Dependence of intermanual difference in hand skill on right or left cerebral motor control in right-handed male and female subjects.

The relations of the mean differences in right and left hand skills (L-R) to the mean right and left hand skills were studied in right-handed male and female subjects with and without familial sinistrality (FS+, FS-). Hand skill was measured by the peg moving task. In FS+ males, there was a significant negative linear correlation between L-R and right hand peg moving times (PMTs). In FS+ females, there was a significant positive linear correlation between L-R and left hand PMTs. There were no significant correlations between L-R and left hand PMTs in FS+ males, and right hand PMTs in FS+ females. FS- subjects could be described as follows. In males and females with right eye and right foot preference, L-R PMTs were found to be positively linearly correlated with left hand PMTs (no correlation between L-R and right hand PMTs). In subjects with left eye and right foot preference, the correlations were found to be similar to those for FS+ subjects. In subjects with mixed eye and right foot preference, there was a negative linear correlation between L-R and right hand PMTs in females; a positive linear correlation between L-R and left hand PMTs in males. There were no significant correlations between L-R and right hand PMTs in males, and left hand PMTs in females. These results indicated that left brain in FS+ males, and right brain in FS+ females would produce the L-R difference between hands in PMTs.(ABSTRACT TRUNCATED AT 250 WORDS)