The shared theme of the chapters in this part is the topic of language and mind. The part develops and justifies a rationale for viewing speech-syn-chronized gestures as windows into the on-line processes of thinking and speaking.

The view through this window, we believe, is striking. Unlike the picture assumed through decades of psycholinguistics research – research focused on the inscribable aspects of speech – the speech–gesture window reveals a wider panorama. In addition to the analytic processes that are embodied in words and syntax, there is imagery. The principal concept that underlies part 2 is that the linguistic code and gesture imagery work together as a single system (a concept assumed in several of the part 1 chapters as well). Utterances possess two sides, only one of which is speech; the other is imagery, actional and visuo-spatial. To exclude the gesture side, as has been traditional, is tantamount to ignoring half of the message out of the brain. The chapters in this part describe ways to examine the full complexity of utterances in this wider framework.

The main difference of part 2 from the first is the approach, which here is that of cognitive psychology. The emphasis is on the mental processes in individual speakers and listeners. This ‘inside’ or process view does not conflict with the ‘outside’ or interaction view of part 1. Every researcher must pick some aspect of speech and gesture on which to focus attention. The terms ‘inside’ and ‘outside’ describe research approaches, not the phenomenon itself. We face a complex phenomenon with both its inside and outside aspects, and there are various routes to fathoming the relationships between them.