This chapter reviews the literature on comprehension of media-based presentations to develop mental models of physical systems. It examines the representations and cognitive processes involved in understanding media-based presentations, the abilities and skills on which this understanding depends, and the effectiveness of different media for communicating different types of content. In reviewing how people construct mental models from media, it considers how people learn about the structure and functioning of physical systems from visual-spatial representations alone, including static and animated diagrams, and later reviews how they learn from combinations of visual-spatial and verbal representations. Iconic static diagrams can be effective for communicating the static structure of a system and can also be the basis for mental animation. Traditional print media, that is, static diagrams accompanied by text, can provide highly effective external representations to aid the development of mental models of dynamic systems.

Dual coding theory proposes that abstract concepts are encoded and stored in memory in the form of symbolic or verbal representations, whereas concrete concepts are dually encoded into memory as both verbal representations and image codes grounded in perceptual experience. This chapter describes the three recent event-related functional magnetic resonance imaging (fMRI) experiments in which word imageability was manipulated during visual lexical decision, semantic decision, and word naming tasks. It attempts to resolve some of the inconsistencies in the imaging literature by using relatively large samples of participants and large numbers of items to ensure reliable activation patterns, by careful matching of concrete and abstract items on all possible nuisance variables, and by matching as closely as possible the task demands for the concrete and abstract conditions. The results were remarkably consistent across studies and provide clear support for some of the basic tenets of the dual-coding model.