What does the Ecological Approach to Perception focus on?
The moving observer and information in the environment
Define Optic Array
A structure created by surfaces, textures, contours in the environment
Define Optic Flow
Appearance of objects as an observer moves past
Define Gradient of Flow
The difference in flow as a function of distance from the observer
Define Focus of Expansion (FOE)
The point in the distance where there is no optic flow
Define Invarient Information
Properties that remain constant while observer moves
Define Self-Produced Information
Flow created by the movement of an observer
What are 2 evidences that support the idea of self-produced information?
- Somersaulting: gymnists use vision to correct trajectory (except newbs)
- “Swinging Room” experiment: 13-16 month babies swayed and fell because of optic flow patterns of swinging walls
What can optic flow be used to judge?
Heading/direction (within 0.5-1 degree)
Explain Britten + Van Wezel’s experiment involving neurons in the medial superior temporal area (MST)
Monkeys were trained to respond to flow (direction) of dots, then MST neurons were electrically stimulated
- Result: monkeys’ judgment changed according to stimulated neurons
- Finding: neurons in the MST respond to optic flow pattens
Explain Land + Lee’s experiment involving optic flow and driving
Drivers had to drive without looking directly at FOE while the angle of steering wheel, speed, and direction of gaze were measured
- Result: drivers use optic flow and additional information to determine heading
What is the Visual Direction Strategy?
Keeping the body pointed towards a target
Explain the Blind Walking experiment
Participants were asked to walk left and then towards a target while blindfolded
- Finding: people can walk without visuals
Explain Hamid’s “Wayfinding” experiment
Participants learned a maze with landmarks, then were asked to go to a specific point
- Result: people spent more time looking at turning point landmarks (rather between turning point landmarks)
Explain Janzen + Van Turennout’s experiment that is evidence of the parahippocampal gyrus’ role in wayfinding
Participants studied a film of a virtual museum with exhibits both at decision point and non-decision points, and were given recognition tasks (were objects part of the museum?)
- Result: greater activation in parahippocampal gyrus for objects at decision points (even if object was not recognized)
What evidence is there of the retrosplenial cortex’s role in wayfinding?
Retrosplenial cortex damage leads to a loss of ability to judge direction
What evidence is there of the hippocampus’ role in wayfinding?
Patient T.T.: a taxi driver who had hippocampus damage and could not navigate.
- He remembered main streets (learned recently) but not side streets (learned long ago)
What are the 3 primary areas of Wayfinding?
- Parahippocampal gyrus
- Retrosplenial cortex
- Hippocampus
Define Affordances
Information indicating what an object is used for
Even if someone can’t name objects, they can describe how they’re used
Explain Humphrey + Riddoh’s experiment with Patient M.P. who could not name objects (temporal lobe damage)
M.P. was asked to find a target object out of 10 objects after given either the name or function of the object
- Result: M.P. was faster and more accurate when given the function of the object
Explain Fattori’s experiment involving grasping
A monkey looks at a light above object, sees the object when light goes on and grasps when it turns off
- 4 objects required different grip types: whole hand, primitive precision, advanced, finger precision
- Finding: specific neurons (visual motor grip cells) activate, depending on the type of hand grip
- Finding: 3 regions are used in grasping
Explain Schindler’s experiment involving parietal lobe damaged patients
Participants had to reach between 2 cylinders to touch a gray strip
- Result: people with parietal lobe damage had trouble
- Finding: the parietal lobe is important for grasping
What are Mirror Neurons?
Neurons in the premotor cortex that respond when a monkey grasps an object and when watching a person grasp an object (without tools)
What are the 3 roles of mirror neurons?
- Helps with imitating
- Helps with understanding and reacting to animals’ actions
- May help with linking sensory perceptions and motor actions
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Chapter 1: Introduction19
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Experiments0
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Chapter 2: Beginnings Of Perception34
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Chapter 3: Neural Processing + Perception24
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Chapter 4: Visual Cortex + Beyond18
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Chapter 5: Perceiving Objects + Scenes34
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Chapter 6: Visual Attention35
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Chapter 7: Taking Action28
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Chapter 8: Perceiving Motion12
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Chapter 9: Perceiving Colour0
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Chapter 10: Perceiving Depth + Size0
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Chapter 11: Sound + Audition0
