HYPNOSIS ENHANCES RECALL MEMORY - A TEST OF FORCED AND NON-FORCED CONDITIONS

Visual memory recall in hypnosis was investigated. To address criterio n shift problems in previous studies, both forced and non-forced recal l procedures were used. Previous methodological weaknesses with regard to hypnotizability and hypnotic depth were also addressed. Over 300 v olunteers were screened for hypnotizability using the Harvard Group Sc ale of Hypnotic Susceptibility: Form A (Shor & Orne, 1962). Final high and low hypnotizability groups were selected using the Stanford Hypno tic Susceptibility Scale: Form C (Weitzenhoffer & Hilgard, 1962). Part icipants in each hypnotizability group were randomly assigned to eithe r forced or non-forced recall conditions and to hypnosis or waking con ditions. Participants were shown 60 slides of line drawings and then t ested immediately in 3 recall periods. Analysis of variance results sh owed that those exposed to hypnosis and to a forced recall procedure w ere significantly more confident of their responses to correct items t han those exposed to a non-forced recall procedure or a waking conditi on. Participants exposed to hypnosis and forced recall procedures reca lled more correct items than those exposed to a waking condition. The findings support the hypermnesic effects of hypnosis when participants are required to provide a fixed number of responses.