Inner Speech: Philosophical and Psychological Investigations

This project investigates philosophical and psychological aspects of “that little voice in our head”, or inner speech. Research on inner speech has been guided by the assumption that it is essentially a speech phenomenon. This dissertation argues against this assumption from three independent angles. In Chapter 2, I consider the idea that the content of inner speech is speech-specific. After arguing against this position, I go on to claim that the content of inner speech is vocalic. In Chapter 3, I examine models that treat inner speech as a prediction. I show that these models are problematic on both empirical and theoretical grounds. In their place, I argue for a model on which inner speech is treated as a goal state. In Chapter 4, I consider the popular idea that breakdowns in inner speech processing explain auditory verbal hallucination. I argue that inner speech-based explanations of AVH belong to a problematic class of psychological explanations, which confuse phenomenological and scientific understanding. My discussion of inner speech has implications for a wide range of topics, including metacognition, imagery, and the explanation of pathological mental states.