|International Symposium - Issues in Timing: Procedural Standards, Theoretical Concerns and Acquisition of Temporal Control
|Monday, May 26, 2008
|1:30 PM–2:50 PM
|Area: EAB/BPH; Domain: Basic Research
|Chair: Erin A. McClure (University of Florida)
|Abstract: Time is ubiquitous and therefore an obvious subject matter. And yet it has been strangely elusive. Much controversy surrounds the best ways to test the impact of time on behavior and even what questions to ask. The two major areas of timing research are temporal discrimination, or classifying time passed, and temporal production, or responding in a free operant procedure as time of reinforcement approaches. Many variations can be made to these commonly utilized procedures and may hold the key to discrepant results within the timing literature. This symposium will cover a wide range of issues within the timing literature, including procedural standards that are used in behavior analysis and other experimental fields, assessment of theories of timing with regard to dimensions of stimulus dynamics, and how stimulus conditions facilitate the acquisition of temporal control over behavior.
|Rapid Acquisition of Temporal Control in a Multiple-Peak Procedure.
|ELIZABETH KYONKA (University of Canterbury), Randolph C. Grace (University of Canterbury)
|Abstract: Kyonka and Grace (2007) showed that temporal control can be acquired rapidly when reinforcer delays are changed unpredictably across sessions. However, in Kyonka and Grace’s concurrent-chains procedure the delays always summed to 30 s and thus were negatively correlated. Here we asked whether the correlation of delays within sessions facilitated the acquisition of temporal control. Pigeons were trained in a peak procedure with two fixed intervals signaled by the left and right keylights. Schedule values and the location of the shorter interval were determined pseudorandomly each session. In the correlated condition, schedule values always summed to 30 s, whereas in the uncorrelated condition schedule values were determined independently. Six no-food trials for each alternative were distributed throughout the session so that acquisition of temporal control could be observed. After pigeons had had extensive experience with correlated and uncorrelated pairs of intervals, start and stop times calculated on individual no-food trials were linear functions of the interval operating on the same key during that session. There was no evidence of any systematic difference in responding on no-food trials of correlated and uncorrelated conditions, which suggests that temporal control developed independently for each alternative.
|A Review of Procedural Differences that Contribute to the Varying Effects of Amphetamines Observed in the Timing Literature.
|KATHRYN A. SAULSGIVER (University of Florida), Erin A. McClure (University of Florida), Clive D. L. Wynne (University of Florida)
|Abstract: Recent literature has highlighted many procedural differences used across labs in studying timing behavior (Cheng et al., 2007; McClure et al., 2005, 2007). One procedural inconsistency discussed is the varied amount of training allowed for each subject prior to administration of a drug. Cheng et al. (2007) proposed that the varying amount of training allowed in studies using the peak interval (PI) procedure contributed to the effect of drug. Cheng et al. varied the training history of subjects before administering methamphetamine. They concluded that extensive histories led to timing behavior becoming a learned habit, thus altering the “classic” dopamine agonist curve-shift effect. We propose that the variability observed by Cheng et al. is due to the amount of control that the schedules exerted over behavior when drug was given, rather than behavior becoming a learned habit. PI distributions, as well as other parameters, for individual subjects with varying amounts of training will be reviewed in relation to drug effects. Other procedural differences used in timing procedures will also be examined.
|The Role of the Pacemaker in Duration Discrimination of Dynamic Stimuli.
|JOSHUA BECKMANN (Western Kentucky University), Michael Young (Southern Illinois University, Carbondale)
|Abstract: The present study examined the relationship between stimulus dynamics and duration discrimination in humans. Dynamics were defined by how quickly a sphere rotated on its Y-axis. A many-to-one bisection task (Stubbs, 1968) was used to divide short stimulus durations (500 ms to 1700 ms) into two categories, short and long. In Experiment 1, the impact of dynamics was tested over four sphere rotation rates (0, 22.2, 44.4, and 88.9 degrees/second). In Experiment 2, the impact of dynamics on temporal discrimination was examined across a wider range of sphere rotation rates (0 – 711.1 degrees/second). The results indicate that stimulus dynamics influence the point of subjective equality (PSE) and the sensitivity of the discrimination function. Two predominant models of timing behavior, the behavioral theory of timing (BeT) and Scalar Expectancy Theory (SET) were unable to capture the change in the PSE across the tested range of rotation rate. Modifying each model with the inclusion of a stimulus dynamics measure allowed each model to better encompass the effects of dynamics on temporal discrimination.
|Differential Disruption of Timing Due to Procedural Variations in Temporal Discriminations.
|ERIN A. MCCLURE (University of Florida), Kathryn A. Saulsgiver (University of Florida), Clive D. L. Wynne (University of Florida)
|Abstract: Temporal discrimination is typically assessed using a discrete trial, retrospective timing task in which choice alternatives are matched to short or long durations of a stimulus. In one procedure, the response alternatives are defined by the location of response keys; in the other by their color. This minor variation in procedure has been suggested as a cause for a large discrepancy within the temporal discrimination literature. [if you have the words available you might want to spell out what this ‘large discrepancy’ is] The current study compared the effects of several non-pharmacological disruptors, specifically pre-feed, inter-block interval food, and extinction, on temporal discrimination in both of these procedural variations. The results show little effect of the disruptors in the spatial alternative task, while temporal discrimination is affected significantly in the color alternative task. These results add to the evidence that disruptors of a pharmacological and non-pharmacological nature can have similar effects on temporal discrimination, but vary greatly depending on the procedural variation that is used. These results are useful in developing a conceptual framework of timing that focuses on stimulus control, rather than a specific timing mechanism.