Reading in the Brain

Jakob Heinzle (Berlin) and Kevan Martin and K.H. (Zürich)

Outline

• Tutorial on the functional neuroanatomy of vision and eye-movements.

• Microcircuit model of the frontal eye fields.• Biologically realistic cortical model of eye

movement control in reading.• Work in progress.

Cortex (man, left hemisphere)

Cortex (macaque, left hemisphere)

Visual areas in the macaque cortex

Neurons in the feline primary visual cortex V1

Microcircuit in V1

Eye muscles and motoneuron

Descending pathways for saccades

Reading enlarges the language representation in the cortex

Eye movements during reading

FEF model for saccades

Complete network architecture

Interactions: B excitatory, A inhibitory

MathBox

Network activity for a visual saccade

More complex saccade tasks are successfully implemented

FEF model naturally incorporates reading

FEF model during reading

Implementation of the reading rule

Normal reading and word skipping

Reading statistics

Error statistics

• ?• ??• ???• Many unsolved problems: Language,

consiousness

Simplification in the world of text processing: Reading imbedded in sensorimotor actions

Question: what happens in the brain „behind the eye“during reading ?

Copy-Paste between a Pdf-file and a Powerpoint slide: Instructions

1. Click on the Adobe buttom. Go to the page containing Figure 1. Enlarge the image, by clicking on the arrow on the right of the white window and selecting 100%. Center the image.

2. Click on ‚Werkzeuge‘ on the second Adobe control bar. Move to ‚Auswählen und Zoomen‘ and follow the arrow into the context window down to ‚Schnappschuss-Werkzeug‘.

3. Move the cross of the pointer to the left upper corner of Figure 1. Press the left mouse buttom, move it to the right lower corner and let go.

4. Change to Powerpoint,by clicking on its control buttom. Point into the slide and type ‚Ctrl+V‘. Click into Figure 1 and center it in the content field. Type ‚Architecture of the FEF model‘ in the title field.

5. Click on ‚Neue Folie‘. Move to Adobe Click on the ‚Single Page‘ button on the upper control bar and go to the page containing Figure 2. Repeat the same steps, without having to change again into the ‚Schnappschuss-Werkzeug‘.

Nur jedem das Seine (BWV 163)

Nur jedem das Seine! Muss Obrigkeit haben Zoll, Steuern und Gaben, Man weigre sich nicht Der schuldigen Pflicht! Doch bleibet das Herze dem Höchsten alleine.

Gott soll allein mein Herze haben (BWV 169)

Stirb in mir, Welt und alle deine Liebe, Dass die Brust Sich auf Erden für und für In der Liebe Gottes übe; Stirb in mir, Hoffahrt, Reichtum, Augenlust, Ihr verworfnen Fleischestriebe!

Pointers

• J Heinzle, K Hepp, K Martin „A microcircuit model of the frontal eye fields“. J Neuroscience 27:9341 (2007). www.ini.uzh.ch/~jakob/code/FEF_Demo.zip

• J Heinzle, K Hepp, K Martin „A biologically realistic cortical model of eye movement control in reading“. Psychological Review 117:808 (2010). www.ini.uzh.ch/~jakob/code/FEF_READ.zip

• Folien: khepp@phys.ethz.ch