Duration Of Ltm

The duration of LTM is unknown and can not be measured. It is said that LTM can remember the faces of classmates and when showed a picture of school mates and could still recall them after 40 years.

I remember that hot day when my ice-cream melted faster than I could eat it

Ice cream melts unless its kept cool.

Semantic memory

Episodic memory

Bahrick et al (1975): duration in long term memory Aims: bahrick et al aimed to investigate the duration of short term memory (VTLM) to see if the memories could be lost over several decades, and thus support the assumption that the duration of memory can be a life time. They aim to test VTLM in a way that showed external validity but testing memory for real life information. Procedure: and opportunity sample of 392 Americans ex-high school students aged from 17-74 years was formed. They were tested in a number of ways: 1. free recall of the names of as many of their former classmates as possible 2. A photo recognition test where they were asked to identify former classmates in a set of 50 photos, only some of which were there former classmates. 3. A name recognition test 4. A name and photo recognition test. These tests assessed because the time since leaving school was up to 48 years participants accuracy (and thus duration of memory) was assed by company their responses with high school pictures of there former classmates. Findings: bahrick et al found 90% accuracy in face and name recognition even with those participants and left school 34 years previously after 48 years thus declined to 80% for name recognition and 40% for face recognition free recall was considerably lower 60% accurate after 15 years and 30% accurate after 48 years

Conclusion • • • •

The findings show those classmates are rarely forgotten recognition cues have been given. The finding also support the claim recognition is better than recall It can be concluded that memory may not be as unreliable or confoundable as often claimed However the findings that free recall was only 30% after 48 years indicates that many of the memory where fairly weak.

Criticism • •

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Before this research by bahrick et al. it had often been assumed. That information could remain in LTM for a very long periods of time Class mates faces and names are a very particular type of memory information they might have emotional significance and there will have been opportunity for a great deal of rehearsal, given the daily contact classmates will have experienced. The same is not true of other types of information Compared to the vast majority of memory research which taker place in the lab, bahrick et als. Research has high mumdune realism asking participants to recall their classmates tests teal life memory this the is more reprehensive of natural behaviour and sop has high external validity this it may be possible to generalise the finding to other settings

Evaluation of multi store model Limitations: it is assumed that information in short term memory store is encoded in terms of its sound (acoustic coding) where as information in the long term store is encoded in terms of its meaning (semantic coding) and there is an arrow leading from one store to the other it seems like magic as it proceeds along an arrow.

Strengths: there is convincing evidence that the capacity of two stores is radically different the capacity of the short term store is about items (Jacobs, 1887 Simon, 1974) in contrast there are no known limits to the capacity of the long store, and standing et al (1970) found that 90% out of 2560 pictures resented once each were remembered in a test of long term memory.

Limitations: The model is oversimplified its assumption that there is a single long term memory store. As we have seen (e.g. spiers et al 2001) it makes sense to identify several long term memory store, episodic memory semantic memory; declarative knowledge and procedural knowledge. Atkinson and shiffron 1968 focused almost exclusively and declarative knowledge and had practically nothing to say about procedural knowledge

Evaluation of multi store model:

Strength: Evidence from brain damaged patients support the distinction between short term memory and long term memory. Patients with amnesia have problems with long term memory but not with short term memory, and some other brain damaged patients have problems, with short term memory but not with long term memory (Shallice and Warrington 1970).

Limitations: The model argues that the transfer of information from short term memory is through rehearsal however in daily life most people devote very little time to active rehearsal, although they are constantly storing away new information in long term memory. Rehearsal may describe what happens when psychologists conduct experiments in laboratories but this isn’t true to life

Strength: This is evidence that encoding is different in short and long term memory. For example baddeley (1966) found evidence for acoustic or sound encoding in short term memory and semantic memory or meaning encoding on long term memory.

Episodic and semantic memory Tulving (1972) argued for a distinction between two types of long term memory: episodic and semantic. -Episodic memory has an autobiographical flavour. It contains the memories of specific events of episodic occurring in a particular place at a particular time e.g. what you did yesterday or what you had for lunch. -In contrast semantic memory contains information about our knowledge of the world, e.g. the rules and the words of our language, how to calculate percentages, how to set the video, the capital of France and the stars of lord of the rings. Varha-khadem et al. (1997) studied two children, Beth and Jon both of whom suffered brain damage at a very young age Beth and Jon had a very episodic memory for the day’s activities, and television programmes. However, their semantic memory was fine, as shown by the fact that they attended ordinary schools and has normal language development and factual knowledge. This suggests that episodic and semantic memories are different forms of long term memory. Research such as that on Beth and Jon indicates that episodic and semantic memory are separate from each other nevertheless, they depend heavily on each other. For example remembering what you had for lunch last Sunday basically involves episodic memory. However semantic memory is also involved as your knowledge of the world is needed to identify the different food you ate.