The Iranian version of Betts' questionnaire upon mental imagery: translation and confirmatory factor analysis

Mental imagery plays a crucial role in cognitive and motor functioning. The present study aimed to translate, culturally adapt, and psychometrically evaluate the Persian version of Sheehan's shortened form of Betts' Questionnaire Upon Mental Imagery (QMI) among Iranian university students. This study represents the first comprehensive cultural adaptation and psychometric validation of the Betts' Questionnaire Upon Mental Imagery (QMI) in Persian-speaking populations.

A total of 379 students from Shahid Beheshti University (166 women, 213 men; mean age = 20.97 ± 2.95 years) voluntarily participated in the study. The original QMI includes 35 items across seven sensory modalities (visual, auditory, cutaneous, kinesthetic, gustatory, olfactory, and organic), scored on a 7-point Likert scale (1 = vivid image, 7 = no image). A rigorous forward-backward translation protocol involving a multidisciplinary expert panel was implemented. Confirmatory factor analysis (CFA), Cronbach's alpha, and gender comparison using independent t-tests were conducted. Robust Maximum Likelihood Estimation was used in CFA due to non-normality.

CFA confirmed the original seven-factor structure with good fit by multiple indices (CFI=0.96, TLI=0.95, SRMR=0.06, RMSEA=0.06 [90% CI: 0.05, 0.07], p-close = .12; PGFI = 0.73, PNFI = 0.84, χ2/df = 2.18. Internal consistency was strong (Cronbach's alpha = 0.87 overall; all subscales α = 0.65-0.78; McDonald's ω = 0.68-0.92). No statistically significant gender differences were observed in total or subscale scores (p > .05).

The QMI demonstrates sound psychometric properties, confirming its applicability for assessing vividness of multisensory imagery in Persian-speaking populations, however, further validation is required before its broad application in specialized clinical or elite athletic contexts.