Saturday, April 9

Hallucinations and verbal fluency - the same brain processes?

An interesting study in the context of my previous post on creativity and mental illness. Creative writers are very quick at making links and spotting interesting combination of words, and this research study suggests that verbal creativity and hallucinations may involve the same brain systems.

It is known that there is a relationship between schizotypy - people showing some of the same symptoms of schizophrenia - and creativity.  Tsakanikos and Claridge (2005) found that among college students, some signs of schizotypy such as hallucinations showed a correlation with increased levels of verbal fluency. Verbal fluency is tested by seeing how many words of a given category people can say in a limited time, e.g. how many words beginning with 'n'.

Brain areas involved in language
The most common type of hallucination that schizophrenic individuals experience is hearing imaginary voices.  Why does this happen?  The research suggests that overactivity in verbal regions of the brain could be responsible.  Brain cells 'fire' (send out an electrical impulse) when they receive a certain amount of stimulation. It could be that schizotype individuals and people who are creative share a key trait: their brains need less stimulation for the verbal areas to fire, leading to both verbal fluency and, sometimes, hallucinations.

As well as being interesting from a creative writing point of view, this kind of research aims to delve into the causes of schizophrenia, which is a major disorder that leads to the hospitalisation of hundreds of thousands of individuals. In evolutionary terms, it doesn't seem to make any sense for genes for schizophrenia to be passed on, as it is not a survival avantage. This can be explained if the same genes, perhaps in a slightly different combination, can give us very advantageous traits such as a powerful and responsive grasp of language.

Tsakanikos, E.  and Claridge, G. (2005). More words, less words: Verbal fluency as a function of ‘positive’ and ‘negative’ schizotypy.  Personality and Individual Differences, 39(4), 705-713.