A general hypothesis of associative learning should be based on the broadest possible foundation of empirical evidence, including confirmation in both aversive and appetitive situations. For this reason the present experiment was designed to test the surprise hypothesis using a procedure in which the unconditioned stimulus was the presentation of…

There has been considerable interest lately in cases where instrumental conditionability appears to depend on the reinforcer used. Here the effects of Pavlovian conditioned stimuli (CSs)on golden hamster behaviors was observed. The intent was to see whether previously reported differences among the behaviors produced by food reinforcement and…

The study evaluated the effectiveness of superimposition and subsequent removal of a schedule of continuous reinforcement (CRF) as a rate-decreasing procedure in efforts to eliminate unwanted behaviors. Examination of lever-pressing patterns of eight male rats showed responding was substantially reduced during the superimposition of CRF but…

Article reviews evidence on the effects of contrast and matching, that these effects are related, and that both effects are reactions to the same independent variable. (Author/RK)

Three experiments, employing conditioned suppression in rats, examined the extent to which pretraining on one element of a compound stimulus blocked conditioning to the other element when some feature of the reinforcer was changed on compound trials. (Editor)

Stimulus analyzer theory as proposed by Sutherland and Mackintosh (1971) makes the unique prediction that the first-experienced reinforcement schedule will influence resistance to extinction more than subsequent schedules. Results presently reported of runaway acquisition and extinction indicate the opposite: C-P consistently produce substantially…

A dynamic model of how animals learn to regulate their behavior under time-based reinforcement schedules is presented. It assumes serial activation of behavioral states during the inter-reinforcement interval, an associative process linking the states and operant response, and a rule mapping the states onto response rate. (SLD)

Explains the use of pigeons in behavioral psychology research for modeling human behavior and discusses instructional objectives for humans. Topics addressed include the relationship between response rate and reinforcer rate; resistance to alternative reinforcement; choice and matching; and persistence and reinforcement. (Contains 11 references.)…

Choice typically is studied by exposing organisms to concurrent variable-interval schedules in which not only responses controlled by stimuli on the key are acquired but also switching responses and likely other operants as well. In the present research, discriminated key-pecking responses in pigeons were first acquired using a multiple schedule…

Preference between forced choice and free choice in concurrent-chain schedules of reinforcement was investigated in pigeons after exposure to particular combinations of terminal links. In Experiment 1, in which terminal links always ended with reinforcers, one of three pairs of terminal links was arranged as preexposure: (a) both terminal links…

Temporal discounting refers to the decrease in the present, subjective value of a reward as the time to its receipt increases. Results from humans have shown that a hyperbola-like function describes the form of the discounting function when choices involve hypothetical monetary rewards. In addition, magnitude effects have been reported in which…

Effects of repeated administration of cocaine to animals behaving under operant contingencies have depended on when the drug is given. Moderate doses given presession have generally led to a decrease in the drug's effect, an outcome usually referred to as tolerance. When these same doses have been given after sessions, the usual result has been no…

Response rates under random-interval schedules are lower when a brief (500 ms) signal accompanies reinforcement than when there is no signal. The present study examined this signaled-reinforcement effect and its relation to resistance to change. In Experiment 1, rats responded on a multiple random-interval 60-s random-interval 60-s schedule, with…

Given an opportunity to choose between an immediate, small reward and a delayed, large reward, pigeons may commit themselves to the large reward, but if the choice is encountered they will almost always select the immediate, small reward. This study tested a model, developed by H. Rachlin and his co-workers, concerning some general theories of…

These experiments attempt to optimize the possibility of demonstrating blocking in a taste-aversion paradigm and to elucidate the conditions under which this interference occurs. (Author/RK)