Probing Vividness Increment through Imagery Interruption

The purpose of the present study was to trace how visual experience changes over time during mental image generation, by using an interruption paradigm. In one experiment, participants were asked to read the verbal descriptions of eight common objects and imagine these objects. Changes in the quality of the images evoked by the eight stimuli were probed by interrupting the visual mental image generation process at various times from 0 to 1.7 s, and asking participants to rate the vividness of their image at the time of interruption. We found that vividness increased as the time allowed for image generation was augmented. This relationship was consistently detected in half of the participants and for all stimuli. The present findings support the implicit assumption of some current imagery models positing that mental images “improve” over time, and reject the alternative that images are generated in full detail before becoming accessible to consciousness. However, the “incremental” view is unsatisfactory for imagery models which make no (or not enough) room for individual differences.