Interference From Additional Props in an Elicited Imitation Task: When in Sight, Firmly in Mind

A modified elicited imitation task was used to examine the development of the ability to resist and overcome interference in the 2nd and 3rd years of life. In the modified task, distractor props were included in the test array, so that children could imitate the modeled sequence but could also produce actions with the additional props provided, which was predicted to produce interference. Both experiments examined differences between 20-month-olds and 27-month-olds. In Experiment 1, the modified task was compared to the standard elicited imitation procedure; inclusion of distractor props was detrimental to performance, consistent with interference. However, younger and older children were equally affected by the manipulation. In Experiment 2, the task was made more difficult by adding more distractor props. Older children were better able to make use of cues to overcome interference. The effect of the distractor props was different when they were drawn from sequences that shared props with the test sequence. We speculate that this stems from differing demands on cognitive flexibility.