---forgetting--- Flashcards
Peterson and Peterson, 1959
- What is the duration of STM/WM?
- Participants remember a three-consonant sequence.
- Distractor task: count backwards in three’s.
- Accuracy affected by duration of distractor task.
- Only 50% accuracy when distractor task is 6-seconds long.
- Accuracy close to 0% when duration task is 18-seconds long.
- STM/WM traces decay.
- But they may also be sensitive to some interference.
interface or decay?
- Keppel and Underwood (1962).
- Same task in Peterson and Peterson (1959).
- Accuracy declined throughout the task.
- Greater accuracy in the initial trials.
- Accuracy gradually declining throughout the trials.
- Could this be explained by interference?
- Previous stimuli causing interference with new stimuli.
Nairne et al (1999)
• Addressed problem of similar stimuli potentially causing interference.
- (Reduce influence of proactive interference).
• Given distractor task.
• Participants presented words in a random order and asked to recall the order they were originally presented in.
• Accuracy very high up to durations of over 1.5 minutes!
• When interference is limited, very little decay?
Little evidence to suggest that interference has less influence than decay.
Evidence to suggest that interference is important
Little evidence to suggest that interference has less influence than decay.
Evidence to suggest interference isn’t important
- We cannot argue that there is no influence of decay (Ricker et al., 2016).
- When rehearsal is not possible (i.e. remembering unfamiliar characters/images – Ricker & Cowan, 2010):
- Accuracy decreased rapidly after short (i.e. 6 seconds) distractor tasks.
- Information is lost very quickly if it is not rehearsed!
- Stresses the importance of what is controlled for in memory tasks!
traces decay
- Not the rapid decay we observe for sensory memory.
- When information not rehearsed in STM/WM, it decays.
- Interference affects the rehearsal process.
forgetting in LTM: Decay
- Memory traces erode with the passage of time.
- Jenkins & Dallenbach (1924)
- Examined memory recall of non-existing syllables.
- Recall better after sleep.
- Emphasis on ‘interference’ rather than ‘decay’.
- No longer a valid theory of forgetting
- Lack of physiological evidence for LTM’s decaying.
- Older memories are not forgotten first.
Jenkins & Dallenbach (1924)
- Participants learned nonsense syllables either in the evening before going to sleep, or in the morning after waking up.
- They were tested on the memory of the nonsense syllables 1, 2, 4, or 8 hours later.
- The key difference across the two conditions was whether the participant was awake or asleep – the time between learning and reproduction of the nonsense syllables was either spent awake or asleep.
- The rate of forgetting was worse when participants were awake
- There is a continued decline of forgetting when awake. Whereas, when asleep, the rate of forgetting has a small initial decline, but then rate of forgetting remains at a constant level
Forgetting in LTM: lack of encoding
- Do we forget what we were told, or not encode the information in enough detail?
- Often, we don’t even encode the features necessary to ‘remember’ an object/event (i.e., details on a coin).
interference
- When you keep calling your partner by your ex’s name.
- When you forget which of your passwords belongs to your account.
- When you realise you’ve gave someone your old number, not your current number.
• Some memories ‘interfere’ with other memories.
• Interference is stronger when material is similar.
• We can search our memory, but due to competition, we can end up selecting the wrong memory.
• We have experienced a lot, so there is a lot of interference.
proactive intereference
- Old memories interfere with ability to remember new memories.
- Interference when retrieving new memories.
retroactive interference
- New memories interfere with ability to remember old memories.
- Interference when retrieving old memories.
