Measuring imagery strength in schizophrenia: no evidence of enhanced mental imagery priming

Recent research shows ambivalent results regarding the relationship between mental imagery and schizophrenia. The role of voluntary visual imagery in schizophrenic hallucinations remains unclear. The aim of the study was to investigate the association between visual imagery, schizophrenia, and the occurrence of schizophrenic hallucinations using an objective visual imagery task.

The sample consisted of 16 participants with schizophrenia (59.1% female; M_Age  = 45.55) and 44 participants without schizophrenia (62.5% female; M_Age  = 43.94). Visual imagery was measured using the Vividness of Visual Imagery Questionnaire (VVIQ) as well as the well-validated Binocular Rivalry Task (BRT). Occurrences of hallucinations were assessed using the Launay-Slade Hallucination Scale.

Participants with schizophrenia showed more hallucinatory experiences but did not score higher on either the VVIQ or the BRT than participants without schizophrenia. A correlation between the VVIQ and the BRT was found, validating the measurement of visual imagery and enabling the interpretation that visual imagery vividness is not enhanced in people with schizophrenia.

The association between mental imagery vividness and schizophrenia found in previous studies may be based on other facets of mental imagery than visual imagery.