Perception and Action part 1

Question 1

Srinivasan, Lehrer & Horridge (1990)

Answer 1

Honey bees were trained to land on ‘flowers’ (small disks with sugar solution)

When the disks were patterned against a patterned background, they were not detected, only when the disk was raised by 2 cm (3D perception)

Bees show a strong tendency to land on the edge of the disks, facing inwards

Question 2

tinbergen 1951

Answer 2

Turn back and look

Fast mapping procedure during turns in the flight away from the target

Question 3

Cartwright and Collett (1979)

Answer 3

6 flights were needed for generating a map

20 flights were needed to land at the correct angle

Cartwright and Collett (1983):
‘Snapshot model’

Question 4

JJ Gibson IN THE LATE 1950S felt that traditional laboratory research on perception was:

Answer 4

too artificial and not ECOLOGICALLY VALID

observers were NOT ALLOWED to MOVE their heads

stimuli were STATIC

Question 5

Gibson put forward the point of view that

Answer 5

motion contributes considerably to visual perception.

Perceptions are extraction of invariants from an environment which is dynamic because we move in it (optical flow)

Question 6

4 Central Concepts in Gibson’s Theory

Answer 6

OPTIC ARRAY - structure created by the surfaces, textures, and contours in the environment

OPTIC FLOW- appearance of objects as the observer moves past them

GRADIENT OF FLOW- difference in flow as a function of distance from the observer

FOCUS OF EXPANSION - point in distance where there is no flow ( THE POINT AT WHICH A PILOT LOOKS IN THE DISTANCE -there is no flow)

Question 7

OPTIC ARRAY…..?

Answer 7

The patterns of light reaching the eye can be thought of as an optic array containing all the visual information available at the retina. This optic array provides unambiguous information about the layout of objects in space.

Question 8

Bottom-up processing

GIBSONS theory was a bottom up processing theory

Answer 8

is also known as data-driven processing, because perception begins with the stimulus itself. Processing is carried out in one direction from the retina to the visual cortex, with each successive stage in the visual pathway carrying out ever more complex analysis of the input.

Question 9

Top-down processing

Answer 9

refers to the use of contextual information in pattern recognition. For example, understanding difficult handwriting is easier when reading complete sentences than when reading single and isolated words. This is because the meaning of the surrounding words provide a context to aid understanding.

Question 10

OPTIC FLOW

3 TERMS

S I E

Answer 10

Self-produced information - flow is created by the movement of the observer (WORLD MOVES PAST BECAUSE THE OBSERVER MOVES)

Invariant information - properties that remain constant while the observer is moving ( A LAND MARK)

Extraction of information that is constant from an environment that is in motion (KEEPING SIGHT OF A LAND MARK WHEN MOVING)

Question 11

MOVEMENT CREATES FLOW. FLOW PROVIDES …….

Answer 11

INFORMATION FOR MORE MOVEMENT.

Question 12

Optomotor Response……?

Answer 12

Optic Flow determines the movement

Kalmus and his fly in 1949

Question 13

Kalmus 1949

Answer 13

Walls with gratings (stripes) were used to test the influence of visual flow perception on movement of the body
When the wall is moving, the grating simulates the optic flow
Kalmus (1949): A fly turns into the same direction as the gratings move

optomotor response = optic flow determines the movement

Question 14

Blondeau & Heisenberg (1982)

Answer 14


when the drum from kalmus experiment was rotated in deferent directions the Fly makes complicated turns to adjust to the grating

Question 15

the swing room

Answer 15

Similar type of ‘optomotor response’ in humans in the ‘Swinging room’ (Lee & Aronson, 1974; Lee & Lishman, 1975; Lee & Young, 1986)

13- to 16-month-old children and adults placed in “swinging room”

In the room, the floor was stationary, but walls and ceiling swung backward and forward

The movement creates optic flow patterns

Question 16

Visual flow and body balance

Answer 16

13-16 months old infants would sway along with the room, stagger or even fall

Adults sometimes overcompensated in the opposite direction

Results show that vision has a powerful effect on balance and can even override conscious efforts to maintain posture

Question 17

Somersaulting

Answer 17

Somersaulting could be performed by learning a predetermined sequence of moves

Expectation was that performance would be the same with and without vision

Bardy and Laurent (1998) found that expert gymnasts performed worse with their eyes closed

Experts gymnasts used vision to correct their trajectory, but novice gymnasts did not

Question 18

visual flow and body balance in the swing room

Answer 18

13-16 months old infants would sway along with the room, stagger or even fall
Adults sometimes overcompensated in the opposite direction
Results show that vision has a powerful effect on balance and can even override conscious efforts to maintain posture

Question 19

People can determine to which point they are heading with an accuracy of

Answer 19

0.5 to 1 degree (Warren, 1995)

Question 20

Land and Lee (1994) fitted a car with instruments to measure

Answer 20

Angle of steering wheel

Speed of vehicle

Direction of gaze of driver

Question 21

The Physiology of Navigation

which areas are active during navigation

Answer 21

Pre Motor (Mirror area)

Posterior Parietal

Medial Superior temporal area

Question 22

Animal research looked for single cell responses

Optic flow neurons -

Answer 22

neurons in the medial superior temporal area (MST) of monkeys respond to flow patterns

Question 23

different neurons in the MST

Medial Superior Temporal area take on

Answer 23

different tasks in the analysis of the optic flow

MST
Medial Superior Temporal
Medial Superior Temporal
Medial Superior Temporal
Medial Superior Temporal
Medial Superior Temporal

Question 24

Britten and van Wezel (2002)

Answer 24

Britten and van Wezel (2002)
Monkeys were trained to respond to the flow of dots on a computer screen.
Monkeys indicated whether the dots flowed to the right, left, or straight ahead.
As the monkeys did the task, microstimulation was used to stimulate MST neurons that respond to specific directions of flow patterns.
Judgments were shifted in the direction of the stimulated neuron.

