C O G N I T I V E P S Y C H O L O G Y: U N I T
1
AS EDEXCEL PSYCHOLOGY
Cognitive Psychology: definitions & key
terms used in this approach
The cognitive approach relates to mental processes that help us to make sense of the world: these include processes such as perception, language, memory, attention & problem-solving.
One way cognitive psychologists think about this approach is by using the information processing model. This is the idea that our senses receive information (input), our brain interprets & tries to make sense of this information (processing), and we then respond to this, usually with a specific type of behaviour (output).
Cognitive Psychology:
definitions & key
terms used in this approach
Both computers & people have powerful processing abilities – although computers are better at algorithms (working things out systematically), whereas people are better at heuristics (guesswork).
The similarities between human information processing & computer information processing means that we can use computers as models of human thinking.
The cognitive approach also studies brain-damaged people, as case studies of people with brain damage allows researchers to see what a person with a certain area of brain damage can do/how they process information with someone without that damage. However, it is unusual for just one part of the brain to be damaged, and unusual for a person with brain damage to be known to researchers before their condition/injury, so it is hard to gauge what their mental abilities might have been before the damage.
Cognitive Psychology:
definitions & key terms used in
this approach
Encoding – the process of transferring information from the senses into a memory trace, I.e., when we learn something, we are encoding information. Sensory storage – all information we perceive is held for a very short time
in the sensory store while we decide whether to process it further or not; very little information goes beyond this point, unless processed further visual images last for approx. half a second & sound for approx. 2 seconds.
Short-term storage – this is the next stage from sensory storage, it has a limited capacity, approx. 7 +/-2 & limited duration approx. 15-30 seconds without rehearsal.
Long-term storage - this has unlimited capacity & duration (it lasts a lifetime). With rehearsal, information is transferred from short-term to long-term memory.
Retrieval – this is the process of locating & extracting stored memories so that they can used.
In depth area of study:
Memory & Forgetting
Memory: Can you
describe & evaluate:
Levels of Processing
theory. AND:
Reconstructive
Memory. OR:
The Multi-Store Model
of Memory. OR:
The Working Memory
Model
Forgetting: Can you
describe & evaluate:
Cue Dependent
Forgetting. AND:
Displacement theory.
OR:
Trace-decay theory.
OR:
MEMORY: Levels of Processing
Levels of Processing theory (Craik & Lockhart,1972) maintains that memory depends on how we process information; memory is by-product of depth of processing, I.e., how deeply we process information. There are 3 ways we process information:
Structural/visual processing – we process information according to how it looks, e.g., if a word is in upper or lower case. This is the shallowest form of information processing.
Phonetic processing – we process information according to how it sounds, e.g., does a word rhyme with another, the sound made by the word.
Semantic/deep processing – we process information according to meaning, e.g., what is the meaning of the word. This is the deepest form of processing & the one which leads to the greatest recall/recollection.
MEMORY: Levels of Processing
Evaluation
There is a lot experimental research which supports this theory, e.g., Craik & Tulving (1975). They tested the theory by putting participants into 3 conditions: the structural/visual, phonetic & semantic. All the participants were told the experiment was a test of reaction speed & had to identify either structural, phonetic or semantic properties of words. Participants were then given an unexpected test for recall of the words in the reaction test. Results: structural (is the word in upper case % recall=15; phonetic (does the word rhyme with windy) %recall=35; semantic (is the word a kind of food % recall=70%).
Physiological evidence (Nyberg, 2002) shows that semantic information results in more brain activity, which could be an indicator of deeper processing.
It has practical applications, e.g., to enhance learning & revision. Nordhielm, 1994, found that viewers remembered adverts better if they processed them semantically; Riding & Rayne, 1998, showed that students learn better when they process information semantically.
MEMORY: Levels of Processing
Evaluation
(continued)
Maybe the nature of the task, i.e., what is to be recalled is more important than depth of
processing. Morris (1977) found that lists of words were better recalled if they were processed phonetically rather than semantically.
Other factors can also affect how well-remembered information is independently of
depth of processing, e.g., Reber et al. (1994) showed that the emotional content of words affected recall; similarly distinctiveness & vivid imagery can improve recall, but these are independent of depth of processing.
