Does the Default Mode Network Mediate an Ongoing Internal Narrative? An Evaluation of Menon's (2023) Hypothesis.
Level 5 - mechanism / opinion, no new human data
Theoretical evaluation and narrative review with no new empirical data (CEBM Level 5).
PubMed 40554791 · doi:10.1162/JOCN.a.66
What was done
The author conceptually evaluated Menon's (2023) hypothesis proposing that the default mode network (DMN) functions to create an ongoing internal narrative that emerges developmentally from childhood self-directed overt speech. The evaluation examined the theoretical and empirical plausibility of this claim under two distinct definitions of an internal narrative: a narrow interpretation centered on inner speech and a broader interpretation centered on situation models.
What was found
The abstract reports no quantitative data or statistical analyses. The critique identified five major challenges to the narrow inner-speech interpretation: inner speech does not clearly derive from self-directed overt speech; inner speech frequency varies widely across individuals, contradicting a universally ongoing narrative; nonhuman animals possess a homologous DMN without possessing language or inner speech; inner speech is frequently condensed rather than a continuous narrative; and only a few neuroimaging studies show DMN activation during inner speech. The author argued that redefining the internal narrative as a coherent sequence of situation models influenced by, but not strictly reliant on, language resolves most of these challenges.
Why it matters
This evaluation refines a prominent unifying theory of DMN function by resolving conceptual contradictions between language-dependent inner speech and cross-species DMN architecture. It provides a clearer theoretical framework for future empirical investigations into the neurobiology of spontaneous thought.
Limits
The paper is entirely conceptual and presents no original empirical data, quantitative synthesis, or systematic search methodology. It evaluates competing functional interpretations of previous literature without directly testing the proposed situation-model framework.
Cited by
- supports The default mode network of the brain is associated with self-referential thought.