Week 3 lecture 1- Visual disorders

Question 1

Information processing

Answer 1

Passive
Bottom-up process

Question 2

Perception

Answer 2

Active
Both top-down and bottom-up
Can be disturbed

Question 3

Representation

Answer 3

Knowing the position of things

Question 4

Visual perception

Answer 4

Reconstruction of a distal stimulus based on a (weaker) proximal stimulus
Allows us to understand the environment and interact with it
Allows us to predict out environment

Question 5

Types of neuro visual disorder (visual disorders after ABI)

Answer 5

1. Lower order
   -Hemianopia, achromatopsia
   -assessed by optometrist or ophthalmologist
2. Higher order
   -Visual agnosias
   eg. prosopagnosia, balint’s syndrome
   -assessed by neuropsychologist

Question 6

prosopagnosia

Answer 6

Not being able to recognise faces that should be similar
still recognise people by the way they walk, talk, posture, clothing
Can be caused by damage to fusiform face area (ffa)

Question 7

Alternative approach to causes of impaired visual perception

Answer 7

1. Eyesight not optimal for circumstances (brain has to work harder)
2. Quality of distal stimulus
3. Something goes wrong in reconstruction process

Question 8

Hemianopia symptoms

Answer 8

Visual:
restricted overview
feeling disoriented
bumping into objects or people; not seeing them in time
reading problems (not understanding what they read)
Non visual:
Anxiety
Mood disorders

Question 9

Interventions for hemianopia

Answer 9

Adjustment of environment
Adaptation
Restoration of brain function
training of impaired brain function
compensation

Question 10

distal and proximal stimulus

Answer 10

Distal: real world, far away
Proximal: what your eyes can see

Question 11

Agnosia

Answer 11

Agnosia: inability to visually recognize or identify objects or people despite having ‘normal’ visual functions, memory, attention, etc

Question 12

interventions for prosopagnosia

Answer 12

compensating- Look at voices, hair, clothing
Change distal stimulus

Question 13

balint’s syndrome

Answer 13

Disorder of the reconstruction of the space around us

Question 14

Types of balint’s syndrome

Answer 14

1. Dorsal simultanagnosia
2. Optic ataxia
3. Oculomotor apraxia (‘sticky fixation’)

Question 15

Dorsal simultanagnosia

Answer 15

• Not being able to ‘see’ two objects at the same time (i.e. not able to keep an active representation of more than one object at the same time)
• Not being able to relate objects in different spatial positions to each other
• Impaired spatial cognition
• Impaired spatial attention

Question 16

Optic ataxia

Answer 16

• Seeing an object, but being unable to locate it, relate it to a certain position in space
• Disturbed direction of hand and arm movements to reach for an object (because the position of body with respect to the object is not
  clear)

Question 17

Oculomotor apraxia

Answer 17

• Not being able to make voluntary eye movements from one object to an other object (i.e. not being able to perform a visual search task)
• Bottom up processing of objects that ‘demand’ attention is still possible

Question 18

Alternative to traditional approach to visual disorders

Answer 18

-Neurovisual disorders can be defined as ‘disorders of reconstruction’ of the distal stimulus
-agnosias and anopsias: One specific aspect of reconstruction is impaired or not taking place at all. Typically occurring after focal brain damage (e.g. ischemic stroke)

Question 19

PD Visual problems

Answer 19

Difficulty reading
Blurred vision, trouble focussing
Problems with reduced contrast
Being blinded more often by (bright) light
Needing more light
Double vision, hallucinations, needing more time to see, participation
in traffic
Greater impact of visual problems in daily life compared to control
group

Question 20

MS visual problems

Answer 20

Being blinded by bright light
Having difficulties adjusting to changes in light
and dark
Needing more light
Needing more time to see
Reduced contrast