Inner voice missing? Your brain may be wired differently

You might assume everyone has an "inner voice," unless you don't have one. New research reported in Scientific American reveals striking variation in inner speech experiences. Participants were asked to rate how highly they agreed with "I think about problems in my mind in the form of a conversation with myself" on a one to five scale. Some people report an almost constant internal dialogue, while others describe a virtual absence of self-talk.

The study, by cognitive scientist Gary Lupyan and Johanne Nedergaard, demonstrates these differences have real cognitive impacts. Participants with less inner speech performed worse on verbal memory and rhyme judgment tasks. Intriguingly, speaking aloud seemed to compensate for lacking inner speech. (I wonder if this is why it is helpful for people to keep journals as a way to clarify issues they are contending with.)

The researchers propose the term "anendophasia" for a lack of inner speech. This mirrors the coining of "aphantasia" for those who lack visual mental imagery, which helped spur research and online communities around that phenomenon.

Some experts caution against labeling it as a condition. Charles Fernyhough argues, "I'd rather promote the message that diversity in inner experience should be our starting point—no two minds are the same."