Experimental Psychology PSY 433

1. Experimental PsychologyPSY 433 Chapter 9 Conditioning and Learning (Cont.)

2. Maze Times (Both Labs)

3. Maze Errors (Both Labs)

4. ANOVA (Repeated Measures) Tests of Within-Subjects Effects Measure: MEASURE_1 Source Type III Sum of Squares df Mean Square F Sig. Time Sphericity Assumed 21082.344 14 1505.882 9.128 .000 Greenhouse-Geisser 21082.344 1.236 17062.838 9.128 .004 Huynh-Feldt 21082.344 1.284 16420.288 9.128 .004 Lower-bound 21082.344 1.000 21082.344 9.128 .008 Error(Time) Sphericity Assumed 39263.785 238 164.974 Greenhouse-Geisser 39263.785 21.005 1869.285 Huynh-Feldt 39263.785 21.827 1798.892 Lower-bound 39263.785 17.000 2309.634

5. More Talented Animals • Sweet Sundance – Gong Show act • https://www.youtube.com/watch?v=YO7lAHsn84Q • Cirque de Sewer – Gong Show act • https://www.youtube.com/watch?v=SGxuEKcE_94

6. Choosing an Experimental Design • Between vs within subjects designs offer different tradeoffs, but there are more than practical considerations at stake. • Choice of design may affect the actual outcome of the research. • Sometimes using a between-subjects and a within-subjects design produces different results. • Carryover effects may exist without the experimenter’s knowledge.

7. Order Effects • Order effects (practice effects) = experiencing one level affects behavior in another level • Effects of practice, boredom, fatigue • Example: Does content (biology text vs. novel) affect proofreading speed? Order is Biology-Novel • Order effects are controlled in within-subjects designs by randomizing or counterbalancing the presentation orders.

8. (no practice) (practice) Group 1 Biology Novel 1 2 (no practice) (practice) Group 2 Novel Biology 1 2 Order Effects in Proofreading

9. Differential Carryover Effects • Carryover effects, differential/asymmetrical transfer effects occur when experiencing one level affects performance on the next. • The effect of the first level on the second level differs depending on which comes first. • Effect of B following A ≠ effect of A following B • Confound occurs when one level consistently precedes the other.

10. (no practice) (practice) Group 1 Neutral instructions Special instructions 1 2 (no practice) (practice) Group 2 Special instructions Neutral instructions 1 2 Differential Carryover Effects in Problem Solving

11. Classical Conditioning Example • Grice and Hunter (1964) - human conditioning • UCS is air puff; UR is blinking • Vary CS intensity (loud or soft tone) • Done between-subjects or within-subjects • 500 ms CS – 500 ms ISI – US • Varying CS intensity in BS design has no effect on % CR • Varying CS intensity in WS design has large effect.

13. Contrast Between Stimuli • In a WS design, subjects can compare two levels of a stimulus in the same experiment and may respond to the two stimuli differently. • This effect occurs despite the randomization and counterbalancing that were used to control for differential order effects: • First, choose a random order (LSSLSLLLS) • Then counterbalance the random order: ½ got it, ½ got the reverse (SLLSLSSSL)

15. Instrumental Conditioning Example • Bower (1961) –3 groups of rats trained to run down an alley (maze) for food. • Two IVs: kind of reward & color of maze. • Reward: • Constant 8 – got 8 pellets per maze run • Constant 1 -- got 1 pellet per maze run • Contrast – got 1 pellet in one colored maze, 8 in the other colored maze (black/white) • All 3 groups: ½ got black & ½ got white maze.

18. ABBA Counterbalancing • Define 2 conditions: A and B or S and L • In Bower’s case, 1 pellet (S) & 8 pellet (L) • Present in order: ABBA (SLLS) • If order effects are linear, they will then be distributed evenly across conditions. • If nonlinear, do not use ABBA, or give practice trials first. • Bower used both ABBA and BAAB. • Use Balanced Latin Square with >2 groups.

19. Small-n Designs • Behavior often cannot be studied in large groups (large-n designs) • Small-n frequently used in therapeutic situations • Reversal designs: ABA or ABAB • A = baseline recording of behaviors • B = introduction of treatment • IV is essentially treatment / no treatment.

20. Increases Bill crys Adults attend Example: Crying Behavior Reinforcement + Removing the positive reinforcement (attention) extinguishes crying behavior.

21. FIG: Kanto7e 9-8, Hart data

22. Multiple Baseline Designs • Observe different behaviors, before and after learning. • Can be done two ways: • Observe multiple behaviors in one individual -- like a within-subject design • Observe a single behavior in different individuals – between-subjects • Treatments are introduced at different times.

25. Example: Siblings Compared • 3 pairs of autistic vs normal siblings • Baseline -- observed target behaviors (counting, letter ID, etc) • Treatment -- trained normal sib to reinforce behaviors of autistic sib • DV -- number of correct performances of behaviors.

27. Changing Criterion Design • Instead of comparing different people or different behaviors, progress in shaping behavior over time is measured. • The target behavior needed for reinforcement is changed as a behavior is acquired. • Range-bound changing criterion – instead of a target, a range for reinforcement is established. • Distributed-criterion design – targets are spread across several behaviors.