[Eye movements of children with cerebral function disorders diagnosed by different methods].

Saccadic eye movements were recorded in 31 children with cerebral dysfunction as evidenced on different levels (neurophysiological or neuropsychological deficits or specific learning disabilities, see Schmidt et al. 1984), 20 restless underachievers with concentration problems but without cerebral dysfunction and 28 normal third graders while the children followed a jumping spot of light. The recorded data were analyzed off-line. Measures of performance and activation were calculated and the values plotted as functions of stimulus jumping frequency (0.1 to 1.2 Hz). All three subgroups with cerebral dysfunction first showed a normal tendency to anticipatory responses, but the neurophysiology and learning disabled subgroups did not perform as well as the other groups above 0.5 Hz. The compensatory increase in activation (effort effect) usually associated with an increase in task difficulty was seen only in the learning-disabled subgroup and the two control groups. The results show that the children in the neurophysiology and neuropsychology subgroups did not have optimal adaptation of activation to task difficulty. This deficit was coupled with a performance deficit in the neuropsychology subgroup only, however. The children in the neurophysiology subgroup performed almost as well as those in the control groups in spite of this inadequate regulation. Even though the learning-disabled children showed no abnormalities in activation behavior, they still performed poorly. The conclusion was therefore drawn that their poor performance was the result of deficits in cognitive abilities prerequisite to the task.