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In each of 4 experiments animals were given a structural discrimination task that involved visual patterns composed of identical features, but the spatial relations among the features were different for reinforced and nonreinforced trials. In Experiment 1 the stimuli were pairs of colored circles, and pigeons were required to discriminate between patterns(More)
The results from five experiments are considered in relation to two of Spence's (1937, 1938) proposals concerning discrimination learning. In Experiments 1 and 2, we investigated whether his ideas about the interaction between excitatory and inhibitory generalization gradients can be used to understand how animals solve a complex patterning discrimination.(More)
A formal account of the relationship between attention and associative learning is presented within the framework of a configural theory of discrimination learning. The account is based on a connectionist network in which the entire pattern of stimulation presented on a trial activates a configural unit that then enters into an association with the trial(More)
Four experiments with rats examined the origin of outcome-selective Pavlovian-to-instrumental transfer (PIT). Experiment 1 used a standard procedure, where outcomes were embedded within extended conditioned stimuli (CSs), to demonstrate the basic effect: Pavlovian stimuli augmented instrumental lever presses that had been paired with the same outcomes.(More)
The acquisition of a conditioned response to a stimulus when it is paired with a reinforcer is retarded if the stimulus has previously been repeatedly pre-exposed in the absence of the reinforcer. This effect, called latent inhibition, has previously been found to be insensitive to lesions of the medial prefrontal cortex (mPFC) in rats. Using an on-baseline(More)
In this paper, we describe the challenges of prototyping a reference application on System S, a distributed stream processing middleware under development at IBM Research. With a large number of stream PEs (Processing Elements) implementing various stream analytic algorithms, running on a large-scale, distributed cluster of nodes, and collabo-ratively(More)
A novel paradigm is presented that was designed to mimic aspects of cue and response competition seen in humans in conflict procedures such as the Stroop task. Rats were trained simultaneously on two biconditional discrimination tasks, one auditory and one visual, in two different contexts: C1, in which A1:LP1-->R, A2:LP2-->R; and C2, in which V1:LP1-->R,(More)
In 3 experiments, pigeons acquired a discrimination between patterns comprising the same features. Thus vertical green bars beside horizontal red bars might have signaled food, and horizontal green bars beside vertical red bars might have signaled no food. The solution of this discrimination can be explained by assuming each pattern is represented either by(More)
In two experiments pigeons received a complex negative patterning discrimination, using autoshaping, in which food was made available after three stimuli if they were presented alone (A, B, C), or in pairs (AB, AC, BC), but not when they were all presented together (ABC). Subjects also received a positive patterning discrimination in which three additional(More)
Pigeons received a discrimination in which the spatial relationship between 2 adjacent rectangles filled with different colors signaled the trial outcome. Test trials then involved the same rectangles separated horizontally by a gap. The tests in Experiment 1 disrupted the discrimination more when the rectangles were tall and thin than when they were short(More)