P&A

Question 1

What is perception?

Answer 1

Decoding of information about the world within a given modality.

Question 2

According to DeBruine, Hahn & Jones (2016), which statements are correct regarding perception of infant faces?

a) Men have greater preference for infant faces that resemble them
b) Women’s perception of facial cuteness varies throughout the menstrual cycle
c) Women on the contraceptive pill have poorer performance on a test discriminating between high and low-cuteness versions of infant faces
d) Cuter infants are perceived to be healthier

Answer 2

a, b and d are correct. Sprengelmeyer et al found women on hormonal contraception had better discrimination for facial cuteness in infants. However, other studies have found no difference in performance between women using and not using hormonal contraceptives.

Question 3

What do the ventral and dorsal visual streams do?

Answer 3

The ventral stream is involved in perceptual processing and object recognition.

The dorsal stream is involved with guiding our movements.

Question 4

Where does evidence for a separate ventral and dorsal stream come from?

Answer 4

Milner & Goodale studied a patient, DF, who had brain damage affecting object recognition. This patient was still able to interact with objects, suggesting a separate stream for object recognition and motor interaction.

On the other hand, patients with optic ataxia are able to recognise objects but are unable to generate purposeful movement towards the object. This is thought to be due to damage to an area involved in the dorsal stream (posterior parietal region).

Question 5

What is perceptual categorisation?

Answer 5

Determining whether one has seen the object previously.

Question 6

What is semantic categorisation?

Answer 6

Naming objects and identifying their function.

Question 7

What is meant by ‘stimulus equivalence’ in object recognition?

Answer 7

The fact that a countless number of retinal images could correspond to the same object, making object recognition difficult.

Question 8

What was the ‘grandmother cells’ hypothesis?

Answer 8

The suggestion that individual neurons were responsible for every view of an object. This has been criticised as it would require an unrealistic number of cells. For example, it is now thought that face cells do not respond to specific faces but a subset of all faces.

Question 9

What is aperceptive agnosia?

Answer 9

A deficit of perceptual categorisation. The individual has trouble recognising objects from unusual views.

Question 10

What is associative agnosia?

Answer 10

A problem with semantic categorisation. The person can recognise objects in isolation but is unable to link two objects that share the same function eg: an open and closed umbrella.

Question 11

What is prospagnosia?

Answer 11

An inability to recognise faces.

Question 12

An ordinal cue:

a) Is a binocular cue telling you which order objects are in
b) Is a monocular cue telling you which order objects are in
c) Makes use of horizontal disparities
d) Makes use of vertical disparities

Answer 12

b) An ordinal cue is a monocular cue telling you which order objects are in.

Question 13

Egocentric distance perception describes:

Answer 13

Gauging the distance of an object from your body.

Question 14

Which statements are true regarding a ‘robust statistic’?

a) The mean is a robust statistic.
b) A robust statistic describes the data when outlying values are not present
c) A robust statistic describes the data when outlying values are present
d) The nervous system is ‘robust’, having evolved to deal with erroneous information

Answer 14

c and d are true. The mean is not a robust statistic whereas the median is. A robust system is one that optimally describes the data when outliers are present.

Question 15

Which statement is true regarding distance perception?
a) Accommodation is the most important distance cue for humans.
b) Accommodation can act as a source of ordinal
depth information in the absence of other depth cues,
c) Vergence is not a useful source of distance information
d) Accommodation provides relative information regarding distance

Answer 15

b) Mon-Williams and Tresilian (2000) argued that accommodation can act as a source of ordinal
depth information in the absence of other depth cues. They suggested that accommodation’s ordinal role might be related to the use of vergence angle caused by the neural crosslinking of accommodation and vergence.

Question 16

Which statement is correct?

a) Doubts about the usefulness of vergence as a distance cue came from studies which placed objects less than 3m from the participant.
b) Horizontal image disparities provide body scaled information regarding the distance of the object being fixated.
c) Horizontal image disparities provide relative information regarding layout.
d) Vergence relies on occlusion of objects.

Answer 16

c is correct.

a is incorrect as studies which found vergence was not a useful distance cue placed objects more than 3m away from the participant. It is unlikely vergence provides useful information at such large distances.

Horizontal retinal image disparities provide a powerful impression of layout but need to be ‘promoted’ in order to provide body-scaled information. In order to promote the information it is necessary to know fixation distance. It appears that the system uses a combination of vertical disparity and vergence information in
order to gauge fixation distance for the purpose of promoting retinal image disparities.

Ordinal information relies on occlusion.

Question 17

Tresilian and Mon-Williams explored how humans used vergence in distance perception and found:

a) Vergence weighting increases with increasing fixation distance
b) Vergence weighting decreases as other cues become available.
c) Vergence plays a larger role in distance perception if it is discrepant with other information about an object’s distance
d) Vergence angle gets smaller with decreasing fixation distance.

Answer 17

b is correct. Vergence weighting decreases as other cues become available.

Vergence weight decreases with increasing fixation distance.

The degree to which the cue conflicts with other cues (its discrepancy) reduces the weight given to that cue.

The vergence angle gets smaller with increasing fixation distance so the reliability of vergence decreases with distance.

Question 18

What are the two phases in prehension?

Answer 18

1) Pre-contact phase

2) Grip-and-lift phase

Question 19

What is meant by a ‘redundant system’?

Answer 19

There are countless numbers of possible routes open to the system meaning if one route is blocked another can be used.

Question 20

Which statement is correct?

a) Load force only occurs once gravity has been overcome
b) Visual size cues influence the force produced regardless of memory of the force required to lift the object.
c) Due to the size-weight illusion, someone will lift a small object which weighs the same as a larger object with increased force.
d) As a memory representation of the object becomes available, the influence of visual size decreases.

Answer 20

d is correct. Memory of the weight of the object in relation to its size reduces the effect of visual size.

During the loading phase, the load force has to overcome the gravitational force on the object in order for it to be lifted.

When the size-weight illusion occurs, the larger object of the same weight will be lifted with greater force. The smaller object will be reported as feeling heavier.