Neglect

Question 1

What is the method of “reverse engineering” in neuropsychology?

Answer 1

It involves inferring a cognitive mechanism or the function of a brain region by removing it (e.g., through injury) and measuring the effects on the rest of the system.

Question 2

Give an example of reverse engineering in neuropsychology.

Answer 2

A stroke resulting in the inability to recognize fruit, animals, or trees but retaining the ability to recognize tools, vehicles, and furniture suggests living and non-living objects are represented differently in the brain.

Question 3

What is neglect in neuropsychology?

Answer 3

Neglect is a “failure to report, respond, or orient to novel or meaningful contralesional stimuli” (Heilman et al., 1985).

Question 4

What are common behaviors of patients with neglect?

Answer 4

1. Shaving/making up only one side of their face
2. Eating off one side of a plate
3. Reading text on one half of the page
4. Bumping into walls or ignoring people on the left
5. Being unaware of their difficulties (anosognosia)

Question 5

What is the most common cause of neglect?

Answer 5

A stroke affecting the right side of the brain, particularly the right parietal lobe.

Question 6

What are common tests used to assess neglect?

Answer 6

1. Line bisection: Marking the midpoint of a line
2. Picture copying
3. Cancellation tasks: Made harder by using crowded arrays

Question 7

Does neglect only affect vision or visual perception?

Answer 7

No, neglect can affect both egocentric (self-centered) and object-centered reference frames, indicating it is more complex than just a visual problem.

Question 8

What happens during recovery from neglect?

Answer 8

Neglect often recovers spontaneously within weeks or months. This can be illustrated through self-portraits of patients, like Anton Raederscheidt, over time.

Question 9

What does “egocentric reference frame” mean in neglect?

Answer 9

It refers to neglect operating based on the patient’s own perspective, where they ignore the left side of their personal space.

Question 10

What is “object-centered reference frame” in neglect?

Answer 10

Neglect operates on the left side of an object’s intrinsic axis, even if that side is not on the patient’s egocentric left.

Question 11

What is the phenomenon of “blind-sight” in neglect?

Answer 11

It refers to patients showing responses or behaviors indicating unconscious processing of visual information in neglected areas.

Question 12

How is neglect for mental representations assessed?

Answer 12

By asking patients to draw objects from memory (e.g., clocks or flowers) or through experiments like Bisiach’s Milan Square test.

Question 13

What is extinction in the context of neglect?

Answer 13

A milder form of neglect where patients fail to detect a stimulus on the neglected side only when stimuli are presented simultaneously in both visual fields.

Question 14

What did Rees et al. (2000) demonstrate about extinction?

Answer 14

A patient correctly identified 58/60 stimuli in the left visual field when presented alone but only 2/60 when presented alongside a stimulus in the right field.

Question 15

What non-spatial deficits are associated with neglect?

Answer 15

1. Poor working memory
2. Larger and longer attentional blink
3. Problems with sustained attention

Question 16

What does neglect reveal about visual processing and attention?

Answer 16

1. Neglect operates in multiple spatial and object-centered reference frames.
2. High-level processing occurs in the absence of awareness.
3. Visual imagery is processed similarly to sensory input.

Question 17

What is the summary definition of neglect?

Answer 17

Inattention to (usually) the left side of space, typically caused by a stroke affecting the right parietal lobe.