2. MEMORY (Coding, capacity & duration of SM/STM & LTM) Flashcards
What are the features of the Sensory Register?
- Capacity: Unlimited
- Duration: Very limited (250-500 milliseconds)
- Coding: Unprocessed form (iconic for visual, echoic for auditory, and other sensory types like haptic, gustatory, and olfactory)
How does information enter the Sensory Register?
- Information from all five senses (sight, hearing, smell, taste, touch) enters in an unprocessed form and is held for a very short period (a few milliseconds to seconds).
What study investigated the capacity and duration of the Sensory Register?
- Sperling (1960)
- Aim: To investigate the capacity and duration of the sensory register.
- Method: Participants saw a 3x4 grid of letters for 50ms and were asked to recall them. When asked to recall rows after specific tones, they could recall about 3 items.
- Conclusion: Capacity is a minimum of 4 items, and duration is about 250-500 milliseconds
What are the two main stores within the Sensory Register?
- Iconic store: Visual information
- Echoic store: Auditory information
(Other stores include haptic, gustatory, and olfactory for touch, taste, and smell respectively.)
What are the features of Short-Term Memory (STM)?
- Capacity: 7+/-2 items
- Duration: 18-30 seconds (with no rehearsal)
- Coding: Acoustic (processed through sound)
What study investigated the capacity of Short-Term Memory?
- Miller (1956)
- Method: Digit span technique, participants were shown lists of numbers and asked to recall them.
- Conclusion: STM can hold 7+/-2 items; chunking increases memory capacity (e.g., phone numbers).
What study investigated the duration of Short-Term Memory?
- Peterson and Peterson (1959)
- Method: Participants were shown consonant trigrams and asked to recall them after intervals (3, 6, 9, 12, 15, or 18 seconds), with interference (counting backwards) to prevent rehearsal.
- Conclusion: Duration of STM is around 18-30 seconds if rehearsal is blocked.
What are the features of Long-Term Memory (LTM)?
- Capacity: Unlimited
- Duration: Lifelong
- Coding: Semantic (meaning-based)
What study investigated the duration of Long-Term Memory?
- Bahrick et al. (1975)
- Method: Graduates were tested on photo recognition and recall of classmates from a high school yearbook over a 50-year period.
- Conclusion: LTM can last a long time (at least 48 years).
What study investigated coding in STM and LTM?
- Baddeley (1966)
- Method: Participants were shown a list of 10 words, either acoustically or semantically similar or dissimilar, and asked to recall them.
- Conclusion: STM uses acoustic coding, and LTM uses semantic coding.
What is the capacity of Long-Term Memory?
- Capacity: Unlimited. The potential capacity of LTM is vast, and memory fades due to decay or interference, not because of lack of space.
What factors can influence the coding of information in memory stores?
- STM: Acoustic coding (sounds).
- LTM: Semantic coding (meaning).
What is the duration of information in Long-Term Memory?
- Duration: Lifelong. LTM can store memories for decades, with some evidence suggesting they can last for at least 48 years, like in Bahrick’s (1975) study.