A03 Types of long-term memory

• Clinical evidence

  Molaison and Wearing both had their episodic memories severely impaired as a consequence of amnesia. They had great difficulty in recalling events that occurred in the past
• HM and Wearing's semantic store

  Their semantic memory was unaffected: HM could not recall stroking a dog half-an-hour ago yet he understood the concept of a dog
• HM and Wearing's procedural store


  Their procedural memory were also intact: they both knew how to tie shoe laces, how to walk and Wearing knew how to read music notes due to his musician career
• Evidence for Tulving's theory

  HM and Wearing support his theory as they had one store damaged but the other stores still worked allowing them to recall certain memories
• Neuroimaging evidence

  Tulving et al got ppts to perform various memory tasks while being scanned by a PET scanner
• Findings from brain scans

  Episodic and semantic memory stores were recalled from prefrontal cortex which is divided into two, one on each hemisphere of the brain. Left prefrontal cortex was for semantic memories and right prefrontal cortex was for episodic memories
• Brain scans support LTM theory

  Brain scans give a physical reality to the different types of LTM stores within the brain and further research supports this causing the validity to increase
• Real-life application

  Belleville et al demonstrated that episodic memory in older people with mild cognitive impairment can be improved. Trained ppts performed better on a test of episodic memory than the control group
• Episodic memory and mild cognitive impariment

  Episodic memory is often most affected by mild cognitive impairment and this highlights the benefit of being able to distinguish between the types of LTM as this enables specific treatments to be created
• Problems with clinical evidence

  Psychologists were very interested in studying ppts with brain injuries. HM and Wearing provided lots of useful information about what happens when memory is damages and helped researchers understand how memory works normally. But there is a lack of control of all sorts of variables
• Three or two types of LTM?

  Cohen and Squire agree with the procedural memory store but argue that the episodic and semantic memory stores are stored together in a store called declarative memory
• Declarative memory

  Memories that can be consciously called and procedural memory is non-declarative