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| Topics in Timing |
| Sunday, May 28, 2006 |
| 10:30 AM–11:50 AM |
| Hong Kong |
| Area: EAB; Domain: Basic Research |
| Chair: Erin A. McClure (University of Florida) |
| Abstract: Behavior analysts have been exploring timing behavior since the field's earliest days. There are now several methods available for assessing how behavior is controlled by the passage of time, and how well different models of timing account for the obtained results. Stimulant and depressant drugs as well as purely behavioral techniques have been employed in this endeavor. This symposium will highlight significant topics within current timing research. |
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| D-amphetamine’s Effects on Differential Reinforcement of Low Rates of Responding. |
| KATHRYN A. SAULSGIVER (University of Florida), Erin A. McClure (University of Florida), Eric Beecher (University of Florida), Clive D. L. Wynne (University of Florida) |
| Abstract: The sensitivity to the passage of time by animals in experimental research has been conceptualized as a behavior that is controlled by internal stimuli (Laties, 1966). Since there is a lack of external control it has been suggested that this type of behavior is more sensitive to drug effects. The present study examined the effects of d-amphetamine on a continuous DRL 8-sec discrete-trial DRL 8-sec schedule. When this schedule is examined more closely two types of timing behavior appear to be occurring: Timing from a stimulus and timing from the subjects own behavior. Essentially, these are two different types of stimulus control. In addition this experiment explored the influence of d-amphetamine on respondent and operant key pecks. This schedule allowed for the separation of responses that were externally controlled, those responses occurring after reinforcement in the continuous DRL and all responses in the discrete-trial DRL schedule, from those that were controlled by internal stimuli, responses that occurred after unreinforced responses in the continuous DRL schedule. In addition by analyzing the IRT distributions produced by these schedules this procedure allowed us to see the effects that d-amphetamine had on respondent and operant key pecks, if they exist. |
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| Accounting for Cyclic Responding in Timing using Binary Counting. |
| FEDERICO SANABRIA (Arizona State University), Peter Killeen (Arizona State University) |
| Abstract: Strong and theoretically challenging effects deserve more attention, not less. Timing theories rarely deal with one such effect: the reoccurrence of responding near the end of probe trials--when responding has never been reinforced--in the peak procedure. Timing models that lack cyclic features can neither account for this effect, nor for its circumscription to specific training-to-probe trial duration ratios. Responding cyclicity and its dependency on experimental parameters is well accounted for by a timing model based on probabilistic binary counting. |
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| Effects of d-amphetamine on Stimulus Control and Temporal Discrimination in Position and Color-matching Variants of the Interval-bisection Procedure. |
| RYAN D. WARD (Utah State University), Amy Odum (Utah State University) |
| Abstract: Recent research suggests that the effects of drugs on behavior maintained by temporal-discrimination procedures might be produced by a general disruption of stimulus control, rather than specific effects on timing. This experiment examined whether d-amphetamine would have different effects on temporal discrimination and stimulus control depending on the nature of the temporal-discrimination procedure. Four pigeons responded on a multiple schedule of interval-bisection procedures. In one component (position), responding to one key was reinforced following short samples, while responding to the other key was reinforced following long samples. In the other component (color), responding to one key color was reinforced following short samples, and responding to another key color was reinforced following long samples. Acute d-amphetamine administration decreased accuracy in both components, although more so in the color matching component. Analysis of the psychophysical functions showed that d-amphetamine produced decrements in accuracy in both components by decreasing stimulus control, rather than affecting timing. We are currently assessing the effects of d-amphetamine on both versions of the interval bisection procedure across conditions. |
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| Analysis of Behavior Mediating Timing in Two Procedures used to Assess Temporal Discrimination in Pigeons. |
| ERIN A. MCCLURE (University of Florida), Kathryn A. Saulsgiver (University of Florida), Eric Beecher (University of Florida), Clive D. L. Wynne (University of Florida) |
| Abstract: When rats are trained on spatial procedures, which require responding on one lever after a short stimulus and responding on a different lever after a long stimulus, the introduction of amphetamine commonly causes a leftward shift in the psychophysical function for time. However when pigeons are trained on non-spatial procedures, with colored keys as response alternatives, the effect of the drug is mainly on stimulus control and not on 'timing'. The current study explored whether this difference between species could be attributable to procedural differences by comparing the performance of pigeons trained on a spatial task to pigeons trained on a non-spatial task. Effects of amphetamine on the pigeons' responses was more like that found in rats when the pigeons were tested with the spatial procedure. For pigeons tested on the non-spatial procedure, amphetamine administration led to disruption of behavior and decrease in stimulus control. Video analysis indicated that the different effects of the drug on the two procedures were due to different mediating behaviors that developed by the different arrangements of the choice alternatives. |
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