PSYC 325 Chapter Notes - Chapter 7: Auditory Cortex, Episodic Memory, Retrograde Amnesia
27 Nov 2020
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PSYC 325 Chapter 7: Semantic and Episodic Memory
• Behavioral processes
• Part 1: Review (no lecture)
• Part 2: Lecture
• Brain substrates
• Clinical perspectives
Part 1: Review (no lecture)
Behaviour
• Learning is based upon experience and results in: – Gaining new
knowledge; and/or
– A relatively permanent change in behaviour
• Memory
– The outcome of learning – it’s how we use our prior experiences
– involves the encoding, storage, and retrieval of information
Memory Processing Stages
1. Encoding: conversion of sensory inputs results in memory traces that can be accessed and
later retrieved. Steps:
a. Acquisition: Only some sensory stimuli are sustained and make the cut into
short term memory.
b. Consolidation: Changes in the brain stabilize a memory over time resulting in
storage of a long term memory.
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Memory Processing Stages
2. Storage: the result of encoding; the permanent record of information in the brain
3. Retrieval: accessing stored information. It may enter conscious awareness, and/or it
may result in a learned behaviour, such as a motor skill.
Brain Surgery and Memory Loss
Who was H.M.? Henry Molaison
• Severe epilepsy in his 20s – multiple seizures per day
• Seizure locus in medial temporal lobe known to be common –
removal could stop seizures
• 1953 – age 27 – bilateral removal of medial temporal lobe
structures: hippocampus, amygdala, entorhinal cortex
– ONLY BILATERAL LESIONS RESULT IN SEVERE AMNESIA
• Epilepsy improved greatly, but now he had profound amnesia
• Cognitively normal otherwise – a unique and special case with no issues other than
amnesia
• https://www.youtube.com/watch?v=KkaXNvzE4pk
H.M.’s Memory
• Remembered everything (knowledge, life events) up until ~ 2 years prior to surgery –
blank after that
• Could follow a conversation or watch TV shows (commercials caused forgetting what came
before), but could not encode new long-term memories
– Short term memory was intact
H.M. and Memory Systems
Studies of H.M. were the first to show that aspects of memory function depend on specific
structures (medial temporal lobe).
• Could still work with new information: intact short-term memory
• Could still remember life before surgery: old memories intact
• Could not transfer new information from short-term to long-term memory:
impaired consolidation process
H.M.’s Memory
Psychologist Brenda Milner discovered that HM could form some types of lasting memories:
• Priming was intact (e.g., word stem completion)
• Procedural: mirror drawing
• Skills: learned to play backgammon
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• All this was done without conscious awareness: HM did not recall learning these
things and would amaze himself with his own skill.
Human Memory
Forms of Memory
Long-Term Memory
• Duration of days, months, years... indefinite
• Theoretically there is no limit to how long you can remember information.
• Declarative: memories with content that can be communicated (verbal)
• Nondeclarative: memories with content that is demonstrated (nonverbal)
Document Summary
Psyc 325 chapter 7: semantic and episodic memory. Learning is based upon experience and results in: knowledge; and/or. The outcome of learning it"s how we use our prior experiences involves the encoding, storage, and retrieval of information. Memory processing stages: encoding: conversion of sensory inputs results in memory traces that can be accessed and later retrieved. Steps: acquisition: only some sensory stimuli are sustained and make the cut into short term memory, consolidation: changes in the brain stabilize a memory over time resulting in storage of a long term memory. Memory processing stages: storage: the result of encoding; the permanent record of information in the brain, retrieval: accessing stored information. It may enter conscious awareness, and/or it may result in a learned behaviour, such as a motor skill. Severe epilepsy in his 20s multiple seizures per day. Seizure locus in medial temporal lobe known to be common removal could stop seizures.
