Intro :

1. Test-Retest Reliability of Sleep-dependent memory consolidation Test-Retest Reliability of Sleep Dependent Memory Consolidation Kimberly Tweedale and Allison Conner Intro : Results – Reliability: Results – Individual Differences : • Declarative memory is maintained better after a period of sleep than after an equal interval of wakefulness, likely due to consolidation processes occurring during sleep. • Previousstudies have assumed that individuals have a stable and measurable ability to consolidate information across multiple testing points. • No study to date has evaluated consolidation within an individual at multiple time points. • The goal of the present study was to examine the test-retest reliability of consolidation, looking specifically at paired-associates memory. • Individual performance was significantly correlated across assessment periods. • Performance on one standardized tests of intelligence (ACT score) is negatively correlated with memory loss over time. • These findings indicate that consolidation ability within an individual is reliable and may be important to academic success. • Individual performance in word pairslost is negatively correlated to self-reported ACT scores (r=-.41; p<.05) (fig. 7) • Individual performance in word pairs maintained show no significant relationship with ACT score (fig. 6) • Individual performance in word pairs gained show no significant relationship with ACT score (fig. 8) • Average performance improved across the 12-hour retention interval, providing evidence that consolidation is occurring. • Participants correctly recalled an average of 32.5 words pairs across immediate cued-recall tests, and correctly recalled an average of 39.3 word pairs correctly across delayed cued-recall tests (fig. 2) Number of correctly recalled word pairs ACT Score ACT Score R=-.41; p<.05 R=.26 Figure 2.Number of correctly recalled word pairs from during the immediate and delayed cued-recall tests. Maintain Loss • Individual performance for the two consolidation periods were significantly correlated forword pairs maintained (r=.71; p<.05)), lost (r=.40; p<.05) , and gained (r=.56; p<.05), providing evidence that consolidation for paired-associates memory is reliable. • Maintain: Pairs recalled at immediate and delayed cued-recall (fig. 3) • Loss: Pairs recalled only at immediate cued-recall (fig. 4) • Gain: Pairs recalled only at delayed cued-recall (fig. 5) Figure 6.Relationship between word pairs maintainedand ACT score Figure 7.Relationship between word pairs lost and ACT score Methods : • Participants • Right handed, undergraduate students at Michigan State University who are native English speakers (n=71) • Design • 2 consolidation assessments, administered one week apart • Trained and immediately tested on two lists of semantically-related word pairs (fig. 1) • Delayed cued-recall test after12 hour retention interval (sleep) • Performance assessed using three categories: maintained (recalled on both tests), gained (recalled only on the second test), and lost (recalled only on the first test • Procedure • Session 1 (Week 1, 8:45pm) and Session 3 (Week 2, 8:45pm) • List of 68 word pairs was studied in a paired associates task • • Cued-recall test of 60 word pairs with feedback given on every trialparticipants trained to33% correct • Session 2 (Week 1, 8:45am) and Session 4 (Week 2, 8:45am) • • Delayed cued recall test • Session 4 (Week 2, 8:45am) • • Ability evaluations: ACT scores • GPA scores, working memory • capacity primacy and recency • measures and verbal fluency • were also assessed via self • report, OPSPAN and RSPAN • tasks, free recall tasks, and • a vocabulary test. ACT Score R=.71; p<.05 R=.08 R=.40; p<.05 List 1 Gain List 1 Figure 8. Relationship between word pairs gainedand ACT score Conclusions : List 2 List 2 Figure 3. Relationship between word pairs maintained for List 1 and List 2 Figure 4.Relationship between word pairs lost for List 1 and List 2 • The paired associates task is reliable in terms of items maintained, lost and gained • Consolidation seems to be a stable and measurable individual ability • Individuals with higher scores on standardized intelligence tests (ACT) are subject to reduced memory loss over time • Because ACT score is related to loss but not maintenance or gain, different factors may be contributing to these aspects of memory • Consolidation ability seems to be related to several memory processes that affect academic success R=.56; p<.05 CAT– FUR TEACHER– DESK NURSE– HEALTH STOVE- SINK List 1 References : Fenn, K. M. & Hambrick, D. Z. (2011. Journal of Experimental Psychology Plihal, W. & Born, J. (1997). Journal of Cognitive Neuroscience 9(4), 534–547. Unsworth, N, Spillers, G. & Brewer, G. A. (2010). Journal of Experimental Psychology: Learning, Memory, and Cognition 36(1), 240–247. Figure 1. Sample of word pairs used in the paired associates task List 2 Figure 5. Relationship between word pairs gained for List 1 and List 2