Hemispheric asymmetry in the identification of four-letter names traced in the right and left palms

Forty right-handed males were asked to identify four-letter names traced in either the right or left palms while their eyes were closed. The name stimuli were traced in a right-side-up or upside-down orientation (i.e., vertical or rotated 180 degrees). Mean percentage of errors served as the dependent variable. On the first block of 40 trials, the left palm/right hemisphere (LP/RH) was significantly more accurate than the right palm/left hemisphere (RP/LH) at identifying these names. This advantage, however, was only manifest when the name stimuli were traced in the upside-down orientation. On the second block of 40 trials, as the name stimuli became more familiar and the subjects became more practiced, a similar LP/RH advantage was observed; however, the impact of the rotation variable was no longer in evidence (i.e., the LP/RH was slightly more accurate on both upright and inverted names). These results are interpreted in light of a process-oriented tactile asymmetry as proposed by M. W. O'Boyle, F. Van Wyhe-Lawler, and D. A. Miller (1987, Brain and Cognition, 6, 474-494).