psych of perception chapter 7 Flashcards
optic array
the structure created by the surfaces, textures, and contours of the environment, how movement of the observer causes changes in the optic array.
The ecological approach to perception focuses on how perception occurs in the environment by:
(1) emphasizing the moving observer—how perception occurs as a person is moving through the environment—and (2) identifying information in the environment that the moving observer uses for perception.
optic flow
one source of the information for perception that occurs as you move is optic flow. the movement of elements in a scene relative to the observer
optic flow
appearance of objects as observer moves past them
optic flow characteristics
(1) the flow is more rapid near the moving observer, and (2) there is no flow at the destination toward which the observer is moving
gradient of flow
the difference speed of flow - fast near the observer and slower farther away (provides information about the observers’ speed)
focus of expansion (FOE)
The absence of flow at the destination point is called the focus of expansion (FOE). Because the FOE is centered on the observer’s destination, it indicates where the observer is heading.
invariant
property that remains constant under different circumstances (conditions)
self-produced information
an observer’s movement provides information that the observer uses to guide further movement
your ability to stand up straight, and to keep your balance while standing still or walking, depends on systems that enable you to sense the position of your body
these systems include the vestibular canals of your inner ear and receptors in the joints and muscles
swinging room
moving the room toward the observer creates an optic flow pattern associated with moving forward, so observer sways backward to compensate
vision provides a frame of reference that..
helps the muscles constantly make adjustments to help maintain balance
what does swinging room research results suggest?
results show that vision has a powerful effect on balance, and even overrides other senses (e.g., vestibular system) that provide feedback about body placement and posture
visual direction strategy
observers keep their body pointed toward a target. If they go off course, the target will drift to the left or right, when this happens, the walker can correct course to recenter the target
blind walking experiments
show that people can navigate without any visual stimulation from the environment
navigating activates
right hippocampus and part of the parietal cortex
place cells
respond when the experimental animal was navigating a certain location in the testing area
place field
the area of the environment where place cells fire
grid cells
cells in the hippocampus arranged in a grid layout (may indicate spatiotopic regularity in the arrangement of some hippocampal cells)
affordance
objects have a property called its affordance, which is related to the object’s function
a person with extinction
can identify a stimulus in the right or left visual field if just one stimulus is presented
parietal reach region (PRR)
Calton found that the parietal neurons fired during this delay if the monkey was planning to reach, but did not fire if the monkey was planning to look. Neurons in the posterior parietal cortex that respond when a monkey is planning to reach, or is actually reaching, constitute the parietal reach region (PRR)
Dorsal and ventral pathways
Identify the object (ventral)
Position hand and fingers to grasp (dorsal)
mirror neurons
firing provides information about the characteristics of the action because the neuron’s response to watching someone else perform the action is the same as the response that occurs when the observer performs the action
