Post on 21-Dec-2015
What is the issue?
• Memory as constructive process
• Coherent memory– Bits of actual memory– Context– Repetition
False Memory Experiment
• Quantitative Measurements– Inherent difficulties
• Simple measurable tasks = little error• Reproductive VS Reconstructive?
– Henry Roediger/Kathleen McDermott’s experiments
Method
• Lists of Words• “Critical Lure”• Bidirectional associations• 42-item lists read aloud• Subject wrote down as
many as could be remembered without ‘guessing’
• At the end asked to judge if they had seen certain words on the list
Experiment Results
• Critical Lure 55% (higher than in exp1)
• Recall Condition Enhanced Effect
• Had physical memories of the lures
Implications
• False Memory is quantifiable
• All memory is constructive, not reproductive – even rote recall
• Effects were substantial in a lab setting, in a traumatic situation effects are likely even more powerful
Parallel Distributed Process
• Experiences are represented in the mind by their several aspects (within descriptive categories)
• Different experiences share aspects
• Connections between two aspects are strengthened when both are activated
Dynamic Nature Of PDP Memory
• Later events alter connections
• When one aspect is used as trigger for memory, it activates all others that it is connected with
• A lack of a strong connection will allow for several weak connections to be asserted, giving rise to confusion or generalization
False Memory Simulator
• Purpose: To replicate Roediger and McDermott’s results with a neural network
• All words in list related to each other• Primarily activate themselves, but to some
extent activate similar words• If a word (critical lure) reaches a certain
threshold of excitement it will register as having been on the list
Implementation
• Each word has a weight with all other words on list– Weights stored in a matrix– Strong weight associated between a word and
itself– Vector of input words put through matrix
determines net excitation of all words– If a specific threshold is reached, the network
will output it as a recalled word