Proceedings of the Annual Meeting of the Cognitive Science Society

It is commonly assumed that inner speech – the experience of thought as occurring in a natural language – is both universal and ubiquitous. Recent evidence, however, suggests that similar to other phenomenal experiences like visual imagery, the experience of inner speech varies between people, ranging from constant to non-existent. We propose a name for a lack of the experience of inner speech – anendophasia – and report four studies examining some of its behavioral consequences. We found that people who report low levels of inner speech have lower performance on a verbal working memory task and have more difficulty performing rhyme judgments based on images. Task switching performance, previously linked to endogenous verbal cueing, was unaffected by differences in inner speech. Studies of anendophasia, together with aphantasia, synesthesia, and differences in autobiographical memory are providing glimpses into what may be a large space of hitherto unexplored differences in people’s phenomenal experience.