Strategy Manipulation and the Stroop Effect in Hypnosis

When asked to name the ink color of an incompatible color word (e.g., the word red printed in green ink), people show strong interference from the word. This phenomenon-the Stroop effect-has become a benchmark measure of attention, and is notoriously difficult to modulate. This study examined Stroop interference in subjects who were either high or low in susceptibility to hypnosis. Compared with performance in the waking state, the Stroop effect actually increased under hypnosis, a result particularly evident in the high-susceptible subjects. This contradicts the notion that high-susceptible subjects freely select appropriate strategies when hypnotized, a conclusion strengthened by an analysis of reported strategies in the two states. However, when provided with an attentional focusing instruction under hypnosis, high-susceptible subjects sharply reduced the Stroop effect, whereas low-susceptible subjects decreased it only slightly. One role of hypnosis may be to assist the subject in tuning attention, but only when an appropriate strategy is provided