words: hemispheric lateralization, limb dominance, mental disorders.