The Adaptive Nature of Memory J. R. Anderson & L. J. Schooler

Introduction The function of memory Neisser “ecological approach” “real world” More evolutionary explanations Forgetting Flaw: access to one’s past Adaptive Response: Focus on current information Human memory faces constraints

Rational Analysis How our memory system adapts Framework (three quantities): C = Cost G = Gain/the value of the memory P = Probability of a memory being needed. PG – C PG < C Artificial memory systems: information retrieval systems, libraries, and file management systems.

The Analysis of Need Probability “The probability that a particular memory is needed in a particular context” (p. 558) H = hypothesis of the memory is needed E = elements in the context Conditional Probability – P(H|E) Bayes Theorem:

The Analysis of Need Probability cont. History Factor (Prior Odds) – the history of the use of the memory. Context Factor (The Likelihood Ratio) – current context and relevancy.

Likelihood Ratio Decomposed

Odds of Recall and Latency Odds of Recall Time for Recall

The History Factor of History Factor Focus was on the effects of amount of practice and retention Practice Effect Retention Effect Need odds in relation to practice and retention:

Environmental Databases Speech of Children New York Times Authors of electronic mail Probability-in-the-future = a * probability- in-the-past Odds-in-the-future = a’ * odds-in-the-past

New York Times Recency Analysis

Interaction Between Study Lag and Retention Lag

The Relationship Between Amount of Practice and Retention Interval

Criticisms and Issues Human Communication Hominids Probability of something appearing

The Contextual Factor

The Effects of Content

Conclusion