Forgetting

In this section:

• Explanations for forgetting: interference: proactive interference & retroactive interference
• McGeoch & McDonald (1931) – retroactive interference
• Baddeley & Hitch (1977) interference in real life
• Explanations for forgetting: retrieval failure and the encoding specificity principle
• Tulving & Pearlstone (1966) categories and meaningful links
• Explanations for forgetting: context dependent cues
• Godden & Baddeley (1975) – Divers and context dependent memory and forgetting
• Grant (1998) – matching and mismatching environments
• Aggleton & Waskett (1999) OR Baker (2004) context dependent memory and forgetting
• Carter & Cassidy (1998) state dependent memory and forgetting

Interference

Interference – forgetting because one memory blocks another, causing one or more memories to be distorted or forgotten. Interference has mainly provided an explanation in forgetting long-term memories.

Types of interference:

Proactive interference (PI) – forgetting occurs when older memories, already stored, disrupt the recall of newer memories. The degree of forgetting is greater when the memories are similar.

For example an Essex man (let’s call him Kevin) is about to enjoy a moment of passion with his new girlfriend Tracey (‘Trace’ to her mates), and he calls out the name of Sharon, his ex girlfriend!

*Having the same ‘pet name’ like ‘babe’ for all of your partners gets around this particular problem!

Retroactive interference (RI) – forgetting occurs when newer memories disrupt the recall of older memories already stored. The degree of forgetting is again greater when the memories are similar.

For example you guys have learned so much information for your Psychology course this year, that you struggle to remember the content of your GCSE’s from last year.

Group 1 were given a list of words that they practiced until they could recall with 100% accuracy. They were then given a second list to remember which contained words with similar meanings to the first list.

Group 2 were also given a list of words that they practiced until they could recall with 100% accuracy. However, the second list they they were given contained totally different info e.g. 3 digit numbers.

When asked to recall the first list (which they had previously recalled accurately) it was found that those who had learned synonyms, had the worst recall.

In conclusion, the results showed the existence of retroactive interference because the second list (the recent, newer memory) disrupted the older memory of the first list. In addition, it also suggests that retroactive interferences is worse when new information is similar to old information

Baddeley & Hitch (1977)

Investigated interference not only in real life but in a real sport! They wanted to find out if interference was a better explanation for forgetting than the passing of time. They asked rugby players to remember the names of the teams that they had played against so far in that season, week by week.

The results very clearly showed that the recall of teams names did not depend on the how long ago the matches were. What seemed to play more of a role was the amount of games played. They found that players who had played in fewer games recalled proportionately more names than those who had played in the most games. In conclusion, it would appear that retroactive interference can be used to explain forgetting in real life situations because if there is more new information being received (e.g. names of rugby teams) this blocks and interferes with the old memories (teams that were played in the past).

Research to support Proactive Interference:

Keppel and Underwood (1962) examined the effect of proactive interference on long-term memory, in an experiment that resembles Peterson and Peterson (1959). Participants were presented with meaningless three-letter consonant trigrams (for example, THG) at different intervals (3, 6, 9 second, etc). To prevent rehearsal the participants had to count backwards in threes before recalling.

They found that participants typically remembered the trigrams that were presented first, irrespective of the interval length. They concluded that the results suggest proactive interference occurred, as memory for the earlier consonants, which had transferred to long-term memory (past info), was interfering with the memory for new consonants, due to the similarity of the information presented.

Evaluation:

Strengths:

• Research to support: for proactive and retroactive interference as outlined above.
• Ecological validity – Some research has high ecological validity due to applying it to real life memories. This makes research more generalisable – Baddeley & Hitch. This means that the theory is more likely to be accurate in real instances of forgetting.
• Lab experiments – Due to use of lab experiments there is high control and therefore there is good reliability. The research can be easily replicated to check for consistency of results. This can improve the credibility of the theory because it has the ability to prove that interference happens in multiple trials. If it was only supported by one study, it could be thought to be a one off fluke.
• Useful Applications – Advertising can benefit from the research, as they understand that if adverts are similar, people won’t remember them – explain why knowing this is beneficial?

Weaknesses:

• Research to oppose: Tulving (1971) gave participants five lists of 24 words, each list organised into 6 categories. For example, hut, cottage, tent, hotel, cliff, river, hill, volcano, captain, corporal, sergeant, colonel, ant, wasp, beetle, mosquito, zinc, copper, aluminum, bronze, drill, saw, hammer, chisel. The categories were not explicitly told to them, but it was assumed that they would be obvious to participants. Recall was about 70% for the first list of 24 words, but this fell as participants were given each additional list to learn, presumably due to interference. However, at the end of the 5 lists, they were given a ‘cued recall test’ – they were told the names of the categories as a clue, recall rose again to about 70%. This reduces the credibility of interference as an explanation of forgetting because if interference did occur, participants would have completely forgotten the words and would not be able to recall them, even with a clue. The fact that participants could recall them after being given a clue shows that the words were still stored in LTM. They were available, but not accessible. This finding cannot be explained through interference, thus reducing the explanatory power.
• Ecological validity – As seen in research by McGeoch & McDonald, research into memory is tending to use artificial tasks in laboratories.  There is that ever-present possibility that this research is telling us little about how interference occurs in everyday life.  Also the time allowed for remembering the lists of words is usually brief.  Again this is not typical of real life situations where learning is usually ‘spread out’ over a period of time. Therefore, the theory of interference may not always provide an accurate explanation of forgetting in everyday experiences.
• Takes a nomothetic approach and ignores Individual differences – Research does not consider individual differences. Some people will experience interference and still remember things really well. Why is this? And why is this a problem with research into interference?
• Subjective – When measuring memory it is difficult to remain objective. Memory is an abstract concept which cannot be seen i.e. you can’t open up someone’s head and see what they are thinking. We can only infer what has happened to memory, from what we observe in behaviour. It also is unable to measure unrecalled memories. The memories could be there, it’s just the measuring tools were not effective in bringing them forward in behaviour?

This is a great video which outlines interference and an evaluation. I highly recommend that you watch it if you are struggling to understand the content.