Long Term Memory

• Baddeley (1966) presented participants with word lists with the aim to explore the effects of acoustic and semantic encoding in STM and LTM
• In the LTM study, Baddeley gave each participant a list of ten words and their recall was tested after an interval of 20 minutes
• Baddeley found that the words with similar sounds were much harder to recall using STM than words with dissimilar sounds. Similarity of meaning had only a very slight detrimental effect on STM
• When ps were recalling from LTM, recall was much worse for semantically similar words than for semantically dissimilar words. Recall from LTM was the same for acoustically similar and acoustically dissimilar words
• Baddeley concluded that STM relies heavily on acoustic encoding and the LTM primarily makes use of semantic encoding
• The use of the experimental method allows a causal link to be drawn between type of coding used in STM and LTM and the accuracy of recall
• The conclusions of Baddeley’s study may not reflect the complexity of encoding. Evidence from other studies shows that, in certain circumstances, both STM and LTM can use other forms of coding
• Bahrick (1975) presented participants with a college year book with the aim to establish the existence of a very long term memory and to see whether there was any difference between recognition and recall
• Bahrick tracked down graduates from a particular high school in America over a 50 year period. 392 graduates were shown photographs from their high school yearbook. For each photo, ps were given a group of names and asked to select the name that matched the person in the photo and another group of ps were asked to name the people in the photos without being given a list of possible names
• Bahrick found that in the name matching condition, ps were 90% correct even 14 years after graduation. After 25 years, these ps were 80% accurate; after 34 years, 75% accurate and even 47 years, 60% accuracy
• The 2nd group who had to identify the photos without any name cues weren’t as successful. They were 60% accurate after 7 years, but the level of accuracy had dropped to less than 20% after 47 years
• Bahrick concluded that people can remember certain types of information for almost a lifetime. The accuracy of VLTM is better when measured by recognition tests than by recall tests
• what’s good about Bahrick’s experiment is that the study used meaningful stimulus material and tested people for memories from their own lives. This give the research ecological validity
• Episodic memory are personal memories of events, like what someone did yesterday or their first childhood memory. They may recall the time and place of such events as well as who was there. Episodic memories have three elements: specific details of the event, the context and the emotion
• Semantic memory are shared memories for facts and knowledge. This is shared by everyone rather than the personal kind. Semantic memories may relate to things like the functions of objects, may relate to abstract concepts like maths or appropriate behaviour
• Procedural memory are memories for doing things like riding a bike or learning how to read. It’s concerned with skills, like knowing how to tie your shoes laces so it’s about remembering how to do something rather than knowing the rules. It’s important that procedural memories are automatic because otherwise it prevents you from acting them out
• Frost (1972) showed that long-term recall was related to visual as well as semantic categories, and Nelson and Rothbart (1972) found evidence of acoustic coding in LTM. therefore it seems that coding in LTM isn't simply semantic but can vary according to circumstances
• in the study by Baddeley, STM was tested by asking ps to recall a word list immediately after hearing it. LTM was tested by waiting 20 minutes. it's questionable as to whether this is really testing LTM. this casts doubt on the validity of Baddeley's research because he wasn't testing LTM after all