Question 25

Experiment by Maguire et al. (1998)

Answer 25

Observers learned the layout of a “virtual town”
In a PET scanner, they were told to navigate to locations in the town

Navigating activated the right hippocampus and part of the parietal cortex
Activation was greater when the navigation between points was accurate than when it was inaccurate

Question 26

Observers studied a film that showed them through a “virtual museum” (Janzen & Van Turennouts, 2004)

Answer 26

They were told that they should be able to act as a guide within the museum.
Exhibits appeared both at decision points where turns were necessary and non-decision points
Results showed the greatest activation for objects at decision points (landmarks) in the parahippocampal gyrus

TURNING POINTS ARE essential for navigating in space

Question 27

London cab drivers played an interactive computer game with accurate depictions of London streets (Spiers and Maguire, 2006)

Answer 27

They were given instructions to drive towards a destination.

In mid-route, the destination was changed
They also heard a statement unrelated to the destination

After the trip was finished, they viewed a playback and were asked what they were thinking at different points

Question 28

Spiers and Maguire looked at what for the first time in their virtual reality test with cab drivers

Answer 28

thinking protocols and brain scans

Question 29

Affordances – Visual Object Function

Answer 29

Gibson believed that you can SEE affordances of objects, i.e. there is visual information in the object about function

Affordances indicate “potential for action” as part of our perception

People with certain types of brain damage show that even though they may not be able to name objects, they can still describe how they are used or can pick them up and use them

Question 30

The Cups Experiment

Answer 30

Patients with damage to parietal lobe can show extinction - the inability to direct attention to more than one thing at a time

The left cup on the left was not detected unless there was a handle added

The fake handle did not support object detection on the left side (random choice)

Researchers concluded that the affordance for grasping may have been activating a specific network in the brain

Question 31

Affordances indicate…..

Answer 31

“potential for action” as part of our perception

Question 32

Carlton et al. (2002) identified these neurons responding specifically to goal-directed actions in the parietal reach region (PRR)

Answer 32

Parietal Reach Region (PRR)

Question 33

who detected neurons responding to specifically goal directed actions in the PRR

Parietal Reach Region

Answer 33

Carlton et al in 2002

Question 34

Observers looked a fixation point and were given a cue for the location of a target (Connolly et al. 2003)

Answer 34

After a nine-second interval, they pointed to the target
Delay: Keep the target in mind
Control condition: Just wait and see
Higher FMRI activation in the PRR region during the delay

WHEN THEY WERE THINKING ABOUT REACHING……THE PRR WAS ACTIVATED

PARIETAL REACH REGION

Question 35

Neurons in the premotor cortex of monkeys that

Answer 35

Respond when a monkey grasps an object and when an experimenter grasps an object

Response to the OBSERVED action “mirrors” the response of actually grasping

There is a diminished response if food was grasped by a tool (such as pliers) instead of hands NONSENSE-ACTIONS

Question 36

Overlap of Perception and Action

Firing occurs when the monkey sees

Answer 36

experimenter breaks peanut which produces a sound
experimenter breaks peanut
experimenter produces sound
monkey itself breaks peanut and hears sound
ACTION FEATURES ARE ENCODED

Question 37

ACTION FEATURES ARE ENCODED

Answer 37

Overlap of Perception and Action
FIRING OCCURS when the monkey sees

experimenter breaks peanut which produces a sound

experimenter breaks peanut

experimenter produces sound

monkey itself breaks peanut and hears sound

ACTION FEATURES ARE ENCODED

Question 38

Mirror Neurons in Premotor Cortex

Possible functions of mirror neurons

Answer 38

To help UNDERSTAND another animal’s actions and REACT to them appropriately

To help IMITATE the observed action

Audiovisual mirror neurons - respond to ACTION and the accompanying SOUND

Mirror neurons may help LINK –
——Sensory perceptions and Motor actions

Question 39

Experiment by Calvo-Merino et al. (2005)
Tested three groups

Professionally trained ballet dancers
Professionally trained capoeira dancers (Brazilian dance with karate-like movements)
Control group of non-dancers

They watched two videos
One with standard ballet movements
One with standard capoeira movements

Answer 39

Pre-motor cortex activation was

Greatest for ballet dancers while watching ballet
Greatest for capoeira dancers while watching capoeira
Same response for both for non-dancers

WATCHING YOUR OWN DISCIPLINE ACTIVATES THE PRE MOTOR CORTEX.