Semantic memory as the root of imagination

“Imagination is what makes our sensory experience meaningful, enabling us to interpret and make sense of it, whether from a conventional perspective or from a fresh, original, individual one. It is what makes perception more than the mere physical stimulation of sense organs. It also produces mental imagery, visual and otherwise, which is what makes it possible for us to think outside the confines of our present perceptual reality, to consider memories of the past and possibilities for the future, and to weigh alternatives against one another. Thus, imagination makes possible all our thinking about what is, what has been, and, perhaps most important, what might be.”—Nigel J. T. Thomas (2004, as cited in Manu, 2006, p. 47)1. Investigations of the information processing mechanisms that underlie imaginative thought typically focus on a single branch of imagination, such as prospection, mental imagery or creativity, and are often generalized as being insightful to understanding the workings of imagination in general. In reality, however, there is very little in the way of theoretical or empirical exchange between the scientific communities that conduct research within the different domains of imagination. As a result, the research impetus in each of the sub-domains may be skewed to the pursuit of hypotheses that are not particularly viable in terms of understanding imagination as a whole. An example of this is pegging the roots of imagination to the processes of episodic memory—a reasonable assumption to make based on studies of episodic prospection. However, the associated findings and theoretical conclusions that follow are not entirely consistent with the literature on the mechanisms underlying creativity (Bubić and Abraham, 2014), which is another core realm of imagination. In an effort to promote interchange across the frontiers of imagination, in this Opinion Article we put forward the idea that all aspects of imagination emerge from semantic memory with increasingly higher-order levels of imaginative information processing emanating from and interacting with existing systems, eventually expanding beyond these to form new systems (Figure 1). We compare the associated neurocognitive findings and assumptions in terms of their fit with current knowledge in other fields of imagination and discuss their implications for reformulating hypotheses regarding imagination as a whole.