When reading silently to ourselves, we often recognize the sound of our own voice reciting the content as we read, even though we’re not making any external sounds. This is referred to as internal monologue. The phenomenon also happens when we’re thinking, and though this is something that occurs in all people, very little is known about how this process works.
The current hypothesis is that inner monologue is controlled by a brain signal, called corollary discharge, that allows us to distinguish internal sensory experiences from external stimuli, and efferent copy, the function of the brain that plans and predicts movements and actions before they occur.
Though efferent copy is used for planning movements and actions, it’s possible that the same function allows us to make these predictive movements without following through--like when you’re reading to yourself, or thinking. The follow-through is where corollary discharge comes in, matching your inner dialog simultaneously with your external dialog, so that the voice in your head matches the sound coming out of your mouth and does not create an echo.
We also know that tiny muscular movements in the larynx accompany inner verbalization, which implies that internal monologue relies on similar biological mechanisms as speech. Beyond that, neuroscientists have found that the area of the brain known as Broca’s area is active both when we speak out loud and during inner speech.
Another way our internal monologue is used is in our conscience, a seemingly omnipotent voice that sways our opinions and actions to do what we believe is right. This can become an issue when someone’s conscience is encouraging them to do bad actions and believe that their inner voice is being influenced or is originating from outside their own mind.
By learning more about how this process works, neurologists hope to better understand certain pathological conditions, in which individuals tend to hear internal monologue in multiple voices, speculatively confusing them into believing the voices are originating from external forces.
Here at Plasticity Brain Centers, we believe that better understanding the inner workings of the brain, like efferent copy and inner monologue, can help to improve health and wellness in numerous aspects of life. To learn more about what we do at Plasticity Brain Centers, please contact us.