The best coverage of the story comes from The Sun [link now defunct]:
THE majority of people simply have a brain inside their bonce.
But not KYLIE MINOGUE.
The Aussie pop Princess manages to keep a whole committee inside her 39-year-old cranium.
She has so many conversations with said committee that she sometimes thinks she’s been speaking to friends and family.
A Kylie committee spokesperson (Kylie) said: “It’s not about having two different personalities – it’s about having a whole committee in your head.
“It’s about having this discussion with the committee about something really important, and assuming it took place for real.
“Like, recently, I was telling my friend William Baker about my next tour and what we’re going to be doing on it, and he was looking at me, like, ‘What tour, when?’
Quite a lot of research has been done on the properties of inner speech. Some from a rapid search:
- Oppenheim and Dell (2008) [Inner speech slips exhibit lexical bias, but not the phonemic similarity effect. Cognition, 106, 528-537] asked participants to remember and recite tongue twisters. They found lexical bias (making word over nonword errors) in both overt and inner speech; a phonemic similarity effect (misproducing words with similar phonemes) in overt speech; but no phonemic similarity effect in inner speech. The latter effect was detected by allowing participants to report when they had mispronounced a word, indicating that their inner speech has successfully reproduced it.
- People with autism spectrum conditions use inner speech to the same extent as neurotypicals (Williams, Happé & Jarrold, 2008 [Intact inner speech use in autism spectrum disorder: evidence from a short-term memory task, Journal of Child Psychology and Psychiatry 49 (1), 51–58]).
- In tests of multitasking it has been found that doing two tasks, A and B, in an order something like ABABAB… results in slower reaction times and more errors than if you do something like AAA…BBB…. Disrupting inner speech increases the switch cost for the former pattern (Emerson & Miyake, 2003 [The role of inner speech in task switching: A dual-task investigation, Journal of Memory and Language, 48, 148-168]).
- McGuire, Silbersweig, Murray, David, Frackowiak and Frith (1996) [Functional anatomy of inner speech and auditory verbal imagery, Psychological Medicine 26, 29-38.] examined neural correlates of inner speech and imagining someone else speaking. Inner speech was associated with increased neural activity in the left inferior frontal gyrus; imagining speech showed activity in the same area, the left premotor area, and left temporal cortex.
What I really want is a collection of self-reports of people’s inner speech and results from batteries of cognitive tests. No doubt out there somewhere. Has to be as entertaining to read as hippies’ descriptions of their experiences with hallucinogenics.