Capacity and encoding Flashcards
What is Capacity?
Capacity is the measure of how much can be held in memory. It is measured in terms of bits of information such as number if digits.
What is Encoding?
The way information is changed so that it can be stored in memory. Information enters the brain via the senses. It is then stored in various forms, such as visual codes (images), acoustic forms (sounds), or a semantic form (the meaning of an experience). Information in STM is mainly encoded acoustically, whereas information in the LTM tends to be encoded semantically.
What is Chunking?
A proposition by Miller that the capacity of STM can be enhanced by grouping sets of digits or letters into meaningful units of ‘chunks’.
What is a digit span technique?
Digit span technique is a way of accessing STM where a participant must recall an increasing number of digits in sequence.
Describe Jacobs’s study.
Jacobs (1887) used digit span technique and a letter equivalent to test peoples STM. He found that average span for digits was 9.3 items, while it was 7.3 for letters.
Jacobs suggested this difference was because there are only 9 digits and 26 letters.
Describe Miller’s study.
Miller (1956) reviewed 35 studies in a meta-analysis and found that most people could recall 7 items, plus or minus 2. He also found that many bits of information can be collected into one item if they were ‘chunked’ into something meaningful.
Describe Simon’s study.
Simon (1974) found that people had a shorter memory for larger ‘chunks’ such as a 8 word phrase being harder to remember than a one syllable word.
Describe Cowan’s study.
Cowan (2001) also did a meta-analysis on STM capacity studies and concluded that STM is limited to 4 chunks.
This was supported by Vogel et al (2001) who found that 4 items was the limit for visual information.
Describe Baddeley’s studies on Acoustic and Semantic encoding.
Baddeley (1966a) found that acoustically similar words were difficult to recall in the short-term but not in the long-term.
Baddeley (1966b) found that semantically similar words were recalled well in STM but were muddled in LTM.
Describe Brandimote et al’s study.
Brandimote (1992) found visual encoding was used in STM if the task was visual and they were prevented from encoding acoustically in the retention period.
Mention Studies other than Brandimote’s which evaluate Baddeley’s findings on encoding.
Wickens et al (1976) - STM sometimes uses semantic encoding.
Frost (1972) - Showed that LTM was related to visual encoding as well as semantic.
Nelson and Rothbart (1972) - Showed LTM might also use acoustic encoding.
