Fear-relevant stimuli such as snakes and spiders are thought to capture attention due to evolutionary significance. Classical conditioning experiments indicate that these stimuli accelerate learning, while instructed extinction experiments suggest they may be less responsive to instructions. We manipulated stimulus type during instructed aversive…

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…

Hippocampal ? (3-12 Hz) oscillations are implicated in learning and memory, but their functional role remains unclear. We studied the effect of the phase of local ? oscillation on hippocampal responses to a neutral conditioned stimulus (CS) and subsequent learning of classical trace eyeblink conditioning in adult rabbits. High-amplitude, regular…

Aversive events can trigger relapse of extinguished fear memories, presenting a major challenge to the long-term efficacy of therapeutic interventions. Here, we examined factors regulating the relapse of extinguished fear after exposure of rats to a dangerous context. Rats received unsignaled shock in a distinct context ("dangerous"…

Strain comparison studies have been critical to the identification of novel genetic and molecular mechanisms in learning and memory. However, even within a single learning paradigm, the behavioral data for the same strain can vary greatly, making it difficult to form meaningful conclusions at both the behavioral and cellular level. In fear…

Although infants display preferences for social stimuli early in their lives, we know relatively little about the mechanisms of infant learning about the social world. In the current set of studies, 1-month-old infants underwent an adapted eyeblink conditioning paradigm to examine learning to both "social" and non-social cues. While infants were…

Eyelid conditioning has proven useful for analysis of learning and computation in the cerebellum. Two variants, delay and trace conditioning, differ only by the relative timing of the training stimuli. Despite the subtlety of this difference, trace eyelid conditioning is prevented by lesions of the cerebellum, hippocampus, or medial prefrontal…

Memory consolidation is thought to involve the gradual transfer of transient hippocampal-dependent traces to distributed neocortical sites via the rhinal cortices. Recently, medial prefrontal (mPFC) neurons were shown to facilitate this process when their activity becomes synchronized. However, the mechanisms underlying this enhanced synchrony…

The auditory conditioned stimulus (CS) pathway that is necessary for delay eyeblink conditioning was investigated using reversible inactivation of the medial auditory thalamic nuclei (MATN) consisting of the medial division of the medial geniculate (MGm), suprageniculate (SG), and posterior intralaminar nucleus (PIN). Rats were given saline or…

This article presents an interpretation of autoshaping, and positive and negative automaintenance, based on a neural-network model. The model makes no distinction between operant and respondent learning mechanisms, and takes into account knowledge of hippocampal and dopaminergic systems. Four simulations were run, each one using an "A-B-A" design…

Research was conducted on two selective attention systems in learning situations. The theoretical and experimental approaches are presented in a set of six papers. One paper considered directions in attention theory and five papers report experiments with pigeon and children subjects. The two attention systems are (1) coding response, which…

Analyzes associative structures underlying goal-directed behavior using well-developed techniques for studying Pavlovian conditioning. Identifies the roles of the stimulus, response, and reinforcer in instrumental learning. A response and its reinforcer must be associated for acquisition and maintenance of instrumental behavior. (Author/LHW)

Pigeons were trained to respond to stimuli from a continuous stimulus dimension (tonal frequency) with response values from continuous response dimension. Both the number of points of correspondence and problem difficulty were varied. Following training, subjects were tested with stimulus values intermediate to those trained. During these test…

Using a fixed-choice procedure subjects were conditioned to emit personal reference statements by two experimenters functioning high on the dimensions of empathy, positive regard, and genuineness and two low-functioning experimenters. Comparison of learning slopes of conditioned subjects with a control group supported the efficacy of facilitative…

The present investigation studied the effectiveness of implicit analogies as advance organizers in children's learning. It was hypothesized that analogies which were structurally isomorphic to the target concept would facilitate learning of the latter even though linkages between components of the two concepts were not overtly specified.…