Visual Perception Week 11 Notes
Visual Perception Week 11 Notes PSYC 3124
Popular in Visual Perception
verified elite notetaker
Popular in Psychlogy
This 5 page Class Notes was uploaded by Freddi Marsillo on Thursday March 24, 2016. The Class Notes belongs to PSYC 3124 at George Washington University taught by Dr. John Philbeck in Spring 2016. Since its upload, it has received 25 views. For similar materials see Visual Perception in Psychlogy at George Washington University.
Reviews for Visual Perception Week 11 Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 03/24/16
Visual Perception Week 11 Notes 3/24/16 12:51 PM The Moon Illusion – Kaufman & Rock • Two theories exist to explain why the moon at the horizon is larger than the moon at its zenith: o Apparent-Distance Theory: horizon moon looks larger due to it seeming farther away o Angle-of-Regard Theory: zenith moon looks smaller due to the elevation of the viewers’ eyes/head Boring disagrees with Ptolemy nd • Ptolemy supported the Apparent-Distance Theory in the 2 Century • Boring sees flaws in Ptolemy’s claim and experiments to support the Angle-of-Regard Theory • Boring’s initial findings are that most people perceive the horizon moon as nearer, a complete contradiction to the Apparent-Distance Theory • This inspires Boring to search for a further explanation Angle-of-Regard Theory – Boring • Postural positions affect our judgment of the size of objects (i.e. neck craned or viewed straight on) • Conducted a series of experiments which allowed viewers to see both horizon and zenith moon “straight on” and with “eyes raised” o Subjects lifted neck to view zenith moon straight on and laid supine to view horizon moon with “eyes raised” (manipulated posture to produce illusion) o Found that “straight on” view correlated with illusion of larger size Challenges to Angle-of-Regard Theory Kaufman & Rock (1962) challenged Boring’s method of producing the illusion • Proposed that even with the manipulated postures, it was impossible to compare the moon to disk sizes because the objects were not “commensurable,” or not measurable by the same standard due to the moon’s more or less “indeterminate size” over a seemingly “infinite” distance Erna Schur’s Support of Angle-of-Regard Theory • She was able to recreate the moon illusion in a dark zeppelin hanger by projecting disks of light on the walls. Boring and Holway conducted a similar experiment with a sun illusion. In both cases, there was no terrain, again seemingly contradicting the Apparent- Distance Theory. • Kaufman and Rock replicated Schur’s experiment and found that eye elevation only had a slight effect. This brought them back to how participants perceived the horizon moon as nearer. • They hypothesized that size would influence the perception of what moon was nearer or farther. When the zenith moon was larger than the horizon moon, participants said it was nearer and vice versa • Came to the conclusion that: had to do with the size as well as the terrain Apparent Distance Theory • If two objects at unequal distances from the observer form images of the same size on the retina, the more remote object must be larger • If the moon looks farther away when it is on the horizon than when it is higher in the sky, it should look larger Experiment • Pointed artificial moon apparatus at the horizon • Had observers viewing the “moon” through the hole in a sheet of cardboard that masked the terrain • The horizon moon looks no larger than the zenith moon • Pointed two of devices at the horizon: o A) Moon is viewed through a mask o B) Moon is seen over unobstructed terrain • Results: Moon B is 1.34 times larger than Moon A Terrain • Terrain is the key point for the moon illusion • The horizontal moon looks larger only because it is seen over terrain • It is possible to reverse the illusion by moving the terrain overheard with a mirror or prism • As expected, the illusion does reverse: the moon on an overheard horizon appears larger than the moon at a horizontal zenith, with a ratio of 1:1.34 Terrain + Cloudiness Effects • Visible horizon is now 2000 feet away 30 degrees to the left • The illusion is greater when being seen over the more distant horizon o Group A – viewed the artificial moons against a completely overcast sky o Group B – viewed against partial cloud cover o Group C – viewed against a clear sky • Far : Near = 1.51 : 1.36 • A:B:C = 1.52 : 1.45 : 1.34 • Inversion • 1.28 (inverted) : 1.66 (Normal) 3/24/16 12:51 PM 3/24/16 12:51 PM
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'