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Results for “GENERALIZATION LEARNING”

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PubMed1982

Training teachers in generalized writing of behavior modification programs for multihandicapped deaf children.

In contrast to previous studies where teachers were instructed how to implement behavior modification programs designed by an experimenter, teachers in the present experiment were taught how to write as well as implement behavior modification programs. The generalized effects of two training conditions on teacher and pupil behaviors were assessed by a multiple baseline design where, following baseline, two teachers of multi-handicapped deaf children were taught to set objectives and measure pupil performance (measurement training), Later, through a training manual, they learned a general problem-solving approach to writing behavior modification programs (programming training). After both training conditions, experimenter feedback was given for teachers' application of training to a target behavior for one pupil and generalization was measured across target behaviors for the same pupil and across pupils. It was found that measurement training had little general effect on either teacher behavior or pupil behavior. However, after programming training, teachers increased their program writing and correct use of behavior modification procedures and generalized this training across pupils and target behaviors. Along with these effects, there was improvement in pupil behaviors. Possible explanation for generalized effects of teacher training were considered.

Adult↗

PubMed1992

Faces as reinforcers: effects of pairing condition and facial expression.

The reinforcing properties of faces were investigated in two experiments in which tones were first paired with an adult female face and subsequently tested for their ability to potentiate visual fixation when compounded with a checkerboard pattern. In Experiment 1, infants who had been presented six pairings of a 65-dB, 1000-Hz tone with a smiling face later fixated a checkerboard pattern significantly more when it was compounded with the tone than when it was tested alone. Infants in random and backward controls fixated the checkerboard pattern roughly equal amounts in the presence absence of the tone, and infants in a no tone control did not exhibit a novelty response when shifted from the face to the checkerboard pattern. In Experiment 2, facial expression was varied across groups and the effects on conditioning of a 65-dB tone that immediately preceded the face were studied. On test trials, greater fixation in the presence of the tone than in its absence was observed when a smiling or a surprised expression was presented, but not when a neutral expression was presented. Differences scores (fixation on tone minus no tone test trials) were significantly greater than zero in the smiling and surprised conditions, and significantly greater in the surprised condition than in the neural condition. These findings demonstrate the feasibility of a conditioned visual fixation paradigm for the study of the reinforcing properties of faces and of infant associative learning in general, and suggest that the expression portrayed by a face contributes to its effectiveness as a reinforcer.

Acoustic Stimulation↗

PubMedDate not supplied

Neuron types, receptors, behavior, and taste quality.

Neurophysiological studies on chorda tympani (CT) single fibers and behavioral studies on generalization of learned aversions in hamsters (Mesocricetus auratus) are reviewed. The work on hamsters is compared to work on other species, including the laboratory rat and several primate species, including humans. This body of data demonstrates associations between response profiles of physiologically defined specialist CT neurons and behavioral stimulus generalizations on one hand, and characteristics of putative taste receptors, on the other. Response profiles of generalist CT neurons are similarly associated with receptor characteristics, but are not associated with specific behavioral discriminations. The associations of peripheral nerve data with both receptor and behavior strongly suggest specific codes for "sucrose-like" and "NaCl-like" taste qualities. Definitive conclusions regarding "patterns" or "labeled lines" requires an understanding of mechanisms of central neural processing of the several specialist and generalist taste-afferent inputs.

Animals↗

PubMed1993

Long-term learning in vernier acuity: effects of stimulus orientation, range and of feedback.

In hyperacuity, as in many other tasks, performance improves with practice. To better understand the underlying mechanisms, we measured thresholds of 41 inexperienced observers for the discrimination of vernier displacements. In spite of considerable inter-individual differences, mean thresholds decreased monotonically over the 10,000 stimuli presented to each observer, if stimulus orientation was constant. Generalization of learning seemed to be possible across offset-ranges, but not across orientations. Learning was slightly faster with error feedback than without it in one experiment. These results effectively constrain the range of conceivable models for learning of hyperacuity.

Feedback↗

PubMed2005

Refining the experimental analysis of academic skills deficits: Part I. An investigation of variables that affect generalized oral reading performance.

Experimental analyses for improving reading fluency deficits have rarely targeted generalized increases in academic responding. As a consequence, the variables that may help students to generalize newly learned forms of academic responding like reading are not well understood. Furthermore, experimental analyses of reading fluency interventions have not systematically examined difficulty level as a variable that may affect instructional outcomes. The experiment reported in this paper expands (a) the measurement of the dependent variables to include generalized increases across tasks (reading passages) and (b) the combination of independent variables used to produce measurable generalized increases. The results demonstrate the importance of combining reward and instructional variables (including difficulty level) to produce generalized increases and how those variables can be meaningfully investigated prior to making treatment recommendations.

