Eye-tracking performance and engagement of attention.

Eye-tracking dysfunction has previously been demonstrated in psychotic patients. To investigate possible influences on this finding of factors related to attention, subjects were required to read numbers while tracking an oscillating pendulum or a pendulum-like target displayed on an oscilloscope tube. Subjects for the pendulum task were 16 nonpatients and 21 patients; 10 nonpatients and 14 patients performed the other task. Introduction of the number-reading maneuver greatly improved tracking performance in both tasks in patients and nonpatients. The results indicate that poor eye-tracking can be improved by facilitating attentional effort; it is suggested that the number-reading maneuver improved tracking by providing extra feedback cues. The poorer the base line performance, the greater the improvement. However, differences between patients and nonpatients were not abolished with number reading.