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Results for “Conditioning, Operant”

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PubMed1991

PET measured evoked cerebral blood flow responses in an awake monkey.

We have developed a method to measure task-related regional cerebral blood flow (BF) responses in an awake, trained monkey using positron emission tomography (PET) and H215O. We trained an animal with operant conditioning using only positive reinforcement to climb unassisted into a modified primate chair that was then positioned in the PET scanner. A special headholder and acrylic skull cap permitted precise placement and accurate repositioning. We measured BF qualitatively with bolus injection of H215O and 40-s scan. Each session included scans at rest interposed with scans during vibration of a forepaw. Regional responses were identified using subtraction image analysis. After global normalization, a resting image was subtracted on a pixel-by-pixel basis from a comparable image collected during vibration. The region of peak response occurred in contralateral sensorimotor cortex with a mean magnitude of 11.6% (+/- 3.2%) of the global mean value for 10 separate experiments, significantly greater than the mean qualitative BF change (0.4 +/- 3.6%; p less than 0.00001) in the same region for seven rest-rest pairs. This newly developed technique forms the basis for a wide variety of experiments.

Animals↗

PubMed2002

Activity in human ventral striatum locked to errors of reward prediction.

The mesolimbic dopaminergic system has long been known to be involved in the processing of rewarding stimuli, although recent evidence from animal research has suggested a more specific role of signaling errors in the prediction of rewards. We tested this hypothesis in humans, using functional magnetic resonance imaging (fMRI) and an operant conditioning paradigm for the discrete delivery of small quantities of fruit juice, along with a control experiment in which juice was substituted with a neutral visual stimulus. A local estimation of the activity in the ventral striatum showed a significant differentiation when the juice was withheld at the expected time of delivery; this finding was not replicated in the case of visual stimulation, providing evidence for time-locked processing of reward prediction errors in human ventral striatum.

Adult↗

PubMed1976

A tangibly reinforced speech reception threshold procedure for use with small children.

Forty normal-hearing children between 17 and 56 months were tested using a new method for determining speech reception thresholds. The words employed were names for parts of a device that was in the form of a colorful clown. The device automatically rewarded the child with a small piece of candy each time he pressed the part of the clown that had been announced through the sound field system of a speech audiometer. Results showed that operant conditioning speech audiometry using tangible reinforcers is feasible for small children. Both boys and girls can be tested accurately by this method down to age two and one-half years.

Audiometry↗

PubMed1989

A comparison of audiometric test methods for 2-year-old children.

Visual reinforcement audiometry (VRA), visual reinforcement operant conditioning audiometry (VROCA), and play audiometry were compared in terms of conditionability and number of responses obtained prior to habituation on normal 2-year-old (24-27 months) children. Results indicated that a higher percentage of children could be conditioned to VRA than to either VROCA or play audiometry. Results also indicated that for children who could be conditioned, the play audiometry group showed more responses prior to habituation than were obtained from the other two groups.

Age Factors↗

PubMed1985

Response strength of young children in operant audiometry.

An operant conditioning discrimination paradigm was evaluated in terms of relationships between response behavior of young children and two stimulus components of the paradigm, the discriminative stimulus (DS) and the reinforcing stimulus (RS). Experiment I measured response performance in normal 1-year-old subjects as a function of differences in intensity and/or complexity among three DSs. Results showed no significant differences in conditioning rate, habituation, or consistency of the conditioned response relative to variable properties of the DS. Experiment II examined response performance of normal 2-year-old children as a function of two modifications in the RS, reinforcement schedule and reinforcement novelty. Subjects reinforced on a variable-ratio schedule of intermittent reinforcement and subjects reinforced on a 100% schedule demonstrated equivalent response habituation and consistency. In the second part of the experiment, subjects receiving novel RSs showed significantly greater response recovery than subjects reinforced with familiar RSs. Comparison of normal 1- and 2-year-old children revealed similar rates of conditioning and response consistency. However, 2-year-olds habituated more rapidly than 1-year-olds.

Acoustic Stimulation↗

PubMed2000

Differential learning-stage dependent patterns of c-Fos protein expression in brain regions during the acquisition and memory consolidation of an operant task in mice.

