Simple span task:

Children were presented with increasing lists of words (two to eight) with five trials at each list length. If children successfully remembered any one list in correct serial order from the five trials at a given list length they moved on to the next list length. If they failed to recall all lists within a given list length, testing was terminated at that point. Children were presented with a digital audio recording of words in a male voice and 3 cm high color illustrations of those words for 1,000 ms in the centre of the computer screen. A blank screen appeared briefly between each word. At the end of each trial, a cartoon character appeared alongside a question mark and children were prompted to recall the words in the order they had heard them.


Complex span task:

This task followed the span procedure used in the simple span task (with the same number of trials at each of the same list lengths, and the same continuation and stopping criteria), but using digits. Digits were presented in a male voice as digital audio recordings, simultaneously with the appearance of the item in black in the centre of the computer screen measuring approximately 2 cm high for 1,000 ms. Between each digit, children were presented with a large colored circle measuring around 4cm high (either brown, pink, or blue) in the centre of the computer screen and told to name the color of the circle as quickly as they could. As soon as the participant had named the circle the experimenter tapped the spacebar of the computer, and the computer moved on to another colored circle. This processing task automatically ended after 3,000 ms, regardless of the number of circles that the child had named in that time. The child was then presented with the next digit in the list. A cartoon character alongside a question mark appeared when the participant was required to begin recall, and they were told to recall the digits in the order they had heard them.


Free recall task:

Participants were presented with word lists spoken in a male voice ranging from 2 - 8 items in length, with five trials at each list length, giving a total of 35 trials. In contrast to the two span tasks just described, list lengths were pseudo-randomly organized in five testing blocks, so that list length was unknown to the child before presentation of any given list. Children were presented with a cartoon character and told that he had words for them to remember. The word lists were then presented with the character in the corner of the screen and a speech bubble coming from his mouth in the centre of the screen. An audio recording of each word simultaneous with a 3 cm high color illustration of the word was presented in the centre of the speech bubble for 1,000 ms, followed briefly by a blank screen and the next word. At the end of each trial, a question mark appeared above the characterÕs head, and children were asked to recall as many words as they could, in any order.


Interleaved lists task:

Children were introduced to two cartoon characters, SpongeBob and Patrick, who were identified by illustrations and two distinct male voices. They were explicitly told to pay attention to SpongeBob (i.e., focal stimuli) and try to remember his words in any order, and to try to ignore Patrick (non-focal items).  Four conditions corresponding to total list lengths 3, 4, 5, and 6 were presented. Focal items were always presented first in sequence, and focal and non-focal items were interleaved with one another, for example, the presentation order for a 3 item list was focal Ð non-focal Ð focal, with 2 focal items and 1 non-focal item (4 item lists had 2 focal items and 2 non-focal, 5 item lists had 3 focal items and 2 non-focal, and 6 item lists had 3 focal items and 3 non-focal). Items in each sequence were presented pictorially with a color cartoon image of the word, accompanied by an audio recording of one of two different male voices (one for SpongeBob and one for Patrick). SpongeBob always appeared on the left bottom corner of the screen and Patrick on the right. Images were presented in the center of the screen in a speech bubble originating from the relevant character's mouth, and were displayed for 1,000 ms, with a 250ms pause between each word. Children were only asked to recall focal items. There were five trials in each condition and these were all pseudo-randomly organized within five blocks, so that children did not anticipate list length. After presentation of each trial, SpongeBobÕs speech bubble reappeared in the centre of the screen, highlighted in red alongside SpongeBob, which signaled that the child should try to recall the focal words only. 


Split span task:

Children were presented with two cartoon characters, Charlie Cat and Danny Dog, which were identifiable by corresponding illustrations and two distinct male voices. In this task, six words were presented in each trial and the words were split between each character. The sub-set conditions were formed by the systematic manipulation of the two set lengths, giving conditions 5:1, 4:2, 3:3, 2:4, and 1:5, where the first digit corresponds to the number of items in Set A presented by Charlie Cat and the second to the number of items in Set B presented by Danny Dog.  Audio recordings of each word were presented simultaneously with 3 cm high color illustrations in the centre of the computer screen for 1,000 ms with the related character to the side of the screen (left for Charlie Ð Set A and right for Danny Ð Set B). After the word list had been presented, children were probed to recall either Charlie or Danny's words first by presentation of the relevant character on the screen. After this first probe, children were then probed for the remaining character's words with an image of that character on the screen. Children were told that they could recall words within a sub-set in any order. There were ten trials in each sub-set condition, with five trials probing recall of Set A first and five trials probing recall of Set B first, which resulted in a total of 50 trials.