Sex-related differences in the correlations for tactile temporal thresholds, interhemispheric transfer times, and nonverbal intelligence

The relationship between sensory discrimination and individual differences in intelligence has received renewed attention. This study examined the relationship between tactile temporal thresholds (including interhemispheric transfer times) and nonverbal intelligence. A tactile temporal threshold refers to the longest temporal interval that separates the onsets of two tactile stimuli when they are judged by the observer as simultaneous. Interhemispheric transfer time refers to the amount of time it takes to transfer information between cerebral hemispheres. The findings revealed that women had significantly longer interhemispheric transfer times than men. Correlations between bimanual temporal measures, including interhemispheric transfer times, and nonverbal intelligence were significant for women, but not men. Although women and men perform similarly in general intelligence, these findings suggest that the corpus callosum may facilitate nonverbal performance in women, but not men. These results are congruent with other findings which suggest that men and women may rely on different brain regions even though they achieve similar results on intelligence tests.