1. PLEASE COME! Receive 1 Hour Lab Experience Credit HERE, Thursday Bring 2 #2 Pencils

2. Psychology 150 Introduction to Psychology Lecture 09 - 09/19/01 Finishing Perception – 2D  3D Attention?

3. Sample Problem: Depth Perception Retina is a 2-D surface - How do you perceive depth? Two types of cues…

4. Binocular Cues Binocular Disparity.

5. Binocular Cues Binocular Disparity. – The less the disparity, the greater the distance. – Sufficient for Depth Perception (stereopsis) Eye Convergence

6. Monocular Cues to Depth Motion Parallax

7. Monocular Cues to Depth Motion Parallax Occlusion

8. Monocular Cues to Depth Motion Parallax Occlusion Relative Image Size

9. Monocular Cues to Depth Motion Parallax Occlusion Relative Image Size Texture Gradients & Linear Perspective

10. Monocular Cues to Depth Motion Parallax Occlusion Relative Image Size Linear Perspective Texture Gradients Position Relative to Horizon

11. Problem: Perceptual Constancy Our perception that properties of objects remain constant even when the conditions of stimulation are changed. Example: Color Constancy – Is color perception solely a function of wavelength?

12. Top-Down Effect on Early Perceptual Processing Steven Palmer (1975) Theory: Even Early Perceptual Processes are dependent upon the current cognitive state of the perceiver...

13. Palmer’s Experiment Subjects: Humans Task: Look at Object 1, and then identify a briefly flashed object (Object 2)

14. Palmer’s Experiment Manipulation: Conceptual Relationship between Object 1 and Object 2 (consistent or inconsistent).

15. Palmer cont... Measure: Percent Correct Identification Prediction: Consistent relationship between object 1 and object 2 will increase perceptual identification. Results...

17. Summing Up Perception Goal: Stable representation of reality. Problem: Need to transduce “incomplete” incoming stimulus energy and “construct” a percept. Not a one-to-one relationship between stimulus and perception. Behavioral study can guide neuroscience. Construction Project = Unconscious Inference.

18. Pay Attention: Dropping Rocks and Frog Legs Ahead!

19. &$%#* Brain Again Nice device and all, but… – Finite! – Distracting Stimuli. Attention: A mechanism for selection. Attention is a hypothetical construct.

20. Dropping Rocks How do you demonstrate the properties of gravity? We need a dropping rock for cognition!

21. Frog Legs Helmholtz - Does nerve conduction take time? If nerve conduction takes time…. Reaction Time: The elapsed time between the onset of a stimulus and the subject’s response.

22. An example that puzzled me… Behavior Boy… takes a cognitive course...

23. Background: Basic Detection Paradigm Time 1 Time 2 *