Title: As I sow, so shall you reap
Description: Gesture researchers have focused on how gestures benefit learning. For example, data have shown that the usage of gestures during conversation can enhance concept acquisition and language learning in children. An instructor's gestures also benefit students' learning. For example, by providing gestures that contain semantic value, students remember more and attain deeper understanding of a concept. However, few studies have attempted to find out the function of gestures in learning: how information in a speaker's gestures is represented and constructed in a listener's mind. The present study targets learning of STEM concepts, especially the structure and the behavior of complex systems. It was expected that certain gestures prime a specific type of knowledge. For example, iconic gestures with structure knowledge of a concept facilitate learning of structures of a given concept and action gestures facilitate learning of movements, especially causal relation of the concept. This study also explored the relation between gestures delivered by a speaker and gestures constructed by a listener; in particular, if provided gestures contribute to constructing and representing a listener's knowledge and how it is manifested by learners' explanations.

Participants were randomly assigned to either an action gesture group that watched an instructional video based on action gestures, or to a structure gesture group that watched an instructional video based on structure gestures. The instructional video was about how a four stroke engine works. Except for a type of gestures that a speaker used, both videos were identical in all conditions. Participants were told that after watching the video they would explain a concept in the video to a colleague coming later, therefore a video camera would record their explanation, and the colleague would learn the concept from watching the video that they created. The participants watched the instructional video, and then they were asked to answer questions that were created based on a speaker's verbal script. This was followed by a drawing test, which asked them to draw how a four stroke engine works based on the video that they watched. Findings showed that action gestures facilitated action knowledge of the concept and were more involved in creating a mental representation of the concept based on action.

Also, the structure group represented the concept based on structure. The findings were confirmed by analyzing the participants' gestures and speech showing that the action group used more action gestures and action information units in their explanation and the structure group delivered reliably more structure gestures and structure information units. It was assumed that the mental model of the concept that the action group was harboring was based on action and the structure group was harboring was based on structure of the concept. The knowledge representations that the participants showed corresponded to the type of knowledge within the speaker's gestures in the instructional video that they watched. The results imply that listeners' knowledge is grounded in a speaker's gestures and this relationship depends on gesture type. More specifically, information in gestures is processed and becomes listeners' knowledge based on an attribute that the speaker's gesture has, and speech and gesture work together to manifest this phenomenon.