The disturbing effect of irrelevant information on arithmetic problem solving in inattentive children

Two studies explored the influence of irrelevant information on the problem-solving ability of children rated as inattentive by their teachers, on the basis of symptoms of attention deficit hyperactivity disorder as defined by the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994). In the first study, 20 inattentive children, fourth and fifth graders, and 20 control children matched for IQ, gender, and schooling were administered 12-word arithmetic problems. Four problems included only essential information necessary for the problem's solution, whereas the other problems included irrelevant information, half at the beginning of the problem and half at the end. Although the inattentive children were equal to control children in their ability to solve problems with essential information, they performed more poorly in using appropriate problem-solving procedures when problems included irrelevant information, independent of its position. The second study compared the influence of numerical and verbal irrelevant information. Nineteen inattentive children and 18 control children, selected with similar criteria as Study 1, were presented with 12 problems, 6 with irrelevant numerical-arithmetic information and 6 with irrelevant verbal information. Both kinds of information produced a greater number of procedural errors in the inattentive group, but differences in calculation errors were less evident. Furthermore, inattentive children were more disturbed when the irrelevant information was verbal than when it was numerical, suggesting that inattentive children's difficulties in problem solving are partially due to an inability to inhibit irrelevant information, especially when it conveys a rich semantic knowledge.