Depth perception allows us to see objects in 3D and judge distances. There are two types of depth cues - binocular cues which use both eyes, and monocular cues which use a single eye. Binocular cues include retinal disparity, where each eye sees a slightly different image, and convergence, the inward turning of the eyes to focus. Monocular cues such as size, overlap, and texture are used in 2D images to imply 3D. A study found that some tribes lacked the monocular cue of relative size due to their environment.

1. Depth Perception

2. Depth perception is the ability to see things in a 3-Dimensional way and to judge distance. We use depth cues to gather information on the images we see. These cues can be monocular or binocular. Overview

3. Binocular depth cues use both eyes to perceive information on he 3-dimensional form of an object and it's place in space. There are two types of binocular cues, retinal disparity and convergence. Images seen through both eyes are examples of steroptic vision because the two eyes see two different pictures that combine as one. Binocular Cues

4. Binocular Cues The image your right eye sees is different than your left eye because they are a small distance apart. The image you see using both eyes is the two images merged.

5. Binocular Cues: Fun Fact 3-D movies use the idea of retinal disparity by using two close cameras and merging the image together.

6. Binocular Cues: Convergence When focusing on images less than 4-6 meters away, the eyes turn inward to focus on the same object rather than moving together. The angle the eyeballs turn towards each other is smaller when the object in focus is farther away.

7. Monocular Cues Monocular cues judge the distance of an object using only one eye. These cues are often used in making 2-D images appear to be 3-D, in this case they are called pictorial depth cues .

8. Monocular Cues: Linear Perspective As parallel lines extend into the distance, they appear to meet together.

9. Monocular Cues: Relative Size When viewing two congruent objects, the farther away object will appear smaller even though the objects are still the same size.

10. Monocular Cues: Height in the Picture Plane Objects that are farther away appear higher up in an image, closer to the horizon line.

11. Monocular Cues: Lights and Shadows 2-Dimensional images can appear 3-D when shaded with the appropriate patterns of light and shadow found in "real objects."

12. Monocular Cues: Overlap When multiple objects are in the same visual field, the closest object appears in front of those farther away.

13. Monocular Cues:Texture Gradient The texture in an image appear less detailed as objects become more distant.

14. Monocular Cues: Aerial Perspective Far away objects often appear less clear in color and detail due to haze. A person typically only notices the haze when it is not present. On a clear day, far away objects may seem very close.

15. Monocular Cues: Relative Motion Objects closer in the visual field appear to move by faster than those at a greater distance. The far away objects may not seem like they are moving at all.

16. Turnbull: What You See Is What You've Learned Turnbull studied BaMbuti pygmies and found that the people of their area do not possess the monocular cue of relative size because their environment does not call for them to use it. From this natural observation, it can be concluded that skills of perception are not inborn, we learn them.

17. Turnbull Kenge, a BaMbuti pygmy, had never seen a mountain from a great distance. When Turnbull presented the mountain to him, he could not decide if it was a cloud or a hill.

18. Having never seen a buffalo from a distance, Kenge believed that it had to be an insect because it was so small. Turnbull

19. When presented with a row boat full of people on a lake from a distance, Kenge (at first) refused to believe that the boat was holding people. It was simply to small. Turnbull

20. Slides 1-15: Information: Coon, D., & Mitterer, J. O. (2011). Psychology, modules for active learning (with concept modules with note-taking and practice exams booklet) . (12 ed., pp. 184-187). Belmont, CA: Wadsworth Pub Co. Slide 1: Image: http://www.world-wallpaper.com/user-content/uploads/wall/o/57/New-York-City-Evening-Wallpaper.jpg Slide 2 Image 1: http://aussieapples.com.au/media/images/galleries/apple-photo-gallery/Apples_5.jpg Image 2: http://us.123rf.com/400wm/400/400/bulldogza/bulldogza1104/bulldogza110400177/9340778-the-moon-on-sky-at-night.jpg Slide 3 Image: http://c.universalscraps.com/files/en/eyes.tears/eyes_tears_132.jpg Slide 4: Image: http://vintage-visuals.com/images/retinal_disparity_stereo_283x329.jpg Video: http://www.youtube.com/watch?v=4VGVwOmn6bk Slide 5: Image 1: Created by Lauren Duncan Image 2: http://www.aboutprojectors.com/news/wp-content/uploads/2009/06/3dtheater_a1.jpg Slide 6: Video: http://www.youtube.com/watch?v=qlgw0QLFgOU by Lauren Duncan Slide 7: Image 1: http://3.bp.blogspot.com/-z2PYOaH MgI/Tfeki9SSuxI/AAAAAAAADRw/IXyxxazoeNY/s400/DSC_0001_edited.jpg Image 2: http://www.thirdeyehealth.com/images/depth-perception-2.jpg Slide 8: Image 1: Created by Lauren Duncan Image 2: http://cache2.artprintimages.com/p/LRG/26/2680/R9IUD00Z/art-print/empty-railroad-tracks.jpg Slide 9: Image: Photo by Lauren Duncan Slide 10: Image: http://www.realestatemarketingblog.org/wp-content/uploads/image/home-neighborhood-drawing.JPG

21. Slide 11: Image 1: http://animateart.files.wordpress.com/2010/08/lion-for-blog.jpg Image 2: http://nationalzoo.si.edu/Animals/GreatCats/images/covers/cover_LionPortrait.jpg Slide 12: Image 1: Photo by Lauren Duncan Image 2: http://hgrm.sndimg.com/HGRM/2011/08/18/DP_charalambous-contemporary-living-room-2_s4x3_lg.jpg Slide 13: Image: Photo by Danae Phillipus Slide 14: Image 1: http://images.travelpod.com/users/argieuk/3.1318903910.the-mountains-through-the-early-morning-haze.jpg Image 2: http://www.innergeek.us/blog/2007/10/pretty-mountain.jpg Slide 15: VIdeo: http://www.youtube.com/watch?v=CQopEKTsc-Y&context=C35058d9ADOEgsToPDskJ88Zdd2KsPEI-ReyYuLShK by Lauren Duncan Slides 16-19: Information: http://apsych-pd.wikispaces.com/file/view/states+studies+5+n+7.pdf Slide 16: Image: http://static.guim.co.uk/sys-images/Guardian/Pix/pictures/2009/9/29/1254221699771/Deforestation-in-DRC-009.jpg Slide 17: Image 1: http://mw2.google.com/mw-panoramio/photos/small/38759600.jpg Image 2: Photo taken by Lauren Duncan Slide 18: Image: http://www.kansastravel.org/08redbuffaloranch8.JPG Slide 19: Image: http://www.cleanfish.com/system/images/BAhbB1sHOgZmIjIyMDExLzAyLzE1LzEyLzM3LzA4Lzg4MC9Sb3dfQm9hdF9pbl9XYXRlci5qcGdbCDoGcDoKdGh1bWIiDTQ1MHg0NTA+/Row_Boat_in_Water.jpg