Thinking!

1. Thinking! Psychology 2606

2. Some introductory thoughts • We are clearly the most cognitively complex animals on this planet • We can think about objects that are not present • We can think about abstract ideas • We use symbolic and syntactic language • We plan and string events together

3. So, how is thought encoded in the brain? • Monkeys, dots, motion and V5 • So, individual cortical neurons were detecting motion and making decisions • Hebb’s idea of the cell assembly • The association cortex is key in thought • Anything not primary is association (that is most of the cortex) • Receives input from the thalamus, but from areas that themselves get input from primary sensory areas

4. Spatial cognition • Our ability to deal with spatial stimuli may have helped us evolve ‘consciousness’ • That and the standing up and big heart thing • We seem to have specialized sub systems to deal with different types of information • Modules if you will

5. A Purely Geometric Module in Human Spatial Representation? David R. Brodbeck 1 Andrea E. Pike 2 Cory Spracklin 1 Department of Psychology 1-Sir Wilfred Grenfell College, Memorial University of Newfoundland, Corner Brook, NL 2-Memorial University of Newfoundland, St. John’s, NL

7. Introduction • 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

8. 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.

9. 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)

10. Method • 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?

14. Uncued Test Results

17. Cued Rectangle Results

18. So what? • Well, it seems that whenever they can, people will use geometry in this task • Even if there is a reliable cue • What if we made geometry useless? • A square

19. Uncued Square

20. Cued Square

21. What does it all mean? • Evidence of a feature independent geometric module • People will use features, if forced • Under certain circumstances • Rotational errors disappear when geometry is useless • Errors then become based on the feature

22. So, What Does It All Mean? • Clear evidence (we think) of a feature independent, geometric module in human spatial processing • Perhaps if we slowed the rotation we would find better performance, and fewer rotational errors in the cued condition • (Rotation was titrated until we found errors reliably)

23. Future Directions • Does Length : Width follow Weber’s Law? • What if the dot was put closer to the centre of the stimulus? • Touch screen • Hmmm what about pigeons?

24. Thanks to

25. So we have a spatial module • It may be the case that input from this spatial module, or cell assemblies on top of cell assemblies comes together in associative areas • These modules can be isolated WITHOUT wet neurophysiology • So, ‘the dot is here’ could be considered a ‘thought’

26. Putting it together • In the cortex there are columns, individual bunches of cells that go across layers of the cortex that seem to for circuits together • Is this the unit of thought? • Well, it might have something to do with it • But still, we put all of our sensory and memorial thoughts together to form an experience

27. We started philosophically, why not end that way • So, how are all of these things put together into an experience? • The Binding Problem • This, and the engram may be the holy grails of neuroscience and psychology