Cognitive Psychology

This unit is split into 4 aspects:  The nature of memory, including its stages, capacity, duration, encoding  Models of memory, including the multi-store model and working memory  Theories of forgetting, including trace decay, displacement, interference, cue-dependent forgetting  Eyewitness testimony; applications, eg crime and accidents, factors affecting eye witness testimony. Loftus and Palmer (1974) study.

Cognitive Psychology  See Atypical Behaviour notes re. core beliefs of Cognitive psychologists.  Mind is like a computer:. InputProcessingOutput Storage

Nature of Memory  Stages of the memory process:  Task: You are responsible for getting the round in. Everyone in the class will give you their order. You have no pen or paper. Now try ordering at the bar (me). How many did you remember?  How many did you remember?  How many do you think you’d be able to remember if the bar was busy?  What strategies did you use to help you remember?  What other strategies might be used? EncodingStorage Retrieval

Short Term Memory  Encoding – Creating a memory. Information in STM is normally encoded through noise. (See Baddeley, 1966) but can also be visual.  Capacity – How much can be stored. (See Jacobs, 1887; Miller, 1956)  Duration – How long the information is stored for. (See Peterson and Peterson, 1959)

Encoding Task  In your pairs, decide who will be experimenter and who will be participant.  Each experimenter will be given a list of words to read to the participant.  Participants should attempt to immediately recall those words.  Experimenter, take a note of:  The letter of the list you have been given (A,B,C or D)  The number of words correctly recalled.

Next stage:  Swap roles  Experimenter - read out the new set of words.  Participant – listen and then copy out the next slide.

Duration of STM – Peterson and Peterson, 1959  Aim:  To study the length of time information can be contained in STM  Method & Procedure:  24 students given 3 letters then asked to count backwards for either 3,6,9,12,15 or 18 seconds then recall the original 3 letters. Each ppt was given 2 practice trials then 8 recorded trials.  Results:  90% recall at 3 seconds  2% recall at 18 seconds  Conclusion:  If verbal rehearsal is prevented, information can be retained in the STM for less than 18 seconds.  Evaluation:  Mundane Realism  Biased sample

Baddeley, 1966  Carried out the above encoding task that you have just completed.  In the original condition (when ppt had to recall the words immediately) he found that participants performed worse if given list A. This list was acoustically similar.  In the second condition he found that list C did worse. This list was semantically similar.  He concluded that:  STM encodes acoustically (more mistakes were made when they sounded similar)  LTM is encoded semantically (more mistakes were made when they had similar meanings)

Long Term Memory  Encoding –. Semantics (meanings/knowledge), episodic (experiences) and procedural (how to do something). Baddeley, 1966 – mainly semantic.  Capacity – Limitless? Impossible to measure.  Duration – Limitless? Bahrick et al, 1975

Revision Questions  Explain the ways in which information is encoded in both the STM and LTM.  Explain the capacity and duration of STM and LTM.  State the 3 stages of memory.  Compare and contrast the LTM and STM.