For the second pair, we used a story

line that emphasized the substitution, by showing two puppets swapping location. In this story, first the experimenter took a puppet from the box and placed it on the top of the box, narrating, “He is calling a friend”. She then took a Ceritinib molecular weight second puppet out of her sleeve and proceeded to exchange the location of the two puppets: the puppet from the sleeve went to the box, and the puppet from the box went to the sleeve. In both events, the substitution puppet was strictly identical to the original puppet. Fig. 5 presents the findings. Children’s performance differed across conditions, as indicated by a significant interaction between the factors of Condition (identity vs. substitution) and Set Size (5 or 6 puppets), F (1, 22) = 4.5, p = .046, ηp2=.17. As in Experiment 1, children tested in the identity condition searched longer for a 6th puppet when the set contained 6 puppets, F (1, 11) = 8.1, p = .016, ηp2=.42. Thus, they were able to reconstruct the exact number of puppets over an intervening event that involved the removal and

return of one element of the set but preserved the identity of each element. In contrast, children did not modulate their searching time with set size in the substitution condition, F(1,11)<1,ηp2=.04. The findings of Experiment 4 provide evidence that children are able to preserve a one-to-one correspondence relation over events in which an http://www.selleckchem.com/products/MDV3100.html object is removed from and then returned to a set, an event that does not change either the set’s cardinal value or the identity of any of its members. This result confirms and extends the findings of Experiment

1, by showing that children are able to remember a one-to-one mapping between a large number of branches and puppets while attending to Org 27569 an intervening event. Indeed, the events presented in the identity condition were neither shorter nor simpler than those in the addition/subtraction conditions from Experiment 2; thus, children’s patterns of success and failure across conditions could not easily be related to the complexity of the intervening transformation. In contrast, children failed to use one-to-one correspondence relations to reconstruct a large set after a substitution event in which one puppet of the set was replaced by another puppet. Importantly, the identity and substitution transformations were equivalent in terms of numerical operations: one puppet exited the box, and later an identical-looking puppet entered the box. The children were nonetheless affected by the identity or distinctness of the puppets exiting and re-entering the box, i.e., whether a single individual participated in both transformations. These results provide strong evidence that the children were not processing the events numerically (in which case the two conditions would have been equivalent), and instead were registering individual objects.