 We have seen that the negative definition of mental imagery as perceptual representation that is not directly triggered by sensory input allows for lateral triggering of this perceptual representation. This amounts to perceptual representation in one sense modality, say vision, triggered by sensory input in another sense modality, say, audition. As this is not a direct trigger (your eyes could be closed, so nothing triggers your visual representation directly), this is a form of mental imagery. And it is what is known as multimodal mental imagery (Spence and Deroy 2013, Lacey and Lawson 2013, Nanay 2018a).