A new study provides direct experimental evidence that a brain region important for reading and word recognition contains neurons that are highly selective for individual real words.
The research, published by Cell Press in the April 30th issue of the journal Neuron, provides important insight into brain mechanisms associated with reading and may lead to a better understanding of reading disabilities.
The ability to read is a complex cognitive skill that is thought to depend on neural representations built as a result of experience with written words. "Although some theories of reading as well as some neuropsychological and experimental data have argued for the existence of a neural representation for whole real words, experimental evidence for such a representation has been elusive," explains senior study author Dr. Maximilian Riesenhuber from the Department of Neuroscience at the Georgetown University Medical Center.
Previous neuroimaging studies have identified an area in the left visual cortex, called the visual word form area (VWFA), as being important for reading words. However, thus far, scientists have not demonstrated that this brain region has a preference for real words when compared with pronounceable nonsense words, known as pseudowords (i.e. "farm" versus "tarm"). Dr. Riesenhuber and colleagues performed a series of experiments using a neuroimaging technique that allowed very sensitive examination of neuronal activity. Subjects were imaged while performing reading detection tasks using real words and pseudowords.