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Stability of human V1 retinotopy measured with moving patterns. Junjie Liu David Ress Satoshi Nakadomari Brian A. Wandell. Stanford University. V1 retinotopic organization. Calcarine sulcus. (deg). Occipital pole. (Credit: J.C. Horton). Human V1. Calcarine sulcus. Occipital pole.
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Stability of human V1 retinotopy measured with moving patterns Junjie Liu David Ress Satoshi Nakadomari Brian A. Wandell Stanford University
V1 retinotopic organization Calcarine sulcus (deg) Occipital pole (Credit: J.C. Horton)
Human V1 Calcarine sulcus Occipital pole
FMRI Measurement Coherence 1.0 0.4
Eccentricity Map 20 deg Occipital pole
In Out We confirm data in Whitney et al.(Science, 2003). 1 0 -1 FMRI Signal (%) 1 But, these are merely responses to motion direction changes. 0 -1 0 12 24 Time (sec) Motion-dependent Responses In vs. Out · · · In Out In Out 0 12 24 Time (sec)
Retinotopic representations In vs.Out does not measure retinotopic representations. We measure: In vs. Blank · · · In Blk In Blk
Retinotopic representations In vs.Out does not measure retinotopic representations. We measure: In vs. Blank · · · In Blk In Blk Out vs. Blank · · · Out Blk Out Blk 0 12 24 Time (sec)
Out vs. Blank No significant difference In vs. Blank Coherence: 0.4 1.0
Distance measurement, Bins along calcarine In Blank 2 1 0 FMRI Signal (%) -1 -2 0 12 24 Time (sec) FMRI Amplitude: 2.1% (Dougherty et al., 2003) Quantitative measurements(All voxels in V1)
FMRI Amplitude (%) Amplitude Profile 3 In vs. Blank 2 1 0 0 10 20 30 40 50 Cortical distance (mm) anterior posterior
Stable retinotopic representations: 3 In vs. Blank Out vs. Blank 2 FMRI Amplitude (%) 1 0 0 10 20 30 40 50 Cortical distance (mm)
“shift” model 3 In vs. Blank Out vs. Blank 2 Shift FMRI Amplitude (%) 1 0 0 10 20 30 40 50 Cortical distance (mm)
“edge” model 3 In vs. Blank Out vs. Blank 2 Asymmetrical edge response FMRI Amplitude (%) 1 0 0 10 20 30 40 50 Cortical distance (mm)
In vs. Out: Responses to motion direction changes 3 2 In vs. Out FMRI Amplitude (%) 1 0 0 10 20 30 40 50 Cortical distance (mm)
Three independent measurements 3 In vs. Blank Out vs. Blank 2 In vs. Out FMRI Amplitude (%) 1 0 0 10 20 30 40 50 Cortical distance (mm)
Responses to motion direction changes Differences between retinotopic representations (In vs. Out)>(In vs. Blank) – (Out vs. Blank) 1 (In vs. Blank) – (Out vs. Blank) In vs. Out FMRI Amplitude (%) 0 0 10 20 30 40 50 Cortical distance (mm)
Retinotopy is Stable In vs. Out • 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. In vs. Blank Out vs. Blank