Child↗

PubMed2004

Matching: its acquisition and generalization.

Choice typically is studied by exposing organisms to concurrent variable-interval schedules in which not only responses controlled by stimuli on the key are acquired but also switching responses and likely other operants as well. In the present research, discriminated key-pecking responses in pigeons were first acquired using a multiple schedule that minimized the reinforcement of switching operants. Then, choice was assessed during concurrent-probe periods in which pairs of discriminative stimuli were presented concurrently. Upon initial exposure to concurrently presented stimuli, choice approximated exclusive preference for the alternative associated with the higher reinforcement frequency. Concurrent schedules were then implemented that gave increasingly greater opportunities for switching operants to be conditioned. As these operants were acquired, the relation of relative response frequency to relative reinforcement frequency converged toward a matching relation. An account of matching with concurrent schedules is proposed in which responding exclusively to the discriminative stimulus associated with the higher reinforcement frequency declines as the concurrent stimuli become more similar and other operants-notably switching-are acquired and generalize to stimuli from both alternatives. The concerted effect of these processes fosters an approximate matching relation in commonly used concurrent procedures.

Animals↗

PubMed2006

Generalization and categorization of spectral colors in goldfish. II. Experiments with two and six training wavelengths.

In part I of this study (Kitschmann and Neumeyer 2005), goldfish categorized spectral colors only in the sense that wavelengths in a range of about twice as large as the just noticeable difference were treated as similar to a given training wavelength. Now, we trained goldfish on more than one wavelength to prevent very accurate learning. In one experiment goldfish were trained on six adjacent wavelengths with equal numbers of rewards, and, thus, equal numbers of learning events. Generalization tests showed that some wavelengths were chosen more often than others. This indicated that certain spectral ranges are either more attractive or more easily remembered than others. As this is a characteristic of the "focal" colors or centers of color categories in human color vision, we interpret the findings in goldfish accordingly. We conclude (Figs. 5 and 6) that there are four categories in spectral ranges approximately coinciding with the maximal sensitivities of the four cone types, and three categories in-between. Experiments with two training colors indicate that there is no direct transition between categories analogous to human "green" and "red", but that there is a color analogous to human "yellow" in-between (Figs. 2, 3; Table 1).

Animals↗

PubMed1997

Supervised adaptive Hamming net for classification of multiple-valued patterns.

A Supervised Adaptive Hamming Net (SAHN) is introduced for incremental learning of recognition categories in response to arbitrary sequences of multiple-valued or binary-valued input patterns. The binary-valued SAHN derived from the Adaptive Hamming Net (AHN) is functionally equivalent to a simplified ARTMAP, which is specifically designed to establish many-to-one mappings. The generalization to learning multiple-valued input patterns is achieved by incorporating multiple-valued logic into the AHN. In this paper, we examine some useful properties of learning in a P-valued SAHN. In particular, an upper bound is derived on the number of epochs required by the P-valued SAHN to learn a list of input-output pairs that is repeatedly presented to the architecture. Furthermore, we connect the P-valued SAHN with the binary-valued SAHN via the thermometer code.

Artificial Intelligence↗

PubMed1986

The effects of television form and violent content on boys' attention and social behavior.

An experiment is reported that examined the independent effects of television content (violence) and television formal features (action level) on children's attention to programs and their postviewing social behavior. Pairs of preschool boys participated in two experimental sessions in which they saw animated and live television programs that varied in violent content (high or low) and formal features (high or low action level). They then played with toys that contained cues for either aggressive or prosocial interaction. Rapid character action facilitated visual attention to the programs; violent tv content did not facilitate attention. On measures of social behavior, strong effects of toy cues were found independently of television treatment effects. Aggressive toys produced aggressive behavior, and prosocial toys produced prosocial behavior; these patterns included some nonspecific, generalized influences in addition to direct demands of the play materials. Violent tv content led to changes in subjects' style of interaction and was also associated with increases in some prosocial behaviors. Television action level had no systematic effects on subjects' behavior. Results are discussed within the theoretical frameworks of observational learning and general arousal. Implications for children's television programming are also discussed.

Aggression↗

PubMed1984

Effects of the training dose on generalization of morphine stimulus to clonidine.

