Topic 7: Perception and Action Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Ecological Approach to Perception

A

this approach focuses on specifying the information in the environment that is used for perception, emphasizing the study of moving observers to determine how their movements results in perceptual information that both creates perception and guides further movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Optic Flow

A

the flow of stimuli in the environment that occurs when an observer moves relative to the environment

forward movement causes an expanding optic flow, whereas backward movement causes a contracting optic flow

some researchers use the term optic flow field to refer to this flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Gradient of Flow

A

in an optic flow pattern, a gradient is created by movement of an observer through the environment

the “gradient” refers to the fact that the optic flow is rapid in the foreground and becomes slower as distance from the observer increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Focus of Expansion (FOE)

A

the point in the flow pattern caused by observer movement in which there is no expansion

according to J.J. Gibson, the focus of expansion always remains centered on the observer’s destination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Invariant Information

A

environmental properties that do not change as the observer moves relative to an object or scene

for example, the spacing, or texture, of the elements in a homogenous texture gradient does not change as the observer moves on the gradient

the texture of the gradient therefore supplies information for depth perception

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Affordances

A

the information specified by a stimulus patter that indicates how the stimulus can be used

an example of an affordance would be seeing a chair as something to sit on or a flight of stairs as something to climb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Action Affordances

A

a response to an object that involves both its affordance (what it is for) and the action associated with it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Visual Direction Strategy

A

a strategy used by moving observers to reach a destination by keeping their body oriented toward the target

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Spatial Updating

A

process by which people and animals keep track of their position within a surrounding environment when they move

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Wayfinding

A

the process of navigating through the environment

wayfinding involves perceiving objects in the environment, remembering objects and their relation to the overall scene, and knowing when to turn and in what direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Landmarks

A

object on a route that serves as a cue to indicate where to turn

a source of information for wayfinding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Cognitive Map

A

a mental map of the spatial layout of an area of the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Place Cells

A

neurons that fire only when an animal is in a certain place in the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Place Field

A

area of the environment within which a place cell fires

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Grid Cells

A

cells in the entorhinal cortex that fire when an animal is in a particular place in the environment, and which have multiple place field arranged in a grid-like pattern

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Parietal Reach Region (PRR)

A

network of areas in the parietal cortex that contains neurons that are involved in reaching behavior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Visuomotor Grip Cells

A

a neuron that initially responds when a specific object is seen and then also responds as a hand grasps the same object

18
Q

Proprioception

A

the sensing of the position of the limbs

19
Q

Size-Weight Illusion

A

erroneously predicting weight when observing two differently sized objects that have the same weight

the error occurs when the perceiver predicts that the larger object will be heavier, and therefore uses more force to lift it, causing it to be lifted higher and to feel lighter

20
Q

Audiovisual Mirror Neurons

A

neuron that responds to actions that produce sounds

these neurons respond when a monkey performs a hand action and when it hears the sound associated with this action

21
Q

Mirror Neuron System

A

network of neurons hypothesized to play a role in creating mirror neurons

22
Q

Action-Specific Perception Hypothesis

A

hypothesis that people perceive their environment in terms of their ability to act on it

23
Q

What are the assumptions made in the ecological approach?

A

emphasized evolution: natural selection has shaped our perceptual system, considered perception in the natural environment, understanding motion of observer is important

all info required for perception is available in environment (bottom-up): optic array (stimulus pattern in the environment) is highly organized

the visual scene is analyzed in terms of whole objects and surfaces, not edges, colors, etc. that comprise objects: certain characteristics of the environment are invariant: a particular relationship holds constant

perception is direct, immediate: do not require further computation/mental operations, or additional info based on inferences or experience, no top-down processing

24
Q

What is optic flow?

A

stimulus array changes in a logical way as observer moves through the environment

25
Q

What was the Lee & Reddish (1976) research example of the ecological approach?

