Thinking! Psychology 2606

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

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

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

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

Introduction Cheng (1986) got the ball rolling Cheng (1986) got the ball rolling Or the cocoa puff, as the case may be… 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 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 Most of their errors were to rotations of the originally baited location

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

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

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

Uncued Test Results Original Dot Location 31.0% +/ % +/ Reflection Error 18.2% +/ % +/ Reflection Error 17.4% +/ % +/ Rotational Error 33.4% +/ % +/- 3.94

Cued Rectangle Results Original Dot Location 37.2% +/ % +/ Reflection Error 11.6% +/ % +/ Reflection Error 10.8% +/ % +/ Rotational Error 40.4% +/ % +/- 3.62

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

Uncued Square Original Dot Location 23.2% +/ % +/ Reflection Error 24.8% +/ % +/ Reflection Error 23.4% +/ % +/ Rotational Error 28.6% +/ % +/- 4.00

Cued Square Original Dot Location 34.2% +/ % +/ Reflection Error 23.2% +/ % +/ Reflection Error 28.0% +/ % +/ Rotational Error 14.6% +/ % +/- 3.77

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

So, What Does It All Mean? Clear evidence (we think) of a feature independent, geometric module in human spatial processing 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 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) (Rotation was titrated until we found errors reliably)

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

Thanks to

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 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 These modules can be isolated WITHOUT wet neurophysiology So, ‘the dot is here’ could be considered a ‘thought’ So, ‘the dot is here’ could be considered a ‘thought’

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 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? Is this the unit of thought? Well, it might have something to do with it 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 But still, we put all of our sensory and memorial thoughts together to form an experience

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