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Results for “Conditioning, Operant”

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PubMed1994

Dualistic behavior of ATP-sensitive K+ channels toward intracellular nucleoside diphosphates.

ATP-sensitive K+ (KATP) channels are intracellular ligand-gated channels which regulate diverse cellular functions. Intracellular nucleoside diphosphates (NDPs) are essential for the physiological opening of KATP channels which would otherwise be permanently closed by their overt sensitivity to intracellular ATP. We find that KATP channels exhibit dualistic behavior toward NDPs depending on their operative condition. When channels are in the spontaneous operative condition, NDPs antagonize channel inhibition by intracellular ATP. When channels have "run down", NDPs induce channel opening but no longer antagonize intracellular ATP. The switch of the KATP channel response to the same ligand, i.e., NDPs, is controlled by a Mg-ATP-dependent reaction. The condition of the target protein therefore determines the effect of the ligand. This property provides a novel basis to evaluate the dynamic regulation of ion channels by their ligands.

Adenosine Triphosphate↗

PubMed1971

Pavlovian pattern learning by nonlinear neural networks.

This note describes laws for the anatomy, potentials, spiking rules, and transmitters of some networks of formal neurons that enable them to learn spatial patterns by Pavlovian conditioning. Applications to spacetime pattern learning and operant conditioning are then possible, if the conditioning is viewed as multi-channel Pavlovian conditioning in a highly inhomogeneous anatomy. In suitable anatomies, biases in learning because of axon collaterals with nonuniformly distributed diameters can be corrected if one properly couples the action potential to transmitter potentiation, and chooses signal velocity proportional to axon diameter. These anatomies can contain any number of cells. Anatomies exist in which patterns may be learned without their being practiced overtly, whereas persistent recall of old patterns without the learning of newly imposed patterns is impossible. Physiologically, this constraint has the trivial interpretation that signals from one cell to another first pass through the intervening synaptic knob. Mechanisms that control learning rates at times important to the network (e.g., reward and punishment times) can be discussed. Serial behavior like that described by Lashley is possible: this consists of sequential learning and performance of patterns faster than would be allowed by a motor-feedback control, at velocities influenced by arousal level, with the possibility of abrupt termination of performance if conflicting environmental demands arise. Analogs of pattern completion and mass action exist, as do phase transitions in memory (for some rate parameters and anatomies, memory is rigid, for others, it is plastic). The laws limit the ways in which these networks can be interconnected to yield specific discrimination, learning, memory, and recall capabilities.

Action Potentials↗

PubMed2003

Preferred food rewards for laying hens in behavioural experiments.

1. Laying hens showed a clear preference for maggots over whole grain wheat, feed pellets and other food stuffs in a preference test. 2. Motivation to work for maggots in an operant conditioning task was high and unaffected by periods of food deprivation of up to 6h before testing. 3. By extrapolation, motivation to work for maggots was equivalent to the motivation of the hens to work for their normal ration after approximately 9 h food deprivation. 4. Food deprivation is a common prerequisite for laying hens in operant conditioning and other behavioural techniques but can be avoided if an attractive food, such as maggots, is used. The mild distress associated with the deprivation is thereby removed and, in the UK, the procedure would not require regulation under the Animals (Scientific Procedures) Act 1986.

Animals↗

PubMed1978

Biofeedback in the treatment of gastrointestinal disorders.

A wide range of secretory (salivation, gastric acid and bile secretion) and motor functions (rumination, esophageal and anal sphincter contraction, gastric and colonic motility) have been successfully modified using operant conditioning procedures or biofeedback training. The clinical syndromes to which these studies have been addressed include rumination, reflux esophagitis, hypersecretion of acid associated with peptic ulcer, irritable bowel syndrome, and fecal incontinence. The available evidence strongly suggests that biofeedback is effective and is the treatment of choice for some types of fecal incontinence, and the evidence supports the effectiveness of operant conditioning for the treatment of intractable rumination in infants or retarded individuals. There is suggestive evidence that a nonspecific biofeedback technique, EMG biofeedback for skeletal muscle relaxation, may contribute to the healing of peptic ulcers, but the data are so far inconclusive. Biofeedback approaches to the treatment of other clinical syndromes are at the investigational stage only, and no predictions can be made regarding their efficacy.

Biofeedback, Psychology↗

PubMed1997

Anoxic encephalopathy: a neurobehavioural study in rehabilitation.

This study examined an operational conditioning paradigm designed to train procedural learning channels in a patient with anoxic encephalopathy. Prior to treatment the patient had been incontinent to bowel and bladder incontinent, minimally participant in daily activities and aggressive toward staff and residents for two years. Previous rehabilitation attempts had been unsuccessful in changing these behaviours. Based on the literature, it was hypothesized that through operant conditioning the patient could be trained on three behaviours: 1) bowel and bladder continence 2) activity level and 3) level of aggression. Results indicated that at a 4 month interval following the initial training, the patient had improved in all areas of functioning.