A

analyzed diving behavior of gannets

tau: ratio of target’s retinal size at two different times divided by the rate of change of its retinal size over time (i.e., time to impact)

note tau is independent of object distance or observer velocity; it is an invariant; based on optic flow

gannets always retract their wings right before hitting surface of the water, regardless of initial height, indicating sensitivity to time to collision (tau?)

26
Q

How is object perception functional?

A

affordances: actions one can perform with an object

e.g., tree is for climbing, chopping, hugging, not eating
e.g., atmosphere affords visual, auditory, & olfactory perception

27
Q

What are the pros and cons of the ecological approach?

A

pros: identifying invariants adds to understanding

cons: perceptual processing exists; is important

28
Q

What is the lateral IP area?

A

represents location you plan to move your eyes to (“saccade planning area”)

29
Q

What is the medial IP area?

A

represents area one can reach to

responds to visual and somatosensory input (“parietal reach region”)

30
Q

What is the ventral IP area?

A

responds to moving nearby visual input/tactile input to face

important for feeding behavior

31
Q

What is the anterior IP area?

A

represents important shape information for grasping objects

located between sensory and motor areas

contains neurons that respond to visual stimuli and physical action

nearby neurons (in intraparietal sulcus) implicated in cognitive functins that require integration of sensory and motor information (e.g., movement planning, spatial attention, and decision-making)

sends projections to premotor cortex and then to motor cortex

32
Q

What are the types of AIP neurons?

A

motor-dominant
visual-dominant
visual and motor

33
Q

What are motor dominant AIP neurons?

A

respond when action performed in the dark or in the light, but not to seeing visual cue

34
Q

What are visual dominant AIP neurons?

A

respond when action performed in the light, but not in the dark

35
Q

What are visual and motor AIP neurons?

A

respond to action in the light, and to a lesser degree to action in teh dark, or to visual cue alone

36
Q

How were mirror neurons discovered?

A

probed premotor cortex (area F5) in brain of macaque monkeys

neurons responded when monkeys grasped a piece of food

by coincidence, one researcher reached for a banana, and some of the neurons reacted

37
Q

What are mirror neurons?

A

activated when a goal-directed action is performed, and when a similar action is observed

found for grasping, manipulating, or placing objects

38
Q

What are the features of mirror neurons?

A

require biological motion: no response if object picked up with pliers

seems to be an execution-observation matching system (e.g., mirror neurons active as novice guitarists watched a professional play chords)

no response when action observed without object

no response to mere visual presentation of objects

audio-visual mirror neurons can be triggered by visual information and by the sound of a particular action

mirror neurons infer the goal of an observed action

mirror neuron activation dependent on understanding intentions; intentions transcend the context of an action; they require comprehension of the “hypergoal”

39
Q

What was the research by Ramachandran (1996) on mirror neurons in humans?

A

patients with a right-hemisphere stroke have paralysis of the left side of their body; about 5% of patients deny their paralysis (“denial syndrome” or anosognosia) and that of other patients too

some evidence suggests Broca’s area (speech production) in humans is comparable to F5 in monkeys

activation found in areas of the human premotor cortex when: reading literal phrase, watching a video of fruit being bitten or a pen being grasped, but not by a metaphorical phase

40
Q

What was the research by Saygin et al. (2012) on biological motion and mirror neurons?

A

fMRI brain scans taken of observers watching video of recognizable actions by: a person, an android, a robot endoskeleton

less activity in anterior intraparietal sulcus when viewing robot endoskeleton

activity may be due to mirror neuron system

41
Q

What role have mirror neurons played in evolution?

A

changes in human development over time are not due simply to increases in brain size, or unaccounted evolutionary changes

mirror neurons may account for rapid spread of innovations (“see one, do one, teach one”)

mirror neurons may simply have become activated by environmental triggers, causing the so-called big bang; perhaps due to an increase in “learnability”

mirror neurons are necessary, but not sufficient for advances to occur