Effects of imitating gestures during encoding or during retrieval of novel verbs on children's test performance
Research has shown that observing and imitating gestures can foster word learning and that imitation might be more beneficial than observation, which is in line with theories of Embodied Cognition. This study investigated when imitation of gestures is most effective, using a 2 x 2 x 2 x 3 mixed design with between-subjects factors Imitation during Encoding (IE; Yes/No) and Imitation during Retrieval (IR; Yes/No), and within-subjects factors Time of Testing (Immediate/Delayed) and Verb Type (Object manipulation/Locomotion/Abstract). Primary school children (N = 115) learned 15 novel verbs (five of each type). They were provided with a verbal definition and a video of the gesture. Depending on assigned condition, they additionally received no imitation instructions, instructions to imitate the gesture immediately (i.e., during encoding; IE), instructions to imitate (from memory) during the first posttest (i.e., during retrieval; IR), or both (IE-IR). Based on the literature, all three imitation conditions could be predicted to be more effective than no imitation. On an immediate and delayed posttest, only the object-manipulation verbs were differentially affected by instructional method, with IE and IR being more effective than no imitation on the immediate test; IE-IR and no imitation did not differ significantly. After a one week delay, only IR was more effective than no imitation, suggesting that imitation during retrieval is most effective for learning object-manipulation words.