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Operant Variability |
Saturday, May 23, 2015 |
1:00 PM–2:50 PM |
006C (CC) |
Area: EAB |
Chair: Kathleen Doolan (The University of Wiakato) |
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The Role of a Variability Contingency on Sequence Learning in Humans |
Domain: Basic Research |
KATHLEEN DOOLAN (The University of Wiakato), Stacey ter Veer-Burke (The University of Waikato), Lewis A. Bizo (The University of Waikato), James McEwan (The University of Waikato) |
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Abstract: Research shows that reinforcement of variable responding facilitates sequence learning in rats but may interfere with sequence learning in humans. Experiment 1 examined sequence difficulty in humans by manipulating sequence length and task instruction. Experiment 2 investigated the effect of removing or adding a variability contingency within the experimental session for a 6-item sequence. Participants were allocated to either a Control or Variable group. The Control group only received reinforcement for production of the target sequences. The Variability group received reinforcers on a Variable Interval 60-s schedule if the sequence met a variability criterion and for production of the target sequence. In Experiment 2 after 10 reinforcer deliveries the variability contingency was either removed or added. In Experiment 1, the Control group produced more target sequences for the 6-digit conditions, the Variable group produced more target sequences for the 9-digit condition and there was no difference between groups for the 12-digit condition. Task instructions had little impact on the results. In Experiment 2 the Control performed better than the Variability group – addition or removal of the variability contingency had little effect on performance. Results will be discussed in relation to previously published research on sequence learning with animals and humans. |
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Reinforcing Behavioral Variability: An Examination of it's Generalizability and an Analysis of U-Value as a Measure of Variability |
Domain: Basic Research |
XIUYAN (KITT) KONG (University of Waikato), James McEwan (The University of Waikato), Lewis A. Bizo (The University of Waikato), Therese Mary Foster (University of Waikato) |
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Abstract: Two experiments with college students were carried out to examine whether learned variability on two dimensions of a behaviour would generalise to a third dimension that occurred simultaneously using Ross and Neuringer"s (2002) rectangle drawing task. The dimensions being measured were the sizes, shapes and the locations on the screen of the rectangles. Performances of a group receiving reinforcement independent of the variability of all three dimensions and another group receiving reinforcement contingent on the variability of two of the three dimensions were compared. Results showed that overall, the variability in the shapes and locations of the rectangles was higher when these two dimensions occurred with other two dimensions that were required to vary; however, no difference was found for the variability in sizes between the two groups. The results suggested it was likely there was generalization from reinforcing variability on sizes and locations to shape and from reinforcing variability on sizes and shapes to locations. U-value as a measure of variability was also examined, with simulated data and data collected from one of the experiments. Limitations of the measure were identified. The attentions needed to report U-values would be discussed. Cautions needed when interpreting U-values as a measure of variability would be highlighted. |
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Systematic Operant Preferences and Variability in Human Participants: Analyzing Noncriteral Aspects of Behavior |
Domain: Basic Research |
LAURILYN DIANNE JONES (The Mechner Foundation/Oslo & Akershus University College), Francis Mechner (The Mechner Foundation) |
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Abstract: All operant behaviors have both criterial and noncriterial dimensions, the former being those that must occur in order for the operant to be completed, and the latter consisting of the rest of the physical performance of the operant. Noncriterial aspects of operant behavior are not often measured; however, when they are recorded they can provide valuable data on exactly how participants are likely to approach the performance of behaviors of the type studied. Furthermore, analysis of quantifiable noncriterial operant dimensions is a powerful way to measure operant variability/stereotypy. In two experiments participants performed operants consisting of a string of keypresses on the computer keyboard: the space bar (marking the start), at least 12 letters from those available, and finally the enter key (marking the end). The required number of keypresses had to occur for each operant to be counted, but which letters were chosen was noncriterial and left up to the participant. In Experiment 1 operants were reinforced with money on a VR schedule for 9 sessions, followed by an extinction session. In Experiment 2 operants were reinforced with positive feedback stimuli for 9 sessions, followed by a session in which each correct operant not identical to the previous two earned 80 cents. Participants’ preferences for individual letters, and patterns of letter keypresses, were in line with previous research on bias in experiments using a keystroke operant; in addition, the variability of the letter patterns emitted varied systematically and predictably both over time and in response to particular stimuli. |
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