EMR and nonretarded children's reactions to contradiction.

Sensitivity to logical contradiction, as manifested by surprise reaction to the Jastrow illusion, was investigated in nonretarded children, EMR children equaled for CA, and EMR children equated for MA. Each subject was asked to select the "big" ring segment; then the position was reversed and the subject was asked to identify the "little" segment. The lower segment in this illusion always appears to be larger. Changing position results in what was previously identified as big by the subject now appearing to be little. MA-matched peers (nonretarded and EMR children) performed at a similar level on the task and at a significantly higher level than EMR children equated with the nonretarded children for CA. These results indicated that sensitivity to logical contradiction is more fundamentally related to MA than to CA in EMR children when their performance is compared to that of nonretarded children.