Lecture 19 - Spatial Cognition

Question 1

What is path integration?

Answer 1

It is a continuous tracking of position and direction in relation to a starting point, based on cues derived from self-motion

Question 2

What is egocentric and allocentric frames?

Answer 2

egocentric = distances and directions of external objects relative to the observed

allocentric = distances and directions of external objects relative to each other and the environment

Question 3

Describe an experiment which identifies the neural basis of path integration

Answer 3

1. Rats placed in the dark and followed scented trails of food then return to home cage
2. Lesion to the fimbria of hippocampus retraced the outbound route instead of following homing vector
3. Deficit in similar task following lesion in MEC (medial entorhinal cortex)
4. Path integration relies on hippocampus and MEC computation

Question 4

Name three multi-sensory sources which provides self-motion cue

Answer 4

Vestibular system, optic flow and proprioception

Question 5

Name three navigational strategies

Answer 5

path integration
route learning
cognitive mapping

Question 6

Which structure is responsible for path integration? What experimental evidence are there?

Answer 6

Hippocampus and MEC

Rats followed trails of scented food in the dark and head to home cage after wards
- Lesions showed impaired ability to heading to home cage using homing vector it traced the outbound route it previously took instead

Question 7

What is route learning?

Answer 7

Navigation along specific route through a series of decision points encoded in terms of body movement

Question 8

Path integration, route learning and cognitive mapping: which one is egocentric and which one is allocentric?

Answer 8

ego = path integration and route learning

allo = cognitive mapping

Question 9

Which structure is responsible for route learning? What experimental evidence are there?

Answer 9

Right caudate nucleus

• VR experiment: test taker asked to followed the same route trained from memory
• Compare to control, route retrieval accuracy depends on activity in right caudate nucleus

Question 10

Which structure is responsible for cognitive mapping?

Experimental evidence?

Answer 10

Hippocampus

Rats with lesioned in hippocampus: impaired in learning hidden platform task

In humans: VR, take the shortest route between two locations
Way-finding accuracy associated with hippocampus activation

Question 11

What is the differences between cognitive mapping and route learning?

Answer 11

Cognitive mapping

• Flexible computation of novel routes - route learning don’t
• Allocentric - route learning = egocentric
• Representation of the location of objects and places relative to the environment

Question 12

What are place cells?

Answer 12

Cells that fire whenever the animal occupies a particular location within its environment INDEPENDENT of the direction the animal is facing

Question 13

What are grid cells and where are they found?

Answer 13

Grid cells are individual cells fires at regular intervals along vertices of imaginary hexagonal grid

Medial Entorhinal Cortex

Question 14

Grid, Place and HD cells are controlled by

Answer 14

Visual cues

Self-motion cues

Question 15

What are head direction cells and where are they found?

Answer 15

HD cells are cells that fire according to where the animal is facing, independent of its location

Postsubiculum and retrosplenial cortex in RATS

Question 16

Place cells are predominantly controlled by

Answer 16

Visual cues

Question 17

How can place cells fire without visual cues?

Answer 17

Firing updated when animals moved around in darkness
Place cells also received and can use non-visual information about self-motion

In the dark, self-motion cues can maintain place cells firing

Question 18

Grid cells combine information of … and is thought to support ….

Answer 18

distance and direction

path integration