EFFECTS OF ATTENTION AND DISTRACTION ON CONTINGENT NEGATIVE VARIATION IN NORMAL AND NEUROTIC SUBJECTS

In Experiment I the effect of simple distraction on the CNV was studied, using an automatic averaging technique, in forty chronic neurotic patients and forty non-patient control subjects. Basic CNV levels were established, the stimuli employed being paired Click and Flicker. Distraction was then introduced in the form of an irregular tone stimulus presented between trials. The high anxiety patient group showed a significantly smaller basic CNV than the non-patients controls. Both groups showed a significant reduction in CNV amplitude in the distracting condition. Reduction in the case of the patients was on the average 80% and in the case of the controls 30%. Experiment II investigated, in twelve non-patient subjects, the effect on the CNV of more complex forms of distraction and of voluntary concentration. The various forms of distraction were accompanied by reduction in the amplitude of the CNV. The results suggested that the extent of the reduction was related to the degree of attention focussed on the distracting stimuli as opposed to the stimuli directly relevant to the experimental task. When a conditional or warning stimulus was itself made intrinsically interesting, and thereby distracting, reduction in amplitude and changes in the latency of the CNV suggested division of attention between the intrinsic and imperative aspects of the stimulus. Concentration resulted in a small increase in the amplitude of the CNV. Results are discussed in the context of a possible use of CNV data as a diagnostic aid in psychiatry. © 1968.