Reading and dyslexia

Jason D. Zevin, PhDAssistant Professor of Psychology in

Psychiatryjdz2001@med.cornell.edu

What is reading?

What can go wrong with reading?

What do we know about the brain basis of reading?

What is reading?

What can go wrong with reading?

What do we know about the brain basis of reading?

Let’s read some words out loud together. Just say them out loud as they come up on the screen…

HINT

MINT

PINT

HORS D’OEUVRES

What happened there?

There are (at least) two ways to read a word.

- You can figure out how it’s pronounced based on “rules.”

- You can remember how it’s pronounced because you’ve learned it before.

Coltheart et al., 2001, Psych Review

PINT

P as in PITI as in ITN as in NAPT as in TIE

is pronounced with a ‘long I’

A historically important model is based on more or less this intuition…

English is quirky

What is reading?

What can go wrong with reading?

What do we know about the brain basis of reading?

Marshall & Newcombe, 1973

PHASE -> FACEREAPPLY -> REPLYDEVOUR -> “DAVER”

(but also):GAUGE -> JUGGOAL -> GOLDLOGIC -> LUGUS

SICK -> ILLLARGE -> BIGBERRY -> GRAPES

(but also):SYMPATHY -> ORCHESTRARESIGN -> CROWNFREQUENT -> “um, something to do with trains, wagon train…SLOW” (?!)

Summary of a large number of cases by Crisp & Lambon Ralph, 2006

An alternative perspective…

Consider:

Phonological dyslexics typically have more general phonological problems.

Consider:

Woollams et al., 2010 (Psych Review)

There is a strong association between “exception word” reading and general semantic abilities.

What is reading?

What can go wrong with reading?

What do we know about the brain basis of reading?

Turkeltaub et al., 2002, meta-analysis of 11 studies

Richlan et al., 2009, Human Brain Mapping (meta-analysis of 17 studies of developmental dyslexia)

Some take-away points

Reading is complicated.* The brain is complicated.So it’s difficult to reverse-engineer cognitive processes from complex ramifications of brain lesions.

Luckily, we have brain imaging. (So we can see that really an awful lot of the brain is involved in reading.)

The puzzle is trying to fit our cognitive models (which work pretty well) together with what we know about the brain.

*So far we’ve mainly been talking about single words!!