Chapter 21 - Spatial Behaviour

Question 1

Topographic memory?

Answer 1

• A memory for the organization of the world (used to spatially navigate properly)

Question 2

Cognitive maps?

Answer 2

• A neural representation of a cognitive process such as spatial localization

Question 3

Grasping space vs. Distal space?

Answer 3

• Grasping space - space that immediately surrounds the body
• Distal space - space through which the body travels

Question 4

Time space?

Answer 4

• Encompasses autonoetic awareness

Question 5

What are the different types of spatial behaviours used by animals?

Answer 5

1) Route following - moving toward/away from a cue
2) Piloting - topographic guidance, involves cognitive guidance
3) Caching - rely on distal spatial cues (no local landmarks), humans don’t really do this
4) Dead reckoning - cues generated by animal’s movement used to calculate distance/direction from starting point

Question 6

Morris swimming tasks?

Answer 6

• Developed by Richard Morris
• rats must navigate to find platform
• There are different variations to test specific types of spatial memory

Question 7

What are the different variations of Morris’s swimming task?

Answer 7

A) Place-learning task - rat in pool must find hidden platforms, must take into account visual cues in room. A form of piloting
B) Matching-to-place task - hidden platform in new location each day, but will remain there for the rest of the trials
C) Landmark-learning task - rat must follow cue on side of pool wall. The wall cue is moved each trial. A form of route following

Question 8

Can you infer an animal’s degree of spatial memory based solely on their hippocampal volume?

Answer 8

• Yes
• Greater hpc volume = greater spatial memory

Question 9

When is dead reckoning used by rats?

Answer 9

• When animal is travelling in the dark
• In novel environments (cues are unfamiliar)
• In a location where visual cues change frequently
  *Can be impacted by lesions to hpc and fimbria fornix

Question 10

Which brain regions are engaged in mental rotation?

Answer 10

• Superior parietal lobule and the intraparietal sulcus

Question 11

What’s topographic disorientation?

Answer 11

• Disability in finding one’s way in relation to salient environmental cues; likely due to topographic agnosia or amnesia
• Can’t form new cognitive maps
• 4 main types

Question 12

Egocentric disorientation?

Answer 12

• Difficulty in perceiving the relative location of objects with respect to self
• Usually caused by unilateral or bilateral lesions to posterior parietal cortex
• Can get lost in their own homes
• Poor mental rotation and distance judgement, optic ataxia

Question 13

What’s heading disorientation (allocentric disorientation)?

Answer 13

• Inability to set course to a pre-set destination, but can recognize landmarks
• Can recognize their own location in relationship to landmarks and describe where they want to go.
• Associated with damage to right posterior cingulate cortex

Question 14

What’s landmark agnosia?

Answer 14

• Inability to recognize salient environmental landmarks to navigate
• Relatively typical object recognition for broad categories of info but impaired at recognizing specific instances
• Usually damage to right (or bilateral) medial occipital lobe, often affecting libgual and fusiform gyri, and sometimes the parahippocampal gyrus

Question 15

Anterograde disorientation?

Answer 15

• Difficulty in navigating in novel environments
• Visual learning impaired
• Visually-guided reaching usually spared
• Caused by damage to right parahippocampal gyrus (can’t create new cognitive maps)
• Like a spatial amnesia

Question 16

What’s the Ray-Osterrieth complex figure task used for assessing?

Answer 16

• Can provide patient with a complex figure to copy and this can help determine visuospatial memory (and other things)

Question 17

What cells are used to help position the brain in space?

Answer 17

1) Place cells
2) Head-direction cells
3) Grid cells

Question 18

What are place cells?

Answer 18

• Hippocampal cells that fire preferentially when animal enters a specific location in its environment
• They’re also, by extension, found in the subiculum and the entorhinal cortex
• hey can combine to form place fields

Question 19

What are head direction cells?

Answer 19

• Increased firing rate when an animal points its head in a specific direction
• Found in much of the rat limbic system
• Location doesn’t really matter

Question 20

What are grid cells?

Answer 20

• Neurons of the entorhinal cortex fire when an animal passes certain locations. Together, these locations form a grid
• Forms a coordinate system, almost like they represent longitude and latitude

Question 21

How do the three positioning cells interact and contribute to spatial behaviour?

Answer 21

• Place cells - contribute to navigation based on external cues (allocentric guidance)
• Head direction cells - role in navigation in relationship to the animal’s own location (egocentric guidance)
• Grid cells - indicated size of a space and the animal’s location within that space

Question 22

What do the end spots of place, head-direction, and grid cells all indicate?

Answer 22

• All their info ends at the hpc
• Indicates that the hpc is the location of our spatial maps

Question 23

Which area of the hpc is enlarged in London taxi drivers?

Answer 23

• The right posterior enlarged over time
• Increases in size and function as years spent as a taxi driver