Lecture 12 Flashcards
Describe action based accounts of perception
the purpose of perception is to create a representation in the mind of how one can interact
with their environment
Describe the action-specific perception hypothesis
that one’s environment is perceived in
terms of how they are able to act on it
What is a rule about attentional capture
motion attracts attention
Describe event boundaries and motion
- Motion is also a cue that we rely on for distinguishing between event
boundaries - e.g. changes in speed/acceleration of actor’s hands was a good predictor
of subjective judgments about events (Zacks et al. 2009)
What is akinetopsia?
an inability to perceive motion
What is real motion?
when an object is physically moving
What is apparent movement?
stationary
stimuli are presented in slightly different locations
Describe induced motion
movement of one object (usually a larger object, e.g.
clouds) results in the perception of movement in another object (usually a
smaller object, e.g. the moon)
Describe motion aftereffect
Observer looks at movement of object for 30 to 60 seconds,
then a stationary object, and movement appears to occur in opposite direction from
original movement
What is an example of motion aftereffect
Waterfall illusion
Describe Larsen study
- Control condition: two squares in slightly different positions are briefly
presented simultaneously - Real motion condition: a small square is moved back and forth
- Apparent motion condition: two squares are quickly alternated on alternate
sides of the display so as to create illusory motion
What is the ecological approach?
what/how information directly
available in the environment is useful to guide perception/action
What is the optic array?
the structure created by surfaces, textures, and contours in
the environment, which change as the observer moves through space
What are the 2 things that can influence the optic array?
- Local disturbances in the optic array: Objects moving relative to background (e.g. such
that portions of stimuli are periodically covered and uncovered, e.g. the background and
objects) - Global optic flow: Overall movement of the entire optic array (as a complete whole, i.e.
without any local disturbances)
When did Gibson think we perceived motion?
one part of the visual scene moves relative to the
rest of the scene
When did Gibson think we didn’t perceive motion?
the entire field moves, or remains stationary
What is corollary discharge theory?
hypothesizes that movement perception depends on
three signals:
- image displacement signal
-motor signal
- corollary discharge signal
What is the image displacement signal?
movement of image stimulating receptors
across the retina
What is the motor signal?
signal sent to eyes to move eye muscles
What is the corollary discharge signal?
derived from the motor signal (essentially a
‘carbon copy’ of whatever the motor signal is doing, though it gets sent to a
different part of the brain for another purpose)
Describe real movement neurons
- Real-movement neurons found in monkeys:
- Respond when a stimulus moves
- Do not respond when eyes move
