Cognitive Psychology

• Cognitive psychology is the study of perception, attention, memory, language, and thinking in humans.
• Information processing is where information from our senses flows through the three stores in memory in a sequential order being processed in each store in order to retain information temporarily in STM or forever in LTM
• Capacity involves how many items a memory store can hold. In the STM, capacity is between 5 to 9 items.
• The duration involves how long a memory will last. For example, the STM can hold information for 0-30 seconds.
• The process of formatting information in different ways. In STM encoding is said to be acoustic.
• The Multi-Store Model of memory (MSM) can be described as an information processing model where information is input, processed then output.
• Information is initially detected by the sense organs, such as sight, or sound, and enters the sensory store in a modality specific form for a very brief time.
• Information that is paid attention to in the Sensory Store is then transferred to the short-term memory (STM) store where acoustic encoding is used.
• The STM is said to have a limited capacity of 5-9 items for information storage and a limited duration of 15-30 seconds.
• If information continues to be rehearsed and consolidated (elaborate rehearsal) information in the STM is then transferred into the Long Term Memory (LTM). Information here is said to be encoded in the LTM store in mainly a semantic format, the capacity is said to be unlimited and the duration lifelong.
• Atkinson and Shiffrin (1968) proposed a three-stage model of memory: a short-term store, a long-term store and a sensory register.
• Descriptive statistics are brief informational coefficients that summarise a given data set, which can be either a representation of the entire population or a sample of a population.
• Descriptive statistics are broken down into measures of central tendency and measures of dispersion (spread).
• Measures of central tendency: Mean, median, mode.
• Measures of dispersion: range, Standard deviation
• Formula for Standard deviation:

  
• STM can hold more information in chunks, but loses accuracy (eg recalling a whole face instead of remembering eye colour).
• Quantitative data is numerical data - closed questions.
• Qualitative data is descriptive written data. - open questions.
• PRO of quantitative data: can be turned into statistics, reliable, easy to analyse, can be used to compare data, can be used to predict future behaviour.
• CON of quantitative data: it is a reductionist - it simplifies too much, a lot of detail and meaning is lost, may lack validity (as it two respondents may get the same score but have different reasons for it).
• Primary data is gathered first hand by the researcher whilst secondary data is information already published.
• Secondary data is used by a researcher as part of their own investigation whilst primary requires conducting research such as experiments to find original data.
• A hypothesis is a predictable statement of what you expect to find after completing your research.
• Hypotheses can be directional or non- directional.
• Directional/one tailed hypothesis - means the direction of the findings is predicted.

  Non-directional/two tailed hypothesis- means the direction of the findings is not known, however a difference is predicted.
• Psychologists use different experimental designs. What does this mean? “Design” refers to how the participants are assigned to different conditions of the IV in an experiment.
• In an experiment with independent groups design, there are actually completely different groups of people in each condition of the IV and no one gets to be in more than one condition. This means that each participant only experiences the IV once.
• Independent groups produce confounding variables because it’s very difficult to make sure that the two groups contain exactly similar people. It’s hard to be sure that the IV is the only difference between the groups. These differences are called participant variables.
• Participant variables are the main problem for independent groups design, because if the different groups aren't the same then the internal validity of the experiment is ruined.
• Another approach is to take a single group of people and make sure they all experience both conditions. In repeated measures design everyone gets to be in the experimental condition and the control condition. In other words, they experience every condition of the IV.
• Fewer participant variables in a repeated measures design as the only difference between the experimental condition and the control condition is the IV (because they’re the same people).
• Repeated measures can suffer from order effects. If you test the same group of people twice, then they might behave differently the second time because they’re familiar with the test – or bored with it.
• Comparing Independent Groups & Repeated Measures

  
• Fatigue effects are order effects where the participants' performance goes down through boredom or exhaustion
• Practice effects are order effects where the participants' performance goes up through familiarity with the test.
• Order effects also make it much more likely the participants will figure out the purpose of the experiment and that introduces demand characteristics: the participants behave unnaturally because they are trying to do what they think the researchers want them to do.
• Solution to the problem of order effects:

  Randomisation means determining which condition a participant experiences by random chance (tossing a coin, drawing a card). Some people might do the experimental condition first, then the control condition; other people might do it the other way round.
• Solution to the problem of order effects:

  Counter-balancing is similar, but there's no randomness. Just split the group into sub-groups: one sub-group does the experimental condition first, then the control; the other sub-group does it the other way round.
• Matched pairs design is a design in which participants are matched on one or more characteristics before the experiment begins. Matched pairs starts out like regular independent groups design. Then you to “match” each person in the experimental condition with a similar person in the control condition. You could match people on their age, sex, IQ, social class or anything else that’s measurable.