eli5 How is it that we can “read in our head” or not talk outloud but still hear our voice?


eli5 How is it that we can “read in our head” or not talk outloud but still hear our voice?

In: Biology

Can you rephrase your question or possibly expand on it? Struggling to understand what you are asking.

It’s called an internal monologue and not everyone experiences it as a voice in their head. How often one experiences this voice going on in their head varies amongst the population that has it as well. Overall, it’s the mind’s way of aiding in decision making and taking in new information

Your internal voice is your brain forming the motorplan for saying those words. That’s why your internal voice can be in a particular language or have a particular accent etc.

One evolutionary hypothesis is that early on parts of our brain were very disconnected and couldn’t directly communicate with one another and so we’d have to speak out loud to indirectly transfer information from one part of the brain to the other. For example, if you hid food somewhere, you might need to say out loud where you hid it so that information could get from your memory to the decision making part of your brain when you went looking for that food again. Eventually this process got moved “indoors” to a shared common mental workspace which all parts of our brain have access to. This shared common mental workspace is how different parts of the brain can “globally broadcast” content or information to all other parts of the brain which they may not be directly connected to.

There is strong reason to think this shared common workspace where information becomes available to all parts of the brain can only involve sensory content (e.g. tastes, sounds, feelings, images). So for you to send information to this global mental workspace you have to send it in the form of the mental plan for speaking the information so that the sounds of you speaking it can appear in this common mental workspace. For example, I can’t just send my belief that the Earth is spherical to the shared mental workspace because a belief isn’t sensory. If I need my belief that the Earth is spherical in my shared mental workspace I can only get it there via the sensory experience of me saying internally “I believe the Earth is spherical” which I produce via forming a motor plan regarding how to speak that sentence. So we are still sharing information between different parts of the brain by speaking them, but no longer out loud. In some sense, we just cut out the “out loud” part and go directly from the motor plan for how to speak it to the same sensory content we get from hearing that sentence then appearing in our shared mental workspace without having to actually hear ourselves saying the sentence out loud.

Fun Fact: languages which have shorter to pronounce numerals enable speakers to do math quicker in their head than languages with longer to pronounce numerals. When you do mental math, you are literally having to internally say the numerals and so longer to pronounce numerals slow down your ability to do mental math.