Nevin, J. A., Davison, M., & Shahan, T. A. (2005).
A theory of attending and reinforcement in conditional discriminations.
Journal of the Experimental Analysis of Behavior, 84, 281-303.
A model of conditional discrimination performance (Davison & Nevin, 1999) is
combined with the notion that unmeasured attending to the sample and comparison
stimuli, in the steady state and during disruption, depends on reinforcement in
the same way as predicted for overt free-operant responding by behavioral
momentum theory (Nevin & Grace, 2000). The rate of observing behavior, a
measurable accompaniment of attending, is well described by an equation for
steady-state responding derived from momentum theory, and the resistance to
change of observing conforms to predictions of momentum theory, supporting a key
assumption of the model. When probabilities of attending are less than 1.0, the
model accounts for some aspects of conditional-discrimination performance that
posed problems for the Davison-Nevin model: (a) the effects of differential
reinforcement on the allocation of responses to the comparison stimuli and on
accuracy in several matching-to-sample and signal-detection tasks where the
differences between the stimuli or responses were varied across conditions, (b)
the effects of overall reinforcer rate on the asymptotic level and resistance to
change of both response rate and accuracy of matching to sample in multiple
schedules, and (c) the effects of fixed-ratio reinforcement on accuracy. Some
tests and extensions of the model are suggested, and the role of unmeasured
events in behavior theory is considered.
Key words: attending, behavioral momentum, conditional discrimination, matching
to sample, signal detection, observing behavior