Cognitive psychology: Research into encoding

Cognitive psychology: Research into encoding

1. Baddeley (1966): Encoding in the STM and LTM

   • Aim and Procedure
     • The aim of the study was to investigate the effects of acoustic and semantic encoding in the STM and LTM
     • Participants were presented with 5 words in 4 categories: acoustically similar and dissimilar and semantically similar and dissimilar
       • The number of words was increased to 10 for the long term memory
     • P's had to recall the words in serial order immediatley for the STM and after 20 mins for the LTM.
       • Rehersal was prevented during the 20 minuets for the LTM condition
       • In the LTM condition, the list of words were presented 4 times
   • Findings and Conclusion
     • P's had difficulty remembering the AS words in the STM
     • P's did not have trouble remembering AS words in the LTM
     • P's had difficulty remembering SS words in the LTM
     • P's did not have difficulty remembering SS words in the LTM
     • It was concluded that the STM relies on acoustic encoding where as the LTM relies on semantic encoding
   • Evaluation

2. Conrad (1964): Encoding in the STM

   • Evaluation
   • Findings and Conclusion
     • P's found it more difficult recalling the AS words
     • P's made the most mistakes of substituting the letters that sounded the same rather than ones that looked the same
     • It was concluded that letters had been encoded by sound therefore the STM relies on acoustic encoding
   • Aim and Procedure
     • To investigate the nature of encoding in the STM
     • P's were presented with several random sequences of 6 consanants
       • Each letter was projected on a screen for 0.75 seconds before moving on to the next letter
     • In one condition, the letters were AS and in the other they were AD
     • Immediately after the presentation, P's were asked to recall the letters in serial order

3. Evaluation of both studies into encoding

   • - Ecological validity - They were lab experiments
   • - Demand characteristics - P's knew they were taking part in an experiment
   • - Generalisability - Only undergraduate students were used
   • + Reliability - they both used standardised procedures
   • + Internal validity - all variables were controlled
   • -/+ Ethics - Frustration of not being able to recall words could have caused stress but all P's were fully consented and debriefed
   • - Opposing research - Frost (1972) found that LTM recall was related to visual as well as semantic categories of encoding