This makes depth of processing hard to define; is it the elaboration of information or the
relevance & distinctiveness of the information? In research into LofP, such as Craik & Tulving (1975), how can we be sure that in the structural/visual condition participants were not processing the information semantically, or that the words had some emotionally meaning/distinctiveness for individual participants: this reduces the experimental validity of the research testing the theory.
The definition of deep processing cannot be identified independently of its effects on
recall; we recall more because of deep processing-deep processing leads to better recall, it is circular logic, the theory describes rather than explains how memory works.
The theory can only explain explicit memories, not implicit ones, things that we don’t
MEMORY: Reconstructive memory
Bartlett (1932) proposed that remembering involves looking at units of memory called schemas: these are ‘mental scripts’ or ‘packets of information’ that we have for every aspect of human life, some of these schemas are inherent, such as grasping, but some are learned through experience. E.g., through experience of going to restaurants we develop a restaurant scheme, how to behave in a restaurant; or may have a schema for ‘boyracers’ what they will be like, what sorts of cars they drive & how they drive them.
Bartlett developed his theory famously using a Native American story called ‘The War of the Ghosts’. He noticed that Western participants, when asked to recall the story after they had read it, made lots of errors. He concluded that because the story was far removed from Western experiences & schemas, this made accurate recollection of the story difficult for Western participants unfamiliar with Native American culture.
MEMORY: Reconstructive memory
(continued)
According to Bartlett, we reconstruct memories from relevant schemas & make use of the information in them, e.g., we witness a car accident, see that 1 of the drivers is a young man, & immediately open our ‘boyracer’ schema to help us reconstruct the memory of the accident. In the War of the Ghosts
story we make use of our own Western, ghost, war & death schemas to help us interpret & recall the story, in this case inaccurately.
Memory: Reconstructive memory
Evaluation
There is some experimental support for the reconstructive memory theory. Allport & Postman (1947) conducted a classic experiment showing white participants a picture of a scruffy white man holding a knife to a well-dressed black man, attempting to rob him. When asked to describe the scene some time later, many participants reversed the scenario, with the black man holding the knife. As racism was commonplace in the US at the time, the explanation is that many of the participants relied on their schemas of white & black citizens to aid their recall of the picture; the schema being that black men more likely to behaving aggressively & criminally.
Memory: Reconstructive memory
Evaluation
(continued)
Carli (1999) showed that participants memories become more stereotypical because of schemas. Participants were either told a story which ended abruptly, or one which ended with a rape. In the latter scenario participants tended to have a more distorted recollection of events in the story than the first; the character committing the rape was described in more sinister terms prior to the rape by the participants in the 2nd condition.
Furthermore, memories of new experiences tend to be less distorted than memories of more familiar experiences. Presumably this is because when recollecting novel experiences we cannot use schemas to help us retrieve the memory because we have no schemas for that experience, thus supporting the role played by schemas in memory retrieval.
Memory: the Multi-Store Model
(Atkinson & Shiffrin, 1968/71)
This theory suggests memory is made up of 3 different types
of store:
Sensory memory store (SM) – is a buffer for all information
we perceive with our senses. This store holds information for
a very short time until we decide whether to process that
information further, if it is processed further that information
it gets transferred to:
Short-term memory store – this is a limited capacity store for
attended information, with a capacity of approx. 7+/-2 and
duration of approx 18-30 seconds. Information is encoded
acoustically. If information in the STM is rehearsed
sufficiently it gets transferred to:
Long-term memory store – this has potentially unlimited
The Multi-Store Model
SM
ST
M
LT
M
Memory: the Multi-Store Model
Evaluation
There is much supporting evidence for the existence of different types of
stores, I.e., Miller (1956) noted the difference in capacity between STM & LTM, indicating different types of memory store. Brown & Peterson (1958) showed that without rehearsal memories of trigrams could only be retained for a very short time. Cunitz & Glanzer (1966) showed that the primacy & recency effect – or serial position curve – can be explained using Multi-store model. Words at the beginning of a list are well-remembered – they have been rehearsed and gone into LTM; words at the end are also well-remembered – they are still available in STM; but words in the middle are lost because they have not been rehearsed sufficiently enough to go into LTM and are beyond the duration of STM.
