The Role of Experience

1. The Role of Experience • Perceptual Development • Effects of Learning and Cognition • Development Vs Hardwiring Anthony J Greene

2. Perceptual Development

3. The Measurement of Infant Perception • A reliable tendency to stare at new stimuli • Comfort responses and preferences for familiar stimuli • Reliable surprise reactions when configurations are altered Anthony J Greene

4. The Development of Visual Acuity • Vary spatial frequency and contrast compared to a gray swatch • The highest frequency and smallest contrast that produce a response determine the acuity of infant perception Anthony J Greene

5. The Development of Visual Acuity Anthony J Greene

6. The Development of Visual Acuity Anthony J Greene

7. L R L R L R L R Stereopsis: Use it or lose it • At Birth, the nerve fibers at the edge of column boundaries are poised to cross over and make connections with columns from the opposite eye that have similar receptive fields Anthony J Greene

8. L R L R L R L R Stereopsis: Use it or lose it • With normal development, corresponding inputs from different eyes cause nerves to overlap • As with phase detectors, different eccentricities are detected in slightly different regions of cortex. Such regions then discern different disparities. Anthony J Greene

9. L R L R L R L R Stereopsis: Use it or lose it • If the inputs do not correspond (e.g. child may be cross-eyed or have a wandering eye), the inputs do not overlap and stereopsis does not develop. Anthony J Greene

10. Object Constancy • By 2 months of age, most children can detect that an object is missing Anthony J Greene

11. The Time Course of Perceptual Development Anthony J Greene

12. The Development of Myopia (childhood into adulthood) • With excessive up-close viewing, the strain on the lens and cilia eventually cause the eyeball to shorten to accmodate more easilly • The Air Force Academy • Eskimos • Chicks • This process can be prevented and reversed by using reading glasses and engaging in distance viewing (e.g., lots of outdoor activity) Anthony J Greene

13. COGNITIVE ASPECTS OF PERCEPTION

14. Top-Down Aspects of Perception 1 Categorization • Attention • Identification & Recognition 4 Competition Between Top-Down & Bottom-Up Information 5 Resolving Ambiguity 6 Context • Imagery • Perception & Action • Perception is Malleable • Is Perception Modal? • Concepts Anthony J Greene

15. 1 Categorization Memory Grouping like objects - category exemplars Generalization Anthony J Greene

16. 2 Attention Behavioral and Physiological phenomenon Acquisition of Sense Data : Cognitive gating of sensory/perceptual input -- Guides Acquisition of Sense Data Competition between Top-Down & Bottom-Up information Anthony J Greene

17. Cognitive Gating Anthony J Greene

18. Cognitive Gating There are benefits to keeping your mind on what you’re doing Anthony J Greene

19. The Physiology of Attention • Amplification (the Pulvinar of the Thalamus) • De-amplification Anthony J Greene

20. 3 Identification & Recognition • Perceptual systems learn to recognize • Identification for previously seen items is faster and more reliable, regardless of whether or not you consciously remember Anthony J Greene

21. Disorders of Identification or Recognition • V3: Visual agnosia • IT: Associative agnosia • Fusiform gyrus of IT: Prosopagnosia Anthony J Greene

22. 4 Process Competition Irrelevant Information Facilitation and Interference Stroop Interference Anthony J Greene

23. Stroop Interference Anthony J Greene

24. 5 Resolving Ambiguity Purpose of perception is unambiguous information Gibson- perception is a behavior which actively resolves ambiguity Perception can be viewed as a probability funnel Anthony J Greene

25. 6 Context and Perception Context can serve to constrain or resolve ambiguity - source of additional information (associative) and clues. Anthony J Greene

26. 7 Imagery • What color is your neighbors house? • Perception in the absence of the stimuli - an aspect of memory I Mental Rotations II Activation of Perceptual Areas III Damage to Perceptual Areas Disrupts Imagery and Memory Anthony J Greene

