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| On the Generality of Interval Timing Processes |
| Sunday, May 24, 2015 |
| 11:00 AM–11:50 AM |
| 007B (CC) |
| Area: EAB; Domain: Basic Research |
| Chair: Shrinidhi Subramaniam (West Virginia University) |
| Abstract: Time is an ever-present dimension of environmental events. When time serves a discriminative function, as in the fixed-interval schedule of reinforcement, behavior is predictably organized around the time to reinforcement availability. Although this pattern of interval timing is assumed to hold across many species in the animal kingdom, a majority of research on the process uses pigeons, rats, and mice as subjects. Further, this extensive research base has been used as evidence for so-called facts of timing such as mean accuracy, scalar variance, and bisection at the geometric mean of learned intervals. An integral step in testing theories of timing and allowing for the translation of theoretical principles to problems of social significance is to identify methods in which the generality of interval timing process holds across species. This symposium begins with a presentation of a theoretical framework within which to view interval timing in the fixed-interval schedule of reinforcement. The symposium concludes with two presentations on research comparing pigeon and human performance on timing procedures derived from the fixed-interval schedule of reinforcement: The fixed-interval temporal bisection procedure and the peak-interval procedure. The generality of interval timing processes and application of timing principles will be discussed. |
| Keyword(s): cross-species generality, interval timing, peak procedure, temporal bisection |
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| Behavioral Microscopes: Isolating the Stochastic Process of Interval Timing |
| CARTER DANIELS (Arizona State University), Federico Sanabria (Arizona State University) |
| Abstract: Interval timing is characterized by an initial suppression of responding followed by a negatively accelerated increase in responding; and is found in many species including pigeons, rats, and humans. Unfortunately, there is still a dearth of knowledge concerning the micro-organization of behavior in time; thus, limiting our understanding of timing processes across species. In the present study, we developed a comprehensive understanding of interval timing. In Experiment 1, 8 naïve male Wistar rats were trained to make head-entries into a reinforcement receptacle for reinforcement on a FI 30 s until a steady-state was achieved. In Experiment 2, 8 naïve male Wistar rats were trained to make head-entries into a reinforcement receptacle for reinforcement on a FI 90 s until a steady-state was achieved, followed by a 5 session pre-feeding manipulation. Behavior was modeled using three theoretically motivated analytic models, one for each component of behavior: latencies, inter-response times (IRTs), and response durations (RDs). Simulations of the data based on the fits of each model revealed that the models provide 1) an adequate description of the data; and 2) an alternative explanation of the effects of pre-feeding on timing performance. We conclude by highlighting the implications of these models. |
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| Human and Pigeon Timing in a Fixed-Interval Free-Operant Psychophysical Choice Procedure |
| ADAM E. FOX (St. Lawrence University), Katelyn Prue (St. Lawrence University), Elizabeth Kyonka (West Virginia University) |
| Abstract: Relatively few studies of interval timing have used typically developing humans as subjects, and even fewer have compared human and non-human timing performance directly on tasks designed to be as similar as possible. Four pigeons and twenty six adult humans were exposed to a fixed-interval (FI) temporal bisection procedure. In the constant phase, the short FI was always the same; the long FI was 2-10 times the short FI and changed across conditions. In the proportional phase, the long FI was four times the duration of the short FI. Across both phases, pigeon mean bisection points were at the geometric mean of the two FIs, and human mean bisection points were in between the geometric and arithmetic means of the two FIs. Variability associated with timing behavior was scalar at the relatively short interval pairs, but variability increased at the long interval pairs in the constant-short phase for both species. The procedure proved to be a rapid and robust means of measuring human and non-human timing behavior. It offers a potential tool for future between-species comparisons, for testing non-human models of psycho-neurological impairments associated with deficits in temporal processing, and for diagnosing temporal processing deficits in human clinical populations. |
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| Human and Pigeon Timing in Multiple and Mixed Peak Procedures |
| SHRINIDHI SUBRAMANIAM (West Virginia University), Elizabeth Kyonka (West Virginia University) |
| Abstract: The peak procedure is among the most widely researched timing procedures in nonhumans. Traditional peak arrangements may not be feasible for human use when the researcher is faced with time constraints, participant boredom, or attrition. We used different procedures to capture the same interval timing process with pigeons and humans. Pigeons pecked in multiple or mixed fixed-interval 2-s and 4-s schedules of food. During occasional 12-s “peak” trials, pecks had no programmed consequences. Humans pressed buttons to fire shots on a computer program in which a target moved from the left to the right side of the monitor. Participants earned points for shots when the target reached the center of the monitor around 2 s or 4 s. The target was masked during 12-s peak trials. Red or green key lights and light or dark green backgrounds differentially signaled time to food or point availability in the multiple schedule. Differential signaling did not occur in mixed schedules. Response gradients across peak trials indicated temporal control, with the highest rate of responding occurring around the time of food or point availability. We discuss similarities in mean accuracy and scalar variance of interval timing across species and describe implications of cross-species generality. |
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