Status Updates From Reading in the Brain: The S...

there's an awful lot of pretty brain pictures so far

Why is it that humans are the only species to invent cultures such as reading, art, music, religion? He refers to neuroesthetics and neurotheology as possible disciplines. Humans have large frontal lobes with masses of neural connections. This makes it possible for humans (alone) to work within a neural workspace where modes can be combined and compared (conscious thought).

The 'what' pathway (ventral) makes mirror generalisations and does not distinguish left/right (b/d), but the 'how' pathway (dorsal), concerned with interaction with objects rather than recognising appearance) enables discrimination. Confusion over symmetrical letters is common with young children but a few dyslexic children have visual problems with placing words and letters spatially, in order.

Brains of dyslexics show abnormalities within the letterbox area present from before birth and linked to genetic factors. Dyslexics are likely to have difficulties in phonological processing, eg distinguishing sounds in words. There are more diagnoses of dyslexia in English speaking countries due to the spelling irregularities. Treatment possibilities are emerging - to use plasticity of brain to compensate/recycle.

Learning to read involves developing neurological connections and the 'letterbox area' converting letters to sounds. Children should be taught phonic correspondences not whole word recognition. This chapter contrasts whole word with phonics, but does not explore difficulties with English alphabet complexity, although Deheane accepts that English speakers take longer to learn to read because of this complexity.

First writing was pictographs which became simplified and used to denote simple sounds, eventually evolving into an alphabet. The human brain is suited to recognising the pared down pictures (in the letterbox area) and this leads to the efficiency of writing/reading. But written language retains its morphemic character as this reduces the memory task, and its phonemic irregularity dealing with homophones ambiguity.

Why is the 'letterbox' area 'chosen' to process letters and words? It is pre-disposed as its neurons are used to recognise repeated shapes essential for recognising objects. There is a hierarchy of neurons with links and overlaps - At the bottom, recognising simple lines etc. further up recognising more complex images, also inconsistencies (so inhibiting faulty recognition). This is recycled and used to read words.

The 'Brain's Letterbox' (left occipitotemporal) identifies the visual form of letter strings. If the word is regular it is 'passed' to the speech sound area, and if it is a real word is then passed to the meaning area (mental lexicon). If the word is not regular it goes to the meaning area and thence to the speech sound area. Hmm does this cover all bases? How/ at what point do we distinguish regular/ not regular?

Deheane describes some of the experiments that have shown the eye-movement process during reading then goes on to point out that we can isolate invariants in the printed or written words and process graphemes, syllables and morphemes. He compares the phonological and lexical routes in reading using various convincing arguments, drawing on features of English spelling to support the idea that both routes are used.

All I have to say is ... fascinating...

Love this book! Readable and understandable of how the brain reads and the evolutionary implications of our brains!