Psychology 225 Final Exam Questions
and Verified Answers 100%
what does our perception of motion depend on? - ✔✔images across our retina
what does our perception of a picture of birds movement come from - ✔✔knowledge and cues
to motion like blurred images
2 ways in which motion perception occurs - ✔✔1. when a stationary observer perceives moving
stimuli (couple crossing the street)
2. when a moving observer perceives moving stimuli (basketball players on a court)
perceiving motion experiment - ✔✔objects moved in various ways, going in and out of the
"house" and sometimes interacting with each other--the nature of the movements led subjects
to make up stories that often described the objects as having feelings, motivations, and
personalities
optic flow - ✔✔as a person moves forward, objects move relative to the person in the opposite
direction (provides information about direction/speed of object)
akinetopsia - ✔✔blindness to motion (person had trouble poring tea or coffee into a cup
because the liquid appeared to be frozen so she couldn't perceive the fluid rising in the cup and
had trouble knowing when to stop pouring)
attentional capture - ✔✔the ability of motion to attract attention (ex person waving in a sea of
people)
perceiving a camouflaged bird - ✔✔prepare stimuli by photocopying the bird and the hatched-
line pattern so they are separated, hold pic of bird up against a window during day (ex. the bird
becomes camouflaged when the random lines are superimposed on it--when the bird is moved
,relative to the lines, it becomes visible, an example of how movement enhances the perception
of form)
**movement provides information about objects
how does our own motion relative to objects add to the information that we have about
objects? - ✔✔reveals shape and features as it moves (car) then when we move around the
horse it reveals the true shape
real motion - ✔✔actual motion of an object (perceiving a car driving by or people walking)
illusory motion - ✔✔perception of motion when there actually is none
most famous and best studied type of illusory motion - ✔✔apparent motion: 2 stimuli in slightly
different locations are alternated with the correct timing, an observer perceives on stimulus
moving back and forth smoothly between 2 locations (no real motion between stimuli--ie
movies, signs, tv, etc
induced motion - ✔✔occurs when motion of one object (usually a large one) causes a nearby
stationary object (usually smaller) to appear to move (ex moon appears stationary in sky but if
clouds move past it it looks like the moon is moving through them--smaller objects seems to
move through larger objects)
motion aftereffects - ✔✔occurs when viewing a moving stimulus for 30-60 sec causes a
stationary stimulus to appear to move (ex waterfall illusion--look at waterfall and then look at
scenery around it and it will appear to be moving the opposite direction)
3 conditions in Larsen's experiment - ✔✔fmri--1. control condition: 2 dots in slightly different
positions were flashed simultaneously, 2. a real motion display: a small dot moved back and
forth, 3. apparent motion display: dots were flashed one after another so that they appeared to
move back and forth
,**result: brain is activated in space that represents the area between 2 dots--where movement
was perceived but no stimuli were present (activation of brain for real motion was similar to
apparent)
conditions for perceiving and not perceiving motion - ✔✔1. look straight as an object moves
past--object moves, eyes stationary, image on observers retina moves, object movement
perceived
2. follow a moving object with eyes--object moves, eyes move, image on observers retina
stationary, object movement perceived
3. look around the room--object stationary, eyes move, image on observers retina moves,
object movement is not perceived
**motion perception can't just be explained by what's happening on the retina
J.J. Gibson - ✔✔founded ecological approach to perception--look for information in
environment that is useful for perception (according to him, movement is perceived when part
of the visual scene moves relative to the rest of the scene, but if it all moves or none of it
moves, movement is not perceived)
optic array - ✔✔the structure created by the surfaces, textures, and contours of the
environment
local disturbance in the optic array - ✔✔hen portions of optic array become covered as he
walks by and then are uncovered as he moves on (covering/uncovering of the stationary
background)
global optic flow - ✔✔the fact that everything moves at once in response to movement of the
observer's eyes or body--signals that environment is stationary
Reichardt detector - ✔✔results in neurons that fire to movement in one direction(right to left)--
excitation and inhibition are arranged so that movement in one direction creates inhibition that
eliminates neural responding, whereas movement in the opposite direction creates excitation
that enhances neural responding
, corollary discharge theory - ✔✔explains motion perception by taking into account 3 signals that
are generated by movement of a stimulus on the retina and by movement of the eyes
**the brain contains a structure called the comparator that receives both the IDS and the CDS
what 3 signals from the retina/eye muscles are taken into account in the corollary discharge
theory? - ✔✔1. image displacement signal (IDS): when image of object moves across retina
(Jeremy walks across Maria's field of view while she stares straight ahead)
2. motor signal (MS): when a signal is sent from brain to eye muscles (Maria moves eyes to
follow Jeremy as he walks across the room)--includes CDS
3. corollary discharge signal (CDS): a copy of the motor signal that is sent to a different place in
the brain (i.e. emailing a cc to someone--copying same message to a different place at same
tame)
if just the IDS or just the CDS reach the comparator what does that mean? - ✔✔relays message
to the brain that movement has occurred
what happens if CDS and IDS reach comparator at the same time - ✔✔cancel each other out so
no signal is sent to area of brain responsible for motion perception
what 2 things does the corollary discharge theory propose about the visual system? - ✔✔it
takes into account both information about stimulation of the receptors and information about
movement of the eyes
behavioral evidence for corollary discharge theory - ✔✔1. eliminating the IDS with an
afterimage: bleached area on retina remains stationary when eye moves in dark--looks like
afterimage moves because corollary discharge signal is sent to the comparator
2. seeing motion by pushing on your eyelid--motor signal sent to eye muscles to hold the eye in
place created corollary discharge signal
physiological evidence for corollary discharge theory - ✔✔1. RW
