The effects of modelling, local stimulus enhancement, and affordance demonstration on the production of object-directed actions in 6-month-old infants

The present study investigated whether local stimulus enhancement and the demonstration of objects' affordances - both of which are inherent in modelling of object-directed target actions - are themselves sufficient to evoke the target behaviour on imitation test trials. Six-month-old infants were presented with a puppet wearing a removable mitten and observed either a demonstration of mitten removal (modelling group), the experimenter pointing at the mitten (stimulus enhancement group), the mitten falling off apparently by itself (affordance demonstration group), or no specific action directed at the mitten (control group). For all infants, the puppet was next presented without any accompanying demonstrations and infants' mitten removal behaviours in the response period were recorded. The results showed that local stimulus enhancement and affordance demonstration were as effective as full modelling in evoking the target action. This finding shows that the performances of 6-month-old infants on imitation tests can be multiply determined and evoked by variables other than modelling of target behaviour.