Coding, capacity and duration of memory

What is coding?

The way that information is stored in memory stores

Who is the key psychologist for coding?

Baddeley

Describe the procedure Baddeley carried out for coding

Had a list of acoustically similar words (cat, cab, can) and acoustically dissimilar words (pit, few, cow)

Had a list of semantically similar words (great, large, big) and semantically dissimilar words (good, huge hot)

Describe the findings for Baddeleys coding study

Immediate recall worse with acoustically similar words

Recall after 20 minutes worse with semantically similar words

What is the coding for short term memory?

Acoustic

What is the coding for long term memory?

Semantic

What is capacity?

The amount of information that can be stored in your memory

Who are the key psychologist for capacity?

Jacobs

Miller

Describe the procedure Jacobs carried out for capacity

Researcher reads four digits and increases until the participant cannot recall the order correctly

What does the final number read out in Jacobs study for capacity mean?

The final number is your digit span

Describe the findings for Jacobs capacity study

Participants could read back 9.3 numbers and 7.3 letters in the correct order immediately after they were presented

Describe the procedure Miller carried out for capacity

He observed everyday practices and found that many things come in sevens e.g days of the week, deadly sins

Describe the findings for Millers capacity study

Span of short term memory is 7 ± 2

How can the capacity for STM increase according to Miller?

Through chunking which is when you group sets of digits/letter into categories

What is duration?

How long information can be stored in your memory before its forgotten

Who are the key psychologists for duration?

Peterson and Peterson

Bahrick et al

Describe the procedure Peterson and Peterson carried out for duration

24 students given a consonant syllable to recall and a 3 digit number to count backwards from

Retention interval varied from 3-18 seconds

Describe the findings for Peterson and Petersons study on duration

After 3 seconds average recall was 80%

After 18 seconds average recall was 3%

What is the duration of STM without rehearsal?

18 seconds

Describe the procedure Bahrick et al carried out for duration

392 American participants aged 17 and 74

• recongition test: 50 photos from high school yearbooks

• free recall test: participants listed names of their graduating class

Describe the findings for Bakrick et als duration study

• recongition test: 90% accurate after 15 years, 70% after 48 years

• free recall test: 60% recall after 15 years, 30% after 48 years

A03 Strength - Baddeley: Identified two memory stores

Although later research has shown that there are some exceptions to Baddeleys findings STM is mostly acoustic and LTM is mostly semantic

Led to the development of the multi store model

Despite being a limited explanation, his research paved the way for future explanations of memory

A03 Limitation - Baddeley: Uses artificial stimuli

Words used had no use/meaning to the pps so tells us little about coding in everyday life

When processing more meaningful info, ppl use semantic coding even for STM

Findings of the study have limited application

A03 Strength - Jacobs: Study has been replicated

Is an old study which may have lacked control over confounding variables as scinetific method wasn’t as refined as today

Jacobs findings have been confirmed in later controlled studies

Study is a valid measure of STM digit span

A03 Strength - Bahrick et al: Has high external validity compared to STM research

Everyday meaningful memories were studied

When lab studies were done with meaningless pictures to be remembered, recall rates were lower

His findings reflect a more real estimate of the duration of LTM