Case studies of brain-damaged people, e.g., Clive Wearing & HM have shown
that people with organic brain-damage often have relatively intact STM performance but poor LTM functioning.
However, case studies of brain-damaged people have shown that LTM is not
affected in a uniform way, I.e., there are different types of LTM, e.g., procedural, episodic, semantic, and they are not all affected in the same way. Thus memory is more complex than suggested by this theory.
There is also evidence from brain-damaged patients to suggest that STM
Memory: Working Memory model
(Baddeley & Hitch, 1974)
This is an alternative to the notion of STM supplied by
Atkinson & Shiffrin.
In the working memory model STM is seen as consisting of
several systems that deal with different types of information:
Phonological loop
: deals with verbal information, especially
its rehearsal: the inner voice
Primary acoustic store
: essentially the inner ear.
Visuo-spatial scratchpad
: deals with visual & spatial
information: the inner eye.
Central executive
: directs the flow of information to the
Memory: Working Memory model
(Baddeley & Hitch, 1974): Evaluation
Seems to face validity, we do seem to be able to picture things, &
although saying things over & over again is a common way to
remember information, it is not the only way.
Participants using one of the systems (e.g., inner voice) for two
different sets of information struggle to recall; however, when the
same two sets of information are encoded using different parts of
system, e.g., inner voice & inner eye, recall is much better. This
supports the theory suggesting that STM is made of more than one
type of system & is more complex than implied by the Multi-store
model.
The Multi-store model often relies on experiments using letters,
words & numbers; however, the working memory model can test
other facets of memory, it is more detailed & dynamic.
The role of the central executive is underdefined & vague, how does
Forgetting: Cue Dependent
Theory
This theory states that we forget things because we do not have appropriate cues to retrieve these memories.
The encoding specificity principle (Tulving) is related. This states that the greater the similarity between the encoding event & retrieval event, the better recall will be, e.g., encoding & recalling in the same place, or being in the same emotional state at encoding & recall.
The Tip of the Tongue Phenomenon (Brown & McNeill, 1966) is often used to support the theory, e.g., we often cannot remember something until we are given some relevant prompt, or cue.
There are 2 types of cue dependent forgetting: Context-dependent forgetting & State-dependent forgetting.
Context-dependent forgetting: This refers to being in the same location/context at encoding & recall in order to improve recall. The environment can also provide context cues, e.g., music (Smith, 1985); smells (Schab, 1990, chocolate; Aggleton & Waskett, 1999, ‘smelly museum’ study, Jorvik Viking Centre, York).
Forgetting: Cue Dependent Theory:
Evaluation
There is a lot of experimental support for both types of cue dependent forgetting: state & context dependent forgetting. Smith (1979) context=participants given a list of 80 words to learn in a distinctive basement. Next day asked to recall in same location or 5th floor room which
was very different. Recall in same location=18/80 in different location 12/80; others recalled in different location asked to imagine themselves back in original room, recall=17/80. Godden & Baddeley (1975) divers study; Abernethy (1940) classroom setting) Environmental context supporting studies: Smith (1985) music: quiet, Mozart or Jazz; Grant & Bredahl (1998) noisy or quiet conditions; Schab (1990) smell of chocolate as a cue; Herz (1997) smell of peppermint, osmanthus & pine: all studies show memory performance better when cues at encoding are present at recall.
Forgetting: Cue Dependent Theory:
Evaluation
(continued)
There is much face validity: it explains the tip-of-the-tongue
phenomena & why when we are given cues, like going back
to old house, or hearing a familiar record, triggers lots of old
memories.
There are many practical applications, e.g., memory can be
improved by introducing context or state cues, e.g., crime
reconstructions, remembering exam material by imagining
you are back in you’re the same place you revised.
However, it cannot explain why some memories are better
Forgetting: Trace-decay theory
This theory states learning causes a physical change in the neural
networks in the brain responsible for memory. This change occurs
at the synapses or gaps between neurones.
When this change occurs a memory trace (or engram) is laid down.
This trace becomes stronger through repetition and rehearsal.
Forgetting occurs when the memory trace is not strengthened by
practice, then the trace begins to break up and disintegrate. Disuse
and the passage of time inevitably leads to the disintegration of a
memory trace.
As STM has limited duration trace-decay is inevitable & very quick;
however, trace-decay takes longer in LTM because the memory trace
is stronger, more secure & profound physical change occurs at the
synapse.
The analogy is with a pathway over grass, i.e., if shortcut is
Forgetting: Trace-decay theory
Evaluation
There is some evidence for physiological changes at the synapses when
learning occurs which is consistent with trace-decay theory.
However, this theory cannot explain why we can recall things that we
have not thought about for a long time; presumably the physical changes
at the synapses would have decayed and the memory trace dissipated.
It cannot explain why we can retrieve ‘old’ or ‘lost’ memories with the
appropriate state or context cue.
Forgetting: Interference
theory
In LTM one explanation for forgetting is Interference; this is when
forgetting occurs because of interference or confusion between old
& new memories.
This does not mean the memory is lost, as in trace-decay theory, but
that it becomes confused or distorted as a result of conflicting
memories.
There are 2 types of interference:
retroactive
&
proactive.
Retroactive
interference is when later/newer or more recently
acquired memories interfere with the recall of earlier
memories/learning: e.g., because you have a new girlfriend, when
you see an ex-girlfriend you cannot remember her name because of
retroactive interference – the name of your current girlfriend
confuses or distorts your earlier memory of names.
Proactive
interference is when earlier learning/memories interferes
Forgetting: Interference theory
Evaluation
There is a lot of research evidence supporting interference theory in
LTM. E.g., see earlier study by Jenkins & Dallenbach (1924); and
McGeoch & McDonald (1931): they gave participants two lists of
information to learn – the more similar the second set of information
was to the first set, the greater the level of interference & the worse
the recall of the first list of information. Also Baddeley & Hitch
(1977) studied 2 groups of rugby players, 1 group had played all the
games that season, one group – because of injury - had missed lots
of games. The first group were worse at recalling the names of all
the teams they had played in the season because they had a higher
degree of interference than the players who missed lots of games
through injury so had played less and had less interference.
However, interference only accounts for a certain type of forgetting;
Forgetting: Displacement
Theory
This is an explanation of forgetting in STM.
STM has a limited capacity, so when that capacity is reached (I..e,
7+/-2) new information displaces older information stored in STM,
e.g., item number 10 displaces or replaces item number 1 in your
STM.
Displacement seems to make sense for STM, but it hard to
distinguish between displacement, interference & trace-decay as an
explanation of forgetting in STM, i.e., item number 1 might have
been lost due to displacement, but equally could have been lost due
to trace-decay (it had been some time since it was rehearsed – STM
has limited duration – and so an engram or memory trace had
disintegrated); or all the items after number 1 had caused
interference and so prevented recollection of that item.
NB., lots of research into memory involves learning lists of
Studies in detail: Can
you describe &
evaluate
Godden & Baddeley (1975)
Cue dependent forgetting/memo ry in divers: AND
Peterson & Peterson (1959)
suppression of rehearsal & interference: OR
Craik & Tulving (1975) Levels of Processing: OR
Ramponi et al. (2004) Levels of
Godden & Baddeley (1975) divers
study: cue dependent forgetting
Name: Godden & Baddeley (1975)
Aim: To investigate whether a natural environment can act as a cue for recall; to ascertain if encoding & recall in the same context/environment improves recall.
Method: 18 divers were randomly allocated to 1 of 4 conditions: 1. learn & recall on dry land; 2. Learn underwater & recall underwater; 3. Learn on dry land & recall underwater; 4. Learn underwater recall on dry land. Participants were also given a recognition test of the words.
Generalisability: Although the study involved divers, the concept under investigation can be generalised; memory is a universal cognitive function.
Reliability: As the research was a field experiment it is harder to control confounding/extraneous variables & having a standardised procedure is more difficult, e.g., very difficult to control diving & weather conditions.
Godden & Baddeley (1975) divers
study: cue dependent forgetting
Results: Recall was 50% higher when
it took place in the same context/environment as encoding (learning). 40% more words were forgotten if recall took place in a different environment to learning. A change of environment between encoding & recall had no effect on the word recognition test. NB., word recall is much harder than word recognition; thus we need more cues to prevent forgetting for recall rather than recognition.
Conclusion: The results suggest that
environment/context does act as cue for recall; we forget more readily of we do not have contextual cues.
