24 - Representations of the Parietal Lobe Flashcards Preview

PSYC3014 - Behavioural & Cognitive Neuroscience > 24 - Representations of the Parietal Lobe > Flashcards

Flashcards in 24 - Representations of the Parietal Lobe Deck (8)
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1
Q

What is an allocentric map?

A

A map, representing where things are relative to an external reference, e.g. the North pole

2
Q

What is an egocentric map?

A

A map which represents things relative to ourselves

3
Q

What are different coordinate frames in the brain used for?

A

Different purposes and body parts and different actions

Always relative to something

4
Q

When representing the space around us, what areas of the brain have important coordinate frames for the most common body parts?

A

Eye-centered; V1, V2, V4 (different angles in visual field fire in a particular place)

Body-Centered; somatosensory cortices (similar to eye-centred, particular body part fires particular part of brain)

Head/ear-centered
Hand centered
- We don’t know any maps that are laid out for these
- Seem to be on the fly

5
Q

What is gaze angle (eye position) needed for?

A

Calculating direction for pointing, walking

Resolving whether, when retinal motion detected, did eyes or object move

6
Q

What are the possibilities for understanding where to move our eyes?

A
  • Direct sensing of eye position (via proprioceptive sensation)
  • Remembering where you told your eyes to move (aka efference copy)
7
Q

What are some experiments which demonstrate that humans have an efference copy rather than sense their eye position when moving their eyes?

A

Finger-in-the-eye Demo

  • get sense whole room moved
  • not sensing eye position
  • brain is used to creating efference copy in the normal way, not when eye is poked
  • but when you do this you’re deflecting other muscles not just the eye

Brindley & Merton (1960)

  • lateral or medial rectus muscle seized through conjunctive with forceps and moved
  • patients perceived objects moving in opposite way
  • both eyes held with forceps and attempt to move eyes
  • patients perceive objects moving again

When attempting to move eyes, brain is creating efference copies and perceive movement

8
Q

What do eye movement commands get sent to maps in the parietal cortex to do?`

A

Update the maps of where things are

Compensate for retinal motion, so you don’t perceive world to move when your eyes don’t move