There is an interesting must watch Video of Paul Phillips discussing dopamine based learning and I have embedded the video below. Please do have a look. Original video with some other relevant information can be found here.

Paul discusses the dopamine surge at the Unconditioned Stimulus/reward (US) before the training being replaced by a dopamine surge at Conditioned stimulus(CS) after the learning and how this has led to the reward prediction theory (Schultz) of dopamine function. He also discusses the Cambridge(UK) or Ken Berridge group of objections to this and their discovery that different regions of the brain react differently (ventral and dorsal striatum have different dopamine surges associated with the same stimulus/reward pair in the same animal). He uses electrochemical methods (suing electrodes implanted in the rats brains) to measure tonic dopamine release and there are interesting and informative graphics as well as videso of rats indulging in approach behavior as soon as CS is presented (after conditioning).

He also discusses model-free and model-based reinforcement learning paradigms and discusses how dopamine is only necessary for model-free (simple value association) learning and is not necessarily involved in model-based learning. this he demonstrates beautifully with videos and graphs of selectively bred mice (bred for locomotion), in which high locomotors follow a different (sign-based or model-free) while the low locomotors display goal based or model-based learning. By dopamine manipulations (giving a dopamine antagonist) he is able to show that dopamine is not really necessary for model-based learning.

All in all a very engaging and informative video. A must, must watch that is very highly recommended for anybody who has given a minor thought also to dopamine and what it does in the brain.

Reblog this post [with Zemanta]
Share
Delicious
Save
GD Star Rating
loading...
GD Star Rating
loading...
Dopamine mediated 'sign' based learning, 9.0 out of 10 based on 1 rating
Wikio
Wikio

Effecient Related Posts:

Related posts:

  1. Causal learning: how different is it from normal learning? I was browsing a write-up on Causal reasoning by Mixing...
  2. Basal Ganglia: action selection, error prediction and reinforcement learning The December edition of Dana Foundation’s online brain journal ,...
  3. Inability to learn from mistakes: The dopamine effect In one of my recent posts on the role of...
  4. Neurogeneisis, learning and small-world networks Continuing this blog’s recent focus on categorization, one possibility of...
  5. Obesity and the dopamine connection I had blogged previously regarding the obesity and dopamine connection...