The relationship between the stimulus properties of morphine and clonidine was tested in rats trained to discriminate morphine sulfate (4, 2 or 1 mg/kg) from saline in a two-lever food-rewarded task. The response trained in the low dose group generalized to low doses of clonidine (0.125 to 0.5 mg/kg) whereas the response trained with the high dose of morphine generalized only to higher doses of clonidine (0.625 to 1.0 mg/kg). Naloxone blocked the generalization in the low dose group but only partially blocked it in the high dose group. Yohimbine blocked the generalization to clonidine in the high morphine dose group and reversed the response rate suppressant effect of clonidine in all groups.

Animals↗

PubMed1999

Template-based procedures for neural network interpretation.

Although neural networks often achieve impressive learning and generalization performance, their internal workings are typically all but impossible to decipher. This characteristic of the networks, their opacity, is one of the disadvantages of connectionism compared to more traditional, rule-oriented approaches to artificial intelligence. Without a thorough understanding of the network behavior, confidence in a system's results is lowered, and the transfer of learned knowledge to other processing systems - including humans - is precluded. Methods that address the opacity problem by casting network weights in symbolic terms are commonly referred to as rule extraction techniques. This work describes a principled approach to symbolic rule extraction from standard multilayer feedforward networks based on the notion of weight templates, parameterized regions of weight space corresponding to specific symbolic expressions. With an appropriate choice of representation, we show how template parameters may be efficiently identified and instantiated to yield the optimal match to the actual weights of a unit. Depending on the requirements of the application domain, the approach can accommodate n-ary disjunctions and conjunctions with O(k) complexity, simple n-of-m expressions with O(k(2)) complexity, or more general classes of recursive n-of-m expressions with O(k(L+2)) complexity, where k is the number of inputs to an unit and L the recursion level of the expression class. Compared to other approaches in the literature, our method of rule extraction offers benefits in simplicity, computational performance, and overall flexibility. Simulation results on a variety of problems demonstrate the application of our procedures as well as the strengths and the weaknesses of our general approach.

Journal Article↗

PubMed2006

A review of learning with normal and altered sound-localization cues in human adults.

Humans use several cues to determine the position of sound sources in space. Here we provide a review of the literature on how practice influences sound-localization performance in human adults. We divided this literature into two categories: adaptation to alterations in sound-localization cues and learning with normal, unaltered cues. For altered cues, partial adaptation has been reported with a variety of cue transformations, except in the extreme case in which the cues were reversed between the two ears. For normal cues, improvement has been observed in some but not all experiments, though the most recent data generally show learning. Thus, the reviewed data indicated that human adults can recalibrate, as well as refine the use of, sound-localization cues, and that training regimens can be developed to enhance sound-localization performance in individuals with normal and impaired localization abilities.

Adult↗

PubMed1996

What can artificial neural networks teach us about neurodegenerative disorders with extrapyramidal features?

Artificial neural networks (ANNs), computer paradigms that can learn, excel in pattern recognition tasks such as disease diagnosis. Artificial neural networks operate in two different learning modes: supervised, in which a known diagnostic outcome is presented to the ANN, and unsupervised, in which the diagnostic outcome is not presented. A supervised learning ANN could emulate human expert diagnostic performance and identify relevant predictive markers in the diagnostic task, while an unsupervised learning ANN could suggest reasonable alternative diagnostic classification criteria. In the present study, we used ANN methodology to try to overcome the neuropathological difficulties in differentiating the subtypes of progressive supranuclear palsy (PSP), and in differentiating PSP from postencephalitic parkinsonism (PEP) and corticobasal degeneration, or Pick's disease from corticobasal degeneration. First, we applied supervised learning ANN to classify 62 cases of these disorders and to identify diagnostic markers that distinguish them. In a second experiment, we used unsupervised learning ANN to investigate possible alternative nosological classifications. Artificial neural networks input data for each case consisted of values representing histological features, including neurofibrillary tangles, neuronal loss and gliosis found in multiple brain sampling areas. The supervised learning ANN achieved excellent accuracy in classifying PSP but had difficulty classifying the other disorders. This method identified a few features that might help to differentiate PEP, supported currently proposed criteria for Pick's disease, corticobasal degeneration and typical PSP, but detected no features to characterize the atypical subtype of PSP. In general, unsupervised learning ANN supported the present nosological classification for PSP, PEP, Pick's disease and corticobasal degeneration, although it overlapped some groups. Artificial neural networks methodology appears promising for studying neurodegenerative disorders.

Basal Ganglia Diseases↗

PubMed1982

A comparison of the behavioral effects of DOM homologs.

