Normality assumption was met for the variable age and for the VVIQ
score for both groups.
Healthy participants scored 77, 75, and 56 (out of max 80) in the VVIQ
questionnaire, while SCI patients scored 54, 69, and 72 (Figure 9(b)).
For example, the numerous studies that have used the Vividness of Visual Imagery Questionnaire (VVIQ
, Marks, 1973) have reported contradictory results.
(2) The VVIQ
is considered a valid and reliable instrument for measuring vividness of visual imagery.
Burton and Fogarty (2003) correlated the previously mentioned image rotation tests with the Betts' Questionnaire Upon Mental Imagery (Sheehan, 1967), and with the Vividness of Visual Imagery Questionnaire (VVIQ
, Marks, 1973), and found that correlations ranged from .12 to .17.
Scientifically, the mental image exists through its effects, its functional consequences--not answers on the VVIQ
. In this light, Denis's research may reveal that imagery instructions create quantitative differences (increased reading times and comprehension scores), but it cannot prove that the low imagers were actually experiencing increased mental imagery as they read the passage.
Results: There was no evidence that change in mean VVIQ
scores were different between the groups (p=0.616).
We made a conscious attempt to differentiate image generation from its vividness, throughout the study, by implementing personal assessments after the first, third, and fifth steps of the treatment, and through the French translation of the VVIQ
. This differentiation was made because the participants may naively assess vividness on the basis of the ease to generate an image, especially if they were not alerted to distinguish them (Howe, 1985).
) ask participants to imagine a variety of real-life scenes or objects.
Three tests on imagery are frequently used; (1) Vividness of Visual Imagery Questionnaire (VVIQ
) Marks (1973), (2) The shortened form of Bett's Questionnaire upon Mental Imagery (QMI) Sheehan (1967), and (3) the Gordon Test of Visual Imagery Control (GTVIC) Gordon (1949).
Later analysis revealed that ANOVA results are not statistically different with or without adjusting memory scores for individual differences in visual imagery abilities as measured by VVIQ
. Hence, ANOVA results are reported here without using VVIQ
scores as a covariate.
In order to determine a participant's imagery ability, the VVIQ
was used (Marks, 1973).