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PubMed2003

Effects of postconditioning inflation on odor + taste compound conditioning.

The within-compound association approach has been proposed as an account of synergistic conditioning in flavor aversion learning. One prediction from the within-compound association approach is that following taste + odor compound conditioning, postconditioning inflation of one element of the compound should increase responding to the second element. In four experiments with rats, the AX+/A+ design was used to determine whether postconditioning inflation of A would increase responding to X. In Experiments 1 and 3, responding to X was significantly stronger after AX+/A+ conditioning, as compared with AX+ conditioning. In Experiments 2 and 4, the specificity of the inflation effect was demonstrated, because AX+/A+ conditioning produced a stronger aversion to X than did AX+/B+ conditioning. Furthermore, it appears that the taste + odor association is symmetrical because inflation of the taste aversion increased responding to the odor (Experiments 1 and 2) and inflation of the odor aversion increased responding to the taste (Experiments 3 and 4).

Analysis of Variance↗
PubMed2003

Elemental versus configural perception in a people-present/people-absent discrimination task by pigeons.

In the present experiment, we investigated whether pigeons rely exclusively on elemental information or whether they are also able to exploit configural information in a people-present/people-absent discrimination task. Six pigeons were trained in a go/no-go procedure to discriminate between 800 color photographs characterized by the presence or absence of people. The people-present stimuli were designated as positive, and the people-absent stimuli were designated as negative. After training and a subsequent generalization test, the pigeons were presented with both familiar and novel people-present stimuli containing human figures that were distorted in one of seven different ways. All the pigeons learned the initial discrimination and also showed generalization to novel stimuli. In the subsequent test, performance on all types of distorted stimuli was diminished in comparison with that on the intact original pictures from which they had been derived. At the same time, however, peck rates clearly exceeded the level of responding found for regular people-absent stimuli. This result strongly suggests that responding was controlled by both the constituting target components and their spatial relations and, therefore, points to the dual importance of elemental and configural information.

Animals↗
PubMed2002

Fruits and vegetables categorized: an application of the generalized context model.

In the study reported in this paper, we investigated the categorization of well-known and novel food items in the categories fruits and vegetables. Predictions based on Nosofsky's (1984,1986) generalized context model (GCM), on a multiplicative-similarity prototype model, and on an instantiation model as applied in Storms, De Boeck, and Ruts (2001) were compared. Despite suggestions in the literature that prototype models predict categorization from large categories better than exemplar models do, our results showed that the exemplar-based GCM yielded clearly better predictions than did a (multiplicative-similarity) prototype model.

Adult↗
PubMed1999

Orientation invariance in naming rotated objects: individual differences and repetition priming.

In naming drawings of complex common objects, unpracticed naming times increase with rotation away from the upright, but this orientation effect is attenuated with practice. In principle, attenuation could result from learning to extract orientation-invariant information or from learning view-specific representations at the trained orientations. We contrasted these approaches by examining repetition priming for prime-target pairs presented on successive trials in either the same orientation (horse at 51 degrees primes horse at 51 degrees) or a different orientation (horse at 154 degrees primes horse at 51 degrees), for two subgroups of subjects. One subgroup showed no orientation effect, even when unpracticed, and a correspondingly high generalization of priming across different views. The other subgroup initially showed high sensitivity to misorientation and little priming across orientations but, with sufficient practice, came to show no orientation effect and complete generalization of priming. Thus, some subjects always used orientation-invariant procedures, whereas others learned to do so.

Adult↗
PubMed2005

Behavioral and electrophysiological evidence of species-specific face processing.

Several recent reports suggest that the behavioral and cortical specificity of face processing may be influenced by experience. To test this hypothesis, behavioral and electrophysiological data were recorded from adults in response to human and monkey faces differing in familiarity and orientation. An analysis of event-related potential and behavioral data revealed differentiation across species, familiarity, and orientation. Behavioral measures were correlated with amplitude and latency measures for each factor of interest. These analyses revealed that accuracy was positively related to the amplitude of the vertex positive potential in the human face task but not in the monkey face task. These findings suggest that previous experience with different categories of faces modulates the link between behavioral and electrophysiological measures of face processing.

