Do acting out verbs with dolls and comparison learning between scenes boost toddlers' verb comprehension?

To better understand how toddlers integrate multiple learning strategies to acquire verbs, we compared sensorimotor recruitment and comparison learning because both strategies are thought to boost children's access to scene-level information. For sensorimotor recruitment, we tested having toddlers use dolls as agents and compared this strategy with having toddlers observe another person enact verbs with dolls. For comparison learning, we compared providing pairs of: (a) training scenes in which animate objects with similar body-shapes maintained agent/patient roles with (b) scenes in which objects with dissimilar body-shapes switched agent/patient roles. Only comparison learning boosted verb comprehension.