This document provides an overview of cognitive psychology and models of memory. It summarizes the multi-store model which includes sensory memory, short-term memory, and long-term memory. Evidence is presented for the capacity, encoding, and duration of short-term memory based on the research of Miller, Baddeley, and Peterson & Peterson. The working memory model is also summarized. Finally, applications to eyewitness testimony and memory improvement strategies are briefly discussed.

1. Psychology Unit 1
By Dominic Edwards

2. Contents
▪ Cognitive Psychology
– Models of Memory
– Memory in Everyday lives

3. Models of Memory – Multi-Store Model
• This Model was devised by Atkinson & Shiffrin (1968)
• There are 3 stages to the Multi-Store model. At each stage there are constraints in Capacity, Encoding and
Duration.
1. Sensory Memory, where information first enters the system from the environment to be registered in
our brain.
– This information will stay for a brief period of time before it is either forgotten or passed onto the next stage, ShortTerm Memory (STM), if
attention is given to the information.
2. STM, if information is rehearsed at this stage then it will be passed on to the LongTerm Memory (LTM).
– Capacity: Small, (7+-2 chunks of information). If not rehearsed then information will be forgotten quickly. Discovered by Miller.
– Encoding: Items held in STM are usually acoustic (sound) however other encodings are possible. Discovered by Baddeley.
– Duration: Information will stay in the STM for roughly 18 seconds before it is forgotten. Discovered by Peterson & Peterson.
3. LTM, the last stage of the model that can only be reached through rehearsal.
– Capacity: Unlimited.
– Encoding: Semantic.
– Duration:Unlimited (Life time).

4. Multi-Store Model
• The model has been labelled as a structural model because it focuses on the storage components of
the system

5. Evidence for Capacity – STM
Miller
• He proposed the Magic number 7 idea based on the fact that most adults can store between 5 and 9 items in their
short-term memory. He thought that STM could hold 7 (plus or minus 2 items) because it only had a certain
number of “slots” in which items could be stored, however he did struggle to specify how much information can
be held in each slot.
• Miller’s theory is supported by evidence from various studies including:
− Research: Jacobs (1887)
Procedure:
• The participants one at a time were presented with a series of numbers or letters.
• They were then asked to repeat them back in what they thought was the correct order.
• The first time it was just one number or letter, after this a new digit or letter was added each time.
• The participant would then reach their own digit span which varies for certain individuals.
Findings:
• The average digit span was 9.3, where the average letter span was 7.3.
• He also stated that this increased with age. It is thought that as we grow we learn “chunking” (we group information
together e.g. 2 0 1 9 become 2019).
Evaluation (Ao2):
 Later studies (Miller 1956) have supported Jacobs’ findings and conclusions. Miller published his findings in an article
entitled “The magic number seven, plus or minus two.”
х No consistency across different stimulus material.
Jacobs therefore supported the idea that the capacity of short term memory consists of 7 +/- 2 items.

6. Evidence for Duration - STM
Peterson & Peterson
• He wanted to find out how long information could be held in the STM without rehearsal. And proposed the idea that
information will last up to 18 seconds and then forgotten.
– Research: Peterson & Peterson
Procedure:
• Presented participants with a consonant trigram.
• Participants were asked to count backwards in 3’s from 451 to prevent any rehearsal of consonant trigrams.
• There were intervals of 3, 6, 9, 12, 15 and 18 seconds.
• This procedure was repeated several times.
Findings:
• Participants recalled 80% at 3 seconds.
• Recall became progressively worse.
• After 18 seconds fewer than 10% could recall the consonant trigram.
Evaluation:
 Lab experiment, investigation was done under very controlled conditions.
 Used repeated measure to avoid individual differences in participants.
х Low mundane realism due to the lack of eco logical validity.
х Methodological issues such as confusion for some participants which caused problems with later trigrams and how well they did.
Peterson and Peterson therefore purport the idea that the duration of our STM is 18 seconds.

