On the 5th block the stimulus appeared randomly, with the following constraints: the stimulus appeared in each spatial location an equal number of times, and with an equal probability of transitions, as in the sequence blocks. After the 5th block had been completed, explicit knowledge of the sequence was assessed by asking children to recall the pattern. There were four recall trials. At the start of each trial the visual stimulus appeared. For Trial 1 in the first position of the sequence, for Trial 2 in the second position, for Trial 3 in the third position and for Trial 4 in the fourth position. Children were then asked to point

to the next nine locations they thought the visual stimulus would appear. We took a liberal approach by counting as correct MLN0128 chemical structure any correct response even if any prior positions were

incorrect. Using this approach, on none of the recall trials were either the SLI or TD children significantly above chance (i.e., above 2.5), nor did they differ significantly from each other. Children’s accuracy and RTs were both recorded. To control for within-subject variability in motor speed, each child’s RTs were converted to z-scores referenced to the median and SD across all correct trials for that child. Normalising data in this way effectively ensured that all children’s shortest RTs have approximately the same value, and similarly for their longest RTs. For Dasatinib molecular weight example, if the longest RT for one child was 5000 msec and longest for another was 1000 msec, after z-normalising the values for both children might be 5 (i.e., 5 SD above the median of their overall RTs). This approach has been previously used to examine differences between children and adults on SRT tasks (e.g., Thomas et al., 2004). Finally, we also addressed potential attention

lapses click here in this task. This was considered important since the task was long, with five blocks each of 90 trials (about 13 min). To deal with this concern, we deleted data points for each child whose RTs were 3 SD or more above his/her mean RT. The average mean number of data points deleted per child was 9.29 (SD = 3.087, Range: 1–17) for the TD group, and 9.35 (SD = 3.827, Range: 1–15) for the SLI group. This difference was not statistically significant [t (100) = .076, p = .940]. Thus removal of outliers did not significantly differentially affect one group. Children’s lexical abilities were assessed with the Expressive One-Word Picture Vocabulary Test (EOWPVT, Brownell, 2000a) and the Receptive One-Word Picture Vocabulary Test (ROWPVT, Brownell, 2000b). In the EOWPVT children are asked to name a presented picture. In the ROWPVT children are shown four pictures, and are asked to point to the one of four pictures that matches an orally presented target word. Each test comprises 170 items. Testing is discontinued if the child makes six errors within eight consecutive items.