Ziyad A. Makoshi Medical Student, MBBS Undergraduate King Khaled University Hospital King Saud...
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Transcript of Ziyad A. Makoshi Medical Student, MBBS Undergraduate King Khaled University Hospital King Saud...
Ziyad A. MakoshiMedical Student, MBBS Undergraduate
King Khaled University HospitalKing Saud University, KSA
What is Movement? Balance? Posture?
Frontal Lobe
Parietal Lobe
Secondary Motor Cortex
Initiating
Planning
Primary Motor Cortex
“The human brain, then, is the most complicated
organization of matter that we know” – Issac A.
MOVEMENT
THE EFFERENCE COPY
F o r w a r d
Supplementary Motor Area
Primary Motor Cortex
Musculoskeletal
System
Efference Copy
M o v e m e n t
Motor Command
1
2
3
Planning
Initiating
Directing
MODEl
SMA PMC Muscles (Movement)
Efference
Copy
Motor Comma
nd& other
areas
Transcranial Magnetic Stimulation (TMS)
Hypothesis
SMA plays a significant role in anticipatory motor planning.
Questions
Does this occur? At what time?
The Experiment
Tynan ^_^
Auditory cue
Infrared sensor
Platform
Release button
Chin rest
Mass
Press button
Platform falls
Arm displaced downwards
Infrared cameras measure amplitude of displacement
Conditions
TMS SITE
Control SiteOccipital lobe
SMA Site
PLATFORM
Experimenter (Passive)
Subject (Active)Subject does not
anticipate the fallBaseline
Subject anticipates the fallAmplitude should be less
First 20 blocks
(no TMS)
Second 70 blocks
(TMS)
I II
Variables
Cue
Platform (RT)
TMS
0 ms
Amplitude
TMS Delay (ms)
0 50 100 150 200 250 300
-5
-4
-3
-2
-1
0
1
2
3
4
5V1
SMA
Cha
nge
in A
mpl
itude
(cm
)
Active (w/o TMS)
Passive
Results
Cue
TMS
0 ms
Amplitude
100 ms
X axis
Y axis
TMS - RT Delay (ms)
0100200300400500600
Cha
nge
in A
mpl
itude
(cm
)
-5
-4
-3
-2
-1
0
1
2
3
4
5
V1SMA
Passive
Active (w/o TMS)
*
*
Results (Cont.)
Cue
TMS
200 ms
Amplitude
100 ms
X axis
Y axis
Platform (RT)
Conclusion
Taken together, our results show that the SMA plays an important role in forming and/or using an efference copy during anticipatory motor planning.
The fact that the effects of TMS were largest at the earliest stimulation times indicates that the SMA makes its contribution to this process well before (i.e., 400-500ms) movement onset.
Future Studies
Focus on the earlier time in the
planning process when the
effect of TMS was most obvious.
Develop a task to better
establish the occurrence of an
efference copy.
Research other areas that might
contribute to efference copy.
cknowledgmentsA
Dr. Paul van
Donkelaar &his lab ,
Robert, Tynan.
SPUR , Dr. Peter
O’Day, &Chelsie Fish
SPUR Interns
University of Oregon
Thank You