1. Space
Psychology 3926

2. Introduction Vitally important Virtually ubiquitous
How is it represented
How is it used?

3. Path Integration Simplest form of navigation that uses memory
Cataglyphis, the Long Legged Desert Ant
Twisting outgoing path, but a direct path home.

4. Path Integration Animal Stores direction and distance
Simple vector mathematics
Animal must maintain a running calculation
Error will be cumulative
How could it be improved?

5. Path Integration and Landmarks
While ‘integrating’ the animal could, periodically, take a fix.
Probably from the stars or the sun
Clock shift experiments show this to be true!
Same thing sailors used to do with a sextant (or a GPS today)
But stellar position changes over time, animal cannot have stellar positions hardwired!

6. Beacons and Landmarks A beacon directs behaviour towards it
A landmark points toward a goal, along with other cues
Both are used by many animals
There have been some great strides made in understanding various species’ use of landmarks in the last 20 years

7. Bees!!
So, the bee seems to be matching the SIZE of the retinal image with the size of the image in memory
Colour change has no effect
Making the landmark a ‘wireframe’ has no effect
Training
Half size test
Double Size test

8. Two Landmarks Bees are sort of half using angular information
Training
Stretch Test
Bees are sort of half using angular information
3 Peak places of search in the Stretch test
Collett, Cartwright, Cheng and their colleagues
Rotation Test

9. Landmark Use in Pigeons
Ken Cheng’s (1989) work
Landmark
Goal

10. Tests of Pigeon Landmark Use
Search
Animal searches along the same axis of landmark shift
Does not COMPLETELY follow the landmark
But, does not shift search in the other direction

11. Further tests of….
Now the shift is up down, so the animal searches in the ‘up/down’ axis
Landmark
Search

12. The Vector Sum Model
Cheng concluded that the pigeons must be adding self – goal and goal to landmark vectors.
This is the only model that explains the search patterns
Eureka!

13. How do we know they are averaging vectors?
Ken Cheng is like way smart
Basically made two predictions
Direction averaging vs vector averaging
Vectors!

14. Environmental Shape Ken Cheng rules the universe
Cheng (1986) got the ball rolling
Or the cocoa puff, as the case may be…
Basically, he found that rats would use geometric information to locate food in a rectangular arena
Most of their errors were to rotations of the originally baited location

15. Cheng (1986) He then applied featural information
walls
corners
The rats still made errors, though most of these were rotational errors
He concluded that the rats were responding to the geometry of the box.

16. Hermer and Spelke (1994) Tried the Cheng task with toddlers and adults
Disoriented the subjects
Using a cue
Toddlers are not unlike rats
Adults are different, seem to follow the cue
Same in Pike (2001)

17. Brodbeck, Spracklin and Pike (2003)
We decided to rotate the object
A rectangle on a computer monitor
Subjects (or participants, or whatever..) were shown a red dot on a black rectangle
The rectangle was spun about the middle
Dot faded
Where was the dot?

21. Uncued Test Results Original Dot Location 31.0% +/- 2.77
Reflection Error
18.2% +/- 3.43
17.4% +/- 2.88
Rotational Error
33.4% +/

24. Cued Rectangle Results
Original Dot Location
37.2% +/- 3.58
Reflection Error
11.6% +/- 3.38
10.8% +/- 2.88
Rotational Error
40.4% +/

25. Uncued Square Original Dot Location 23.2% +/- 2.57 Reflection Error
24.8% +/- 3.46
23.4% +/- 2.99
Rotational Error
28.6% +/

26. Cued Square Original Dot Location 34.2% +/- 2.79 Reflection Error
23.2% +/- 3.63
28.0% +/- 3.01
Rotational Error
14.6% +/

27. So if it is all modular
Well if it is we need integration of information right
So the spatial is just, perhaps, one component of the cognitive map
Different parts coming together to form a (potentially) hierarchical representation

28. Brodbeck, 1994 Chickadees would find a seed in a feeder
Usually return later and eat it
Move them around to dissociate colour and spatial location
The chickadees responded last to the correctly coloured feeder
Non storing Dark Eyed Juncos responded to all three cue types equally

29. Tests of cognitive mapping
Probably the coolest experiment ever to test the idea of a maplike representation was done by Jim Gould
You cannot interpret his results without resorting to mapping

30. Conclusions Spatial stuff is well studied Great example of modularity
Many comparisons have been made, more will be made