As Gary Chevin watched his wife Carol reading a newspaper, he had a sudden realisation. Diagnosed as severely dyslexic at seven, he had always struggled to read.
Gary noticed that Carol was reading without moving her lips, which seemed odd to him as a dyslexic. 'She told me she was reading in her head,' says Gary. 'I asked what that sounded like and she said it was like a voice.
'I have never heard a voice in my head - ever. I was so shocked I nearly fell off my chair.'
Gary, 50, was stunned to learn that when 55-year-old Carol read a letter, she would hear the writer's voice, rather than her own, in her head - and that in her dreams, people spoke.
'It all seemed so alien to me. I have the reading age of a five-year-old so I never read. If I dream, I have visual dreams. They are always totally silent.'
Most people use their inner voice subconsciously. But for those who find they do not have one, it can be a revelation.
'I now understand my actions a lot more,' says Gary, a former builder from Stoke-on-Trent. 'I follow my emotions because I don't have a voice in my head analysing what I'm about to say or do.'
Professor Rod Nicolson, head of work psychology at the University of Sheffield, has been studying dyslexia for many years and was inspired to investigate internal speech after meeting Gary at a conference in 2004. He believes he has found a link between lack of inner speech and poor reading ability.
'Children start off having to say every word out loud,' he says. 'At some stage, as their reading improves, so does their ability to sight-read [to read in their heads] and that is the stage at which reading really takes off.
By the age of eight or nine, most children can read in their heads. The development of the inner voice seems to be automatic for most people, but our data suggests a link with fluent reading, in that the process of learning to sight-read actually helps inner-speech develop.
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