We present evidence that experience and cholinergic modulation in an early sensory network interact to improve certainty about olfactory stimuli. The data we present are in agreement with existing theoretical ideas about the functional role of acetylcholine but highlight the importance of early sensory networks in addition to cortical networks. We…

One experiment with rats explored whether an extinction-cue prevents the recovery of extinguished lever-pressing responses. Initially, rats were trained to perform one instrumental response (R1) for food in Context A, and a different instrumental response (R2) in Context B. Then, responses were extinguished each in the alternate context (R1 in…

Four experiments examined relapse of extinguished observing behavior of pigeons using a two-component multiple schedule of observing-response procedures. In both components, unsignaled periods of variable-interval (VI) food reinforcement alternated with extinction and observing responses produced stimuli associated with the availability of the VI…

Two-way active avoidance (2WAA) involves learning Pavlovian (association of a sound cue with a foot shock) and instrumental (shock avoidance) contingencies. To identify regions where dopamine (DA) is involved in mediating 2WAA, we restored DA signaling in specific brain areas of dopamine-deficient (DD) mice by local reactivation of conditionally…

Behavioral data suggest that distinguishable orientations may be necessary for place learning even when distal cues define different start points in the room and a unique goal location. We examined whether changes in orientation are also important in place learning and navigation in a water T-maze. In Experiment 1, rats were trained to locate a…

To test the hypothesis that pigeons will only code the more salient sample when samples differ markedly in salience, pigeons were trained with samples consisting of a 2-s presentation of food (highly salient sample) and an 8-s presentation of keylight (less salient sample). During retention testing, pigeons tended to respond at longer delays as if…

Appetitive contextual excitation supported by intertrial unconditioned stimuli was more easily overcome by timed conditioned responding in rats using quiet (Experiment 1) rather than noisy (Experiment 2) food pellet deliveries. Head-entry responding in acquisition peaked above the contextual baseline when pellet delivery occurred 10, 30, 60, or 90…

Two experiments with rats examined the dynamics of well-learned response sequences when reinforcement contingencies were changed. Both experiments contained four phases, each of which reinforced a 2-response sequence of lever presses until responding was stable. The contingencies then were shifted to a new reinforced sequence until responding was…

Rats were trained to emit a series of three-response sequences to a criterion (i.e., more than 80% of all emitted sequences correct over five successive sessions). Each rat was trained on a series of different, three-response sequences. After the final three-response sequence was acquired, two extinction tests were administered, and the…

In his comment, Black (AA 526 155) argued that Maier and Seligman (EJ 138 911) incorrectly interpreted competing motor response explanations of the learned helplessness effect. Here, it is argued that no article that has proposed a competing motor response explanation of the learned helplessness effect has alluded to a mechanism similar to the one…

Comments on Maier and Seligman's research (EJ 138 911) on learned helplessness, specifically on their analysis of alternatives to the learned helplessness hypothesis. (Author/RK)

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…

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)

To complement investigations of the direct effects of lithium toxicosis on consummatory behavior, these experiments were designed to determine the aftereffects on drinking of exposure to a conditioned stimulus previously paired with lithium. (Author/RK)

In four different experiments, brief illumination of a localized visual stimulus was followed by grain presentation unless the pigeon approached the light. Results indicate that although response-reinforcer relations do play a role, stimulus-reinforcer contingencies are the dominant factor in establishing and maintaining approaches to the…