Coding, Capacity and Duration of Memory

Question 1

What is coding?

Answer 1

Coding is the way in which information is processed so that it can be stored more easily

Question 2

Which different ways can information be coded?

Answer 2

• Visually
• Acoustically
• Semantically

Question 3

Jacobs (1887)

Answer 3

• Tested STM capacity with the serial digit span method.
• Participants were presented with increasingly long lists of numbers or letters and had to recall them in the right order.
• When participants failed on 50% of tasks, they were judged to have reached their capacity.
• He found the capacity for numbers was nine and letters was seven which demonstrates that the short-term memory capacity is limited.

Question 4

Peterson and Peterson (1959)

Answer 4

• participants listen to various trigrams (e.g. XPJ, ZFB)
• The control group were immediately asked to recall as many as possible.
• The experimental group was given a distractor task,
• Control group: 75% correct and 6% correct.
• STM is 18 seconds.

Question 5

Bahrick et al. (1975)

Answer 5

• Participants were 392 Americans between 17-74 years.
• They completed both a recognition and a free recall test.
• Recognition test- shown 50 yearbook photos and had to identify those people in their graduating year.
  Free Recall Test- had to list the names of their graduating class.
• Results: Recognition test- Participants were 90% accurate after 15 years and 70% accurate after 48 years.
  Free Recall- 60% accurate after 15 yrs and 30% after 47 years.

Question 6

Coding research- Baddeley (1966)

Answer 6

• Presented participants with one of four word list:
  1. List A: Acoustically similar words (cat, mat, sat)
  2. List B: Acoustically dissimilar words (pit, day, cow)
  3. List C: Semantically similar words (big, huge, tall)
  4. List D: Semantically similar words (hot, safe, foul)
• Half the participants were then asked to recall the words in the correct order immediately or after 20 minutes.
• When they had to do the recall task immediately after hearing it (STM recall) they tend to be worse with the acoustically similar words. Participants were asked to recall the words after a 20 minute interval (LTM recall) they did worse with the semantically similar words.
• Proposed STM codes acoustically due to acoustic confusion and LTM codes semantically due to the semantic confusion.