7. Evidence for Encoding – STM/LTM
Baddeley
• He wanted to investigate encoding in the STM and also LTM.Therefore he hypothesized that acoustic encoding
would be the preferred method of encoding in the STM and semantic would be the main encoding for the LTM.
− Research: Baddeley
Procedure:
• He gave a list of words to participants that were categorised into acoustically similar, acoustically dissimilar, semantically
similar and semantically dissimilar.
• Asked participants to write down the 5 words presented immediately in serial order.
• Tested on immediate recall and delayed recall.
• He then extended the list to 10 words in order to test the LTM
• Each list was presented 4 times and recall was delayed by 20 minutes in intervals
Findings:
• Found that words which sounded the similar were much harder to remember, concluding that STM encodes semantically.
• Also found that acoustic similarity had no effect on recall whereas words with similar meanings were poorly recalled.
Evaluation:
 Lab experiment, investigation was done under very controlled conditions.
 No ethical issues in this investigation.
х Used familiar words and not consonants.
х Students are not representative.

8. Distinctions between STM & LTM
Free recall
• This is where participants are asked to study long lists of words and then recall as many as possible in any order.
• It produced a characteristic serial positive curve.
• Words presented at the end were recalled best because they were still in the individuals STM (recency effect).
• Words at the beginning were recalled reasonably well as they have been rehearsed and passed to the LTM (primacy
effect).
• The words in the middle had the lowest recall as there was little time for rehearsal and were therefore forgotten
(asymptote).
• Glanzer and Cunitz carried out an investigation supporting the idea of the primacy and recency effect on free
recall.

9. Models of Memory - Working Memory Model
• This model was devised by Baddely and Hitch.
• They both questioned the STM after results found on a particular case know as KF case study.
− This individual could still transfer information into his LTM with an impaired STM.
− They hypothesised that there must be more aspects to the STM, not just a unitary store.
• The model that they created consists of:
∆ Central Executive, has overall control, limited capacity but can process information from any sensory system
e.g. vision, hearing, taste and olfaction.
∆ The Phonological Loop, limited capacity, temporary storage system for holding verbal information. Then
broken down into two areas:
 Phonological Store
 Articulatory Process
∆ Visuo-Spatial Sketchpad, limited capacity, temporary memory system for holding spatial information. Also
broken down into two areas:
 Inner-Scribe
 VisualCache
∆ Episodic Buffer, this is where information goes after going through the central executive. It will then be
processed into either of the two ‘slave’ systems (Phonological Loop orVisuo-Spatial Sketchpad).

10. Evidence for the WMM
DualTask Method
• Participants performed a reasoning task while simultaneously reciting aloud a list of six digits.
Findings:
• Participants had made few errors on both reasoning tasks.
The conclusion from this study was therefore that the STM must have more than one component it both reasoning task are able to be
complete at the same time.

11. Memory in everyday lives – Eye Witness Testimonies
(EWTS’s) Misleading information
• EWT’s are not always accurate and are vulnerable to many different types of influences.
Misleading Information
− Our memories are fragile and subject to distortion by post-event information.
− Misinformation can cause errors in EWT’s due to recall of event being inaccurate, better know as Misinformation
Acceptance, a term devised by Loftus meaning that people accept wrong occurrences into their memories as actual
events.
Research: Loftus
 Showed 45 students a film leading to a car crash.
 After the film they were divided into a control group and an experimental group.
 Control Group:Were asked consistent questions to what they had actually seen. E.g. “How fast was the white sports car going
when it passed the stop sign?”
 ExperimentalGroup:Were given misleading information in questions asked. E.g. “how fast was the white sports car travelling
when it passed the barn on the country road?”.There was in fact no barn.
 Findings:
 17% absorbed the misleading information in the experimental group and 3% made this mistake in the control group.
 Evaluation (Ao2):
х Low mundane realism as participants knew what was going on, cant relate therefore to real life scenarios. No Eco-logical
validity.
х Ethical issues as this could cause distress for some individuals.

12. Memory in everyday lives – Eye Witness Testimonies
(EWTS’s) Anxiety
• Anxiety and stress whilst witnessing an incident will cause a loss in recall as attention to detail is
impaired by the element of fear. Some anxiety however can help improve later recall.
Research: Loftus – Bloody Knife
 Group 1: overheard an aggressive conversation between two people and then a man merges holding a
bloody knife.
 Group 2: overheard a pleasant exchange in which a man emerges holding a greasy pen.
 Both groups had to then identify the emerging man out of 50 photos.
Findings:
 33% managed to identify the man correctly in the weapon group whereas 49% in group two identified the
man correctly.
 Findings therefore support the idea of participants experiencing weapon focus, causing a lower percentage
score.
Evaluation (Ao2):
х Lacks eco-logical validity, difficult to recreate the same fear that an individual may experience in real life.
х Representation of participants is an issue, people vary coming from different social classes.
х Findings are not generalisable due to low mundane realism.
 This research is easy to replicate and produces consistent results according to supporting studies.
 Carried out in a controlled environment.
 No order effect due to the use of independent groups.

14. Memory in everyday lives – Eye Witness Testimonies
(EWTS’s) Age
• Psychologist began to ask themselves if the same factors effect adults and children.
Research: Poole & Lindsay – Children's Memory.
 Participants aged 3-8 observed a science demonstration.
 The children's parents then read them a story that contained information from the science demo.
 The children were then questioned upon where they think they got this information from, either the science
demo or their parents.
Findings:
 Younger children could not source monitor as they could not identify where they had got this information
from whereas older children could.
To conclude, younger children aged up to 5 a are poorer eyewitnesses than older children aged 6-10. this is because
the younger children will not be able to distinguish original eyewitness memories and post event information.
Evaluation (Ao2):
х Few control variables.
х Parents are subject to social desirability bias as they want there children to come across as smart, meaning
that they could interfere with the investigation by helping their kids.
х Cant be generalised to all classes as the study was only carried out on working class children.
 Clearly supports its own hypothesis that there will be a difference between ages.
 Easy to replicate.

15. Memory in everyday lives – Cognitive Interviews
Geiselman et al.
• The aim of cognitive interviews is to improve the effectiveness of interviews when questioning witnesses.
 There are 4 stages:
1. Context reinstatement, witness must recall the scene including the weather, what may have been going through the
individuals mind at the time or how they were feeling.
2. Report everything, attempt to report absolutely every bit of detail possible because something irrelevant to one person
may be a key factor for the EWT.
3. Recall from a changed perspective, describe the event through someone else at the scene and what they would have
seen from a different angle. E.g. other side of the street or through a shop window.
4. Recall in reverse order, describe the event backwards.This helps pick up on any detail that may have been missed as this
process takes more attention to detail.
 Evaluation:
 Cognitive interviews are now widely used by police and help investigations a lot.
 Successful results, leads to a great amount of extra detail being recalled.
х Very long process, takes time to train police officers to be able to carry out these interviews.Takes time for police officers
to sieve through all the extra information being recalled by the witnesses.
Gieselmans study on the effectiveness of cognitive interviews support its use as there is a greater percentage of recall compared
with standard interviews. An increase in accuracy of up to 20%. However it has been criticised that more inaccurate information is
also being “recalled” than standard interviews.This study is also very artificial and therefore lacks mundane realism.

16. Memory in everyday lives – Memory Improvement Strategies
The role of organisation
Mnemonics based on visual learning:
 Peg-word system, the stronger your mental imagery is of something the more likely you are to remember it.
• One is bun.
• Two is shoe.
• Three is tree.
• Four is door.
• Etc…
 Method of loci, this is the use of places and situational factors instead of rhyme. In order to do this you must relate to
your familiar landmarks such as your house in order to help you recall whatever you need to.
 Encoding and retrieval strategies, such as cues.These help remind you of what it is you have forgotten as they trigger
relatable information.
Evaluation
 Very useful for remembering things that come in lists e.g. shopping list.
х The mnemonic must be remembered also otherwise there is nothing you can link back to in order to help the recall.