The ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) may provide modulatory signals that, respectively, influence hippocampal (HPC)- and striatal-dependent memory. Electrophysiological studies investigating neural correlates of learning and memory of dopamine (DA) neurons during classical conditioning tasks have found DA…

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…

It is often argued that exposure-based treatments for anxiety disorders are only effective if the exposures are presented continuously until a marked decrement in anxiety is achieved (e.g. Foa & Kozak, 1986). However, the data supporting this conclusion is limited. This study compared two treatments for public speaking anxiety: one requiring…

Considering the evidence that the lateral septal area (LSA) modulates defensive responses, the aim of the present study is to verify if this structure is also involved in contextual fear conditioning responses. Neurotransmission in the LSA was reversibly inhibited by bilateral microinjections of cobalt chloride (CoCl[subscript 2], 1 mM) 10 min…

In appetitive Pavlovian learning, animals learn to associate discrete cues or environmental contexts with rewarding outcomes, and these cues and/or contexts can potentiate an ongoing instrumental response for reward. Although anatomical substrates underlying cued and contextual learning have been proposed, it remains unknown whether specific…

A series of experiments used rats to study the effect of a systemic or intra-amygdala infusion of the benzodiazepine, midazolam, on learning and re-learning to inhibit context conditioned fear (freezing) responses. Rats were subjected to two context-conditioning episodes followed by extinction under drug or vehicle, or to two cycles of context…

Research has revealed that fetuses can learn from events in their environment. The most convincing evidence for fetal learning is habituation to vibroacoustic stimulation (VAS) in human fetuses and classical conditioning in rat fetuses. However, these two research areas have been independent of each other. There have been few attempts at classical…

Three 14-year-old boys with diagnoses of autism learned to mand for the delivery or removal of tokens by presenting nonsense syllables (A[subscript 1-5], respectively). A match-to-sample procedure was used t o establish conditional discriminations between the 5 A stimuli and 5 B stimuli and between the B stimuli and 5 C stimuli. Subsequently, each…

This study examined the effects of a modified antecedent during probes for emergent mands following listener versus tact training for children with autism. Eight students, aged 7 to 11, were trained to respond to 3 sets of relational responses (front/back, left/right, on/under), each assigned a nonsense label. Three training types were evaluated:…

Humans discount larger delayed rewards less steeply than smaller rewards, whereas no such magnitude effect has been observed in rats (and pigeons). It remains possible that rats' discounting is sensitive to differences in the quality of the delayed reinforcer even though it is not sensitive to amount. To evaluate this possibility, Experiment 1…

The goal of this series of experiments was to develop an operant choice procedure to examine rapidly the punishing effects of intravenous drugs in rats. First, the cardiovascular effects of experimenter-administered intravenous histamine, a known aversive drug, were assessed to determine a biologically active dose range. Next, rats responded on…

We examined the roles of the amygdala and hippocampus in the formation of emotionally relevant memories using an ethological model of conditioned fear termed conditioned defeat (CD). Temporary inactivation of the ventral, but not dorsal hippocampus (VH, DH, respectively) using muscimol disrupted the acquisition of CD, whereas pretraining VH…

Although intelligence has traditionally been identified as "the ability to learn" (Peterson, 1925), this relationship has been questioned in simple operant learning tasks (Spielberger, 1962). Nevertheless, recent pieces of research have demonstrated a strong and significant correlation between associative learning measures and intelligence…

This study examined how the amount of effort required to produce a reinforcer influenced subsequent preference for, and strength of, that reinforcer in 7 individuals with intellectual disabilities. Preference assessments identified four moderately preferred stimuli for each participant, and progressive-ratio (PR) analyses indexed reinforcer…

The integrity of the rodent anterior cingulate cortex (ACC) is essential for various aspects of instrumental behavior, but it is not clear if the ACC is important for the acquisition of a simple instrumental response. Here, it was demonstrated that post-session infusions of anisomycin into the rat ACC completely prevented the acquisition of…