iv Effects of phonological complexity in different recall conditions There was no significant interaction between task and complexity Visual

inspection o f the mean number o f items correct to each task (see Table 5.3) shows very little difference between phonologically simple and complex lists on the SIPO task. There is an observable difference between recall o f simple and complex lists for the PISO task at T l and at T2, with a trend for more items in the simple lists to be recalled. For performance on the SISO task, there is less difference in recall between simple and complex lists at T l, and a greater difference in recall at T2.

At T l there is a trend for a greater effect o f complexity on recall in the PISO task, than for the SISO task. However, at T2 there is a trend for a greater effect o f complexity on recall in the SISO task, than the PISO task.

5.6

DISCUSSION

5.6.: Differences in Performance between STM Task Paradigms

The finding o f significant main effects o f task at both T l and T2 confirms the hypothesis that there will be differential performance on STM tasks that use different input and output mechanisms. This is in contrast to Adams and Gathercole (2000) who found that there was no difference in recall for STM tasks with spoken presentation and spoken or picture- pointing recall. But Lovatt et al. (2000) found better recall in the picture- pointing response condition than in the spoken response for adults.

Results reported here suggest that at age 4-5 years, if the list presentation is verbal, children find it easier to point to pictures in response rather than to say the words. Children find it more difficult to verbally recall lists presented pictorially, than lists presented verbally. At age 5-6 years, if the list presentation is verbal, children still find it easier to point to pictures in response rather than to say the words. However, they no longer find it more difficult to recall lists presented pictorially rather than verbally.

There are a number o f reasons why children may perform better on the task with spoken presentation and picture-pointing recall (SIPO). There is a greater possibility o f getting some or all o f the items correct by chance in the SIPO task, in that 4 out o f 6 or, 5 out o f 7 pictures presented are correct for each list. If a child is aware o f how many pictures they should select, and then randomly select that number o f pictures, they have quite a high chance o f selecting some or all o f the correct pictures. There would have been less o f a chance element if scoring was based on ordered recall, as was the case in Adams and Gathercole’s (2000) study. Secondly, the

pictures may well act as a reminder sufficient to activate a fading memory trace, and this cue is not present in the spoken recall condition.

The difference in performance between the SISO and the SIPO tasks requires some consideration. Both these tasks used a spoken presentation, so the speech input requirements were the same, it .is the recall mechanism that differs. Therefore, from a speech processing perspective, the difference in task performance suggests that speech output processing m ight constrain STM task performance in some way. This will be discussed more fully in Section 5.6.iii. However, the findings must be considered in the light o f the other advantages o f the picture-pointing response proposed above. A more stringent test o f whether or not the poorer performance on spoken recall was due to speech output constraints might include scoring for order o f recall, and / or presenting more distracter items for the picture-pointing response.

The relationship between performance on the two tasks with spoken recall changes over time. At age 4-5 years children recall more words with spoken presentation, than with pictorial presentation, however by the age o f 5-6 years, there is no difference in performance for these two presentations. One factor to consider, is that o f phonological recoding of picture material. As discussed in the literature review, there is some debate about the age at which children use the phonological loop to maintain picture material in STM. One interpretation o f these results is that at age 4- 5 years, the children are using different strategies to recall spoken and pictorial stimuli, but by 5-6 years o f age, a similar strategy is being used to recall both types o f material and so performance is much more similar. This suggests phonological recoding o f picture material is occurring by the

age o f 6 years, which is earlier than suggested by Hitch et al. (1989a, 1989c), but in line with findings o f Hulme et al. (1986) and Hitch et al. (1988)

In this study the children were not prevented from naming the pictures as they were presented, and in this respect was unlike the studies o f Hitch et al. (1989a, 1989c) and Longoni and Scalisi (1994). Observation was that some children did name some or all o f the pictures as they were presented. W hether or not children chose to do this might reflect individual differences in processing preferences and / or in developmental level. Some o f the children may have been ready to phonologically recode the picture material, and naming the pictures supported this process. Palmer (2000) reports individuals differences in age at which phonological re­ coding takes place, from the age o f 5 years in some children. Another factor to consider is that the response mechanism was spoken. Although Hitch et al. (1988) and Longoni and Scalisi (1994) argue that picture material may not be recoded until the point o f spoken output, in younger children, it is possible that the children recoded the pictures at input, recognising that this form would be needed for output. One way to address this would be in a study comparing picture presentation tasks with a spoken response and with a picture pointing response, to see if a spoken response was more likely to trigger phonological recoding and thus phonological similarity or word length effects.

Better performance for spoken rather than picture-pointing presentation at T l, and the lack o f a difference between spoken and pictorial presentation at T2, suggests that speech input processing skills may not play an important role in STM task performance.