When given to pigeons, the direct-acting dopamine agonist apomorphine elicits pecking. The response has been likened to foraging pecking because it bears remarkable similarity to foraging behavior, and it is enhanced by food deprivation. On the other hand, other data suggest the response is not related to foraging behavior and may even interfere…

When subjects learn to associate two sample durations with two comparison keys, do they learn to associate the keys with the short and long samples (relational hypothesis), or with the specific sample durations (absolute hypothesis)? We exposed 16 pigeons to an ABA design in which phases A and B corresponded to tasks using samples of 1 s and 4 s,…

The relation between reinforcer magnitude and timing behavior was studied using a peak procedure. Four rats received multiple consecutive sessions with both low and high levels of brain stimulation reward (BSR). Rats paused longer and had later start times during sessions when their responses were reinforced with low-magnitude BSR. When estimated…

The notion that non-human animals are capable of episodic memory is highly controversial. Here, we review recent behavioral work from our laboratory showing that the fundamental features of episodic memory can be observed in rats and that, as in humans, this capacity relies on the hippocampus. We also discuss electrophysiological evidence, from…

Neuroscientific approaches to drug addiction traditionally have been based on the premise that addiction is a process that results from brain changes that in turn result from chronic administration of drugs of abuse. An alternative approach views drug addiction as a behavioral disorder in which drugs function as preeminent reinforcers. Although…

There is much debate as to the extent and nature of functional specialization within the different subregions of the prefrontal cortex. The current study was undertaken to investigate the effect of damage to medial prefrontal cortex subregions in the rat. Rats were trained on two biconditional discrimination tasks, one auditory and one visual, in…