EXAM: Disorders of visual attention

Question 1

Visual attention definition

Answer 1

Visual attention is the cognitive process that allows individuals to selectively process information from their visual environment, focusing on important stimuli while filtering out irrelevant ones.

Question 2

INTRO

Answer 2

Define visual attention

• State that damage to specific brain regions can lead to distinct attentional syndromes
• Introduce the two key disorders: Neglect and Balint’s Syndrome
• Briefly justify the value of studying brain-damaged individuals: helps us understand which brain areas are involved in attention and what happens when they malfunction

Question 3

PARA 1a - NEGLECT defintion and symptoms

Answer 3

a. Definition & Symptoms:

• Neglect is a lack of awareness of stimuli on the side opposite to brain damage (usually left side after right hemisphere damage).
• Not due to blindness – it’s an attentional deficit.
• Examples: not shaving left side of face, leaving food on left of plate, only turning right when giving directions (Brian, 1941).

Question 4

PARA 1b - NEGLECT types

Answer 4

b. Types of Neglect:

• Spatial Neglect – not scanning the left side of a scene.
• Egocentric Neglect – failure from own spatial perspective (e.g. line bisection task).
• Allocentric Neglect – failure to perceive left side of objects (e.g. clock drawing task).

Question 5

PARA 1c - NEGLECT causes and brain areas

Answer 5

Causes & Brain Areas:

• Commonly caused by stroke, particularly in the middle cerebral artery.
• Often involves damage to right posterior parietal cortex, especially Brodmann areas 39 and 40.
• Vallar & Perani (1986): found inferior parietal region as a common damage site across neglect patients.

Question 6

PARA 1d - EXCNTINCTION

Answer 6

Milder form of neglect

• Patients can detect left-sided stimuli only when no competing stimuli are present.
• Example: shoulder tapping test – only feel the right tap when both sides are tapped simultaneously.

Question 7

PARA 2a - BALINT SYNDROME definition and causes

Answer 7

a. Definition
* Rare disorder caused by bilateral parietal lobe damage.

Question 8

PARA 2b - BALINT SYNDROME symptoms

Answer 8

b. Symptoms:

o Simultagnosia – can’t perceive more than one object at a time.

o Optic ataxia – impaired hand-eye coordination.

o Oculomotor apraxia – difficulty moving eyes smoothly to scan the environment.

Question 9

PARA 3a - EVALUATION AND COMPARISON - theoretical value

Answer 9

Theoretical value:

Both syndromes reflect the dorsal vs. ventral attention system distinction

Neglect - Disruption of ventral (bottom-up attention).

Balint’s - Disruption of dorsal (top-down, goal-directed attention).

Question 10

PARA 3b - EVALUATION ANDS COMPARISON - clinical relevance

Answer 10

Early detection is crucial for stroke and brain injury recovery.

Tools developed from research:
o Neglect: line bisection, clock drawing.
o Balint’s: reaching tasks to assess optic ataxia.

Question 11

PARA 4 - LIMITATIONS

Answer 11

Patient variability - symptoms and damage locations differ across individuals so absolute conclusions that generalise onto whole population cannot be drawn

Neglect vs. extinction: exact relationship still unclear

Question 12

CONCLUSION

Answer 12

• Studying neglect and Balint’s syndrome gives valuable insight into how attention is organised in the brain.
• Each disorder highlights the importance of different attention systems (ventral vs. dorsal).
• Despite some limitations, research has led to both theoretical advancements and practical tools in clinical neuropsychology.