The context in which reward-paired cues are encountered can resolve ambiguity and set the occasion for appropriate reward-seeking. The psychological processes by which contexts regulate reward-seeking remain unclear as contexts are diffuse and difficult to isolate from other stimuli. To overcome this, we modeled a context as a phasic and discrete…

When discrete localizable stimuli are used during appetitive Pavlovian conditioning, "sign-tracking" and "goal-tracking" responses emerge. Sign-tracking is observed when conditioned responding is directed toward the CS, whereas goal-tracking manifests as responding directed to the site of expected reward delivery. These…

The watermaze delayed matching-to-place (DMP) task was modified to include probe trials, to quantify search preference for the correct place. Using a zone analysis of search preference, a gradual decay of one-trial memory in rats was observed over 24 h with weak memory consistently detected at a retention interval of 6 h, but unreliably at 24 h.…

In resurgence, an operant behavior that has undergone extinction can return ("resurge") when a second operant that has replaced it itself undergoes extinction. The phenomenon may provide insight into relapse that may occur after incentive or contingency management therapies in humans. Three experiments with rats examined the impact of several…

Many insignificant events in our daily life are forgotten quickly but can be remembered for longer when other memory-modulating events occur before or after them. This phenomenon has been investigated in animal models in a protocol in which weak memories persist longer if exploration in a novel context is introduced around the time of memory…

New approaches, techniques and tools invented over the last decade and a half have revolutionized the functional dissection of neural circuitry underlying "Drosophila" learning. The new methodologies have been used aggressively by researchers attempting to answer three critical questions about olfactory memories formed with appetitive…

Prospective memory involves the encoding, retention, and implementation of an intended future action. Although humans show many forms of prospective memory, less is known about the future oriented processes of nonhuman animals, or their ability to use prospective memory. In this experiment, a chimpanzee named Panzee, who had learned to associate…

Heterotrimeric G(o) is an abundant brain protein required for negatively reinforced short-term associative olfactory memory in "Drosophila". G(o) is the only known substrate of the S1 subunit of pertussis toxin (PTX) in fly, and acute expression of PTX within the mushroom body neurons (MB) induces a reversible deficit in associative olfactory…

This article introduces a novel hypothesis regarding amygdala function in psychopathy. The first part of this article introduces the concept of psychopathy and describes the main cognitive and affective impairments demonstrated by this population; that is, a deficit in fear-recognition, lower conditioned fear responses and poor performance in…

Learning to select optimal behavior in new and uncertain situations is a crucial aspect of living and requires the ability to quickly associate stimuli with actions that lead to rewarding outcomes. Mathematical models of reinforcement-based learning to select rewarding actions distinguish between (1) the formation of stimulus-action-reward…

Neuronal activity regulated pentraxin (Narp) is a secreted protein that regulates [alpha]-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptors (AMPAR) aggregation and synaptogenesis. Mapping of Narp-positive neurons in brain has revealed it is prominently expressed in several limbic system projection pathways. Consistent with this…

For many years, it has been suggested that drugs that interfere with dopamine (DA) transmission alter the "rewarding" impact of primary reinforcers such as food. Research and theory related to the functions of mesolimbic DA are undergoing a substantial conceptual restructuring, with the traditional emphasis on hedonia and primary reward yielding…

Research on human and animal behavior has long emphasized its hierarchical structure--the divisibility of ongoing behavior into discrete tasks, which are comprised of subtask sequences, which in turn are built of simple actions. The hierarchical structure of behavior has also been of enduring interest within neuroscience, where it has been widely…

Helplessness, a belief that the world is not subject to behavioral control, has long been central to our understanding of depression, and has influenced cognitive theories, animal models and behavioral treatments. However, despite its importance, there is no fully accepted definition of helplessness or behavioral control in psychology or…

The game of Matching Pennies (MP), a simplified version of the more popular Rock, Papers, Scissors, schematically represents competitions between organisms with incentives to predict each other's behavior. Optimal performance in iterated MP competitions involves the production of random choice patterns and the detection of nonrandomness in the…