Clh

Figure 3.9. Data from Cowell and colleagues (1993) showing width of the callosal isthmus as measured by CC factor width 77-85 in 104 human subjects as a function of sex and hand preference. (Group sample sizes are at the base of each bar.) Nonconsistent right-handed (NCRH) men had larger regional widths than consistent right-handed (CRH) men. In both men and women left-handers, consistency had the opposite effect as in right-handers; consistent left-handers (CLH) had larger widths than nonconsistent left-handers (NCLH). When the four handedness groups were pooled across sex, a significant hand by consistency effect was the result, with the NCRH and CLH groups having larger isthmal width than CRH and NCLH groups. (These data have been adapted from Cowell et al., 1993, with permission from Lippincott-Raven Publishers.)

Female Male

Figure 3.9. Data from Cowell and colleagues (1993) showing width of the callosal isthmus as measured by CC factor width 77-85 in 104 human subjects as a function of sex and hand preference. (Group sample sizes are at the base of each bar.) Nonconsistent right-handed (NCRH) men had larger regional widths than consistent right-handed (CRH) men. In both men and women left-handers, consistency had the opposite effect as in right-handers; consistent left-handers (CLH) had larger widths than nonconsistent left-handers (NCLH). When the four handedness groups were pooled across sex, a significant hand by consistency effect was the result, with the NCRH and CLH groups having larger isthmal width than CRH and NCLH groups. (These data have been adapted from Cowell et al., 1993, with permission from Lippincott-Raven Publishers.)

Figure 3.9). Furthermore, direction and degree of hand preference interacted with sex, and these effects were regionally specific to the callosal isthmus. Our study showed that nonconsistent right-handers had larger CC isthmuses than consistent right-handers, but only in men. A different effect was found for left-handers whereby consistent left-handers of both sexes had larger CC isthmuses than nonconsistent left-handers. By collapsing nonconsistent right-handers and nonconsistent lefthanders into one group of mixed-handers, Jancke and Steinmetz may have inadvertently obscured size differences in the CC by ignoring the independent dimensions of direction and degree of manual laterality.

Was this article helpful?

0 0

Post a comment