The Phenomenological Control Scale: Measuring the Capacity for Creating Illusory Nonvolition, Hallucination and Delusion

Abstract

Phenomenological control is the ability to generate experiences to meet expectancies. There are stable trait differences in this ability, as shown by responses to imaginative suggestions of, for example, paralysis, amnesia, and auditory, visual, gustatory and tactile hallucinations. Phenomenological control has primarily been studied within the context of hypnosis, in which suggestions are delivered following a hypnotic induction. Reports of substantial relationships between phenomenological control in a hypnotic context (hypnotizability) and experimental measures (e.g., the rubber hand illusion) suggest the need for a broad investigation of the influence of phenomenological control in psychological experiments. However, hypnosis is not required for successful response to imaginative suggestion. Because misconceptions about the hypnotic context may influence hypnotizability scores, a non-hypnotic scale which better matches the contextual expectancies of other experiments and avoids the hypnotic context is potentially better suited for such investigation. We present norms for the Phenomenological Control Scale (PCS), an adaptation of the Sussex Waterloo Scale of Hypnotizability (SWASH) which is free of the hypnotic context. Mean scores for the PCS are higher than for SWASH, and the subjective scales of PCS and SWASH show similar reliability. The PCS subjective scale is a reliable tool for measuring trait response to imaginative suggestion (i.e., phenomenological control) outside the context of hypnosis.