The establishment of flavor-flavor associations using a sensory preconditioning training procedure

In Experiment 1, rats drank two distinct flavors in sequence during preconditioning; during training, the second of these flavors was paired with a toxin. During testing, there was an aversion to the flavor not directly paired with the toxin. In Experiment 2, the time interval between the two flavors (0, 3, 9, and 27 sec) in the preconditioning phase was varied; learning occurred only if the flavors were separated by 9 sec or less. Experiment 3, using a 60-sec interstimulus interval also did not reveal learning. These results reveal that the temporal gradient for flavor-flavor associative learning is similar to conventional audio-visual sensory preconditioning delay gradients and different from those obtained in flavor-toxicosis experiments. The results are discussed in terms of their critical implication for Revusky's concurrent interference theory of associative learning.     

A process model for water jug problems

We develop and evaluate a model for the water jug task in which a subject is required to find a sequence of moves (pouring operations) which produce a specified amount of water in each jug. Experiment 1 was designed to evaluate the meansends, move selection heuristics that are assumed by the model. Experiment 2 tested the model's predictions concerning those aspects of the water jug task that determine problem difficulty.A three stage process model incorporating GPS-like, means-ends heuristics and assumptions concerning the utilization of short- and long-term memory was able to account for differences across problems as well as details of the performance of subjects solving a given problem. We conclude that a GPS-like model that only selects one move at a time (no forward planning of move sequences or setting up of subgoals) can provide a good account of solution behavior in the water jug task.     

Effects of vicarious consequences on imitation and recall: Some developmental findings

Two experiments were conducted using a multiple-item list in which each item consisted of a pair of pictures. The model indicated which member of each pair she preferred and was either positively reinforced, negatively reinforced, or received neutral consequences. The S then indicated his preferences (imitation test). Following the imitation test, each S was asked to recall the model's choices. Age was an independent variable in both experiments. Imitation scores of the children, preschool to sixth-grade age range, were strongly influenced by differential vicarious reinforcement. Vicarious reward increased imitation and vicarious punishment decreased it. College students' imitation scores were only minimally influenced by differential vicarious reinforcement. Within- and between-subjects variations of vicarious reinforcement had similar effects. Recall scores were surprisingly high and were not significantly influenced by differential vicarious reinforcement. Interestingly, age and percentage of correct recall were negatively correlated.     

Wyckoff's observing response: Pigeons learn to observe stimuli for free food but not stimuli for extinction

Four pigeons received periods of free food delivery alternating with periods of extinction. The experimental chamber was divided in half. Initially the subjects could produce stimuli selectively associated with these schedules by standing on the right side of the chamber and later by standing on the left side. In both phases, subjects produced the free food stimulus most of the time it was available but did not increase above baseline the time spent producing the extinction stimulus. Thus, when alternative stimuli are available, the pigeon prefers the stimulus associated with the greater frequency of reinforcement although the choice results in no biological advantage.     

Nature of spelling errors in transcortical sensory aphasia: A case study

The nature and extent of spelling errors in a patient with transcortical sensory aphasia were investigated. The two experimental conditions required the patient to spell monosyllabic and polysyllabic words both verbally and in written form. Analysis of the spelling errors revealed partially preserved knowledge of the visual image of a word as a whole, as well as preserved knowledge of temporal order. Our patient's error patterns in both conditions were more similar than dissimilar. These findings in conjunction with results reported in the literature indicate that patients exhibiting different aphasia syndromes use separate spelling strategies.     

Visual attention at three months as a predictor of cognitive functioning at two years of age

The purpose of the present study was to examine the predictive power of various cognitive skills at 3 months of age in terms of later cognitive functioning. Habituating to redundant and recovering to novel stimuli at 3 months of age were found to predict later intellectual functioning at 24 months better than 3-month global intelligence or object permanence scores. In terms of information processing skills, recovery predicted later intelligence test scores better than habituation. It is suggested that changes in cognitive functioning may be viewed as a transformation of skills from one age to another rather than as a continuum of the same skills. With regard to the cognitive abilities of the 3-month-old, it is suggested that information processing may be central to cognitive functioning at this age.     

Anticipatory threat and physical danger trait anxiety: A signal-detection analysis of effects on autonomic responding

The method of Signal-Detection Theory (SDT) was applied to the analysis of autonomic data in two experiments. In the first, apprehension surrounding the administration of loud tones was induced through preliminary information; in the second, it was increased by selecting subjects scoring high on a physical-danger trait anxiety scale. Despite enhanced autonomic reactivity, those in the first study who were led to believe that the tones would be extremely disturbing subsequently rated them as less disturbing than did their counterparts who were given comparatively benign expectations. The signal-detection analysis of heart rate and skin conductance suggested enhanced “preparedness of response” among the high-threat subjects; given the diminished subjective ratings, increased response readiness at the autonomic level may have reflected physiological activity assuaging subjective aversiveness of the tones. Contrary to the first study, the psychometrically designated threatened group in the second experiment produced both greater autonomic reactivity along with elevated subjective ratings of disturbance. The SDT analysis provided evidence of greater autonomic sensitivity to noxious stimulus properties. Results were discussed in terms of their implications for theories of anxiety; the comparative utilites of signal-detection theory and conventional methods of autonomic-response scoring were elaborated.     

Interference with ingestional aversion learning produced by preexposure to the unconditioned stimulus: Associative and nonassociative aspects

Preconditioning exposure to a lithium chloride unconditioned stimulus (US) interferes with the subsequent conditioning of a taste aversion. Multiple US preexposures produce a long-lasting or durable interference with aversion learning, whereas a single US exposure produces a transient interference effect. The present experiments demonstrate that the durable US preexposure effect is substantially reduced if the method of drug treatment (infusion versus injection of the drug into the peritoneal cavity) or the spatial cues present during drug treatment (home cage versus a distinctive environment) are changed between the preexposure and taste conditioning phases of the experiment. In contrast, these manipulations do not attenuate the proximal/transient US preexposure effect. These findings indicate that different mechanisms are responsible for the two US preexposure effects. The results are consistent with previous suggestions that the durable effects of lithium preexposure are due to associative interference produced by the exteroceptive stimuli that accompany drug administrations and indicate that the proximal/transient US preexposure effect is mediated by nonassociative mechanisms.