Inner speech and the body error theory.
Frontiers in psychology January 1, 2024 DOI: 10.3389/fpsyg.2024.1360699 via PubMed
Summary
Inner speech, the experience of a voice inside the mind, may arise from a cross-modal illusion. The Body Error Theory (BET) proposes that subtle, confirmed activities in the speech musculature during inner speech combine with ordinary quiet nonverbal sounds—such as breathing or background noise—to create a mistaken perception of speech sounds. This illusion explains the 'voice within the mind' without requiring a suppressed copy of overt speech. The theory integrates with standard speech-monitoring accounts, accommodates insights from leading theories, and is supported by experience-sampling data. BET offers a testable alternative to existing explanations.
Study at a glance
| Characteristics | Theoretical or philosophical paper Peer reviewed |
|---|---|
| Keywords | Consciousness Cross-modal perception Illusionism Inner speech Speech monitoring |
| Citations | 3 |
| Key finding | Inner speech is a cross-modal illusion in which activities in the speech musculature mix with quiet nonverbal sounds to produce a mistaken perception of speech sounds. |
Abstract
Inner speech is commonly understood as the conscious experience of a voice within the mind. One recurrent theme in the scientific literature is that the phenomenon involves a representation of overt speech, for example, a representation of phonetic properties that result from a copy of speech instructions that were ultimately suppressed. I propose a larger picture that involves some embodied objects and their misperception. I call it "the Body Error Theory," or BET for short. BET is a form of illusionism, but the particular version I favor is a cross-modal illusion. Newly described here, my hypothesis is that the experience of inner speech arises from a mix of interoception and audition. Specifically, there is the detection of slight but well-confirmed activities in the speech musculature that occur during inner speech, which helps to transform representations of normal but quiet nonverbal sounds that inevitably occur during inner speech, from breathing to background noise, into a mistaken perception of inner speech. Simply put, activities in the speech musculature mix with sounds to create the appearance of speech sounds, which thus explains the "voice within the mind." I also show how BET's cross-modal system fits with standard information processing accounts for speech monitoring and how it accommodates the central insights of leading theories of inner speech. In addition, I show how BET is supported by data from experience-sampling surveys and how it can be empirically tested against its rivals.