Charles Fernyhough

So, you know, talking to caregivers, other adults, other children, and gradually internalizing those conversations, they become conversations with the self.

Yeah, exactly.

That is the theory of a great Russian psychologist called Lev Vygotsky who was writing this stuff about 100 years ago.

His work has become increasingly influential in recent years and it's a really simple, neat little theory that nobody's got to the bottom of yet because it is so rich.

It has such implications for the way our minds work.

Well, as you'd expect, you see the language systems that we know about, mostly lateralized onto the left hemisphere.

A bit towards the front called Broca's area, which is often involved in producing complex action patterns.

A bit further back called Wernicke's area, which is responsible for processing speech, including speech from other people.

Those two areas create a kind of resonating loop, which always shows up when we ask people to speak to themselves or out loud in the scanner.

These days, it's going to be an MRI scanner when we're doing fMRI research on the topic.

So we see those systems lighting up.

But I mean, that bit of the front broker's area lights up when we do a whole load of different things.

So we can't really pin too much onto that.

So we know it's important, but it's not the whole story.

So one of the things that we've argued, if inner speech comes from a dialogue with other people, it should have the structure of a dialogue.

In order to do that, your language system has got to be working, all that stuff on the left hemisphere that you'd expect to be working, but some other stuff must be going on as well.

Yeah, and what we find when we look at people doing dialogic inner speech, as opposed to something that's more like a single line of conversation, is that yes, you get that language system in the left hemisphere firing,

But you also get another region way on the other side of the brain, which we know from previous research is involved in representing other people's minds.

So you're representing yourself as a partner in that conversation.

The cool thing about working with Russ was that we had a study where we got people used to using descriptive experience sampling.