Stability of human V1 retinotopy
measured with moving patterns
Junjie Liu
David Ress
Satoshi Nakadomari
Brian A. Wandell
Stanford University
V1 retinotopic organization
(Credit: J.C. Horton)
(deg)
Calcarine sulcus
Occipital pole
Human V1
Occipital pole
Calcarine sulcus
FMRI Measurement
Coherence
1.0
0.4
Eccentricity Map
20 deg
Occipital pole
From Science, 2003
Motion-dependent Responses
In
Time (sec)
Out0 12 24
· · ·
In vs. Out
We confirm data in Whitney et al.(Science, 2003).
But, these are merely responses to motion direction changes.
In Out
In Out
FM
RI
Sig
nal (
%)
Time (sec)0 12 24
0
-1
1
0
-1
1
Retinotopic representations
We measure:
In vs. Out does not measure retinotopic
representations.
In Blk In Blk · · ·
In vs. Blank
Retinotopic representations
We measure:
In vs. Out does not measure retinotopic
representations.
In Blk · · ·
In vs. Blank
Out
Time (sec)
Blk0 12 24
· · ·
Out vs. Blank
In Blk
Out Blk
No significant difference
Out vs. BlankIn vs. Blank
Coherence:1.00.4
Quantitative measurements (All voxels in V1)
In Blank
FM
RI
Sig
nal (
%)
Time (sec)
0
2
-2
-1
1
0 12 24
FMRI Amplitude: 2.1%
(Dougherty et al., 2003)
Distance measurement,Bins along calcarine
FM
RI A
mpl
itude
(%
)
Amplitude Profile
0 10 20 30 40 50
3
2
1
0
Cortical distance (mm)
In vs. Blank
posterior anterior
Stable retinotopic representations:
0 10 20 30 40 50
FM
RI A
mpl
itude
(%
)
3
2
1
0
Cortical distance (mm)
In vs. Blank
Out vs. Blank
“shift” model
0 10 20 30 40 50
FM
RI A
mpl
itude
(%
)
3
2
1
0
Cortical distance (mm)
In vs. Blank
Out vs. Blank
Shift
“edge” model
0 10 20 30 40 50
FM
RI A
mpl
itude
(%
)
3
2
1
0
Cortical distance (mm)
In vs. Blank
Out vs. Blank
Asymmetricaledge response
In vs. Out: Responses to motion direction
changes
0 10 20 30 40 50
FM
RI A
mpl
itude
(%
)
3
2
1
0
Cortical distance (mm)
In vs. Out
Three independent measurements
0 10 20 30 40 50
FM
RI A
mpl
itude
(%
)
3
2
1
0
Cortical distance (mm)
In vs. Blank
Out vs. Blank
In vs. Out
(In vs. Out) > (In vs. Blank) – (Out vs. Blank)
Responses to motion direction changes
Differences between retinotopic
representations
0 10 20 30 40 50
FM
RI A
mpl
itude
(%
)
1
0
Cortical distance (mm)
(In vs. Blank) – (Out vs. Blank)In vs. Out
Retinotopy is Stable
• We confirm the (In vs. Out) measurements.
• Additional measurements (e.g., In vs. Blank), show that retinotopic representations do not shift, or shift very little, with stimulus motion direction.
• Hence, this stimulus manipulation has negligible impact on estimated retinotopic maps.
Out vs. BlankIn vs. Blank
In vs. Out
Thank you!
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