and Verified Answers 100%
what does our perception of motion depend on? - ✔✔images across our retina
what does our perception of a picture of birds movement come from - ✔✔knowledge and cues
to motion like blurred images
2 ways in which motion perception occurs - ✔✔1. when a stationary observer perceives moving
stimuli (couple crossing the street)
2. when a moving observer perceives moving stimuli (basketball players on a court)
perceiving motion experiment - ✔✔objects moved in various ways, going in and out of the
"house" and sometimes interacting with each other--the nature of the movements led subjects
to make up stories that often described the objects as having feelings, motivations, and
personalities
optic flow - ✔✔as a person moves forward, objects move relative to the person in the opposite
direction (provides information about direction/speed of object)
akinetopsia - ✔✔blindness to motion (person had trouble poring tea or coffee into a cup
because the liquid appeared to be frozen so she couldn't perceive the fluid rising in the cup and
had trouble knowing when to stop pouring)
attentional capture - ✔✔the ability of motion to attract attention (ex person waving in a sea of
people)
perceiving a camouflaged bird - ✔✔prepare stimuli by photocopying the bird and the hatched-
line pattern so they are separated, hold pic of bird up against a window during day (ex. the bird
becomes camouflaged when the random lines are superimposed on it--when the bird is moved
,relative to the lines, it becomes visible, an example of how movement enhances the perception
of form)
**movement provides information about objects
how does our own motion relative to objects add to the information that we have about
objects? - ✔✔reveals shape and features as it moves (car) then when we move around the
horse it reveals the true shape
real motion - ✔✔actual motion of an object (perceiving a car driving by or people walking)
illusory motion - ✔✔perception of motion when there actually is none
most famous and best studied type of illusory motion - ✔✔apparent motion: 2 stimuli in slightly
different locations are alternated with the correct timing, an observer perceives on stimulus
moving back and forth smoothly between 2 locations (no real motion between stimuli--ie
movies, signs, tv, etc
induced motion - ✔✔occurs when motion of one object (usually a large one) causes a nearby
stationary object (usually smaller) to appear to move (ex moon appears stationary in sky but if
clouds move past it it looks like the moon is moving through them--smaller objects seems to
move through larger objects)
motion aftereffects - ✔✔occurs when viewing a moving stimulus for 30-60 sec causes a
stationary stimulus to appear to move (ex waterfall illusion--look at waterfall and then look at
scenery around it and it will appear to be moving the opposite direction)
3 conditions in Larsen's experiment - ✔✔fmri--1. control condition: 2 dots in slightly different
positions were flashed simultaneously, 2. a real motion display: a small dot moved back and
forth, 3. apparent motion display: dots were flashed one after another so that they appeared to
move back and forth
,**result: brain is activated in space that represents the area between 2 dots--where movement
was perceived but no stimuli were present (activation of brain for real motion was similar to
apparent)
conditions for perceiving and not perceiving motion - ✔✔1. look straight as an object moves
past--object moves, eyes stationary, image on observers retina moves, object movement
perceived
2. follow a moving object with eyes--object moves, eyes move, image on observers retina
stationary, object movement perceived
3. look around the room--object stationary, eyes move, image on observers retina moves,
object movement is not perceived
**motion perception can't just be explained by what's happening on the retina
J.J. Gibson - ✔✔founded ecological approach to perception--look for information in
environment that is useful for perception (according to him, movement is perceived when part
of the visual scene moves relative to the rest of the scene, but if it all moves or none of it
moves, movement is not perceived)
optic array - ✔✔the structure created by the surfaces, textures, and contours of the
environment
local disturbance in the optic array - ✔✔hen portions of optic array become covered as he
walks by and then are uncovered as he moves on (covering/uncovering of the stationary
background)
global optic flow - ✔✔the fact that everything moves at once in response to movement of the
observer's eyes or body--signals that environment is stationary
Reichardt detector - ✔✔results in neurons that fire to movement in one direction(right to left)--
excitation and inhibition are arranged so that movement in one direction creates inhibition that
eliminates neural responding, whereas movement in the opposite direction creates excitation
that enhances neural responding
, corollary discharge theory - ✔✔explains motion perception by taking into account 3 signals that
are generated by movement of a stimulus on the retina and by movement of the eyes
**the brain contains a structure called the comparator that receives both the IDS and the CDS
what 3 signals from the retina/eye muscles are taken into account in the corollary discharge
theory? - ✔✔1. image displacement signal (IDS): when image of object moves across retina
(Jeremy walks across Maria's field of view while she stares straight ahead)
2. motor signal (MS): when a signal is sent from brain to eye muscles (Maria moves eyes to
follow Jeremy as he walks across the room)--includes CDS
3. corollary discharge signal (CDS): a copy of the motor signal that is sent to a different place in
the brain (i.e. emailing a cc to someone--copying same message to a different place at same
tame)
if just the IDS or just the CDS reach the comparator what does that mean? - ✔✔relays message
to the brain that movement has occurred
what happens if CDS and IDS reach comparator at the same time - ✔✔cancel each other out so
no signal is sent to area of brain responsible for motion perception
what 2 things does the corollary discharge theory propose about the visual system? - ✔✔it
takes into account both information about stimulation of the receptors and information about
movement of the eyes
behavioral evidence for corollary discharge theory - ✔✔1. eliminating the IDS with an
afterimage: bleached area on retina remains stationary when eye moves in dark--looks like
afterimage moves because corollary discharge signal is sent to the comparator
2. seeing motion by pushing on your eyelid--motor signal sent to eye muscles to hold the eye in
place created corollary discharge signal
physiological evidence for corollary discharge theory - ✔✔1. RW
