Sense Perception Visual Illusions Selectivity of Perception.
Motion Perception Chapter 8 - Princeton...
Transcript of Motion Perception Chapter 8 - Princeton...
![Page 1: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/1.jpg)
Motion Perception Chapter 8
Lecture 14
Jonathan PillowSensation & Perception (PSY 345 / NEU 325)
Fall 20171
![Page 2: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/2.jpg)
Strabismus• eyes not aligned, so diff images fall on the fovea• If not corrected at an early age, stereopsis will not develop
stereoblindness: inability to use binocular disparity as a depth cue.
Defects in Stereopsis
(chap 6 leftovers)
2
![Page 3: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/3.jpg)
Müller-Lyer Illusionhttp://www.michaelbach.de/ot/sze_muelue/index.html
Depth Illusions
3
![Page 4: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/4.jpg)
In which image are the two horizontal lines the same length?
(Ans: second from left)4
![Page 5: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/5.jpg)
Two figures are the same size
5
![Page 6: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/6.jpg)
“Terror Subterra”
6
![Page 7: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/7.jpg)
“Terror Subterra”
7
![Page 8: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/8.jpg)
Depth / Size illusion
• all 3 cars take up the same space in the image + on your retina!8
![Page 9: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/9.jpg)
Binocular Rivalry
9
![Page 10: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/10.jpg)
Two stimuli battle for dominance of
the percept
10
![Page 11: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/11.jpg)
• monocular depth cues • binocular depth cues (vergence, disparity)• horopter • crossed / uncrossed disparities• free fusing• random dot stereogram• stereoscope• “correspondence problem”• panum’s fusional area• strabismus / stereoblindness• binocular rivalry (in book)
Chapter 6 Summary:
11
![Page 12: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/12.jpg)
Motion Perception Chapter 8
12
![Page 13: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/13.jpg)
Main point of this chapter:
Motion = Orientation in Space-Time
time
space
13
![Page 14: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/14.jpg)
which motion is faster?
time
space
time
space
slow fast
14
![Page 15: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/15.jpg)
Real vs. Apparent motion
Apparent motion - motion percept that results from rapid display of stationary images in different locations
time
space
time
space
apparent(movies, flip-books) “real”
Q: why don’t we notice the difference?15
![Page 16: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/16.jpg)
How does the nervous system encode motion? What makes a Motion Receptive Field?
Answer: a surprisingly simple neural circuit called a “Reichardt detector”
16
![Page 17: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/17.jpg)
Reichardt
detector
simple summing neuron
delay line
17
![Page 18: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/18.jpg)
space
time
excitatoryinhibitory
Reichardt detector in space-time
firstRF
secondRF
2nd neuron has a spatially separated Receptive Field (RF), and a shorter temporal delay
18
![Page 19: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/19.jpg)
space
time
excitatoryinhibitory
Smoother Reichardt detector
Like an oriented V1 receptive field, but oriented in space-time!19
![Page 20: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/20.jpg)
space
time
excitatoryinhibitory
Reichardt detectors respond to real and apparent motion
20
![Page 21: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/21.jpg)
Figure 7.3 Constructing a neural circuit for the detection of rightward motion (Part 1)
21
![Page 22: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/22.jpg)
Figure 7.3 Constructing a neural circuit for the detection of rightward motion (Part 2)
22
![Page 23: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/23.jpg)
Clockwise or Counter-clockwise rotation?
(web demo)
Correspondence problem (motion): • problem of knowing the correspondence between features in successive frames (which points in frame 1 are the same objects in frame 2?)
http://sites.sinauer.com/wolfe3e/chap8/correspondenceF.htm
23
![Page 24: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/24.jpg)
• Aperture problem: when a moving object is viewed through an aperture, the direction of motion may be ambiguous
24
![Page 25: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/25.jpg)
• Aperture problem: when a moving object is viewed through an aperture, the direction of motion may be ambiguous
25
![Page 26: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/26.jpg)
• Aperture problem: when a moving object is viewed through an aperture, the direction of motion may be ambiguous
26
![Page 27: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/27.jpg)
• this is a problem because each neuron only sees the scene through a small aperture (its receptive field!)
• how can the brain figure out the “global” direction of motion?
• Aperture problem:
27
![Page 28: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/28.jpg)
aperture problem / correspondence problemhttp://sites.sinauer.com/wolfe4e/wa08.02.html
28
![Page 29: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/29.jpg)
building a global motion detector
29
![Page 30: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/30.jpg)
Motion aftereffect (MAE): The illusion of motion that occurs after prolonged exposure to a moving stimulus
http://www.michaelbach.de/ot/mot-adapt/index.html
30
![Page 31: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/31.jpg)
Motion after-effect
• Always gives rise to motion in the opposite direction of the adapting motion
• Also known as: “waterfall illusion” - stare at a waterfall; stationary objects will then appear to move upwards.
• evidence for “opponent channels” in processing motion
31
![Page 32: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/32.jpg)
Interocular transfer: The transfer of an effect (such as adaptation) from one eye to another
• MAE: exhibits interocular transfer
• Remember: Input from both eyes is combined in area V1
Q: What does this tell us about where in the brain motion is computed?
32
![Page 33: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/33.jpg)
“Motion After-Effect”
33
![Page 34: Motion Perception Chapter 8 - Princeton Universitypillowlab.princeton.edu/teaching/sp2017/slides/Lec14_Motion_Chap8a.pdf• horopter • crossed ... Motion Perception Chapter 8 12.](https://reader034.fdocuments.in/reader034/viewer/2022042206/5ea9071c2ae7e80d6423980c/html5/thumbnails/34.jpg)
“Motion After-Effect”
34