Saccadic Eye Movements: A New Diagnostic Tool for FASD Research James N. Reynolds Department of Pharmacology & Toxicology, Centre for Neuroscience Studies, Queen’s University, Kingston, Ontario, Canada

Saccadic Eye Movements: Integration of activity across multiple neural circuits Executive Control: ability to control behaviour flexibly –Responding automatically to a stimulus in one set of circumstances –Suppressing the automatic response in favour of an alternative in a different situation

Saccadic Eye Movements: Developmental regulation of the ability to perform the anti- saccade task Young children (< 8 years of age) have difficulty suppressing the automatic pro-saccade –Not due to difficulty understanding the task Suppression ability develops gradually in school age children –Adult performance levels at around 18 years of age Attributed to protracted maturation of the frontal lobes into the second decade of life Improved inhibitory control over the saccade-generating circuitry (plasticity)

Multiple Brain Areas Involved in Controlling Saccadic Eye Movements Posterior parietal cortex Dorsolateral Prefrontal cortex Supplementary Eye Field Frontal Eye Field Cerebellum Visual Cortex Brainstem Reticular Formation Basal Ganglia Superior Colliculus

Fetal Alcohol Spectrum Disorders Neuropathological and/or functional deficits reported in brain structures involved in saccadic eye movements –Prefrontal cortex, caudate putamen, thalamus, cerebellum Neurobehavioural deficits in executive function –e.g., planning, response inhibition, abstract thinking, flexibility Hypothesis: Individuals diagnosed with FASD will have specific abnormalities that can be measured with eye movement testing

Pilot Study Children with a diagnosis of FASD –8-12 years of age, male and female Education History Medical History Family History Conners’ Parent Rating Scales Tower of London Woodcock-Johnson Tests for Visual Scanning Pro-saccade, Anti-saccade tasks

Pro-Saccade TaskAnti-Saccade Task Stimulus-response compatibilityStimulus-response incompatibility Pro/Anti-Saccade Task

Munoz and Everling, Nature Reviews in Neuroscience 5 (2004)

Delay Pro- / Anti-Saccade Task FP T Correct Response delay period Timing Error Direction Error Direction and Timing Error

Preliminary Results

N = 7 FASD and 10 Control Subjects

Preliminary Results N = 7 FASD and 10 Control Subjects

Preliminary Results

Acknowledgements Courtney R. Green Douglas Munoz, Ph.D. Dr. Sarah Nikkel, M.D. Dr. Brenda Stade, R.N., Ph.D The Botterell Foundation, Queen’s University