Memory

Memory

1. Multi store model

   • Sensory register
     • Capacity - Large as the detail within is in unprocessed, highly detailed formats
       • Sperling - 3x4 grid, recall = high
     • Duration - brief
       • Sperling - delayed presentation of grid, more delay more info lost
       • Walsh & Thompson - 500 milliseconds
     • Encoding - visual, auditory and tactile
       • Crowder - SR retains different types of info for different lengths of time, suggests diff stores within SR
   • STM
     • Capacity - 5+/- 2
       • Jacobs - serial digit span method, increasingly long list
     • Duration - 18 to 30 seconds
       • Peterson & Peterson - nonsense trigrams, 90% recall after 3 secs, 5% after 18
     • Encoding - mainly acoustic
       • Baddeley - when given acoustically similar list to recall, puts performed worst, suggesting acoustic confusion
   • LTM
     • Capacity - limitless
       • Anokhin - estimated no. of possible neuronal connections to be 1 followed by 10.5 mil km of noughts
     • Duration - potentially a lifetime
       • Bahrick et al - ex school friends photos and names
     • Encoding - mainly semantic
       • Baddeley - same as for STM, however, given 20 min interval, list c was performed worse (semantically similar)

2. Working memory model

   • Phonological loop - auditory info
     • Trojani & Grossi - case study of SC with brain damage affecting PL but not VSS - separate
   • Visuo-spatial sketchpad - holds visual and spatial info
     • Baddeley et al. - couldn't carry out two visual tasks but could do a visual and verbal task
     • Klauer & Zhao - interference between visual tasks
   • Central executive - filters and drives whole system
     • Baddeley - ppts slowed during dual tasks, suggesting they were competing for CE resources, limited capacity D'Esposito - used fMRI to find pre-frontal cortex was activated during simultaneous tasks but not when performed separately
   • Episodic buffer - temp store that communicates between WMM and LTM
     • Alkhalifa - patient with impaired LTM had high STM capacity, suggesting existence of EB

3. Explanations for forgetting

   • Interference theory
     • proactive - old interferes with new