Psychology - memory

What is the sensory register - including capacity, duration and encoding

The sensory register is the first store and receives information from the environment through the five senses capacity - very large capacity duration - very short duration of 50 milliseconds encoding - through the five senses

What is memory

is the ability to take in information (encode it), store it, and recall it at a later time

What is encoding

changing information into a form so that it can be stored in the brain

What is duration

how long something lasts for

What is capacity

how much something can hold

What did Sperling investigate?

he investigated the capacity and duration of the sensory memory - specifically iconic memory

What he did do?

participants were shown a grid of 12 letters for less than a second and they had to recall as many letters as possible

He found that participants recalled about 4 letters

This shows that the sensory register has a large capacity (iconic memory holds up to 10 items but decays before we can report), but the information fades extremely quickly - within about 2 seconds or less

What did Peterson and Peterson investigate?

They investigated the duration of the STM

What did they do?

Participants were shown three-letter trigrams, and then they had to count backwards in threes to create interference

They found that recall was 80% after 3 seconds and only 10% after 18 seconds

This shows that without rehearsal, the memory fades, suggesting that STM has a very short duration if rehearsal is prevented

What did Miller investigate?

He wanted to investigate the capacity of the STM

he found that the capacity of the STM is 7 +/-2 items

Miller proposed that things come in groups of 7 e.g seven days of the week, suggesting we are predisposed to remembering things in this quantity

He suggested "chunking" information can help us to recall things better and increase the amount of information we can hold.

What did Bahrick et al. investigate?

He investigated the duration of the LTM They tested people's ability to recognise photographs of classmates from their high school yearbooks

The participants had left school 15- 46 years earlier

He found that, from 396 participants, recognition decreased from 90% to 70% between 15 years and 46 years of graduating

This shows that long term memories can have a very long duration, potentially a lifetime

What did Baddeley investigate?

He wanted to see the type of coding used in short term memory What did he do?

participants were given a list of words and asked to recall them and these words were either acoustically similar or dissimilar to investigate STM coding

he found that recall was worse for acoustically similar words, suggesting that the STM uses mainly acoustic coding due to the confusion around similar sounds which leads to mistakes

What did Baddeley investigate for the LTM?

He investigated the encoding of the LTM

Participants recalled lists of words that were semantically similar or dissimilar

He found that more mistakes are made when recalling semantically similar words 20 minutes after learning them (LTM recall)

This shows that encoding in the LTM is semantic

What are the three different types of sensory memory

iconic memory - holds visual details for a brief moment, allowing you to make sense of what you are seeing before the information fades - has a duration of 0.2 - 0.4 seconds

Echoic memory - captures sounds and holds them for a few seconds even after the speaker has finished talking - has a duration of 2-4 seconds

Haptic memory - briefly holds information related to physical sensations like texture, warmth - has a duration of 1 - 2 seconds

Multi store model

What are the three stores

Sensory memory, short term memory and long term memory

Multi store model

What is the capacity, duration and encoding of the sensory memory

Capacity - very high

duration - 50 miliseconds

encoding - via the 5 senses

(for example, the iconic memory lasts for 0.2 - 0.4 seconds)

When you pay attention to information it transfers to the STM

When you don’t pay attention to information it decays

Multi store model

What is the capacity, duration and encoding of the STM

Capacity - 7 ±2 bits of information

Duration - 18-30 seconds

Encoding - acoustically

When information is rehearsed, it goes into the LTM

When information isnt rehearsed, it decays or is displaced

Multi store model

What is the capacity, duration and encoding of the LTM

Capacity - unlimited

Duration - potentially up to a lifetime

Encoding - semantically

Information in the LTM can be retrieved to the STM if needed

Information in the LTM can be lost through decay, retrieval failure and interference