Optimizing Schedules for Category Learning: When Should We Block or Interleave Category Exemplars? Sharon M. Noh1, Veronica X. Yan2, Tyson K. Kerr2, Robert A. Bjork2 & W. Todd Maddox1 1The INTRODUCTION University of Texas at Austin; 2University of California, Los Angeles METHODS Dual-Learning Systems • Two competing, neurobiologically-grounded learning systems exist, and learning in each system is optimized under different training conditions4. • Rule-based (RB) Learning • Hypothesis-testing system, uses verbalizable rules • Frontally mediated • Information-Integration (II) Learning • Associative learning by trial-and-error, rules are not easily verbalizable • Striatally mediated EXPERIMENT 2 (N=149) Procedure • Study Phase: 16 stimuli per category (total 64) • Test Phase: 16 new stimuli per category (total 64) EXPERIMENT 1 (N=159) Procedure • Training Phase: 32 stimuli per category (total 128) • Test Phase: 24 new stimuli per category (total 96) Materials • Same relevant dimensions as Exp 1 • Addition of 2 irrelevant, varying dimensions Materials • Lines w/ 2 relevant, varying dimensions RB Category Structure Sample Stimulus • II Category Structure Ellipse length (height fixed) and stimulus position II Category Structure RB Category Structure Schedules that Optimize Learning • Recent research on category learning has shown that interleaving (I) exemplars from different categories, rather than blocking (B) examples by category leads to better inductive learning1,2 Artificial stimuli, highly rule-based • Generally, category structures and dimensionality are not well controlled, and no studies have considered the dual-systems framework with optimal learning schedules. RESEARCH QUESTIONS 1. Are optimal schedules different for rulebased vs. information-integration learning? 2. Does increasing stimulus dimensionality differentially affect optimal schedules for learning RB vs. II categories? GENERAL METHODS Design • 2 x 2 between-subjects: • Category Structure (RB vs. II) • Study Schedule (blocked vs. interleaved) Schedules • Blocked Presentation: AAAABBBBCCCCDDDD • Interleaved Presentation: BADCACBDADCBCDAB Category Structures Rule-Based Information-Integration DISCUSSION Experiment 1 Experiment 1: Low-dimensional Stimuli 0.75 Blocked Experiment 2 0.75 Interleaved 0.65 Blocked • I > B, regardless of stimulus type Interleaved 0.65 Accuracy • RESULTS 0.55 0.45 Experiment 2: High-dimensional Stimuli 0.45 • B > I for RB stimuli 0.35 0.25 0.25 RB II Category Structure • Blocking facilitates hypothesis-testing and rule-discovery, when rules are more difficult to notice • I > B for II stimuli RB II Category Structure MODELING RESULTS 1 Blocked Accuracy in Optimal Strategy Users 0.65 Interleaved 0.8 0.6 0.4 • Interleaving makes it difficult (high WM load) to hold and test multiple rules across categories Interleaved 1. Yes, optimal schedules differ for RB and II category learning: • • 0.45 0.35 0 0.25 II Blocked 0.55 0.2 RB • Interleaving discourages the use of rule-based strategies CONCLUSIONS Modeling results of participants’ accuracy and strategy use in Experiment 2 Proportion of Optimal Strategy Use • Stimuli seems simple enough that interleaving/spacing doesn’t tax working memory 0.55 0.35 Accuracy • Some research, however, has found that dimensionality can affect optimal schedules3: Accuracy High dimensional stimuli, information-integration based Proportion Optimal • Blocking facilitates hypothesis-testing process for RB learning Interleaving helps II learning by discouraging rule-based strategies 2. Yes, but for RB stimuli only: • • RB II REFERENCES 1. Kornell, N., & Bjork, R. A. (2008). Learning concepts and categories is spacing the “enemy of induction”?. Psych Sci. 2. Kang, S. H., & Pashler, H. (2012). Learning painting styles: Spacing is advantageous when it promotes discriminative contrast. Applied Cognitive Psychology. 3. Zulkiply, N., & Burt, J. S. (2013). The exemplar interleaving effect in inductive learning: Moderation by the difficulty of category discriminations. Memory & cognition. 4. Ashby, F.G. & Maddox, W.T. (2011). Human category learning 2.0. Annals of the NY Academy of Sciences. Int > Block for low-dimension stimuli Block > Int for high-dimension stimuli Acknowledgments: University of Texas Diversity Mentoring Fellowship to SMN This research was funded by the James S. McDonnell Foundation Grant to RAB & ELB Contact: Sharon Noh smnoh@utexas.edu http://homepage.psy.utexas.edu/HomePage/Group/Mad doxLAB/index.htm QR Code: