Our inner voice is not universal. How the absence of internal monologue influences language processing in the brain.
A study conducted by researchers from the University of Copenhagen in Denmark and the University of Wisconsin-Madison in the US introduces a term for the condition of lacking inner speech: anendophasia.
This term aligns closely with anauralia, introduced in 2021, which describes individuals unable to experience an inner voice or imagine auditory elements such as melodies or alarms.
For the study, 93 participants were selected, divided into two groups: one with minimal inner speech and the other with highly active internal monologues. These individuals completed various tasks, including remembering word sequences and matching rhyming words.
“A challenging task for all, but it was hypothesized that the absence of an inner voice would make it even harder since repeating words internally aids memory,”
explains Johanne Nedergård, a linguist at the University of Copenhagen.
The findings supported this hypothesis.
Participants reporting frequent inner voices during daily life performed significantly better in tasks compared to those without inner monologues. Inner speakers demonstrated greater accuracy in word recall and quicker responses when matching rhyming words, suggesting that internal dialogue may play a role in processing language.
Interestingly, when participants spoke aloud to solve problems, performance differences disappeared. This indicates that audible speech may serve as an effective alternative to inner speech in certain situations.
In tasks focused on multitasking and distinguishing shapes, no performance variations were observed. This finding suggests that the influence of inner speech on behavior might depend on the nature of the activity.
“Alternative strategies may be developed by individuals without inner voices. For instance, some participants mentioned tapping their index or middle fingers as task-specific cues.”
Johanne Nedergård
Researchers highlight that these differences do not appear to impact regular conversation. Current studies are in the early stages of exploring how conditions like anendophasia and anauralia might influence cognitive functions.
Preliminary research from the University of Auckland suggests that individuals with a “silent mind” retain verbal information similarly to those with typical auditory imagery. However, potential subtle differences remain unexplored.
One area of interest involves therapeutic practices such as cognitive behavioral therapy, which relies on altering thought patterns. The role of inner voices in facilitating or hindering such practices merits further investigation.
“The experiments revealing group differences primarily involved sound and self-hearing of words. Future research could explore whether this is due to the absence of auditory language processing or a lack of linguistic thought patterns altogether.”
Johanne Nedergård
https://doi.org/10.1177/09567976241243004
Abstract
It is commonly assumed that inner speech—the experience of thought as occurring in a natural language—is a human universal. Recent evidence, however, suggests that the experience of inner speech in adults varies from near constant to nonexistent. 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 adults who reported low levels of inner speech (N = 46) had lower performance on a verbal working memory task and more difficulty performing rhyme judgments compared with adults who reported high levels of inner speech (N = 47). Task-switching performance—previously linked to endogenous verbal cueing—and categorical effects on perceptual judgments were unrelated to differences in inner speech.
