AREA OF STUDY 2

MEMORY

UNIT 3THE CONSCIOUS SELF

CONSOLIDATION THEORY

Proposes that structural changes occur in brain neurons when something new is learned, and immediately after

learning

•These neuronal changes require a period after learning takes place to ‘consolidate’

•If memory formation is disrupted during consolidation, information may not be embedded in LTM and may be lost

•The information being remembered is vulnerable to disruption for at least 30 minutes

•It is believed that the hippocampus plays a crucial role in consolidation

CONSOLIDATION THEORY

RESEARCH ON CONSOLIDATION THEORY

We can conduct research on people who have experienced brain trauma or have received electroconvulsive therapy (ECT) to provide evidence of

consolidation theory

These people are frequently unable to report any memory of events immediately before the accident or treatment

In many instances they cannot remember anything that occurred during a period of 30 minutes before the brain trauma (Squire & Kandel 1999)

HUDSPETH, McGAUGH & THOMSON (1964) – RAT MAZEGROUP

CONDITION RESULT

A ECT administered immediately No memory of learning

B ECT administered 20 seconds after learning

Partial retention of maze

C ECT administered 30 minutes after learning

Partial retention of maze

D ECT administered 60 minutes after learning

Full retention of maze

CONSOLIDATION THEORY

RECONSOLIDATION

After memory is activated and retrieved from LTM, it needs to be consolidated again in order to be stored back in LTM

GAZZANIGA & HEATHERTON (2006)

•Rats injected with drugs that interfere with memory storage after a memory has been activated•Rats were unable to reliably or accurately recall information that was once stored in LTM

•This suggests that newly reconsolidated memories may differ from their original versions

HOMEWORK

LEARNING ACTIVITY 7.6 (pg.296)

AMNESIA

Refers to the loss of memory, either partial or complete, temporary or permanent

•Anterograde amnesia

•Retrograde amnesia

AMNESIA

• Brain trauma caused by an inflicted or acquired head injury commonly results in some kind of amnesia

• Severity of injury determines type of amnesia• Typically a temporary loss of consciousness followed by a period of confusion• The period forgotten generally decreases over time, often leaving some ‘residual’ amnesia

of only a few seconds to a minute for events preceding the injury• The duration of amnesia can vary:

(KOLB & WHISHAW 1996)10% Less than one week

30% Duration 2-3 weeks

60% Duration 3+ weeks

AMNESIA

There are many different kinds of amnesia:

•People can become amnesic for the meaning of nouns, but not verbs (and vice versa)•People can become amnesic for animals but not humans•People can become amnesic for human faces but not objects•Sometimes only STM is affected•Some people have difficulty learning new information•People have difficulty accessing information from LTM

AMNESIAANTEROGRADE AMNESIA

Occurs when brain trauma causes loss of memory for information or events after the trauma occurs

• Memories of information or events experienced prior to the trauma still remain

• People with anterograde amnesia lose the ability to form or store new memories

KORSAKOFF’S SYNDROME

• A neurodegenerative disease involving severe memory disorders associated with brain damage, deep within the middle of the brain where the thalamus is located

• Mainly occurs in people who are chronic alcoholics• They have relatively normal IQ, are alert and attentive, appear motivated

AMNESIARETROGRADE AMNESIA

Occurs when brain trauma causes loss of memory for information or events before the trauma occurs

• The memory loss may extend back a few moments, days, weeks or sometimes years

• Usually temporary in nature and often caused by a blow to the head

READ EXAMPLE OF RITCHIE RUSSELL (pg.299)

• People who experience retrograde amnesia typically find that their inability to remember information and events leading up to the brain trauma gradually disappears

• They find the period right before the trauma is never recovered

HOMEWORK

LEARNING ACTIVITY 7.7 (pg.300)