The present study analysed the effects of the stage of learning of an appetitive operant conditioning task on the spatial and temporal patterns of c-Fos protein levels in the brain of BALB/c mice. c-Fos levels were assessed by immunohistochemistry at either 60, 120 or 180 min after either the first, the second or the fifth daily training session and compared to sham animals. The results show an increase of c-Fos-positive nuclei in several subcortical and cortical brain regions, 60-min post-acquisition. Because these activations were a function of task mastery, the data indicate that they were specifically related to learning. Following the first acquisition session, significant increases in c-Fos-positive neurons were observed in the dorsal hippocampus (CA3), anterior cingulate, occipital and parietal cortices. Following the second daily training session, c-Fos was highly expressed in some subcortical regions, the hippocampus, the subiculum, the entorhinal, and posterior cingulate areas. Moreover, a significant correlation was found between the progression of performance from day 1 to day 2 and c-Fos expression on the hippocampal CA1 subfield. Following complete acquisition, no further task-dependent increases in c-Fos-labelled nuclei was observed in any brain region sampled, suggesting that the intervention of c-Fos-induced mechanisms in the consolidation process were terminated. The training stage-dependent changes in regional post-training c-Fos expression in the hippocampus and the connected limbic regions suggest that this neuronal network is actively engaged in memory consolidation processes.

Animals↗

PubMed2005

Early age-related cognitive impairment in mice lacking cannabinoid CB1 receptors.

The molecular mechanisms contributing to the normal age-related decline of cognitive functions or to pathological learning and memory impairment are largely unknown. We demonstrate here that young mice (6-7 weeks) with a genetic deletion of the cannabinoid CB1 receptor performed as well as WT mice, or often better, in a number of learning and memory paradigms, including animal models of skill-learning, partner recognition, and operant conditioning. In contrast, the performance of mature mice (3-5 months) lacking CB1 receptors was much worse than that of age-matched WT animals. In most tests, these mice performed at the same level as old animals (14-17 months), suggesting that the decline in cognitive functions is accelerated in the absence of CB1 receptors. This rapid decline in CB1-deficient animals is accompanied by a loss of neurons in the CA1 and CA3 regions of the hippocampus.

Aging↗

PubMed2003

Importance of the CNGA4 channel gene for odor discrimination and adaptation in behaving mice.

Odor stimulation of olfactory sensory neurons (OSNs) leads to both the activation and subsequent desensitization of a heteromultimeric cyclic-nucleotide-gated (CNG) channel present in these cells. The native olfactory CNG channel consists of three distinct subunits: CNGA2, CNGA4, and CNGB1b. Mice in which the CNGA4 gene has been deleted display defective Ca(2+)calmodulin-dependent inhibition of the CNG channel, resulting in a striking reduction in adaptation of the odor-induced electrophysiological response in the OSNs. These mutants therefore afford an excellent opportunity to assess the importance of Ca(2+)-mediated CNG channel desensitization for odor discrimination and adaptation in behaving animals. By using an operant conditioning paradigm, we show that CNGA4-null mice are profoundly impaired in the detection and discrimination of olfactory stimuli in the presence of an adapting background odor. The extent of this impairment depends on both the concentration and the molecular identity of the adapting stimulus. Thus, Ca(2+)-dependent desensitization of the odor response in the OSNs mediated by the CNGA4 subunit is essential for normal odor sensation and adaptation of freely behaving mice, preventing saturation of the olfactory signal transduction machinery and extending the range of odor detection and discrimination.

Adaptation, Physiological↗

PubMed1992

Role of gender, season, and familiarity in discrimination of conspecific song by zebra finches (Taeniopygia guttata).

Operant conditioning techniques were used to assess how gender and song familiarity affect song discrimination in adult zebra finches (Taeniopygia guttata). Twenty-five males and females, divided into five cohorts, were trained to discriminate between conspecific songs at different times of year. Males discriminating between their own and another song from their own aviary reached criterion in the fewest number of trials, followed by males discriminating between two songs from their own aviary, then by males discriminating between songs they had not heard before. Females discriminating between two songs from their own aviary required more trials than males to reach criterion, but, unlike in males, song familiarity did not have a significant effect on song discrimination by females. The number of trials required to reach criterion was greater in winter than in summer, suggesting a photoperiodic effect in what has been regarded as a nonphotoperiodic species. Gender, season, and familiarity appear to affect how zebra finches discriminate between conspecific songs.

Animals↗

PubMedDate not supplied

Effects of low lead exposure on neuro-behavioral function in the rat.

Small doses (45-180 micrograms/g) of lead acetate were administered to male rats by gavage every day during the first 3 wk of life. A blood concentration of approximately 59 micrograms/100 ml blood produced signs of disturbances in reflex development and some changes in emotional behavior. Larger doses resulted in subtle changes in the neuromotor coordination function. The effect of low levels of lead exposure on the cognitive function in operant conditioning could not clearly be observed. Brain lead concentration tended to be higher than in other tissues examined. At approximately 10 months following cessation of lead acetate administration, the brain lead concentration had decreased to almost the same level found in control rats, and no distinguishable differences were observed between the lead-treated rats and controls in emotional behavior and neuromotor coordination.

