Presleep suggestion related to a phobic object: successful manipulation of reported dream affect.

Twenty-four female subjects with a strong dislike of snakes slept for four nonconsecutive nights in the laboratory. They were divided into four groups of six, each group receiving a different presleep suggestion on Nights 3 and 4. On Nights 2, 3, and 4, before sleep, the subjects saw but did not have to touch a live snake and their dreams were collected for each REM period. The results showed that, when compared with the subjects who received the negative affect suggestions, subjects who received positive affect suggestions had significantly higher levels of positive emotions in their dreams, rated their own dreams as more pleasant, and had significantly lower levels of anxiety, sadness, and aggression. These results support the hypothesis that presleep suggestion can be an effective technique in influencing the affective dimension of the dream.