Memory

Memory

1. Coding, capacity, duration

   • Coding
     • Baddeley
       • Acoustically similar words (cat,cab) or dissimilar words (pit,few). Semantically similar words (big, huge) or dissimilar (good, hot)
         • STM = acoustic - recall worse of acoustically similar words immediately. LTM = semantic, recall after 20mins worse with semantically similar words.
           • Limitation: didn't use meaningful material - can't generalise
   • Capacity
     • Jacobs
       • Digit span - Researcher reads 4 digits and increases until pps cannot recall the order correctly.
         • Pps could repeat back 9.3 numbers and 7.3 letters
           • Limitation: Old study, lacked control of extraneous variables. Results not valid. HOWEVER... studies have been repeated and found similar results
   • Duration
     • Bahrick et al
       • 392 Americans aged between 17 and 32
         • 1) Recognition test - 50 photos from yearbook. 2) Free recall test
           • Pps tested 48 years after graduation 70% accurate in photo recognition, free recall less.
             • Strength: High external validty, meaningful material. HOWEVER confounding variables not controlled

2. Multi-store model of memory

   • Sensory register - stimulus passes into SR. Duration - short. Capacity - high. Coding - depends.
     • Transfer from SR to STM - only goes in if ATTENTION payed to it.
       • STM - Duration - 18-30 seconds. Capacity - between 5 and 9 items. Coding - acoustic.
         • Transfer from STM to LTM - Maintenance rehearsal causes it to be passed to LTM.
           • LTM - Permanent memory store. To recall the mems they have to be transferred back to STM (RETRIEVAL). Duration - poss forever. Capacity - poss unlimited. Coding - semantic.
   • Evaluation
     • STRENGTH: Baddeley research supports
     • LIMITATION: Oversimplifies LTM - 2 stores; semantic and episodic
     • LIMITATION: what about elaborative rehearsal - incomplete

3. Long Term Memory

   • EPISODIC
     • Stores events from our lives.
       • Complex: Time stamped, involve several elements - conscious effort to recall them
   • SEMANTIC
     • Stores our knowledge of the world
       • Not time stamped, less personal
   • PROCEDURAL
     • Stores memories for actions and skills - how we do things
       • Recall occurs without conscious awareness
   • EVALUATION
     • STRENGTH - case study evidence HM - semantic memories not affected, couldnt remember stroking a dog half an hour ago but understood what a dog is.
     • STRENGTH - brain scan studies TULVING show that diff areas of the brain contain the different memory stores.
     • LIMITATION - can't generalise evidence from case studies to whole population

4. Working Memory Model

   • Baddeley and Hitch
     • Central executive

5. Explanations for forgetting

6. Eyewitness testimony