Crossmodal mental imagery

While researchers have long pondered over the nature (and even the very existence) of visual mental imagery, it is only in the last few decades or so that serious scientific research has been devoted to the study of this phenomenon in modalities other than vision. That said, the available empirical evidence now supports the view that mental imagery can occur in any sensory modality, though with widely varying degrees of vividness. It is at this point, then, that the question arises as to whether there might also be such a thing as crossmodal imagery. Crossmodal mental imagery has most commonly been reported under those conditions in which the presentation of a stimulus in one sensory modality results in the formation of a mental image in another modality. In this review, evidence supporting the existence of crossmodal mental imagery in neurologically normal adults is critically evaluated. Furthermore, similarities and differences with related phenomena such as crossmodal sensory forms of synaesthesia and crossmodal perceptual completion are also discussed.