Memory

The Three-Stage Model of Memory

• Sensory input is recorded as fleeting sensory memory.

• Information is actively processed in working memory.

• Information is encoded into long-term memory for later

retrieval

Memory Encoding (automatic processing)

• is the unconscious encoding of information such as personally salient events, emotional experiences, or conditioned learning that requires little effort to encode.

Memory Encoding (effortful processing)

Effortful processing is encoding that requires attention and conscious effort (i.e., rehearsal & memorization)

Working memory

• Active processing of information

  • Associating new and old information

  • Solving problems

Working memory capacity

• Working memory has a limited capacity in terms of how much information can be actively processed

• The typical capacity is 7 ± 2

Chunking

• the capacity of memory can be increased by grouping smaller chunks of information

Repetition, Rehearsal, and Retention

What strategies work best to successfully encode and

retain novel information?

The retention curve

• Ebbinghaus studied his own learning and forgetting of

information.

• He tried to memorize lists of unfamiliar items (nonsense

syllables; PUK XOG LOF)

• The more times he rehearsed the list on day 1,

the less time it took to him successfully memorize the

list on day 2.

The Serial Position effect

The tendency to remember the first and the last items in a list

The spacing effect

• Information is retained better when rehearsal is distributed over time.

• Distributed study produces better long-term recall.

• If your distributed practice includes testing (having to answer questions about the material), you will learn more and retain more than if you merely reread.

• Massed practice (“cramming’ or doing your studying on one day) produces speedy short term-learning but poorer long-term recall.

How to improve memory encoding and retrieval (&boost test performance)

• Use active-encoding techniques (e.g., written notes of material)

• Use retrieval practice by testing yourself

• Use distributed (spaced) practice

• Find ways to make the material personally meaningful to you

• Use visual encoding (also known as ‘dual coding’)

The baker-baker paradox

Daniel Tammet

Long-term memory: explicit memory

• Semantic memory: memory of facts and general knowledge

• Episodic / autobiographical memory: memory of personally

experienced events

• These memories often require conscious effort to retrieve/remember

e.g., “What is the limbic system?”; “What did you do last weekend?”

• Processed by the hippocampus; stored throughout the cortex

Long-term memory: implicit memory

• Procedural memory: complex motor skills learned via practice

e.g., riding a bike, playing a musical instrument

• Conditioned associations (via classical & operant conditioning)

• These memories do not require conscious effort to retrieve

• Processed by cerebellum & basal ganglia

Patient HM

• H.M. suffered from epileptic

seizures.

• At 27, he had parts of his

temporal lobes removed

(including his

hippocampus) to prevent

seizures.

• H.M. could easily

remember old memories

from before the surgery.

• He could NOT encode nor

remember any new

information after the

surgery.

Anterograde Amnesia

• After losing his hippocampus in surgery, H. M. was

unable to make new explicit memories. We call this

anterograde amnesia.

HMs Memory

• However, he was able to form new implicit memories.

H.M. learned the Tower of Hanoi game after his surgery. Each time

he played it, he was unable to remember the fact that he had already

played the game, but his performance improved each time he played. why? bc his cerebellum was intact

Childhood memories

• Childhood (infantile) amnesia: the inability of adults to retrieve

episodic memories before the age of about 3 years old.

• Hippocampus and amygdala development is ongoing during this time.

• Recovery’ of these memories is often highly prone to suggestibility.

• Those who do report memories from before this age usually are

relying on other sources (e.g., old photos, parents’ stories, etc.).

False/inaccurate memory

• False memories can be

“planted.”

• Imagining nonexistent events

can create a memory.

• Imagining something and really

perceiving it activate similar

brain areas.

• People with vivid imaginations

(e.g., children) are more likely

to have false memories.

• Suggestive interviewing and

leading questions can also

alter our memories.

Misinformation effect

• Incorporating misleading

  information into the memory of

  an event due to leading or

  suggestive questioning.

  • eg: how fast were they going when the hit eachother/smash each other

• The reported recall of the rate

  of speed and degree of

  damage depended on how the

  question was asked.

  § e.g., false recall of broken glass

  when primed with “smashed”

Eyewitness memory