27. Mental Rotation Reaction Time (RT) Study 1 Shepard Mental Rotation - Internalized Perception Anthony J Greene

28. Mental Rotation (cont.) • Straight slope line indicates mental rotations of 600/sec • If it weren’t a rotation, the slope would be either flat or irregular Anthony J Greene

29. Mental Rotation (cont.) • The fact that the result is a straight line indicates that the subjects must be rotating through the intermediate positions. • Analog Process - Analogous to Physical Rotations; mental rotation is constrained in the same way that our physical interaction with the environment in constrained • The further apart the objects are, the longer it takes to mentally rotate them. Anthony J Greene

30. Mental Rotation (cont.) Can blind people do mental rotation? (i.e. Is vision necessary for mental rotation?) 2 Marmor & Zaback - 2-D mental rotation in the Picture Plane • Subjects: • Sighted Blindfolded • Congenitally Blind • Blind (Late Blindness; have a visual frame of reference) Anthony J Greene

31. Mental Rotation (cont.) • Stimulus: • The figures used here are simpler than those used by Shepard. • Wooden objects fastened to a larger, flat piece of wood. • Present one object to the Left Hand. • Present another (possibly different) object in a different orientation to the Right Hand. Anthony J Greene

32. 2330/sec 1140/sec 590/sec Mental Rotation (cont.) Anthony J Greene

33. Mental Rotations (cont.) • Because all of the lines are straight subjects are constrained to the physical/mental rotation through intermediate positions. • Vision is NOT necessary to do rotation; vision just makes for faster mental rotations. Anthony J Greene

34. 8 Perception & Action • Recall Gibson’s theory that perception is a behavior • As such, part of action must be to help constrain perception (e.g., exploration) or inform (foraging) • Similarly, action is directed and updated by perception Anthony J Greene

35. 9 Perception is Malleable • Prism Effects on reaching • Facilitation • Perception is influenced by expectation Anthony J Greene

36. 10 Is Perception Modal? Do the senses influence one another? • Synesthesia • Barn Owl: Optic Tectum (Colliculus) Anthony J Greene

37. 11 Concepts • Pigeons can learn complicated concepts • From some points of view, concepts are no more than configurations of perceptual information • Or, at least, conceptual processes evolved for the purpose of making the best use of perceptual information • What you perceive depends upon what you know Anthony J Greene

38. Do Concepts Help Us Figure Out What We’re Looking At? Anthony J Greene

39. Innate Vs. Developed Nature Vs. NurtureTwo Species on Their Day of Birth Anthony J Greene

40. Is Perception Innate? Nature vs. Nurture Anthony J Greene

41. Anthony J Greene

42. Turn That Frown Upside-Down Anthony J Greene

43. Facets of Perception That Are Hardwired • Bottom-Up Processes • Neural Organization • Reflex Mechanisms • The Reflex Arc • Visual and Auditory Orientation Reflex • Range of Perception • Capacities of Perception • Attention? • The Ability to Learn Perceptually and Conceptually Anthony J Greene

44. Facets of Perception That Are Hardwired • Bottom-Up Processes? • Neural Organization? • Reflex Mechanisms • The Reflex Arc • Visual and Auditory Orientation Reflex • Range of Perception • Capacities of Perception ? • Attention? • The Ability to Learn Perceptually and Conceptually? Anthony J Greene

45. Facets of Perception That Require Development • Top-Down Processes • Attention • Learning • Fine-Tuned Functioning • Acuity • Stereopsis • Perceptual Facilitation (Priming) • Generalization vs. Discrimination Anthony J Greene

46. Conclusion • Evolution favors what? • Speed versus flexibility trade-off It favors both, but under different circumstances.  In rapidly changing environments, or in species that occupy varied habitats (like humans:  everything from the equator to near the poles, including jungle, desert, plains, citys, farm, etc.) then flexibility is favored.  In species where the lifespan is short and/or mortality rate is high, speed is favored. Anthony J Greene