Application to real life cont’d: that
students scored improved if they recalled information in their usual classroom. Can be used to help police interviews & eye witness testimony (EWT),i.e., going back to scene of crime to interview witness.
Validity: it was a field experiment so
high in ecological validity, I.e., measuring behaviour in a real world situation. The 4 separate conditions ensured that context was likely to be the cause of greater recall, I.e., encoding & recall took place both underwater & on dry land & in both conditions where encoding & recall took place in the same location recall was higher.
Ethics: there are no ethical issues as
Peterson & Peterson (1959): the
duration of short-term memory
(STM)
Name: Peterson & Peterson (1959)
Aim: To investigate how information is
acquired by Long-term memory (LTM); STM duration & how information passes from STM into LTM.
Method: It was a laboratory
experiment; 24 participants were presented with 48 nonsense consonant trigrams, e.g., CFD & were asked to recall these trigrams. However, participants were asked to recall after intervals of between 3,6,9,12,15 or 18 secs. To prevent P’s rehearsing the trigrams they were asked to count backwards in 3s from a set number, e.g., 293.
Results: After 3 secs approx. 80% of
trigrams were correctly recalled, this fell to 50% after 6secs, 30% after 9secs 7 after 18secs fell to under 10%.
Conclusion: STM has a duration
limited to average 20 secs (18-30secs): without rehearsal memory quickly fades. This supports the trace decay theory of memory & also the existence of different types of memory store – STM & LTM & so supporting Multi-Store Model of Memory.
Generalisability: The study involved
24 undergraduate psychology students, but can still be generalised to the wider population because the concept under investigation – memory – is a universal cognitive function: we all have a memory.
Reliability: It was a well-controlled
study, so easy to repeat. Lots of research suggests the limited duration of STM.
Application to real life: we all have
to remember information using STM & LTM in our everyday lives.
Validity: It lacks ecological validity for
2 reasons: we rarely have to recall nonsense syllables & so is unrealistic; the distracter task – counting backwards in 3s & so requiring high concentration – does not reflect the type of interference experienced in the real world.
Ethics: There are no real ethical
Craik & Tulving (1975): Levels of
Processing Experiment
Name: Craik & Tulving (1975)
Aim: To test the Levels of Processing
THEORY (Craik & Lockhart) by analysing recall rates after different levels of information processing.
Method: A laboratory experiment 24
participants shown 60 words via a tachistoscope, which allows visual material to be presented under conditions of very brief exposure, & asked questions about the words requiring either structural (visual), phonetic or semantic processing. Participants were then given a recognition task, where they were asked to recognise the 60 words from a list of 120 (the 60 original words & a further 120 new words).
Generalisability: See comments for
Peterson & Peterson, Godden & Baddeley above.
Reliability: See comments for
Peterson & Peterson above.
Application to real life: In real life
we encode & process information at different levels according to its relevance & meaningfulness.
Validity: Experimental validity was
Craik & Tulving (1975): Levels of
Processing Experiment
(continued)
Results: 17% recognition for
structural (visual) processing; 36% for phonetic processing; & 65% for semantic processing.
Conclusion: Deeper, i.e., semantic
processing, leads to better recognitions & so better recall, supporting the Levels of Processing
theory of memory.
Validity cont’d: not usually
confronted with lists of unassociated words for a very short period of time; we encode & process information at different levels but not usually this kind of information, i.e., the task is unrealistic & presents a simplistic view of memory, ignoring the role of imagery & emotion that are often linked to LTM (e.g., Morris et al., 1977).
Ethics: There are no real ethical
1 Key Issue in Cognitive
Psychology
The reliability of Eye Witness
Testimony (EWT) OR
‘Flashbulb’ Memories OR
Eye Witness Testimony
Levels of Processing, Reconstructive memory, Rehearsal,
Cue-Dependency
Research evidence suggests that EWT is
unreliable:
Loftus & Palmer (1975) showed that
changing a verb used to describe an accident had a dramatic effect on estimations of speed made by participants witnessing video footage of a car accident (e.g., collide, bump, smash.), I.e., the influence of post-event information. Similar studies include Loftus & Zanni: Did you see the broken headlamp/a
broken headlamp (Nb., definite, indefinite article).
