From comparative cognition to comparative cognitive neuroscience

Shigeru Watanabe

Keio University, Japan

I will discuss on relationships between comparison of cognition (function) and comparison of brains (structure). Some cognitive function is executed by different structures. Some "homologous" structure has different functions. And some function seems to not need network system. Followings are topics I will mention.

1) Does visual cognition need neocortex?

We have 6 layered neocortex but dolphins, that have highly developed cognition, do not have such neocortex. Furthermore, birds do not have neocortex even though they showed well sophisticated visual cognition.

2) Does spatial cognition need hippocampus?

The hippocampal damages cause deficits in episodic memory in humans and spatial memory in rodents. There are good correlation between size of hippocampus and capacity of spatial memory in food storing birds. But some animal has good spatial memory without hippocampus.

3) Does reinforcement need nucleus accumbens?

One hypothesis of reinforcement is a general pleasure circuit in the brain. That is, release of dopamine in nucleus accumbens is essential for pleasure. I will demonstrate planarians show amphetamine seeking behavior in conditioned place preference experiment. The results suggest that our stimulants seeking behavior can be traced back to the age of invertebrates. In other words, the pleasure circuit is not necessary for pleasure.

Watanabe, Shigeru

Department of Psychology, Keio University

2-15-45, Mita, Minato-ku, Tokyo, 108-8345, Japan

swat@flet.keio.ac.jp