Language facilitates introspection: Verbal mind-wandering has privileged access to consciousness

- Relations between verbal working memory and mind-wandering awareness were studied.
- Self-caught mind-wandering was more verbal than probe-caught mind-wandering.
- Articulatory suppression decreased mind-wandering awareness.
- Verbal working memory priming increased mind-wandering awareness.
- Verbal vividness predicted mind-wandering awareness in a smartphone application study.

Introspection and language are the cognitive prides of humankind, but their interactions in healthy cognition remain unclear. Episodes of mind-wandering, where personal thoughts often go unnoticed for some time before being introspected, offer a unique opportunity to study the role of language in introspection. In this paper, we show that inner speech facilitates awareness of mind-wandering. In two experiments, we either interfered with verbal working memory, via articulatory suppression (Exp. 1), or entrained it, via presentation of verbal material (Exp. 2), and measured the resulting awareness of mind-wandering. Articulatory suppression decreased the likelihood to spontaneously notice mind-wandering, whereas verbal material increased retrospective awareness of mind-wandering. In addition, an ecological study using smartphones confirmed that inner speech vividness positively predicted mind-wandering awareness (Exp. 3). Together, these findings support the view that inner speech facilitates introspection of one's thoughts, and therefore provides empirical evidence for a positive relation between language and consciousness.