Auditory Imagery and the Phonological Loop

Abstract

The phonological loop is a component of working memory (WM) which supports the ability to maintain verbal information in consciousness through rehearsal. Auditory imagery has been tightly linked with subvocal rehearsal and use of the phonological loop, which is widely regarded as a universal feature of human cognition. However, it is known that individuals vary greatly in their experience of auditory imagery. Some individuals report a complete absence of auditory imagery (anauralia) and as a consequence may perceive the world – and their own mind – very differently. In this study we tested the hypothesis that anauralic individuals may employ distinct rehearsal strategies for maintaining verbal information in WM. Specifically, we hypothesised that anauralics may rely on WM representations that have weaker links with verbal sounds (i.e. phonology). This hypothesis predicts that anauralic participants will differ from controls, with respect to a number of well-described effects that have been interpreted in as demonstrating the role of sound- based representations in verbal WM. These include the phonological similarity effect (difficulty in rehearsing and remembering similar sounding words), the word-length effect (lower memory span for words that take longer to say), and effects of articulatory suppression (repeating a meaningless word out loud while simultaneously trying to remember a sequence). This poster will present preliminary results of a study comparing the working memory performance of 30 control participants with 6 individuals who have reported experiencing anauralia. Effects of phonological similarity, word length, and articulatory suppression effect were evaluated, to investigate possible links between auditory imagery and the phonological loop. The Crawford Bayesian method for single case comparisons was used to compare anauralic participants with controls. Contra hypothesi the verbal WM performance of anauralic participants was similar to that of the controls. That is, the verbal WM performance of anauralic participants and that of controls were both affected, and to a similar degree, by phonological similarity, word length and articulatory suppression. Nevertheless, anauralics may be more inclined to rehearse items using semantic, rather than phonological features, leading to errors such as recalling the word ‘taxi’ when the original word was ‘cab’. In future work, the performance of anauralic and control participants will be compared in a wider range of WM domains, including musical and numerical WM.