Adult↗
PubMed1986

[Cognition of binary-event-sequences: its relation to the sequential attributes].

Sixty subjects were asked to evaluate the degree of similarity among 15 binary-event-sequences which were generated through the Bernoulli process. The averaged similarity matrix of 50 subjects (ten omitted) was analysed by the Hayashi's Quantification Method IV, and the dimensions yielded were compared with the theoretically derived dimensions for the operational interpretation. The result showed that the run structure--the number of runs and the length of the longest run--and the number of one event in a sequence were the important attributes in cognition of binary-event-sequences. These attributes were most frequently employed by subjects, although other attributes and their combinations may be relevant. It was pointed out that the general tendency of judgments, i.e., dependence on the spatial and visual aspects of given sequences, proved subjects' inattention to the characteristics of the probabilistic generation process of sequences.

Cognition↗
PubMed1999

S-16924, a novel, potential antipsychotic with marked serotonin1A agonist properties. IV. A drug discrimination comparison with clozapine.

The novel benzodioxopyrrolidine (S-16924) displays a clozapine-like profile of interaction with multiple monoaminergic receptors, in addition to potent agonist activity at serotonin (5-HT)1A receptors. S-16924 (2.5 mg/kg i.p.) and clozapine (5.0 mg/kg i.p.) generated robust discriminative stimuli (DS) and displayed full mutual generalization. The D4 antagonists L-745,870 and S-18126, the D1/D5 antagonist SCH-39166, and the D3 antagonist S-14297 showed at most partial generalization to S-16924 and clozapine. The D2/D3 antagonist raclopride fully generalized to S-16924, but only partially generalized to clozapine. The 5-HT2A antagonist MDL-100, 907 fully generalized to S-16924 and two further 5-HT2A antagonists, fananserin and SR-46349, showed partial generalization. However, MDL-100,907, fananserin, and SR-46349 showed less pronounced generalization to clozapine. Similarly, the 5-HT2C antagonists SB-200,646 and SB-206,553 more markedly generalized to S-16924 than to clozapine. The 5-HT1A receptor agonist (+/-)-8-dihydroxy-2-(di-n-propylamino) tetralin generalized fully to S-16924 but not to clozapine. Full generalization was obtained to both S-16924 and clozapine for the clozapine congeners, olanzapine and quetiapine. In distinction, the benzisoxazole, risperidone, and the phenylindole, sertindole, weakly generalized to S-16924 and clozapine. However, the benzisoxazole ziprasidone, which possesses 5-HT1A agonist properties, generalized fully to S-16924 but not to clozapine. Finally, the muscarinic antagonist scopolamine generalized fully to clozapine and partially to S-16924. In conclusion, S-16924 and clozapine display both communalities and differences in their "compound" DS; this likely reflects their respective complex patterns of interaction with multiple monoaminergic receptors. Although no specific receptor was identified as underlying the clozapine DS, 5-HT1A agonist as well as D2 and 5-HT2A/2C antagonist properties contribute to the S-16924 DS.

Adrenergic Agents↗
PubMed2001

Taste preconditioning augments odor-aversion learning.

On the basis of previous work that has shown a taste can potentiate odor-aversion conditioning in AX+ conditioning, 6 experiments used rats to examine the effects of pairing a preconditioned taste (A) with a novel odor cue (X) in an A+/AX+ aversion conditioning design. Experiments 1A and 1B demonstrated that a preconditioned taste produced a robust odor aversion that was significantly stronger than a potentiated odor aversion. The results of Experiment 2 showed that the robust odor aversion produced by A+/AX+ conditioning was not the result of the potentiated odor aversion summating with generalization from the taste aversion. The augmented odor aversion was produced only when the taste and odor stimuli were presented simultaneously (Experiment 3) and the preconditioned taste aversion was intact at compound conditioning (Experiment 4). Pairing a novel odor with a preconditioned taste was not sufficient to condition an aversion to odor (Experiment 5), although other results implicated a role for an association between odor and taste in the odor augmentation effect (Experiment 6). The present results have implications for current models of taste + odor interactions in flavor-aversion conditioning.

