Lesson 4 Evaluation of Multi Store Model of Memory

Question 1

Neurobiological evidence

Answer 1

+ Scoville (1957) attempted to treat a patient he referred to as HM’s epilepsy by removing several brain areas, including his hippocampus. This resulted in the patient being unable to code new long-term memories (LTM), although his short-term memory (STM) was unaffected. This supports the idea of separate and distinct STM and LTM.

+ Shallice and Warrington (1970) reported the case study of KF who as a result of a motorbike accident had reduced STM capacity of only one or two digits, yet his LTM was normal. This supports the idea of a separate STM and LTM stores. However, KF had poor STM for verbal tasks but not visual tasks and this suggests that there is more than one type of STM, which contradicts the Multi-Store Model (MSM) of memory. Also, according to the MSM, LTM are retrieved by STM so if STM is damaged it should be difficult to retrieve LTM. However, KF was able to access LTM without any difficulty.

Question 2

Laboratory experiments

Answer 2

+ Murdock (1962) presented participants with a long list of words to be recalled in any order, this was referred to as the free recall experiment. Words at the beginning and the end of the lists were recalled better than those in the middle. This is called the serial position effect. Words at the beginning of the list are recalled because they have been constantly rehearsed and transferred to LTM (the primacy effect), while words at the end of the list are recalled because they are still in STM (the recency effect). This supports the idea of separate and distinct STM and LTM

Question 3

General Evaluation of MSM

Answer 3

• The MSM is over simplified in assuming that there is only one type of STM and one type of LTM. Research studies indicate that there are several types of STM, such as one for verbal information (phonological loop) and another for non-verbal information (visuo-spatial sketchpad). Research also suggests that there are several types of LTM, we have episodic memory for life events, semantic memory for knowledge and facts and procedural memory for motor skills.
• Baddeley and Hitch (1974) claimed that the MSM could not explain the ability to multi-task; if there is only one type of STM then multi-tasking would not be possible. However, people multi-task all the time, for example listening to the radio while driving.