Cognitive Flashcards
What are case studies?
Allows data gathered to be in-depth and detailed. Gathers data from many different sources and different research methods
What type of data do case studies gather?
Qualitative, but can also give quantitative (e.g. IQ tests)
Who was HM?
Henry Molaison
Which part of HM’s brain was removed?
William Scoville removed HM’s hippocampus, which was associated with consolidating memories.
What happened to HM’s memory
He was assessed of having anterograde (loss of ability to make NEW memories) and retrograde (loss of ability to recall events PRIOR to the injury) amnesia.
How did HM contribute to understanding memory?
Shows that there is short term and long term memory storage. Informs us that short term memories need to be transferred to long term storage to be able to be retrieved again.
What is test-retest reliability?
If findings are consistent, and considered reliable, it can be trusted that findings will happen again.
Objectivity
Need to be impartial and judgement free
Internal validity
How well the procedure establishes a causal relationship between manipulated IV and measured DV.
Predictive validity
The extent to which the performance on the measure can predict future performance on a similar criterion.
Ecological validity
The extent to which the research can be generalised to other situations (real life or everyday situations).
Operationalised hypothesis
Defining precisely how you intend to measure the DV and alter the conditions of the IV
What are the 3 experimental designs?
Independent measures, repeated measures and matched pairs
Independent measures design
Using DIFFERENT participants in each condition of the experiment
Repeated measures design
Using the SAME participants in each condition of the experiment
Matched pairs
Using different but similar participants in each condition. An effort is made to match the participants in any important characteristics that might be important to the study.
Order effects
Occurs when repeated measures design is used.
Practice effect - become practised at the test and improve their performance
Fatigue effect - become tired or bored so performance deteriorates
Counterbalancing
Each condition is tested first or second in equal amounts. Divided equally between the conditions and experiment them in different order.
e.g. one group tested in A then B, other group do B then A.
Randomising
Each participant is assigned either Condition A or B first randomly
Extraneous variable
Variable that may have affected the DV but that was not the IV
Confounding variable
Variable that affects the findings of a study directly, so much that you are no longer measuring what was intended
Situational variables
An extraneous variable found in the environment, such as noise, time of day, temperature, disturbances etc.
Participant variables
Participants themselves may affect results as they have different characteristics, such as intelligence, level of motivation, age, personality, skills.
Experimenter/ researcher effect
The way the experimenter may influence the outcome of an experiment by their actions or presence.
Hawthorne effect
Presence of the experimenter can affect performance
Demand characteristics
Participants have certain expectations concerning the experiment. Actual communication, what the participant may have heard about the experiment, effect of the experimenter causes the participant to alter their behaviour to meet the expectations.
Standardisation
Making an experiment the same experience for all participants. Standardised instructions and standardised procedures.
Nominal data
Form of categories
Ordinal data
Ordered in some way, e.g. ranking
Interval data
Real measurements are involved, e.g temperature
Ratio data
Same as interval, but there is a true zero point, e.g. cm or seconds
Who proposed the Multi-store model of memory?
Atkinson and Shiffrin (1968)
What are the 3 basic memory stores?
Sensory buffer, short-term memory and long-term memory
Multi store model of memory
Attended information from sensory register is transferred to STM, from STM information can be transferred to LTM
Sensory Buffer
- One register for each sensory modality e.g. visual, auditory
- Limited, approx. 50 milliseconds duration
- Capacity 3-4 items
- Forgetting by decay
- Retrieval by scanning
STM duration research
Peterson and Peterson - using an interference task to prevent rehearsal. Required to remember a single trigram for intervals of 3, 6, 9, 12, 15 and 18 secs. Correct recall of trigram was likely after a short interval but performance dropped after 15-18 secs.
STM capacity research
Miller - STM limited to around 7 items. ‘Magic number seven, plus or minus two’
Primacy-recency effect
Glanzer and Cunitz - first and last words in the list were recalled well, but middle words were not remembered well. First (primacy effect) had gone into LTM through rehearsal and end (recency effect) is still in rehearsal loop. Middle is not well recalled as it was displaced by new material.
STM encoding
Memory trace was held in an auditory or verbal form because of phonological similarity effect. Suggests STM encoding is primarily acoustic.
STM retrieval
Based on rapid scanning of stored information. Rehearsal is important for maintaining information in the STM, increasing strength of memory trace.
Transfer of information between STM and LTM
Transfer can be a result of rehearsal - leave a weak memory trace. Stronger memory trace by using a medical operation such as a mnemonic.
STM summary
- Acoustic and verbal encoding
- Duration 15 - 30 seconds
- Storage capacity 5 - 9 items
- Forgetting by decay through displacement
- Retrieval by sequential search
Retrieval from LTM
LTM exists for all sensory modalities, multiple copies of a memory were retained.
Tip-of-the-tongue phenomenon (Brown and McNeill 1968) showed that people were able to accurately predict that they could recognise a correct answer even if they could not recall the answer at that moment in time.
Encoding in LTM
Depend on rehearsal process or association between new and pre-existing knowledge. Encoding is semantic.
Duration of LTM
Potentially a lifetime. Bahrick (1975) found that identification of names and faces in High School Yearbook was between 70-80% accurate 48 years after leaving school.
Capacity of LTM
Potentially infinite. Brady (2008) showed 2500 objects over 5.5 hours. Participants were shown the original object paired with a different object, identification was 92% and if different object was similar 88%
LTM summary
- Semantic encoding
- Potentially a lifetime of duration
- Limitless capacity
- Forgetting through decay and interference
- Semantic retrieval
Strengths of MSM
- Supporting evidence
- HM case study gives physiological support
- Shows they have separate stores - Baddeley conducted an experiment and found that semantic words were more difficult to recall, suggests encoding in STM and LTM were different