Long term memory is divided into two main types: explicit memory (knowing something) and implicit
memory (knowing how to do something). Episodic and semantic memories are examples of explicit
memory whereas procedural memories are an example of implicit memory.
Episodic memories are personal memories of events such as what you did yesterday. These
memories are recorded as ‘episodes’ occurring as a part of a larger sequence, hence the name
episodic memory. This type of LTM concerns itself with personal experiences and memories, such as
a birthday party. You may recall the specific details of the event, like the time or place the event took
place in. This may include contextual details surrounding the event such as what happened before or
afterwards. It also includes associated emotions that were present at the time of the event. So,
episodic memory consists of three elements: specific details of the event, the context and emotions.
Semantic memory is the memory of facts and knowledge you have acquired throughout your life. For
example, the capital of England is London, football is a sport, etc. This type of memory concerns itself
with knowledge about the world that is shared by other people rather than the personal knowledge
of different matters that are categorised as episodic memories. Semantic memories start as episodic
memories because we obtain knowledge based on personal experiences. The episodic memory
gradually transitions to semantic when it slowly loses its association with particular events. Although,
sometimes, people continue to have a strong recollection of where and when they learned a certain
fact.
Procedural memory concerns itself with skills and remembering how to do something, such as
driving a car or tying your shoelaces. They are typically acquired through repetition and practice (e.g.
practicing to learn how to play the piano). Unlike episodic and semantic memory, procedural
memory is implicit. We are often less aware of these memories because they have gradually become
automatic. However, it is often the case that if you contemplate these procedural memories too
much, it may prevent you from carrying them out. For example, if you think too much about riding a
bike then it may cause you to lose your balance. The attention given to the fixed step by step
procedure disrupts the automated nature of the memory. It is vital that procedural memories are
automatic so that it allows us to focus on more important tasks while carrying out these everyday
tasks.
Helitz et al (1997) carried out a study that assessed explicit abilities in LTM. They found that, while
females did better than men in tasks involving episodic memory, there were no gender differences in
tasks requiring semantic memory. This suggests that gender is a factor that affects the functioning of
episodic memory but not semantic memory.
Vicari et al (2007) reported the case study of CL, an 8 year old girl who suffered brain damage due to
the removal of a tumour. She had deficiencies in her episodic memory functions but was still able to
demonstrate functioning in her semantic memory. Therefore, this provides proof of a clear
distinction between episodic and semantic memory.
Another study to support the distinction between each type of LTM is Clive Wearing. He was left with
an impaired STM due to brain damage. He has not been able to transfer any new long term
memories since his illness and has difficulty retrieving his existing long term memories. However, he
is able to remember procedural memories (e.g. how to drive a car, play the piano). This supports the
allegation of separate types of LTM as his brain damage affected his episodic and semantic memories
but left his procedural memories intact.
The distinction made between the three types of LTM is supported by research using brain scanning
techniques. Episodic memories are associated with the hippocampus and other parts of the temporal
lobe where the hippocampus is located. While semantic memories are also associated with the