Domain-specific working memory advantage in synaesthetes

Abstract

Synaesthesia is a phenomenon in which the perception of a distinct stimulus, called inducer-for instance a letter or sound-elicits a concurrent sensation, often a coloured experience. Past studies have shown better memory performance for synaesthetes compared to non-synaesthetes. Differences in the cognitive system, during encoding or retrieval in the domains of the inducer or the concurrent may explain this benefit. We tested four groups of synaesthetes (grapheme-colour, sound-colour, grapheme-and-sound-colour and sequence-space-synaesthetes) and four matched control groups. Participants completed a visually presented numeral working memory task. The results show a significantly higher performance of sequence-space-synaesthetes and a numerically higher performance of grapheme-colour-synaesthetes. This argues for a working memory advantage for stimuli of the domain that elicits the synaesthetic experience.