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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 ControllingSaccadic Eye Movements
Posterior parietal cortexDorsolateralPrefrontal cortex
SupplementaryEye Field
Frontal Eye Field
Cerebellum
Visual Cortex
BrainstemReticular 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
• 25-30 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 Task Anti-Saccade Task
Stimulus-response compatibility Stimulus-response incompatibility
Pro/Anti-Saccade Task
Munoz and Everling, Nature Reviews in Neuroscience 5 (2004) 218-228
Delay Pro- / Anti-Saccade Task
FP
T
Correct Response delay period
Timing Error
Direction Error
Direction and Timing Error
Preliminary ResultsCPRS
Conduct
Learn
ing
Psych
osom
atic
Impul-H
yper
Anxiet
y
Hyper
Index
0
25
50
75
100FASDControl* * * *
Behaviours
T-V
alu
es
Preliminary Results
WJ-III (age equiv)
Test 5 Test 6 Test16 Test 200
10
20OFF MedsON MedsControl
Tests
Ag
e E
qu
ival
ent
WJ-III (grade equiv)
Test 5 Test 6 Test 16 Test 200.0
2.5
5.0
7.5
10.0OFF MedsON MedsControl
Tests
Gra
de
Eq
uiv
alen
t
Preliminary Results
FASD Control0
1
2
3
4
p=0.7095
PRO Saccade % Error
Group
Per
cen
t W
ron
g
FASD Control0
100
200
300 *
p=0.0134
PRO Saccade Latency
GROUP
LA
TE
NC
Y (
mS
)
FASD Control0
5
10
15
20
25
p=0.0347
*
Express PRO Saccade
Group
Per
cen
t E
xpre
ss
N = 7 FASD and 10 Control Subjects
Preliminary Results
FASD Control0
10
20
30
p=0.0006
*ANTI Saccade % Error
Group
Per
cen
t W
ron
g
FASD Control0
50
100
150
200
250
300
350
400
450
p=0.0064
*ANTI Saccade Latency
Group
Lat
ency
(m
s)
FASD Control0
1
2
3
p=0.6765
Express ANTI Saccade
Group
Per
cen
t E
xpre
ss
N = 7 FASD and 10 Control Subjects
Preliminary Results
Direction Error
Control
FASD-O
FF Med
s
FASD-O
N Med
s0
2
4
6
8
p = 0.1831GROUP
PE
RC
EN
T O
F T
RIA
LS
Timing Error
Control
FASD-O
FF Med
s
FASD-O
N Med
s0
25
50
p = 0.1913GROUP
PE
RC
EN
T O
F T
RIA
LS
Preliminary Results
Correct Response
Control
FASD-O
FF Med
s
FASD-O
N Med
s0
10
20
30
40
50
60
p = 0.0219
*
Compared to Control*GROUP
PE
RC
EN
T O
F T
RIA
LS
Direction and Timing Error
Control
FASD-O
FF Med
s
FASD-O
N Med
s0
5
10
15
20
25
p = 0.0089
*
Compared to Control*GROUP
PE
RC
EN
T O
F T
RIA
LS
Acknowledgements
Courtney R. GreenDouglas Munoz, Ph.D.Dr. Sarah Nikkel, M.D.Dr. Brenda Stade, R.N., Ph.D
The Botterell Foundation, Queen’s University
