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Sensory-motor integration. Bijan Pesaran May 1 st , 2008. Visual response in PMv centered on hand. Graziano and Gross (1994). Visual response in PMv centered on hand. Graziano and Gross (1994). Invariant visual response in VIP. Duhamel et al (1997). Duhamel et al (1997). - PowerPoint PPT Presentation
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Sensory-motor integration
Bijan Pesaran
May 1st, 2008
Visual response in PMv centered on hand
Graziano and Gross (1994)
Visual response in PMv centered on hand
Graziano and Gross (1994)
Duhamel et al (1997)
Invariant visual response in VIP
Duhamel et al (1997)
PRR neurons are eye-centered
Batista et al (1999)
Batista et al (1999)
Updating of response in PRR
Mechanisms for encoding multiple variables
• Centered tuning curve)(),( HTfTHf
Eye position influences visual response of 7a neurons
Andersen et al (1985)
Mechanisms for encoding multiple variables
• Centered tuning curve
• Multiplicative encoding - gain field)()(),( EThEgTEf
Tuning curveGain field
)(),( HTfTHf
Visual receptive fields in VIP partially shift with eye position
Avillac et al (2005)
Eye positions
Mechanisms for encoding multiple variables
• Centered tuning curve
• Multiplicative encoding - gain field
• Partial shift encoding – intermediate reference frame
)()(),( EThEgTEf
)()(),( EThEgTEf
Tuning curveGain field
)(),( ETfTEf
1
Eye position encoding
• Widespread phenomenon throughout visual and motor cortices
Peaked response
Eye leftEye middleEye right
Response
Target position
Eye position encoding
• Difficulty addressing flanking responses
Peaked response Flanking response
Eye leftEye middleEye right
Response
Target position
n
nnn ThEgTEf ),(
ThEgTEf )(),(
Gain model
n
nnn ThEgTEf ),(
ThEgTEf )(),(
Gain model
n
nnn ThEgTEf ),(
)(),( ETfTEf
Shifting model
Geometry of visually-guided reaching
• Eye-centered• Hand-centered• Relative position vectors
Nonlinear3D geometry and muscle dynamics
HH
TT
EE
T-ET-E
E-HE-H
H-EH-E
T-HT-H
Geometry of visually-guided reaching
Nonlinear3D geometry and muscle dynamics
HH
TT
EE
T-ET-E
E-HE-H
H-EH-E
T-HT-H
MIP PMdBatista et al (1999)Eye-centered
Graziano et al (1997)Hand-centered
PMv
What is code?
T-ET-E
T-HT-H
Pesaran et al(2006)
Decompose the 3-D response matrix
500
exp
1000exp1
1),,(
2ETEH
THEf
Distinguish between different reference frames
500
exp
1000exp1
1),,(
2HTEH
THEf
Define multiple effector reference frames
500exp
500exp
500exp),,(
222 EHHTETTHEf
Multiple reference frames
• Direct visuomotor transformation– Supports Area 5 data (Buneo et al 2002)
Direct Transformation
Serial TransformationHead-on-body
positionEye-in-head
position
Eye-centered
target location
Head-centered
target location
Body-centered
target location
Hand-centered
target location
Body-centeredhand position
+-
Motor output
Eye-centered
target location
Hand-centered
target location
Eye-centeredhand location
+- Nonlinear
3D geometry and muscle dynamics
Motor output
Nonlinear 3D geometry and muscle dynamics
MIP PMd
Nonlinear muscle
dynamics
Encoding relative position
Nonlinear 3D geometry and muscle dynamics
Batista et al 1999
Graziano et al 1997
H
T
E
T-E
E-H
H-E
T-H
PMv
• Coordinating the hand and the eye
• Eye-centered• Hand-centered• Relative hand-
eye position• Vectors in
abstract space
Design reference frame task
0 1 2
Start Cue DelayGo
Hold
Time (sec)
Design reference frame task
0 1 2
Start Cue DelayGo
Hold
Time (sec)
Design reference frame task
• Four initial eye positions
Design reference frame task
• Four initial eye and hand positions
Design reference frame task
• Four initial eye, hand and target positions• 111 PMd neurons and 48 MIP neurons
Example PMd neuron
Example MIP neuron
Sensory-motor transformations
Head-on-bodyposition
Eye-in-headposition
Eye-centered
target location
Head-centered
target location
Body-centered
target location
Hand-centered
target location
Body-centeredhand position
+-
Serial Transformation
+-
+-
Sensory-motor transformations
Eye-centeredhand location
Eye-centeredtarget location
Hand-centeredtarget location
-+
Direct Transformation
Buneo et al.(2002)
Sensory-motor transformations
Eye-centeredtarget location
Hand-centeredtarget location-
+
Relative position Transformations
Eye-centeredtarget location
Hand-centeredtarget location
-
+
Relative location of hand and eye
Eye-centeredhand location
Hand-centeredeye location
Relative position particularly useful for coordination
• Relative hand-eye position could be important for hand-eye coordination– Can map hand and eye onto each other– Computationally efficient
• No need to code for all combinations of locations
H
T
E
T-E
E-H
H-E
T-H
Relative position particularly useful for coordination
• Relative hand-eye position could be important for hand-eye coordination– Can map hand and eye onto each other– Computationally efficient
• No need to code for all combinations of locations
H
T
E
T-E
E-H
H-E
T-H
Relative position particularly useful for coordination
• Relative hand-eye position could be important for hand-eye coordination– Can map hand and eye onto each other– Computationally efficient
• No need to code for all combinations of locations
H
T
E
T-E
E-H
H-E
T-H
