This review examined the hypothesis that mental imagery vividness can be used as a predictor of hallucinatory experience. Earlier studies provided supporting evidences to this hypothesis, showing hallucinating population has higher mental imagery vividness comparing to nonhallucianting population. However, as a result of varied operationalization and measurements of mental imagery, contradicting results abound, showing no significant difference of mental imagery vividness between halluciantors and nonhallucinators. No clear evidences can be used to determine whether the hypothesis is valid or not so far. On the other hand, development of neurological studies provided a new perspective for looking into the relationship between mental imagery and the experience of hallucination. Keywords: mental imagery vividness, hallucination, schizophrenia
Mental Imagery Vividness as a Predictor of Hallucination: A Literature Review
Mental imagery, as defined by Finke (1989), is an experience significantly resembling that of perceiving, but it occurs in the absence of an adequate physical stimulus. It exists in all of the seven sensory modalities, such as visual, auditory, and olfactory (Thomas, 1999). Mental imagery is believed to be in close relationship with some core psychological mechanisms such as perception and memory, and holding its unique role in contributing to cognitive performance (Kosslyn, 1994). For example, evidences suggested that visual imagery ability predicts visuospatial memory performance (Kail, 1997). Hallucination is an experience that largely resembles mental imagery, because of its perceptual nature as well as absence of appropriate stimuli (Sack, Van de Ven, Etschenberg, Schatz, & Linden, 2005). Nevertheless, the two distinguish from each other by the individual’s ability of voluntary control, as well as his/her ability to determine the source of the experience. Specifically, mental imagery is generally regarded as being actively