Lecture 5: The Neuropsychology of Vision for Perception and For action (2)

Question 1

What is Anoxia?

Answer 1

When too little oxygen reaches the brains tissues

Question 2

What is apperceptive agnosia?

Answer 2

A neurological condition where individuals struggle to perceive and process visual information, leading to difficulties recognising objects even though they can see them

Question 3

What are D.F’s symptoms?

Answer 3

• Unable to identify shapes of objects
• Objects recognised by colour
• Ability to identify shades of the same colour and texture
• Unable to identify boundaries of overlapping objects with similar colour or texture

Question 4

What caused D.F’s symptoms?

Answer 4

Carbon Monoxide Poisoning

Question 5

What is the Efron test?

Answer 5

The standard test for visual form agnosia

Question 6

What does the Efron test measure?

Answer 6

Levels of visual form agnosia

Question 7

How is the Efron test measured?

Answer 7

Participants are given two-dimensional shapes that are either identical or slightly different. The patient is then asked to report if the shapes are the same or different.

Question 8

What does a low score on the Efron test signify?

Answer 8

A form of agnosia deficit

Question 9

What are the three other testable abilities

Answer 9

• Grasp Ability
• Negotiating Obstacles
• Matching + Posting

Question 10

How is the grasp ability tested?

Answer 10

Using Efron’s blocks to measure how a participant can grasp differing shape sizes

Question 11

What are Efron’s blocks?

Answer 11

Rectangular blocks that are designed to identical in every way but length and width.

Question 12

What are Blakes Shapes?

Answer 12

Similar to Efron’s blocks, they are made to measure grasping skill, however, these shapes are asymmetrical and therefore the grasp point selection varies

Question 13

What does it mean to navigate obstacles?

Answer 13

To overcome a physical barrier through careful planning and action

Question 14

What is “matching”?

Answer 14

When you match two distinct parts together

Question 15

What is “posting”?

Answer 15

When you put an item into a designated spot

Question 16

What is Good et al’s 1991 task?

Answer 16

A matching and posting task where you turn the card to match the orientation of a slot and post it

Question 17

What is Balint’s syndrome?

Answer 17

A neurological disorder caused by bilateral damage to the posterior parietal and occipital lobe, caused by a stroke or a brain injury

Question 18

What is the triad of characteristics?

Answer 18

• Optic ataxia
• Ocular apraxia
• Simultanagnosia

Question 19

What is the simultanagnosia?

Answer 19

Difficulty perceiving more than one object at a time

Question 20

What is ocular apraxia?

Answer 20

Difficulty shifting gaze

Question 21

What is optic ataxia?

Answer 21

Difficulty reaching for objects

Question 22

What is the “What vs How” system?

Answer 22

A pathway that combines the what and how streams

Question 23

What does “What” refer to in the “What vs How” system?

Answer 23

The ventral stream which processes visual information for object recognition and perception

Question 24

What does “How” refer to in the “What vs How” system?

Answer 24

The dorsal stream that processes visual information for spatial localisation and guiding actions

Question 25

What is the frame of reference?

Answer 25

A system used to describe the location of objects in a visual space

Question 26

What frame of reference does the dorsal stream use?

Answer 26

Egocentric (Spatial information is represented relative to the individuals own body or head perspective)

Question 27

What does the dorsal stream use the relevant frame of reference for?

Answer 27

Can pick up the object

Question 28

What does the ventral stream use as a frame of reference?

Answer 28

Allocentric (Objects and their locations are represented relative to their environment)

Question 29

What does the ventral stream use the relevant frame of reference for?

Answer 29

Identifies the object

Question 30

What are depth cues?

Answer 30

Visual signals that help the brain perceive depth and distance, creating a three-dimensional image

Question 31

What depth cues does the dorsal stream handle?

Answer 31

Stereopsis - Perceiving depth and 3D space through both eyes Convergence - The merging of information from different sources or processing pathways into a single stream or area of the brain

Question 32

What depth cues does the ventral stream handle?

Answer 32

Pictorial depth cues - Monocular cues like perspective, texture gradients and relative sizes.