Weapons effect – Loftus (1979) showed
that when a weapon is involved witnesses often concentrate on the weapon & do not focus on the characteristics of the assailant.
Is this due to stress of situation involving a
weapon or unusualness of situation involving a gun?
Reconstructive memory suggests we use
schemas to help us interpret events which may reduce accuracy.
Cue & state dependent theories of
forgetting suggests we need the right cues to recall accurately.
Is EWT really unreliable?
Much of the research conducted into
EWT is based on laboratory experiments & therefore lacks ecological validity: real life events happen quickly, are confusing & generate intense emotions. Participants in lab. Experiments know they have to pay attention & so are already cued for attention. Also the type of questioning in lab. Experiments do not reflect the importance & intensity of police questioning.
Later studies have tried to use field
experiments, e.g., Yarmey, 2004
In EWT research slides & video footage is
often used – this lacks experimental realism as the emotion & involvement of a real incident are not achieved.
A lot of EWT research lacks population
Eye Witness Testimony
Pickel (1998) showed participants a
video clip of a man entering a hairdressers holding either: scissors, a raw chicken, a wallet or a gun. The objects represented either high or low unusualness or high/low threat or both. Participants could identify the man from a line-up but were poor at remembering the object he was holding the more unusual (for that situation) it was: indicating that the stress/arousal of the situation involving the gun was not necessarily the cause of poor memory, but it was the unusualness of the situation that adversely affected memory.
Schema theory & Stereotyping: EWT
can also be explained using schema theory (reconstructive memory) – as the above study shows. People are often heavily influenced by their schemas – see reconstructive memory, Brewer & Treyens & Allport & Postman.
Research population is not necessarily
homogenous (representative of all parts of society).
Even Loftus has shown that
eyewitnesses can only be mislead about peripheral details of an incident, not necessarily central details, e.g., when asked leading questions about the colour of a stolen purse, participants were not mislead about the colour of it.
Yuille & Cutshaw showed that in real
life situations EWT can be very accurate. They studied statements given 4 months after witnessing a shooting & found that recall was accurate & not affected by leading questions.
Smith & Elsworth (1987) showed that
‘Flashbulb’ Memories
A special form of memory we have evolved
that enables us to remember particularly distinctive events in detail (in evolutionary terms it gives us a survival advantage). Events such as the death of Princess Diana, The Twin Towers attacks & the London Bombings are events we might recall in a lot of personal detail.
Brown & Kulik (1977) found that participants
had very detailed & specific memories for events such as the assassinations of Martin Luther King, John & Robert Kennedy & the deaths of relatives. We tend to have flashbulb memories for events that are more personal to us, e.g., Brown & Kulik found that 75% of black participants reported flashbulb memories for the assassination of Martin Luther King, compared to only 33% for white participants.
Personal relevance/consequences are
important for accurate flashbulb memories. Conway et al. (1994) showed that 86% of UK participants had a flashbulb memory of the resignation of Margaret Thatcher 11 months after event, compared to only 29% of participants from other countries.
Flashbulb memories are not a special form of
memory at all.
Neisser & Harsch (1992) asked students to
report how they learned about the Challenger Space Shuttle disaster 1 day after the event & 3 years after the event. When asked 3 years later to recount how they learned of the disaster, no one produced an entirely
accurate report (compared to the one
produced a day later) & over 1/3 produced a completely inaccurate report even thought hey thought it to be very accurate. Similar findings were reported by Wright (1993) about the 1989 Hillsborough football disaster 5 months after the event.
Neisser argues that flashbulb memories are
The Cognitive Interview
The cognitive interview is a technique
used by the police to try to elicit more accurate recall from an eyewitness, and is based on psychological research into memory.
There are 4 basic component of a
cognitive interview: recreating the context/environment of the incident (mentally); reporting very detail, however seemingly irrelevant; reporting the incident in different orders; reporting how others may have viewed the incident.
It is a more open & less interrogatory
form of interviewing than traditional police interviews. It is designed to provide as many cues to recall as possible. It prevents memory contamination by asking open - not leading – questions, in an attempt to avoid memory reconstruction by introducing new information as a result of leading questions which may trigger pre-existing schemas.
Fisher et al. (1985) reported that recall
was much better using this technique: 42 items compared to hypnosis, 38 items (but with confabulation) and standard interview, 29 items.
