Comment by infinite_spin

I'm very reluctant to believe people when they say they don't have an internal monologue. Studies on the matter all appear to rely on self-reported data, not objective measurements. It's been shown that electromyography can be used to measure myoelectric signals produced when a person subvocalizes their speech (i.e. an inner monologue). It works well enough to reconstruct and synthesize that speech.

So we could test this objectively, and I'm not sure why we haven't.