RESUMO
Sustained attention in children was investigated with a new method in which 4 measures of attention are recorded simultaneously over a period of 30 minutes during a self-paced operant task. A preliminary study with 56 normal children revealed that performance speed and brief lapses in attention have low validity as measures of attention, but errors and especially impulsive reactions have high validity. Impulsive behavior is thus characteristic not only for hyperactive children but also for normal children with attentional problems in everyday situations. The subjects in the main investigation were 12 hyperactive boys aged 8 to 11 years old. Hyperactivity had to be the major complaint, with the diagnosis substantiated by a pediatrician's findings and by a high motor-activity score in a teacher's assessment. Twelve normal boys matched for age, IQ and grade in school served as control subjects. All children attended regular schools and were of normal intelligence. The validity of the selection procedure was confirmed by the significantly lower heart rate found in the hyperactive group. Attention was assessed for 30 minutes under quiet and distraction conditions. The groups differed significantly in number of errors and number of impulsive reactions, but only in the absence of distraction. The stress of sustained attention for 30 minutes did not increase the differences; on the contrary, they decreased. A special type of attentional deficit in hyperactive children could not be confirmed. Our results do not support the hypothesis that hyperactive children are more distractible, have more frequent brief lapses in attention or have a poorer ability to sustain attention than normal children. Rather, they suggest that the attentional deficits represent a personality trait.
