Memory the medial temporal lobe
Download
1 / 18

Memory & the Medial Temporal Lobe - PowerPoint PPT Presentation


  • 88 Views
  • Uploaded on

Memory & the Medial Temporal Lobe. Lesson 22. Memory. Storage of information perceptions learning personality Information processing approach RAM vs. hard drive Multiple memory stores different characteristics Clive Wearing ~. Multiple Memories. Sensory memory

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Memory & the Medial Temporal Lobe' - anoki


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Memory the medial temporal lobe

Memory & the Medial Temporal Lobe

Lesson 22


Memory
Memory

  • Storage of information

    • perceptions

    • learning

    • personality

  • Information processing approach

    • RAM vs. hard drive

  • Multiple memory stores

    • different characteristics

  • Clive Wearing ~


Multiple memories
Multiple Memories

  • Sensory memory

    • capacity: large; sensory receptors

    • duration: < 1 sec.

  • Short-term memory (STM)

    • capacity: 7 ± 2 chunks

    • duration: < 1 min.

    • maintenance: rehearsal ~


Multiple memories1
Multiple Memories

  • Long-term memory (LTM)

    • capacity: functionally unlimited

    • duration: minutes - years

  • Working memory

    • intermediate to STM & LTM

    • information needed longer than 1 min, but not permanent ~


A model of memory

stimuli

transfer

rehearsal

attention

Sensory

Memory

STM

LTM

retrieval

forgetting

forgetting

forgetting

A Model of Memory


Subdivisions of ltm
Subdivisions of LTM

1. Declarative - Explicit

  • Episodic:

    • autobiographical

    • time-tagged, automatic

  • Semantic:

    • generic

    • not time-tagged, effortful ~


Subdivisions of ltm1
Subdivisions of LTM

2. Procedural – Implicit

  • non-declarative, unconscious

  • Motor learning

  • Nonassociative Learning

    • modulation of reflexes

  • Associative Learning

    • Classical & Operant Conditioning ~


  • Neural mechanism of stm
    Neural Mechanism of STM

    • Donald Hebb

    • Change in neural activity

      • not structural

      • temporary

    • Reverberatory Circuits

      • cortical loops of activity

      • activity persists for short period of time ~


    Reverberating loops

    • Maintains neural activity for a period


    Neural mechanism of ltm
    Neural Mechanism of LTM

    • LTM relatively permanent

      • structural change required

    • Hebbian Synapse

      • use strengthens synaptic efficiency

      • requires simultaneous activity

      • pre- and postsynaptic neurons

      • Long-term potentiation (LTP) ~


    Where are memories stored
    Where are memories stored?

    • Engram

      • physical change representing learning and memory

    • Lashley

      • Mass Action & Equipotentiality

    • Classical Conditioning: Eye-blink

      • lateral interpositus nucleus of cerebellum

    • Memories stored locally

      • in different parts of brain ~


    H.M.

    • Greatest contribution to study of memory

      • can’t remember any of it

      • similar to Clive Wearing

    • Bilateral medial temporal lobectomy

      • to control seizures

      • hippocampus (HC) ~


    Hippocampus

    Mid-sagittal View


    Spared some memory
    Spared some memory

    • Personality

    • Intelligence

    • LTM

    • Verbal STM memory OK

    • Motor skills


    Memory deficits

    Trauma

    time

    Memory Deficits

    • Some retrograde amnesia

      • but many old memories intact

    • Severe anterograde amnesia

      • unable to form new memories ~

    Retrograde

    Anterograde


    Evidence of deficits
    Evidence of deficits

    • Digit Span + 1

    • Block tapping memory span

    • Delayed-matching-to-sample

      • verbal OK - rehearsal

      • nonverbal impaired – ellipses ~


    Evidence of spared abilities
    Evidence of Spared Abilities

    • Performance improved with practice

      • Procedural memory

      • but no conscious memory of it

    • Mirror Drawing

    • Tower of Hanoi ~


    Conclusions role of hippocampus
    Conclusions: Role of Hippocampus

    • Removal of HC  deficits

    • Memory Storage?

      • STM not in HC

      • LTM not in HC

    • HC transfers info STM  LTM?

      • Declarative memories: YES

      • Procedural: NO

    • H. M. anterograde amnesia for declarative memories ~


    ad