Análisis de daño residual

Performance of the 4- and 5-year-olds on self-regulation and set shifting did not produce evidence for the hypothesis that external verbal input with variations in certainty produced by language specific markers would vary in their cognitive salience and lead to performance differences on these cognitive measures. There are several possible explanations for the non-significant results. First, it seems plausible that a cognitive salience of tests might be on core dimensions rather than children’s ability to appreciate others’ epistemic states for their behaviour. It seems that once children recognized the rules of the tasks based on dimensions (i.e., shape or colour in DCCS and day or night in Day/Night), differential emphasis on verbs for subsequent action might not be salient. In other words, it is

conceivable that prepotent information to perform such tasks might consist in labels. There is evidence that children’s performance can be improved when reducing cognitive requirements by such as manipulating responses of labels for the Day/Night task (e.g., Diamond, Kirkham, & Amso, 2002; Montgomery, Anderson, & Uhl, 2008; Simpson & Riggs, 2005b; Simpson et al., 2012) or by identifying cards in the DCCS task (e.g., Kirkham et al., 2003; Towse, Redbond, Houston-Price, & Cook, 2000). The ability to inhibit incorrect responses (i.e., saying correct labels) is a key factor to perform the task such as Day/Night successfully. For example, Simpson and colleagues (Simpson & Riggs, 2005b; Simpson et al., 2012) found

that when labelling responses (e.g., saying ‘dog’ for a day card and ‘pig’ for a night card) were not related to the stimuli (e.g., day and night cards), the inhibitory demands were lessened and this led to children’s improved ability to suppress predominant responses. The research seems to suggest that the capacity of inhibitory control evaluated by Day/Night may be relied on the relationships between responses and the stimuli. Hence, it seems possible that external verbal input for modulating behaviour might be overrode by the condition used in the present study which maintained the response-stimuli association that is salient.

Similarly, Towse et al. (2000) found that increased salience of the post-switch dimension in the DCCS task by asking children to identify the rule led to success in sorting cards. In their Experiment 4, 3-year-old children who failed the post-switch phase were given a knowledge question about salient features of the trials (e.g., “Is it a red or green card?”), and then they were asked to sort cards according to the rule of the post-switch phase. Towse et al. found that approximately one third children who previously failed were able to sort cards after they self-labelled the dimension of the post-switch trials. In line with findings from the research with the Day/Night test, studies using the DCCS task also seem to suggest that features of cards may be cognitively salient. Taken together, it appears that dissociation between responses and stimuli or highlighting features of cards may be crucial for improving inhibitory ability. Thus, if this were the case, expressions describing motor inhibition (i.e., do or must do) may have mere or no effects on changing cognitive salience in performing either the Day/Night or the DCCS tasks.

Another possible explanation is that influences of language (i.e., verbalization) on executive control might be dependent on the developmental levels. In other words, as stated in Chapter One, it is conceivable that the role of external verbal input might remain at an early age. According to the early developmental pattern of self-regulation by Kopp (1982), language functions as a mediator in relation to age relevant behaviours. Infants begin to

respond the external verbal input such as a caregiver’s signal at between 9- and 12-months. There is a shift in the directive role of language after the period. That is, reactions to external commands from adults are shown in the second year and children’s regulation progresses to responses to their own speech at 3- and 4-years. It is more likely that the origin of control at the preschool period is from children themselves rather than from influences of others. Indeed, research has shown the role of children’s own speech on self-regulation (e.g., Fernyhough & Fradley, 2005; Winsler, Abar, Feder, Schunn, & Rubio, 2007; Winsler, Manfra, & Diaz, 2007). For example, Fernyhough and Fradley (2005) conducted research on whether children’s overt speech has a supportive role in executing a task which requires cognitive effort. In their study, 5-6-year-olds were asked to solve the Tower of London task in which wooden balls were set into three pegs with different lengths by moving the balls to make certain configurations (see Shallice, 1982 for Tower of London). Utterances the children made during the task were analysed in order to explore the relations between task performance and speech. Fernyhough and Fradley found that children who uttered overt task-relevant speech were more likely to perform the minimum number of moves to make the tower of balls, suggesting that a person’s own speech has an adaptive function for goal-directed behaviours. This role of self-speech (more likely subvocal speech) in regulating one’s behaviour is also observed in adulthood (e.g., Baddeley, Chincotta, & Adlam, 2001; Emerson & Miyake, 2003; Kray, Eber, &

Lindenberger, 2004; Miyake, Emerson, Padilla, & Ahn, 2004). The evidence reviewed above seems to indicate that there is an age-related change in terms of effects of verbalization on performing executive function. It appears that speech plays a role in self-regulation but internal speech rather than external input may critically influence cognitive process after preschool age onward. Therefore, the linguistic markers used by the experimenter might not have made differences in the preschoolers’ performance in the present study.

terms might be comparable. Instructions given by the experimenter to perform the tasks by either –ya hata (must do) or –hata (do) might be equivalent in terms of quality. According to Grice (1975), the maxim of quality is that: (1) do not say what you believe to be false (2) do not say that for which you lack adequate evidence. That is, it seems possible that according to this cooperative principle and as there was no negation in the instructions, children would expect that the statements from the experimenter would be true. In addition, according to Palmer (1986) a declarative sentence conveys beliefs. It is conceivable that children might regard that the experimenter expressed her true belief in informing what they should perform in the tasks. Therefore, the deontic expression might not induce a special effect. Consequently, the lack of an influence of external verbal input used here on executive function might have been resulted from the structural aspects of the tasks carried out along with children’s development of self-regulation in the preschool age.

So far, this section discussed the possibility of non-significant effects of linguistic markers. Taken explanations from the previous study together, there can be several reasons for the findings such as the nature of the executive measures, subtle differences of the linguistic markers, or cultural practice. However, it seems to be difficult to determine a critical factor. As the two experiments did not find the effects of language, no further research was conducted regarding linguistic manipulation in the test question for executive function measures. However, executive function was employed again in order to explore its role on social understanding, in particular selective trust in Chapter Six.

3.4.3. Performance on executive function and its links to social understanding