The neural basis of idiom processing: neuropsychological and neurophysiological evidence

In this paper we review the neuropsychological, neurophysiological and neuroimaging literature on the neural basis of idiom comprehension. We will present the first studies from the seventies to the nineties in 1900, which focused on the role of the right hemisphere only, and then we will move to the more recent research which provides evidence that both hemispheres, especially the left, are involved and that semantic and syntactic analyses are required in order to process idioms. The critical neural structures seem to be the left temporal and the bilateral prefrontal regions. Crucially, we will also show that the patients’ selection criteria, the type of task and the type of idiom are relevant variables in determining the results. Finally, we suggest a possible anatomo-functional model in order to explain how idiomatic strings are processed in the brain