Animals↗

PubMed1992

Noninvasive approaches to pain control in terminal illness: the contribution of psychological variables.

Pain is a common problem for patients with terminal illnesses. The major efforts to control pain for these patients have focused on the appropriate uses of analgesic medication to reduce the sensory aspect of the pain experienced. There are a number of studies in the chronic pain literature, however, that have implicated the important role of a number of psychological factors in the maintenance and exacerbation of pain. Among the most important variables identified are expectancy, anxiety, perceived controllability, self-efficacy, symptom preoccupation, operant conditioning, classical conditioning, and observational learning. In this paper, these psychological variables are examined and their applicability to patients who have pain associated with terminal illnesses is discussed as well as the implications of these variables for complementary treatment with analgesic medications are described.

Conditioning, Classical↗

PubMed2006

Behavioural mechanisms and cognitive-behavioural interventions of somatoform disorders.

Due to the lack of adequate cure or medication for somatoform disorders, cognitive-behavioural intervention or cognitive-behavioural therapy (CBT) seems to be an optimal treatment resource for patients with these disorders, since the cause of the somatoform disorders cannot to be explained by medical illness, but can be analyzed in the process of both responding and operant conditioning. According to the reviews, randomized controlled trials are limited, but the efficacy of the intervention is quite impressive. Most of the studies use multiple treatment strategies, and no standardized treatment methods have been established. In general, the following steps are taken in CBT treatments: (1) assessment; (2) rationale of treatment choice; (3) course of treatment; (4) evaluation of treatment; and (5) reviewing treatment effects. In CBT, functional analysis in the assessment session is the key to success, to identify the relationship among discriminative stimuli and consequences, in order to reduce the undesirable behaviour, and the most effective approach of the treatment would be a combination of multiple techniques. However, as the efficacy of the treatments is established, expansion of accurate knowledge of functional analysis and training sessions for health care providers and patients should be provided. Further research should explore the effect of individual techniques, and comparison should be made to identify the relative benefits of the techniques using both individual, and group format.

Cognitive Behavioral Therapy↗

PubMed2005

Dopamine, learning, and impulsivity: a biological account of attention-deficit/hyperactivity disorder.

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) affects up to 10% of school-age children. The impulsivity which is seen as its core feature persists over years, yet experimental measures of impulsivity can be altered in a single session. In this study, we tested the theory that both the persistence and the variability of impulsivity could be the result of abnormalities in learning mechanisms and environment. METHOD: We extended an existing model of the role of dopamine in operant conditioning to address the delayed response time task, which is one of the standard tests for impulsivity in ADHD. In this task, subjects choose between immediate responding for a small reinforcer and later responding for a larger one. We studied the influence on impulsivity of four key parameters of the model: The learning rate, discount factor, brittleness, and action bias. RESULTS: The behavior of the model is broadly comparable with electrophysiological (monkey) and behavioral (ADHD and normal) data. Variations in any of the parameters can cause impulsivity. All parameters except the discount factor show inverted U-shaped curves for their effects on impulsivity, suggesting, for example, how either hyper- or hypofunctioning of dopamine can cause impulsivity. The model suggests how decision making can be affected by environmental unpredictability, and thus offers an account of one aspect of the natural history of ADHD. CONCLUSIONS: Some types of ADHD may be caused by specific deficits in reinforcement learning and in the use of learned lessons. Environmental factors can interact with these deficits to delay maturation.

Attention Deficit Disorder with Hyperactivity↗

PubMed2004

Stimulus processing of glycine is dissociable from that of sucrose and glucose based on behaviorally measured taste signal detection in Sac 'taster' and 'non-taster' mice.

