Coding, duration, capacity

Question 1

Define coding

Answer 1

Format in which information is stored in the various memory stores

Question 2

Define capacity

Answer 2

The amount of information that can be held in a memory store

Question 3

Duration

Answer 3

The length of time information can be held in memory

Question 4

Research on coding

Answer 4

Baddeley gave different lists of words to 4 groups of ppts to remember:
Group 1 (acoustically similar)
Group 2 (acoustically dissimilar)
Group 3 (semantically similar
Group 4 (semantically dissimilar)

When asked to doo the recall task immediately after hearing it (STM recall), they tended to do worse with acoustically similar words. Therefore STM coded acoustically.

When asked to recall words after a 20 minute interval (LTM recall) they did worse with the semantically similar words. This suggests that info is coded semantically in LTM

Question 5

Research on capacity (jacobs)

Answer 5

Jacobs developed a technique to measure digit span. a researcher gives for example 4 digits and then the ppt recalls them. If they get right the digit increases and so on. He found that the mean span for digits was 9.3 items. The mean span fo letters was 7.3

Question 6

Research on capacity (miller)

Answer 6

Suggested that the span for STM is about 7 items + or - 2. However Miller also noted that people can recall 5 words as well as 5 letters. They do this by chunking

Question 7

Research on the duration of STM

Answer 7

Peterson and Peterson tested 24 undergraduates and each student took part in eight trials. Each trial they were given a trigram to remember and also a 3 digit number. The students were then asked to count backwards to prevent mental rehearsal. They were told on each trial to stop at time intervals. (3,6,9,12,15,18 secs) They concluded that STM has duration of 18 secs unless there is some verbal rehearsal

Question 8

Research on the duration of LTM

Answer 8

Bahrick et al studied 392 ppts from Ohio who were aged 17 and73. Recall was tested in various ways including photo recognition test and free recall where ppts recalled the names of their graduating class.

They found that ppts tested within 15 years of graduation were about 90% accurate in photo recognition. After 48 years this declined to 70% for photo recognition
Free recall was less good as after 15 years 60% accurate dropping to 30% after 48 years

Shows duration of LTM is very long