Tactile discrimination, response mode, and interhemispheric communication by learning disabled children.

32 right-handed, learning disabled children aged 8-10 yr., 11-13 yr., and 14-16 yr. were presented a tactile discrimination task. Pairs of fabrics of different or the same texture were presented to the same hand (uncrossed condition) or alternating hands (crossed condition). Discrimination errors were compared using a verbal response mode and a nonverbal response mode. Analysis indicated that the number of crossed errors was significantly greater in the verbal response mode than in the nonverbal response mode for only the youngest children. These results suggest selective attention-activation bias and/or hemispheric processing limitations for younger learning disabled children.