Effect of Speed Manipulations on Phonological Short-Term Memory

Abstract

Temporal representation in the brain has been recently acknowledged as a fundamental mechanism underlying short-term memory (STM). Nonetheless, the existing body of research presents conflicting results on the extent of this relationship. Some studies propose that rhythmic disruption adversely affects perception and comprehension, and regular rhythm has been associated with the facilitative impact on STM tasks, while others suggest that its influence on STM tasks might not be as substantial. This thesis delves into rhythmic irregularity's impact on STM, particularly when an internally established rhythm is disrupted. Through two verbal STM tasks – the jabberwocky memory task and the Urdu memory task – conducted with thirty participants (31 females), involving the repetition of sentences in native English or foreign Urdu, this experiment investigates whether manipulating the speed of target sentences in relation to prime phrases affects the accuracy of sentence repetition in the assigned tasks. Our hypothesis posited that STM for sentences presented at altered speeds, either slower or faster, would be compromised compared to sentences at a normal pace. However, the outcomes of our study did not reveal any significant differences in repetition accuracy across the three speed conditions within the two STM tasks. Interestingly, our investigation uncovers two noteworthy findings. Firstly, variations in repetition accuracy among the three speed conditions appear to be influenced by participants' bilingual or multilingual backgrounds. Bilingual and multilingual individuals exhibited better performance under slow speed conditions at the syllable level, while monolingual participants displayed enhanced recall accuracy for whole words in the normal speed condition. Secondly, a discrepancy emerges between participants' self-perceived performance across the three speech conditions and their actual performance. These findings emphasize the potential roles of linguistic background and metacognition in shaping both temporal representation and STM performance, thereby prompting further exploration of these intricate interactions.