Mouse strains have been divided into 'tasters' and 'non-tasters' based on their relatively high and low preference, respectively, for low concentrations of sucrose and saccharin. These phenotypic differences appear to be due to a polymorphism in the gene at the Sac locus encoding for the T1R3 taste receptor selectively affecting the functionality of the T1R2+3 heterodimer. To psychophysically examine whether these phenotypes are due to sensory sensitivity as opposed to hedonic responsiveness, we measured taste signal detection of sucrose, glucose, and glycine by Sac taster (C57BL/6J and SWR/J) and non-taster (129P3/J and DBA/2J) strains in an operant conditioning paradigm using a gustometer. The taster mice had lower detection thresholds for sucrose and glucose compared with the non-taster mice. The detection thresholds corresponded well with reported responsiveness to low concentrations of these sugars in two-bottle intake tests suggesting that the Sac taster phenotype has a sensory basis and is not simply a matter of strain differences in the hedonic evaluation of weak intensities of the stimuli. Taster status did not entirely account for the strain differences in detection thresholds for glycine, a 'sweet' tasting amino acid. Collapsed across strains, detection thresholds for sucrose and glucose were highly correlated with each other (r = 0.81), but only modestly correlated with those for glycine (r < or = 0.43). This suggests that stimulus processing of glycine in the perithreshold intensity domain can be dissociated from that of sucrose and glucose. The mechanism underlying this difference may be related to the ability of glycine to bind with the T1R1+3 heterodimer.

Animals↗

PubMed2001

Gender-dependent behavioral and sensory effects of a commercial mixture of polychlorinated biphenyls (Aroclor 1254) in rats.

Developmental exposure to polychlorinated biphenyls (PCBs) has been associated with behavioral and cognitive deficits in humans and animal models. Perinatal exposure to PCBs has also been associated with sensory deficits in animal models. These effects were hypothesized to be mediated in part by ortho-substituted PCBs, which do not or weakly bind to the aryl hydrocarbon (Ah) receptor. The present studies were designed to determine whether perinatal exposure to Aroclor 1254, a commercial mixture of > 99% ortho-substituted PCBs, would affect cognitive and sensory function in Long-Evans rats. Adult male and female offspring of female rats fed Aroclor 1254 (Lot #124-191; doses of 0, 1, or 6 mg/kg/day; gestational day 6 through postnatal day 21; n = eight/group) were trained to perform a signal detection task capable of assessing sensory thresholds. Training included autoshaping and operant conditioning. Thresholds for detecting a 1-s light stimulus were determined under background illuminations ranging from 2 lux to complete darkness. Female rats exposed to Aroclor 1254 autoshaped more rapidly than control females, at a rate akin to control males. Control females had lower thresholds than control males at all levels of background illumination. These differences were abolished by Aroclor 1254, which reduced thresholds in males and increased thresholds in females. These data extend previous findings of gender-specific effects of PCBs on neurobehavioral development to measures of acquisition and sensory function.

Animals↗

PubMed1993

Adding objectivity to infant behavioral audiometry.

This article deals with the limitations of infant behavioral audiometry, which have led us to seek objective methods of audiometry for determining hearing sensitivity in infants. It describes efforts to add objectivity to (or reduce the subjectivity of) behavioral methods of infant audiometry. Several aspects of visual reinforcement audiometry (VRA), including the head turn response, the use of control trials, and adherence to the principles of operant conditioning, serve to reduce the subjectivity inherent in behavior observation audiometry. In addition, computer control of VRA procedures can relieve the examiner of potentially subjective decision-making during the course of evaluation and can facilitate testing with sophisticated algorithms that could not be done manually by a single examiner. Computer simulations to determine the best VRA test parameters are described.

Acoustic Stimulation↗

PubMed1984

An experimental analysis of the interaction of chemotherapy and behavior therapy in anorexia nervosa.

The interaction of imipramine and operant conditioning on weight gain in an anorexia nervosa patient was examined by a single-subject experiment consisting of a baseline and four treatment phases: phase 1--contingency management only; phase 2--contingency management plus imipramine; phase 3--contingency management plus imipramine placebo; phase 4--contingency management only. The results showed that the interaction of drug and behavior therapy had no significant effect on weight gain, but that imipramine may have contributed to a decrease in depression. Observations are made regarding weight changes related to passes and medication refusals.

Adult↗

PubMedDate not supplied

Use of health behavior change theories to guide urinary incontinence research.

BACKGROUND: Urinary incontinence in adults has been the focus of researchers for over 40 years. Health behavior change theories, predominantly operant conditioning, have guided much of the intervention research. In recent years cognitive theories have been used to guide behavioral interventions for urinary incontinence. Most research has focused on individual rather than group or community behavior. Few, if any, health behavior change theories have been tested on population-based interventions. OBJECTIVES: To explore urinary incontinence research guided by health behavior change theories. METHODS: Existing literature on health behavior change theories was analyzed to generate a plan for future research. RESULTS: Gaps in knowledge are identified and discussed and recommendations for future research are made. CONCLUSIONS: The development and testing of new theories will guide the next generation of incontinence researchers and ultimately lead to reducing the incidence and prevalence of incontinence.

Attitude to Health↗