Animals↗
PubMed1991

Cue dimensionality in the three-choice pentylenetetrazole-saline-chlordiazepoxide discrimination task.

Sprague-Dawley rats were trained in a three-choice drug discrimination task utilizing 5mg/kg chlordiazepoxide (CDP), saline (SAL), and 15mg/kg pentylenetetrazole (PTZ) as stimulus conditions. Generalization tests of the three training conditions resulted in exclusively injection-appropriate lever selection. Cross-generalization tests with PTZ or CDP resulted in dose-dependent lever selections confined to the training drug and SAL levers. Morphine and ethanol cross-generalization tests produced saline-appropriate responding, whereas cocaine and caffeine produced PTZ-appropriate responding at high doses. Tests conducted after concomitant administration of both training drugs demonstrated a reciprocal antagonism between the two drugs. More importantly, when the training dose of CDP was held constant and combined with increasing doses of PTZ, a shift from CDP- to PTZ-appropriate responding through a dose range of exclusive SAL-appropriate responding was demonstrated. Overt behavioral indices of seizure activity occurred at dose combinations that engendered only saline responding, but PTZ-appropriate responding did not correspond with the development of overt seizure episodes. These data suggest that the PTZ discriminative cue in the present three-choice paradigm is not primarily linked to its proconvulsant effects. The data are discussed in terms of an hypothesis in which the discriminable interoceptive cues for PTZ and CDP lie at opposite ends of a single continuum that has a neutral centroid, and this continuum more likely reflects an anxiolysis-anxiogenesis dimension than an anticonvulsant-seizure dimension.

Journal Article↗
PubMed1993

Substitution by NMDA antagonists and other drugs in rats trained to discriminate ethanol.

It has been reported that, in animals trained to discriminate ethanol, stimulus control generalized to the non-competitive NMDA antagonists phencyclidine, ketamine and dizocilpine. In the present study, rats were trained to discriminate a dose of ethanol (1g/kg, i.p.) and substitution tests were carried out with phencyclidine, dizocilpine, CGS 19755, eliprodil, triazolam, chlordiazepoxide, abecarnil, alpidem and d-amphetamine. Phencyclidine and dizocilpine produce dose-related substitution for ethanol as did the competitive NMDA antagonist, CGS 19755, and the benzodiazepines, triazolam and chlordiazepoxide. Eliprodil, an NMDA antagonist acting through the polyamine modulatory site, neither substituted for ethanol nor modified the ethanol dose-response curve. d-Amphetamine, and the non-benzodiazepine anxiolytics, alpidem and abecarnil, did not substitute for ethanol. The results show that both NMDA antagonists and compounds acting through (GABA receptors (benzodiazepines) can substitute for ethanol, emphasizing that the ethanol cue may involve several mechanisms. As all the drugs substituting for ethanol, like ethanol itself, are known to produce ataxia and muscle relaxation, it is proposed that this property may be an important aspect of the ethanol cue.

Journal Article↗
PubMed1975

Teaching a simple reading vocabulary to retarded children: effectiveness of fading and nonfading procedures.

Four equated groups of moderately retarded children were trained on a simple eight-word vocabulary, each under a different experimental condition. In the standard condition a printed work was repeatedly paired with a pictured representation. In the faded condition the same procedure was used except that the picture was gradually faded-out over trials. A mixed condition had, on alternate trials, either work-and-picture or word alone, while on alternate trials a control condition had either picture alone or word alone. On immediate and delayed tests of vocabulary learning, subject showed large differences in reading performance with these methods. The order of efficiency of conditions was faded, mixed, standard, and control. Several theoretical interpretations of the superiority of fading were considered. The conclusion favored was that the fading procedure was best because it increased the attention-value of the words in relation to the faded pictures, without sacrificing the superior associative effects of noncontingent pairings of words and pictures.

Association Learning↗
PubMed1950

Electrotherapy.

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Electric Stimulation Therapy↗