Types of long-term memory

• Episodic memory= A long-term store for personal events. It includes memories of when the events occurred and of the people, objects, places and behaviours involved. Memories from this store has to be retrieved consciously and with effort.
• Semantic memory= A long-term memory store for our knowledge of the world. This includes facts and our knowledge of what words and concepts mean. These memories usually also need to be recalled deliberately.
• Procedural memory= A long-term memory store for our knowledge of how to do things. This includes our memories of learned skills. We usually recall these memories without making a conscious or deliberate effort.
• Endel Tulving was one of the first cognitive psychologists to realise that multi-store model's view of long-term memory was too simplistic and inflexible. Tulving proposed that there are in fact three LTM stores, containing quite different types of information. He called them episodic memory, semantic memory and procedural memory.
• semantic knowledge is less personal and more about facts we all share. It contains an immense collection of material which, given its nature, is constantly being added to. According to Tulving, it is less vulnerable to distortion and forgetting than episodic memory.
• One strength is Episodic memory in both men was severely impaired due to brain damage. But their semantic memories were relatively unaffected. They still understood the meaning of words. E.g. HM could not recall stroking a dog half an hour earlier but he did not need to have the concept of 'dog' explained to him. Their procedural memories were also intact. They both still knew how to walk and speak, and Clive wearing knew how to read music, sing and play the piano. This evidence supports that there are different memory stores in LTM- one can be damaged but other stores are unaffected.
• Counterpoint

  studying people with a brain injuries can help researchers to understand how memory is supposed to work normally. But clinical studies are not perfect. A major limitation is that they lack control of variables. The brain injuries experienced by participants were usually unexpected. The researcher had no way of controlling what happened to the participants before or during the injury. The researcher has no knowledge of the individuals memory before the damage. This lack of control limits what clinical studies can tell us about different types of LTM.
• One limitation is that there are conflicting research findings linking types of LTM to areas of the brain.

  E.G. Randy Buckner and Steven Peterson reviewed evidence regarding the location of semantic and episodic memory. The semantic memory is located in the left side of the prefrontal cortex and episodic memory on the right. However, other research links the left prefrontal cortex with episodic memories and the right prefrontal cortex with semantic memories. This challenges neurophysiological evidence to support types of memory as there is poor agreement on where each type might be located.
• Another strength is that understanding types of LTM allows psychologists to help people with memory problems. E.G. as people age, they experience memory loss. But research shown this seems to be specific to episodic memory. Sylvie Belleville devised an intervention to improve episodic memories in older people. The trained participant performed better on a test of episodic memory after training than a control group. This shows that distinguishing between types of LTM enables specific treatments to be developed.