Gieselman (1984) that the cognitive
interview produced 35% more information than the standard interview, with no difference in error rates.
However, some argue that recall may
actually be inaccurate due to witnesses being asked to recall from another’s perspective, leading to witnesses guessing what someone might have seen. Some research has also shown that the cognitive interview fails to provide significant improvement in recall compared to standard interviews & generates greater errors in recall (Memon, 1997).
The cognitive interview may not be
The Cognitive
Interview
Studies such as Loftus & Palmer illustrate how just a change of a
verb can affect eyewitness recall, therefore, a technique such as the
cognitive interview, that takes into the account the power of words is
clearly needed.
The cognitive interview technique is based on well-controlled
laboratory experiments, which were replicated & found to be
reliable, e.g., Loftus & Palmer.
Milne (1997) found that the cognitive interview did not seem to lead
to the recall of more material than any other technique,
contradicting other research (see previous slide)
Memon et al. (1997) found little difference in recall when asking
witnesses to recall from different places/sequences in the witnessed
event than recalling normally.
The enhanced version of the cognitive interview (Fisher &
Research Methods/How Science
Works & Practical
As with the social approach, you will need to
know a range of scientific terminology & be
able to describe & evaluate a range of
different cognitive psychology research
methods.
You will also need to conduct and keep a
Experiments: Laboratory,
Field & Natural
Type of Experiment Strengths Weaknesses Laboratory: the IV is
manipulated and the effect on the DV measured in a controlled environment which aims to reduce effects of extraneous variables, in order to establish causal relationships & test hypotheses.
Because of strict control over extraneous variables a cause & effect relationship is easier to establish; we can also be fairly confident that it is only the IV affecting the DV. Researchers can control who takes part. No ethical problems, consent easy to obtain, withdrawal easy.
The situation is highly artificial so behaviour is very contrived, cannot be applied to real life, demand characteristics may apply as participants are aware they involved in research and researchers themselves may influence participants’ behaviour (experimenter effects).
Field: IV is manipulated and DV measured in participants’ natural environment.
Behaviour is more natural and realistic as it takes place in a natural environment & participants are not aware they are taking part in research so there are no demand characteristics or experimenter effects.
Less control over extraneous variables which could affect validity of study (something other than the IV affecting the DV); this reduces reliability as the
participants may not all be getting the same experience. Ethical problems with consent & withdrawal; difficult to set up & so time consuming. No control over who takes part.
Natural: Similar to a field experiment in that it takes place in a natural environment; however, the IV is not
manipulated by the researcher: it occurs naturally (e.g., Charlton, 1998, study of St.Helena)
More realistic as IV occurs naturally, not contrived & takes place in natural environment so behaviour is not artificial are more ecologically valid. Ethical as behaviour is occurring naturally, it is not a
psychological study as such, the situation has not been engineered by researchers
Hypotheses
See Social Psychology:
Hypotheses can be one tailed (directional) or two tailed
(non-directional).
This means: 1 tailed hypothesis=makes a definite prediction
about the direction of results e.g., participants who are given
the same context cue at recall & encoding will recall more
words than those who are not. I.e., they will remember more
words.
2 tailed hypothesis=something will happen but the direction
Experimental Control & Variables
(NB., only experiments have IVs &
DVs)
Independent Variable (IV): This is the variable that is manipulated or changed by the
researcher – it is the thing under investigation e.g., does alcohol affect reaction time? Alcohol is the IV.
Dependent Variable (DV): This is the variable that is being measured, or the result of
the experiment – the DV depends on the IV e.g., reaction time is the DV, it depends on the level of alcohol consumed.
Extraneous Variables: Any variable that can influence the DV bit which has nothing to
do with the IV, extraneous variables may or may not confound the results.
Confounding Variables: This is variable, other than the IV which has confounded the
results, i.e., has directly affected the DV but is nothing to do with the IV, e.g., tiredness may have affected reaction time, not alcohol consumption. The researcher should try & control/eliminate confounding variables wherever possible.
Situational Variables: The are extraneous variables that could affect the IV which are
related to the situation the study was conducted in, e.g., level of noise, weather conditions, heat, level of crowding could all affect the participants’ performance & so influence the DV; as such they should be controlled/eliminated wherever possible.
