Lecture 7: Timing
Periodic Timing
Introduction
Time and Place Learning
Interval Timing
Peak Procedure
Temporal Generalization
Human interval timing
Timing in the wild
Models of interval timing: Information Processing Model
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1. Periodic Timing
Circadian Rhythms. Daily cycle of activity or physiological state. Controlled by
underlying pacemaker
Circadian rhythms in eye-covered cockroaches-
Entrainment. The process by which the underlying rhythm-maker (the
pacemaker) is brought into synch with environmental signals is called
entrainment. The signal that entrains the rhythm is referred to as the
entraining agent, or the zeitgeber (“time-giver” in German).
Time and Place Learning – e.g., associating a feeding place with a particular time
of day
Biebach, Gordijn, and Krebs (1989) – Experiment with Garden Warblers
Example from the wild- Hunting in Kestrels
2. Interval Timing
- Measurement of elapsed intervals, usually in seconds
Laboratory Procedures: Peak Procedure
Laboratory Procedures: Peak Procedure (Continued)
- Short intervals are judged more accurately
- There is greater variance in peck rate for longer intervals
- Variance is proportional to the duration
Weber’s Law -- the variability of estimation increases in direct proportion
to the magnitude of the estimation
Laboratory Procedures: Temporal Generalization
Example: reinforced for responding after a signal of one duration, but not
after a signal of another duration
Humans and Interval Timing
1. A Note on Methods
Habituation/Dishabituation Paradigm
1. Expose (habituate) infants to an event
2. Present two test events:
Consistent with the habituation event
Inconsistent with the habituation event
2. vanMarle & Wynn (2006)
Interval Timing in the Wild
Henderson et al. (2006): rufous hummingbirds
Models of Interval Timing
Information Processing Model, or the Scalar Expectancy Theory (SET).
(Accumulator Model)
Discrimination depends on the proportional difference between two
values, rather than the absolute difference.
Source of variance in interval timing?