Types of long-term memory

Question 1

what are the types of long-term memory

Answer 1

episodic, semantic, procedural

Question 2

Long term memory

Answer 2

Long term memory is the storage of memories over a long period of time. It is suggested that there are different kinds of LTM. The two main types are Declarative (knowing what something is) and Nondeclarative (knowing how something
is done).

Question 3

Declarative memory :

Answer 3

There are then two types of Declarative memory; episodic memory and semantic memory. An episodic memory is a memory of experiences and specific events. Semantic memory is the memory of facts, meanings, and concepts. Semantic memory is knowledge about the external world.

Question 4

Episodic memories

Answer 4

Episodic memories are stored with reference to the time and place where they occurred. They are recalled using conscious effort and can be expressed with words. They are autobiographical and emotions felt at the time when the memory is encoded influences memory strength. According to brain scan evidence episodic memories initially seems to be coded in the prefrontal cortex, and are then stored across areas of the brain, though recall seems to occur through the hippocampus.

Question 5

Semantic memories

Answer 5

Semantic memories require conscious effort to recall and can be expressed in words. Memories are stronger if processed more deeply (i.e: linked to other long term memories). Semantic long term memories last longer than episodic ones. May not recall when learned/encoded these memories. Episodic memories become semantic over time. A number of brain areas are associated with semantic memories such as the Perirhinal cortex (an area at the base of the brain on the underside of the temporal lobe).

Question 6

Non-declarative memory :

Answer 6

Non-declarative memory is procedural memory (unconscious memory of skills/how to do things).
Examples of procedural memories are motor/muscle memories (i.e: how to ride a bike). Often learnt in childhood. Hard to express in words or consider consciously. More resistant to forgetting than episodic or semantic. Semantic memory may have a connection to procedural due to ability to produce automatic language (i.e: can recall a well-known semantic memory, such as that paris is the capital of France, with very little effort). Procedural memories are located across the brain but particularly in the motor cortex, cerebellum, and prefrontal cortex.

Question 7

Episodic memory research

Answer 7

Hertz (1997)

Vicari (2007)

Question 8

Hertz (1997)

Answer 8

Hertz (1997) took 100 males and females and gave them tasks testing either their episodic or semantic long term memories. Hertz found that females were better on episodic tasks, but there was no difference on semantic tasks. This difference in performance suggests that episodic and semantic memories are separate processes.

Question 9

Vicari (2007)

Answer 9

Vicari (2007) did a case study of CL, an eight year old girl. Had brain damage after removal of a tumour. Vicari found deficiencies in her episodic LTM functions, especially in creating new episodic memories, but had no trouble creating or recalling semantic memories. Shows that semantic and episodic memories are separate and use different brain areas, as the area with the damage was the hippocampus, which was thought to be where her episodic memories were stored, but there was no damage to her perirhinal cortex were semantic memories thought to be stored.

Question 10

Semantic memory evidence

Answer 10

Hertz and Vicari

Question 11

Procedural memory evidence

Answer 11

Finke (2012) studied PM, a 68 year old cellist with brain damage after encephalitis. He had amnesia and it was found that his episodic and semantic memory were both very affected, but ability to play and read music unaffected, including learning new pieces, showing that his procedural LTM to be separate to his semantic and episodic.

Question 12

Evidence for all three LTM

Answer 12

Sacks (2007) Clive Wearing has retrograde amnesia so cannot remember his musical education (episodic), however remembers facts about his life (semantic). He can also play the piano (procedural). He is unable to encode new episodic or semantic memories due to the anteriorgrade amnesia, but under some experimental conditions is able to gain some new procedural memories through repetition. This shows that semantic, procedural, and episodic memories are all separate systems that are perhaps found in different brain areas.

Question 13

Evaluation of types of long term memory

Answer 13

Using case studies such as Sack’s study of Clive Wearing allows us to gain insights that would not be possible in an experimental setting, but lack enough control to suggest a cause and effect relationship between brain areas and memory functions. It could be that the people in these case studies are different to the normal population in some way even before their brain damage (i.e: Clive and PM are both musicians, which may have affected how their brain damage altered their behaviours. Similarly CL was a child, so perhaps her brain was more able to adapt than an adult brain would be).

The use of brain scanning in modern cognitive neuroscience has allowed researchers to study the brain and memory more scientifically, identifying the brain areas where different types of memory are located via which parts of the brain are activated when it is scanned via fMRI.

As both episodic and semantic memories are declarative there may not be a true division between them.