Inner speech speaks volumes about the brain

Whether you’re reading the paper or thinking through your schedule for the day, chances are that you’re hearing yourself speak even if you’re not saying words out loud. This internal speech — the monologue you “hear” inside your head — is a ubiquitous but largely unexamined phenomenon. A new study looks at a possible brain mechanism that could explain how we hear this inner voice in the absence of actual sound.

In two experiments, researcher Mark Scott of the University of British Columbia found evidence that a brain signal called corollary discharge — a signal that helps us distinguish the sensory experiences we produce ourselves from those produced by external stimuli — plays an important role in our experiences of internal speech.

The findings from the two experiments are published in Psychological Science, a journal of the Association for Psychological Science.

Corollary discharge is a kind of predictive signal generated by the brain that helps to explain, for example, why other people can tickle us but we can’t tickle ourselves. The signal predicts our own movements and effectively cancels out the tickle sensation.

And the same mechanism plays a role in how our auditory system processes speech. When we speak, an internal copy of the sound of our voice is generated in parallel with the external sound we hear.

"We spend a lot of time speaking and that can swamp our auditory system, making it difficult for us to hear other sounds when we are speaking," Scott explains. "By attenuating the impact our own voice has on our hearing — using the ‘corollary discharge’ prediction — our hearing can remain sensitive to other sounds."

Scott speculated that the internal copy of our voice produced by corollary discharge can be generated even when there isn’t any external sound, meaning that the sound we hear when we talk inside our heads is actually the internal prediction of the sound of our own voice.

If corollary discharge does in fact underlie our experiences of inner speech, he hypothesized, then the sensory information coming from the outside world should be cancelled out by the internal copy produced by our brains if the two sets of information match, just like when we try to tickle ourselves.

And this is precisely what the data showed. The impact of an external sound was significantly reduced when participants said a syllable in their heads that matched the external sound. Their performance was not significantly affected, however, when the syllable they said in their head didn’t match the one they heard.

These findings provide evidence that internal speech makes use of a system that is primarily involved in processing external speech, and may help shed light on certain pathological conditions.

"This work is important because this theory of internal speech is closely related to theories of the auditory hallucinations associated with schizophrenia," Scott concludes.


  1. andreno reblogged this from neuromorphogenesis
  2. r3dvader-the-starlord reblogged this from neuromorphogenesis
  3. bridgetlikeschicken reblogged this from neuromorphogenesis
  4. ch1cken-b0nes reblogged this from spacetimecontinumm
  5. privatefears-publicplaces reblogged this from we-are-star-stuff
  6. ownapieceofmyheart reblogged this from foreverxxinfinite
  7. foreverxxinfinite reblogged this from speedinglove
  8. ellaeracomolaluna reblogged this from stilljiiggy
  9. speedinglove reblogged this from hesgreatness
  10. hesgreatness reblogged this from beautifulrainnn
  11. beautifulrainnn reblogged this from stilljiiggy
  12. ccacao reblogged this from stilljiiggy
  13. cassandy88 reblogged this from stilljiiggy
  14. lyssyloo reblogged this from we-are-star-stuff
  15. vermilionredamancy reblogged this from mentalalchemy and added:
    Inner speech speaks volumes about the brain Whether you’re reading the paper or thinking through your schedule for the...
  16. curiousmiles reblogged this from smilingendlessly
  17. lil-spoopy-lea-f reblogged this from moderatelyinterestingweirdo
  18. compassneedles reblogged this from we-are-star-stuff
  19. cosibabooks reblogged this from nakederasmus and added:
    They say your reading speed drops way down when you can hear the inner voice say all the words on the page; but I’ve...
  20. hippie-hieroglyphics reblogged this from the36thchamberofshaolinnegro
  21. the36thchamberofshaolinnegro reblogged this from negro-stein
  22. purpleblove reblogged this from liquid-fingerprints
  23. heycgcb reblogged this from ah-thenah
  24. kiteenee reblogged this from ah-thenah
  25. inobgirl reblogged this from ah-thenah and added:
  26. ah-thenah reblogged this from decadentscience
  27. jesstharuthless reblogged this from stilljiiggy
  28. negro-stein reblogged this from paradoxicalparadigms
  29. bozonkwark reblogged this from neuromorphogenesis
  30. mattyblazeright reblogged this from stilljiiggy