Factor-analytic item analysis of the Hemispheric Mode Indicator

A principal component analysis based on data for 1113 undergraduates revealed that, as operationalized by the Hemispheric Mode Indicator, cognitive hemispheric dominance is not a unitary concept. This instrument appeared to evaluate three discrete cognitive preferences: “prefers structure” vs. “prefers flexibility”, “fact-oriented” vs. “feeling-oriented,” and “verbal” vs. “visuospatial.” Furthermore, some items are negatively correlated with most others, are ambiguously worded, are excessively complex, or may suffer from response bias. Most importantly, of the three underlying subscales listed above, only the last is obviously related to an empirically demonstrable aspect of cognitive cerebral laterality. For these and other reasons, it is unlikely that the Hemispheric Mode Indicator is a good measure of demonstrable hemispheric dominance.