STIMULUS PREPROCESSING AND RESPONSE SELECTION IN DEPRESSION - A REACTION-TIME STUDY

Depressed subjects are slower than normal controls in reaction time (R T) tasks. However, it is not clear whether depression affects all stag es of information-processing or only some of them. In the present stud y, this question was addressed by using the additive factor method. Te n inpatients and ten control subjects performed a two-choice visual RT task. Stimulus intensity and stimulus-response compatibility were man ipulated. The effect of intensity was similar in both groups whereas t he effect of compatibility was larger for the patients than for the co ntrols. This suggests that stimulus preprocessing is unaffected by dep ression whilst response selection is impaired.