Although classical and operant conditioning are operationally distinct, it is unclear whether these two forms of learning are mechanistically distinct or similar. Feeding behavior of Aplysia provides a useful model system for addressing this issue. Both classical and operant appetitive behavioral training enhance feeding, and neuronal correlates have been identified. Behavioral training was rep...

To vicariously condition either fear or a positive emotional response, films in which a 5-year-old male model manifested one or the other response were shown to nursery school children. The measure of vicarious conditioning was the children's rate of response to the conditioned stimulus and a controlled stimulus in several operant situations after watching the film. In Experiments 1 and 2, fear...

Single morphine injections induce a state of acute opioid dependence measured by an increase in naloxone potency to precipitate withdrawal. Repeated morphine exposure (daily/weekly intervals) results in further potentiation of naloxone potency, perhaps due to conditioning mechanisms. The current study tested the hypothesis that previously neutral stimuli could elicit a conditioned potentiation ...

We have previously shown that the aerial respiratory behavior of the mollusk Lymnaea stagnalis can be operantly conditioned, and the central pattern generating (CPG) neurons underlying this behavior have been identified. As neural correlates of operant conditioning remain poorly defined in both vertebrates and invertebrates, we have used the Lymnaea respiratory CPG to investigate neuronal chang...

The present experiment examined the effects of different delays of food delivery with and without a response-produced auditory stimulus on the acquisition of a spatially defined operant in rats. The operant was breaking a photoelectric beam located near the ceiling at the rear of the experimental chamber. In five groups of experimentally naive rats, the effects on photobeam-break responses of t...

Experimentally induced and parkinsonian disruptions in dopamine (DA) transmission are associated with motor abnormalities that include a reduced likelihood of behavioral response initiation and an increased duration of executed responses. Here we investigated the dopamine receptor subtypes involved in regulating these two aspects of behavior. We examined the effects of D1 family (D1/D5) antagon...

The freshwater snail Lymnaea stagnalis breaths bimodally either through its skin (cutaneous respiration) or via a rudimentary lung opening called the pneumostome (aerial respiration). Aerial respiratory behaviour can be operantly conditioned. Animals placed in an aquatic, hypoxic environment received a tactile stimulus to the pneumostome area every time they attempted to breathe. Over a period ...

Some questions raised by Amsel's valuable review of his extensive research on reward-schedule effects are considered-questions about the nature of instrumental conditioning, about the distinction between long- and short-term memory, and about evolutionary divergence in learning.

Abstract Operant behavior procedures often rely on visual stimuli to cue the initiation or secession of a response, and provide means for discriminating between two more simultaneously available responses. While primate human studies typically use Liquid-Crystal Display (LCD) Organic Light-Emitting Diode (OLED) monitors touch screens, rodent variety methods present cues ranging from traditional...

We have used extensive V , I photometry (down to V = 20.9) of 33615 stars in the direction of the globular cluster M 55 to study the dynamical interaction of this cluster with the tidal fields of the Galaxy. An entire quadrant of the cluster has been covered, out to ' 1.5 times the tidal radius. A CMD down to about 4 magnitudes below the turn-off is presented and analysed. A large population of...