Long term memory

Long Term Memory

• Long term memory is also referred to as LTM, it is the memory of events that happened in the past, this memory can last anywhere from 2 minutes and 100 years. The long term memory has potentially unlimited capacity and duration and tends to be coded semantically..

What is Capacity?

• Capacity is the amount of data that can be held in a memory store.
• It is a measure of how mach can be held in a memory and it is represented by bits of information e.g. a number of digits.
• Long term memory has a potentially infinite capacity.

The Duration of Long term memory

• What is Duration?
• This is a measure of how long a memory lasts before it is unavailable.
• The duration of LTM was tested by Harry Bahrick. He used 400 participants aged between 17 and 74 to test their memory of classmates. This was done by showing them photos of people, some of which where from their school. The participants where asked to list the names of people that they recognised.
• 15 yrs after graduating = 90% correct
• 48 yrs after graduating = 70% correct
• This study does not however explain why memory recall becomes worse over time, is it because of a limited duration or because of old age affecting it.

What is Coding?

• Coding is the way that information is changed or processed so that it can be stored as a memory. Information enters the brain through the senses, then it is stored in various ways e.g visual codes like photos or acoustic codes like sounds.
• Alan Baddeley tested acoustic and semantic coding on STM and Long term memory. This was done by listing several words either acoustically or semantically similar.
• Acoustically similar = cat, cab, can, mat, mat
• semantically similar = large, big, huge, long
• He found that Long Term Memory was encoded SEMANTICALLY because the participants found them more difficult to recall.

EVALUATION

• LIMITATION
• Baddeley may not have tested LTM. In the experiment the participants only waited 20 minutes which makes it questionable whether this was truly long term memory.
• Secondly, long term memory may not be exclusively semantic, other studies show that long term recall was also visual and acoustic.