Lecture 8

Question 1

Navigation

Answer 1

Involves skilfully getting from one place to another

Question 2

Spatial orientation

Answer 2

• Ability to see and understand relationships between shapes, spaces and areas
• Acquired representation of the goal’s location and how to get it
• Sense of direction

Question 3

Why do animals need to navigate their environment?

Answer 3

1. Find places of refuge or get home after displacement
2. Food sources or something they previously left behind (target finding)
3. New homes or to travel between places (dispersal and migration)

Question 4

Dead reckoning

Answer 4

Using one’s current position to determine the subsequent movement towards a target
Path integration
Egocentric spatial localisation

Question 5

How does dead reckoning work?

Answer 5

Information collected while moving:
1. Step length (translational information)
2. Step orientation (directional information)
3. Turn (rotational information)
When using dead reckoning the animal is not moving toward a set location in space, it is travelling back in the relative direction from which it came

Question 6

Benefits of dead reckoning

Answer 6

• Useful to nocturnal animals
• Useful to cover large areas
• Useful for round-trip excursions to explore new environments before learning about reliable external cues

Question 7

Limitations of dead reckoning

Answer 7

• Errors accumulate

- It does not compensate for an off-course displacement

Question 8

Allocentric spatial localisation

Answer 8

Mechanism to locate a goal or animal with respect to external references (beacon or landmark)

Question 9

Beacon

Answer 9

Proximal (local) cue - close to goal

By-product if Pavlovian conditioning?

Question 10

Landmark

Answer 10

Distal (global) cue - prominent environmental feature located at a distance that guides in navigation
e.g. a mountain located on the way to a bird’s perch

Question 11

How to determine if an animal uses beacons and landmarks for navigation?

Answer 11

The water-maze experiment
Morris 1981
Rat placed in a circular pool of water in which it swims until it finds a small dry platform (cylinder standing in pool)
For some rats the cylinder is black and visible above the water (acts as beacon)
For others the water is opaque and the platform is slightly below the surface, so the rats must use distal cues (landmarks)
Rats can learn to locate an object provided it remains in a fixed spatial location to the landmarks

Question 12

How do animals use landmarks?

Answer 12

1. Template matching and local views e.g. digger wasps and bees
2. Vector sum model e.g. gerbils
3. Multiple bearings model e.g. Clark’s nutcrackers

Question 13

Template matching

Answer 13

Comparing current view of surroundings with ’snapshot’

Honeybees (Cartwright and Collett, 1983)

Question 14

Local view hypothesis

Answer 14

Album of ‘snapshots’ associated with a vector from goal

Question 15

Vector sum model

Answer 15

Cheng 1988
Finding a goal based on the distance the goal is from landmarks
Predicts that when a landmark is shifted in one direction from its usual position, an animal’s peak place of search is also shifted in that direction

Question 16

Multiple bearings model

Answer 16

Kamil and Cheng, 2001

• Finding a goal using bearings (compass directions)
• Additional bearings will increase search accuracy
• Confines the search of the original location to a smaller area
• Clarke’s nutcrackers rely on multiple and perhaps distant landmarks to relocate their buried caches, and can relocate about 80% of hidden food in a month

Question 17

Route formation

Answer 17

1. An animal either learns a chain of responses necessary to get from point A to point B (Lorenz, 1952 - shrews just learn a series of responses)
   or
2. Learns to complete certain navigational manoeuvres at landmarks along a path (memorising distances and directions with respect to landmarks)

Question 18

Why would it be adaptive for animals to ignore some cues?

Answer 18

The larger the number if cues the larger the cognitive demands

Question 19

Cognitive maps

Answer 19

Internal maps that animals have that might serve the same function as a physical map

Question 20

Do animals have cognitive maps?

Answer 20

Difficult to answer, different definitions

Simpler mechanisms may be used instead

Question 21

Latent learning

Answer 21

Ability to take novel shortcuts in mazes