| dc.description.abstract | This study employed the self-referencing task to investigate whether and in what way self-concept could be modified when an individual is being implicitly compared with his or her siblings. Each of the four experiments reported in this thesis comprised two study-test cycles. During the study phases, participants were presented with a series of adjectives, to each of which they had to judge whether it described themselves or another referent well. The participant’s sibling was designated as the companion referent in one of the two cycles and a friend that was of similar familiarity in the other cycle. In the following test phase, the participants’ memory of these adjectives was tested with an old/new recognition test (Experiments I), exclusion task (Experiment II), or free recall task (Experiments III and IV). The affirmation rates (i.e., the proportion of yes responses in the referencing task) and the memory performance were both analyzed with the factors of referent type (self vs. other) and consanguinity (sibling vs. friend).
Experiment 1 showed that the affirmation rate to self was higher in the sibling block than in the friend block, suggesting that the participants were more affirmative about their self-concept when the companion referent was their siblings in comparison to friends. A significant self-reference effect was also observed during the test phase as the adjectives that were referred to the participants themselves were better remembered than those that were referred to the participant’s siblings or friends. Moreover, the recognition memory performance was in general better in the friend block than in the sibling block. The mnemonic self-reference effects were however of equivalent magnitudes in the sibling and friend blocks.
The finding of a higher affirmation rate to the self in the sibling block than in the friend block was replicated in Experiment II. In addition, Experiment II employed the exclusion task and recorded event-related brain potentials (ERPs) to investigate whether the better memory performance in the friend block than in the sibling block resulted from retrieval processes such as retrieval orientation and strategic retrieval. A reliable retrieval orientation effect, indexed by the distinct ERP patterns between the correct rejection trials in the sibling and friend blocks, suggested that the retrieval cues were processed differently in these two blocks.
Experiment III employed the oddball paradigm to investigate mnemonic processes during the encoding phase contributed to better memory performance in the friend block than in the sibling block. In the study phase of both cycles, one-fourth of the adjectives were related to self and the other three-fourths were related to the non-self referent. The P300 and N400 waves elicited by the self and non-self referents were compared to examine the attentional resource allocation and semantic processing in the friend and sibling blocks. In addition, the adjusted ratio of clustering (ARC) score of the recall performance was employed to examine the memory organization in the sibling and friend blocks. The ERP analysis found a greater P300 effect in the sibling block compared to the friend block, suggesting greater attentional allocation when the companion referent was the sibling in comparison to friends. The ARC scores were statistically equivalent in the sibling and friend blocks, revealing no evidence that friends and siblings as different companion referents exerted effects on memory organization.
To ensure that the null result of the ARC analysis in Experiment 3 was not due to the different proportions of self and companion referents in the oddball paradigm, Experiment IV replicated the procedure of Experiment 3 with the modification that the ratio of self to companion referent was 1. In addition, the task difficulty was decreased by presenting four short study lists instead of two long lists. The results from both blocks still remained no difference which verified that the proportion did not influence the results from the previous experiment.
Across the four experiments, the self-evaluation was influenced by the siblings with consanguinity rather than friends. The self-reference effect was observed, while the memory advantage for friend block only exist in general memory but contained less details. Despite that there was no significant difference on memory performance between sibling and friend, neural physiological results suggested that there could be differences in the processes of judging adjectives and retrieval orientation. | en_US |