TACTILE LINE-BISECTION IN NORMAL SUBJECTS

The effects of spatial position, handedness, and hand of performance w ere assessed in 36 normal subjects using a tactile line-bisection task described in 1980 by Bowers and Heilman. An interaction between hand of performance and spatial position indicated that both hemispace and anatomical pathways determine laterality effects. Neither the left-han d superiority nor the leftward error in the midline condition by both hands found in an earlier study could be observed here. Only right-han ders were influenced by starting condition, which in this setting acte d as a spatial cue. Finally, some subjects used nonspatial strategies, a confounding factor that needs evaluation in further studies.