Combined Foot and Eye Dominance Scale in Female Patients with Schizophrenia and Female Healthy Subjects – Compact and Easily Applicable Instrument for Assessment of Laterality

The aim of the study was to provide an objective and more useful tool for assessing laterality by investigating the reliability (internal consistency) of a combined Foot and Eye Dominance Scale in female subjects – patients with schizophrenia and healthy subjects. Ninety-four women – patients with schizophrenia and healthy subjects – were assessed with a Combined Foot and Eye Dominance Scale, consisting of two subscales: Foot Dominance Subscale and Eye Dominance Subscale. Scale reliability statistics (item-scale statistics, summary statistics for the items, Cronbach's alpha), non-parametric Mann–Whitney test and Spearman's rank correlation coefficient were used. We found considerable differences in the contribution of some of the items to the Combined Foot and Eye Dominance Scale. These items show greater means than other items, which suggest greater contribution of these items to the total scale mean. The scale shows good internal consistency with a positive mean correlation between the items. The Combined Foot and Eye Dominance Scale reflects leftedness more strongly and objectively, irrespectively of cultural and national differences and it could be a more compact and easily applicable tool for the assessment of lateralization.