Twenty-four rats, trained to discriminate 1.0 mg/kg of (+/-)-DOM, i.e. (+/-)-2,5-dimethoxy-4-methylphenylisopropylamine, from saline under a VI-15 schedule of reinforcement, were challenged with a series of DOM homologs. The agents examined included the 4-ethyl (DOET), -propyl (DOPR), -butyl (DOBU), -tertiary butyl (DOTB) and -amyl (DOAM) derivatives as well as the R(-)- and S(+)-isomers of DOET. The (+/-)-DOM stimulus was found to generalize to all of the agents, except DOTB and DOAM, where only partial generalization occurred. The results suggest that the stimulus properties produced by the latter two compounds may differ from those of the remainder of the series. Furthermore, the ED50 values obtained, for those compounds to which the DOM-stimulus generalized, correlated significantly (r2 = 0.94) with the human hallucinogenic potencies of these agents.

DOM 2,5-Dimethoxy-4-Methylamphetamine↗

PubMed2002

Impaired skill learning in patients with severe closed-head injury as demonstrated by the serial reaction time (SRT) task.

A group of 20 patients who sustained closed-head injury (CHI) and a matched control group of 20 individuals were tested on the serial reaction time (SRT) task. Three different sequence-learning measures were generated from the task: two implicit and one explicit. The two implicit sequence-learning measures include: (1) the learning rate on the first five blocks of the repeated sequence, assumed to reflect primarily general reaction time learning, and (2) the difference between the fifth block of the repeated sequence and the sixth block, a random sequence that reflects implicit sequence-specific learning. In addition, an explicit measure of sequence learning was generated. The results indicate that the CHI group was impaired on the explicit measure of sequence learning. The groups did not differ on general reaction time learning, one of the implicit measures of sequence learning. However, the control group was superior to the CHI group in learning the specific sequence repeated in the SRT task. This pattern of results is unique to the CHI group, corresponding with neither that of amnesic patients nor with that of patients with dysfunction of the basal ganglia (i.e., Parkinson's diseases).

Adolescent↗

PubMed2000

Serial position effect and selective amnesia induced by scopolamine in mice.

Mice were trained to run through a maze with six gates, each consisting of three doors--two locked and one unlocked. They learned to choose a correct (unlocked) door at the gates close to the beginning and end better than in the middle, showing the primacy and recency effects of serial learning. A low dose of scopolamine unexpectedly enhanced the primacy effect, while a high dose impaired learning in general. The enhancement of the primacy effect can be explained in terms of reduction of retroactive interference.

Amnesia↗

PubMed2003

Selective remodeling of rabbit frontal cortex: relationship between 5-HT2A receptor density and associative learning.

RATIONALE: Associative learning during classical trace eyeblink conditioning has been shown to be regulated by serotonin 5-HT(2A )receptors and to be critically dependent on the integrity of frontal cortex. Chronic administration of 5-HT(2A) ligands has been shown to produce a selective up- or down-regulation of 5-HT(2A) receptors in frontal cortex. OBJECTIVES: We examined whether alterations in 5-HT(2A) receptor density had a functional significance with respect to associative learning. METHODS: Animals received chronic injections of LSD, BOL or MDL11,939 and 1 day later began classical trace conditioning of the eyeblink response. RESULTS: The density of 5-HT(2A) receptors in frontal cortex was significantly increased at 1-4 days after the cessation of chronic injections of the selective 5-HT(2A) receptor ligand MDL11,939. Rabbits demonstrated an enhancement of associative learning when training began at 1 day after cessation of chronic MDL11,939 injections, but acquired at the same rate as controls when training began at 8 days after cessation of injections, a time when receptor density had returned to control levels. Animals that began training 1 day after chronic injections of BOL or LSD, drugs that produce decreases in 5-HT(2A) receptor density, demonstrated normal rates of acquisition. CONCLUSIONS: These results indicate that increases in the density of 5-HT(2A) receptors in frontal cortex are associated with increases in the rate of associative learning, and further support an important role for this receptor in cortical circuitry that mediates learning. More generally, these results suggest an approach for functional remodeling of brain regions in the adult animal.

Animals↗

PubMed1986

Relationship of plasma phencyclidine levels to phencyclidine discrimination in the pigeon.

Plasma phencyclidine levels were determined in pigeons trained to discriminate 1.5 mg/kg phencyclidine from saline under a second-order schedule using a color-tracking procedure. With both cumulative and non-cumulative dosing procedures, pigeons reliably discriminated plasma phencyclidine levels above 200 ng/ml. When the time course of phencyclidine discrimination was determined and compared with the time course of phencyclidine levels in plasma in a different group of birds, a similar relationship between discrimination and plasma phencyclidine was generally observed. Plasma phencyclidine levels did not correlate well with position responding observed in some birds after lower phencyclidine doses.

Animals↗