Steyvers and Hemmer 2012💔 (help me)

• Steyvers and Hemmer Aim 2012


  Measure contributions of episodic and semantic mems to recall objects in naturalistic settings
• s&h procedure

  Lab experiment w independent groups

  96 students in total (prior knowledge -22 and perception -25 and mem experiment -49)

  California uni
• S&h findings (mem exp)

  Error rate for high probability 9%

  low prob error 18%

  when stimuli represent environment recall for us more accurate. ‘False mem’ errors 19% (30% in early studies). Lower number reflects greater accuracy of recall when scene is representative of environment 2secs - mean Objects was 7.75. 10 secs - 10.05 items
• Phase 1 (procedure)

  prior knowledge (semantic). Listed objects they’d expect in 5 settings. some objects expected and some not
• Phase 1 part 2

  Researchers selected 5 images for each setting and showed them to perception group and asked to make objects they saw
• Phase 2


  mem experiment - 2 images from each setting (10 pics total). Saw image for either 2 or 10 secs (short distractor task after each). Then listed objects they could recall (free recall)
• Prior knowledge findings (maybe)

  1st item guessed in prior knowledge phase led to 85% accuracy in mem exp. (Decreasing to 55% after 16 items) - represents contribution of semantic. Actual correct recall in mem exp was over 80%. Gap in accuracy between prior and actual recall represents episodic mem contribution (≈20%)
• S&h conclusion 1

  Semantic has greater contribution than previous research suggests - educational guesses
• Strength 1

  Good ecological validity- used 5 everyday life scenes and studied mem as active process (combo of episodic and semantic)
• Strength 2

  application to eye witness testimony - use prior knowledge shouldn’t be entirely discounted (like reconstructive mem suggests). Conclusion that semantic mem makes good contribution to recall, strategies could be developed to encourage eye witnesses to make educated guesses
• Weakness 1

  Still controlled ie in a lab w photos. Ps don’t experience senses like noise or smells which occur in real life settings
• Weakness 2

  Independent groups design - 3 dif groups of Ps w dif numbers eg prior-22 and mem exp-49. May be individual difs in their mem ability - extraneous variable (can’t compare)