Participant Variables: These are extraneous variables related to the
Operationalisation
In an experiment once the IV & DV have
Participant Design
This refers to how participants are allocated to the conditions in the
experiment, e.g., if testing reaction time & alcohol consumption will
participants be involved in both conditions, I.e., doing the reaction
test sober & after various units of alcohol; or will some participants
do the reaction test sober, others after consuming alcohol.
Independent Measures Design
: Participants are only involved in 1
condition, e.g., one group does the reaction test sober, 1 does it after
consuming alcohol.
Repeated Measures Design
: The same participants are used in
both experimental conditions, e.g., participants do the reaction test
sober & intoxicated.
Matched Pairs Design:
Essentially the same as Independent
Participant Design
(Continued)
Participant Design Strengths
Weaknesses
Independent Measures Design Avoids order effects
(practice/fatigue) Needs more participants. Might be significant differences between the two groups of participants which could skew results (participant variables)
Repeated Measures Design Avoids problems of possible differences between
participants (participant variables)
Same participants doing both conditions might lead to order effects.
Matched Pairs Design Avoids order effects & largely avoids problem of participant variables as participants are equally matched in both conditions
Participant Design (Continued)
Order effects, Counterbalancing,
Randomisation
Order Effects: In a repeated measures design participants take part in all experimental conditions; this may lead to order effects (practice effects or fatigue), where as a result of doing the a similar condition the participants become more practised so perform the 2nd part of the experimental better, or
they become more tired as a result of doing something similar before & so a fatigue effect sets in. Both practice & fatigue can affect participants’ performance and so artificially skew the DV – the DV results are influenced by factors other than the IV.
Counterbalancing: To counter order effects counterbalancing is used. This is where participants are divided equally between the experimental conditions, e.g., half do condition A first then condition B & half do the reverse, condition B first then condition A. If everyone did condition A then condition B results might be skewed by order effects (practice or fatigue).
Demand
Characteristics/Experimenter
Effects
Demand Characteristics
: Human participants may respond to the
experimental conditions that they are involved in, they are not
passive & may alter their behaviour simply because they are in an
experiment. E.g., participants may try & guess the purpose of the
experiment & behave accordingly, either according to the their
perception of the researcher’s expectations, or to contradict what
they believe the researcher’s expectations are.
Experimenter Bias
: This refers to the subtly cues & signals,
Types of Validity & Reliability
Ecological Validity: how well does a
study represent behaviour in the real world, are we measuring how people would behave in the real world, or simply how they would behave in a lab.situation.
Construct Validity: how well does the
study measure the construct or phenomenon being studied, i.e., how well has the construct of aggression been operationalised in the study.
Content/face Validity: does the study
seem to, on the face of it, measure what it claims to be measuring.
Predictive Validity: how well does the
study predict future behaviour, e.g., if a job interview has predictive validity, everyone who did well at the interview would nearly always also be good at the actual job.
Test-Retest reliability: If the
participants take the test again, maybe a few months apart, will their
performance still be similar, or was the original performance a ‘one-off’
affected by variables on the day other than the IV.
Inter-rater reliability: If two
Types of Validity & Reliability
Experimental Validity: Does the
procedure of the study accurately reflect what is being studied; is the experiment credible (e.g., Milgram), would demand characteristics play a big part in the results (e.g., Zimbardo).
Population Validity: Are the
participants a good representative sample of the target population, or are they drawn from one particular type of people, e.g., all strongly religious, or all students.
Concurrent Validity: Are the results
from the behaviour being studied in line with other measures of the same behaviour, e.g., new test of reading ability should be in line with other measures of reading age, if it has concurrent validity.
Equivalent Forms reliability:
Research Methods/How Science
Works: The Practical
(see also Social
Psychology)
Choose an appropriate design: repeated, independent & matched
pairs – why that design?
What will be your procedure?
Note the ethical implications: is the cue material ethical, I.e., not
illegal drugs, do participants leave feeling positive about themselves
& psychology, are debriefed, not caused distress etc.,
Analysing results: mean, median, mode, range, standard deviation.
Graphical representation: Bar graph, frequency graph, histogram.
Was the experimental procedure Valid (experimental, ecological,
