17Su11Lec10

17Su11Lec10 - CS17 Neurobiology of Cognition Summer 2011...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
CS17 Neurobiology of Cognition Summer 2011 Lecture 10: Learning and Memory LEARNING = The development of a permanent change in behavior based on experience - Law of Effect : Stimulus/Context/Act associated with Reinforcement, will be repeated = “ Conditioning - Classical Conditioning = Developed association between stimuli - e.g. Dog salivates to Food. Pair Food (Pos Reinforcer=StimA) w/Bell (Conditioned Stimulus=StimB); Soon dog salivates to Bell alone, via association between Stim A & Stim B - Operant Conditioning = Developed association between stimulus and response -e.g. If pigeon pecks (Response) Target (Cond Stimulus) gets Food (Pos Reinf); Soon pecks often - e.g. While pigeon pecking target, Shocked (Neg Reinforcer) but only when Light (Conditioned Stim) on; Soon pigeon will stop pecking (Cond Resp) whenever light comes on (thus avoiding aversive shock) - Temporal Contiguity critical in both i.e. above events must Co- Occur to become associated in learner’s mind - Presumably, it is this co-occurrence that leads to the neural co-activity of the stimulated circuits - Hebbian Cell Assemblies (proposed by Hebb as the fundamental neural process involved in Learning) = Co-activated neural circuits involved in learning and retrieval of associations (Fire Together:Wire Together ) - Mechanisms responsible include structural or metabolic changes in NT availability, release, and/or reception - In contemporary computational models, involves development of “weighting” chang es across Neural Nets Long-Term Potentiation (LTP) (Semi-)permanent structural and connectivity changes , via variety of mechanisms: - Post-Synaptic : Include structural changes in Receptor Sites, Dendritization, etc. - e.g. Hippocampus in the Rat, in which the best- studied mechanisms of LTP involve… - Cells w/multiple types of Glutamate Receptor Sites on the same cell; Some sites harder to trigger than others - AMPA Receptor Sites respond well to Glutamate (Ionotroipic: Allow Na+ in to excite Post-Synaptic cell) - NMDA Receptor Sites only respond to Glutamate if cell already partially hypo-polarized by above - Typically Magnesium ions ( Mg++ ) block these gates that, when opened, allow Na+ & Ca++ to enter
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/07/2011 for the course COGS 17 taught by Professor Pineda during the Spring '06 term at UCSD.

Page1 / 2

17Su11Lec10 - CS17 Neurobiology of Cognition Summer 2011...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online