Memory

Memory

1. Attkinson-Shiffrin's Multistore Model of memory

   • Sensory Memory
     • Short-term memory
       • Long-Term memory
         • Capacity- Potentially unlimited. Duration- Long
         • Explicit memory
           • Episodic- biographical
           • Semantic- facts
         • Implicit memory
           • Procedural- how to
           • Classically conditioned
         • Methods to retrieve LTM
           • Recall- involves reproducing info stored in memory
             • Free recall- involves reproducing as much info as possible in no particular order with no cue
               • Serial recall- involves reproducing info in the order it was presented no cue
                 • Cued recall- involves reproducing info with the use of specific prompts to aid retrieval
           • Recognition- Involves identifying the original learnt info. The presence of the correct info acts as a cue
           • Relearning- involves learning info again that has been previously learnt. -if info is learnt quicker the second ime it is assumed that some info must ahve been retained or saved from teh first learning experience
             • Savings score= (T1-T2)/T1 x 100/1
           • Sensitivity of measures of retention. -Refers to its ability to assess the existence of information in memory. -The greater the sensitivity= the more likely it is to retrieve information from LTM. -Recall is least sensitive. (hardest to remember) -Recognition -Relearning is most sensitive. (best).
           • Reconstruction -Combination of what is in LTM and what you are currently thinking about. -An active process influenced by past experience, values, psychological state, past info, expectations etc. -Our reconstructions are not always accurate and may contain errors. -Can occur for both semantic and episodic memories
       • Capacity- 7 +/- 2 items Duration- 18-20 sec
       • Rehearsal- increases the duration of STM
         • Mental rehearsal- involves repeating the words over and over again
           • Elaborative rehearsal- involves adding meaning
       • Chunking- increases capacity of STM
         • -groups letters or numbers. eg. V, C, A, T becomes VCAT
     • Capacity- Potentially Unlimited Duration 1/3 to 4 sec
     • Iconic Memory Visual memory, 1/3 of a sec
     • Echoic Memory,- auditory memory up to 4 sec

2. Brain Trauma

   • Neurrodegenerative disease
     • A disorder characterised by the progressive decline of neurons
     • Amnesia
       • Loss of memory inconsistant with normal forgetting
       • Anterograde amnesia
         • -Lose ability to form or store new long term memories -Damage to medial temporal lobe (hippocampus) -Only explicit memories are affected -results from a failure of memory encoding and memory storage because of disruption to consolidation

3. Specific regions of the brain

   • Brain surgery
     • -Brain surgery affects explicit memories and their transfer to the cerebral cortex for storage -Proved that STM is different to LTM Right hippocampus removal -Difficulties with learning and remembering the location of objects and places. -Spatial learning and memory. Left hippocampus removal -Difficulty remembering verbal information but have no difficulty recalling visual designs. -Verbal learning and memory
       • -Impaired classically conditioned fear response -Impaired ability to recognise facial expressions of emotion, particullary fear
         • -Brain surgery to the cerebellum affects classically conditioned learning and memory of very specific reflexive movements
           • -Brain surgery drastically affects the retrieval process
     • Alzheimers disease
       • -A type of dementia characterised by the gradual widespread degeneration of brain neurons, progressively causing memory decline, deterioration of cognitve and social skills and personality changes
         • -The outer part of the brain is usually the first area affected by teh disease, therefore STM is the first symptom. As the disease progresses to deeper parts of the brain, LTM is increasingly impaired. Explicit memories are primarily affected. An accurate diagnosis can only be made after death
           • Psychological symptoms
             • 1. Build up of amyloid plaques= inhibits neuron communication
             • 2. Build up of neurofibrillary tangles- neuron stops recieving blood etc.
             • 3. Reduced level of neurotransmitter ACH- plays a vital role in memory formation
             • 4. Shrivelled brain and decreased cortical areas
   • Hippocampus
     • Amygdala
       • Cerebellum
         • Cerebral cortex
           • -Long term explicit memories are stored throughout the cerebral cortex -Different parts of memory are located throughout, depending on the area it was first processed. -When required, the seperate parts are gathered together adn reconstructed as a single integrated memory for retrieval into our concious awareness
         • -Involved in the learning and execution of fine motor skills -Involved in the encoding and storage of implicit memories
       • --Plays a crucial role in procesing our emotional responces and memories, these can include classically conditioned fear responses Doesnt store them -Due to release of adrenaline -Also 'flashbulb memory
     • -Responsible for turning STM memories into LTM -Vital for the consolidation of explicit memories -Important for spatial memories -After memories have been consolidated they are transferred to the ceberbal cortex

4. Summary of Loftus Studies

   • Loftus’ studies involved showing participants video clips and then using leading questions to see if their memories can be reconstructed. For example, after viewing a video clip of a car crash participants were asked how fast the cars were going when they smashed/collided/bumped/hit/contacted. The verb in the question influenced on the speed estimate given by participants.
   • Another experiment used the same words, but asked if there was glass. Those with words like smashed said yes, bumped said no.

5. Factors influencing ability and inability to remember

   • Serial position effect -A finding that free recall is better for items at the end and the beginning of a list than for items in the middle of the list.
     • Primacy effect -Describes superior recall at the beginning of a list. -Linked to long term memory as items that are rehearsed are more likely to pass into LTM.
       • Recency effect -Describes the superior recall at the end of a list. -This is linked to Short term memory as items that have been recently presented will still be in STM.
   • Context and state dependent cues
     • Context dependent-Are environmental cues in the situation where a memory was formed that act as retrieval cues to help access the memories that were formed in that context. -These can include sights, sounds or smells at the specific environment.
       • State dependent cues -Are associated with an individual's physiological and/or psychological state at the time the memory was formed. -You are more likely to remember info if you are in the same 'state' as when you learned it. Eg. If you are drunk you will remember what you did again when you are drunk. Refers to bodily or emotional state.

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