1) Coding, Capacity and Duration of Memory

Explain what is meant by coding in relation to memory?

Information is stored in different forms, depending on the store it is in.

• Each store has a preferred format.

Coding is the process of converting information between different stores.

What is meant by visual, semantic and acoustic information in regards to coding?

Visual- pictures

Acoustic- sounds

Semantic- meaning

Outline one research study into the coding of short term memory?

BADDELEY:

He presented participants with 4 lists of words.

• They were either acoustically similar or dissimilar.

  • e.g: flip, flop, flap

• Or they were either semantically similar or dissimilar.

  • e.g: big, large, enormous

Participants were asked to recall the correct order of words immediately, and then after 20 minutes.

Findings:

Participants struggled to immediately recall acoustically similar words.

• The STM suffers acoustic confusion.

After 20 minutes, participants struggled to recall semantically similar words.

• The LTM suffers from semantic confusion.

Conclusion:
STM: Codes acoustically

LTM: Codes semantically

Evaluate research into coding?

strength: separate memory stores

Baddeley’s research identified clear differences between STM and LTM.

• This ultimately improved our understanding of memory.

• It also led to later research such as the multistore model of memory.

limitation: artificial stimuli

Stimuli used by Baddeley had no personal meaning to the participants.

• So, they may not have been the best way to measure the DV as they do not tell us about coding in every day life.

  • Thus, it lacks external validity.

  • More meaningful information would be needed to test it.

Explain what is meant by the term capacity in relation to memory?

Capacity is the amount of information that can be stored in the memory at one time.

Name two researchers that looked into the capacity of the STM?

• Miller

• Jacobs

Describe Miller’s research findings into the capacity of the STM?

MILLER (1956)

He suggested that the capacity of STM was around 7 (plus or minus 2) items/numbers.

• This is known as the magic number.

Miller also noted that people can recall 5 words as easily as 5 letters.

• Due to a process known as chunking.

Chunking is where we group sets of digits or letters into larger, more meaningful, and familiar units.

Describe Jacobs research findings into the capacity of the STM?

JACOBS (1887)

He used the digit span technique to assess capacity in STM.

• He found that the average span for digits was 9.3 items and 7.3 for letters.

What is another name for numbers when discussing memory research?

items

Briefly describe why there is no research into the capacity of the LTM?

The LTM’s capacity cannot be tested, as there could be an unlimited capacity.

Evaluate research into capacity?

strength: a valid study

Later research was able to replicate Jacob’s findings.

• So, despite being older, Jacob’s research appears to be a valid test of average digit span.

limitation: not so many chunks

According to later research, Miller may have overestimated how many chunks of information could be held in STM.

COWEN:

He suggested that 4 chunks (plus or minus one) could be more accurate.

VOGAN ET AL:

Conducted research, and found that for visual information, 4 is the limit.

• Thus contradicting Miller.

Explain what is meant by the term duration in relation to memory?

Duration is the length of time memories are available for retrieval.

Outline one study into the duration of the STM?

PETERSON AND PETERSON

In the experiment, participants were given ‘nonsense trigrams’ to remember.

They were also given a 3 digit number.

• Participants had to recall the trigram after a retention interval of 3, 6, 9, 12, 15, or 18 seconds.

  • During the retention interval, participants had to count backwards from their 3 digit number.

    • This was designed to prevent rehearsal of the nonsense trigram.

Findings:

After 3 seconds, 80% recalled correctly.

After 10 seconds, fewer than 10% recalled correctly.

• Recall gets worse as the delay increases.

Conclusion:

30 seconds is the maximum duration of the STM.

Provide further details about the nonsense trigram in Peterson and Peterson’s study and provide an example?

• There were no consonants

• They were not semantically linked.

e.g: GHZ

Outline one study into the duration of the LTM?

BAHRICK ET AL

He used 392 × 17-74 year olds.

Recall was tested by asking participants to name people from year books.

1) Photo Recognition Task

Participants were asked to name people from a yearbook with photos.

• 90% accuracy if graduated within 15 years.

• 70% accuracy if graduated within 48 years.

2) Free Recall Task

Participants were asked to recall people without photos.

• 60% accuracy if graduated within 15 years.

• 30% accuracy if graduated within 48 years.

Suggests that LTM can potentially last a lifetime.

Evaluate research into duration?

strength: good external validity

Bahrick et al used meaningful materials in their study (yearbooks).

It was also found that recall was better than in studies where meaningless materials were used.

• Reflects the real life duration of LTM, as it has a high mundane realism.

limitation: meaningless stimuli in STM study

Peterson and Peterson used nonsense trigrams which lack external validity.

• They do not reflect everyday memory activities with meaningful materials.

• So, it has a low mundane realism.

However, the study was very controlled and eliminated extraneous variables.

• So it has a high internal validity.