Adult↗

PubMed1992

Anesthesia for laparoscopic cholecystectomy. Is nitrous oxide contraindicated?

Since it has been suggested that the use of nitrous oxide (N2O) may contribute to bowel distention, we evaluated the effects of N2O on operating conditions during laparoscopic cholecystectomy in 50 healthy patients using a double-blind protocol design. All patients received the same preanesthetic medication (midazolam, 2 mg intravenously) and induction of anesthesia consisted of intravenously administered fentanyl 1.5 micrograms.kg-1, thiopental 4-6 mg.kg-1, and a nondepolarizing muscle relaxant. For maintenance of anesthesia, patients were randomly assigned to one of two treatment groups: group 1 (n = 26) received isoflurane with 70% N2O in oxygen (O2), whereas group 2 (n = 24) received isoflurane in an air/O2 mixture. The surgeon (blinded to the anesthetic technique) estimated the degree of technical difficulty before beginning the operation using a five-point scale. At 15-min intervals throughout the operation, the surgeon was asked to evaluate both "overall operating conditions" and degree of "bowel distension" using independent five-point scales. At the end of the operation, the surgeon was asked whether or not N2O had been used as part of the anesthetic technique. There were no significant intraoperative differences between the two groups with respect to operating conditions or bowel distension. More importantly, there was no time-related change in either variable during the course of the operation. Finally, the incidence of postoperative nausea and vomiting was similar in both treatment groups. The surgeon was able to correctly determine that N2O had been administered only 44% of the time. Thus, N2O had no clinically apparent deleterious effects during laparoscopic cholecystectomy.

Adult↗

PubMed2003

Suppression of adult neurogenesis impairs olfactory learning and memory in an adult insect.

Although adult neurogenesis has now been demonstrated in many different species, the functional role of newborn neurons still remains unclear. In the house cricket, a cluster of neuroblasts, located in the main associative center of the insect brain, keeps producing new interneurons throughout the animal's life. Here we address the functional significance of adult neurogenesis by specific suppression of neuroblast proliferation using gamma irradiation of the insect's head and by examining the impact on the insect's learning ability. Forty gray irradiation performed on the first day of adult life massively suppressed neuroblasts and their progeny without inducing any noticeable side effect. We developed a new operant conditioning paradigm especially designed for crickets: the "escape paradigm." Using olfactory cues, visual cues, or both, crickets had to choose between two holes, one allowing them to escape and the other leading to a trap. Crickets lacking adult neurogenesis exhibited delayed learning when olfactory cues alone were used. Furthermore, retention 24 hr after conditioning was strongly impaired in irradiated crickets. By contrast, when visual cues instead of olfactory ones were provided, performance of irradiated insects was only slightly affected; when both olfactory and visual cues were present, their performance was not different from that of controls. From these results, it can be postulated that newborn neurons participate in the processing of olfactory information required for complex operant conditioning.

Animals↗

PubMed2006

Obtaining highly enriched cultures of Candidatus Accumulibacter phosphates through alternating carbon sources.

Candidatus Accumulibacter Phosphatis is widely considered to be a polyphosphate accumulating organism (PAO) of prime importance in enhanced biological phosphorus removal (EBPR) systems. This organism has yet to be isolated, despite many attempts. Previous studies on the biochemical and physiological aspects of this organism, as well as its response to different EBPR operational conditions, have generally relied on the use of mixed culture enrichments. One frequent problem in obtaining highly enriched cultures of this organism is the proliferation of glycogen accumulating organisms (GAO) that can compete with PAOs for limited carbon sources under similar operational conditions. In this study, Candidatus Accumulibacter Phosphatis has been enriched in a lab-scale bioreactor to a level greater than 90% as quantified by fluorescence in situ hyrbridisation (FISH). This is the highest enrichment of this organism that has been reported thus far, and was obtained by alternating the sole carbon source in the feed between acetate and propionate every one to two sludge ages, and operating the bioreactor within a pH range of 7.0-8.0. Simultaneously, the presence of two known groups of GAOs was eliminated under these operational conditions. Excellent phosphorus removal performance and stability were maintained in this system, where the phosphorous concentration in the effluent was below 0.2 mg/L for more than 7 months. When a disturbance was introduced to this system by adding sludge from an enriched GAO culture, Candidatus Accumulibacter Phosphatis once again became highly enriched, while the GAOs were out-competed. This feeding strategy is recommended for future studies focused on describing the physiology and biochemistry of Accumulibacter, where a highly-enriched culture of this organism is of high importance.

Acetates↗

PubMed1976

Isotachophoretic analysis of peptides.

Operating conditions for the qualitative and quantitative determination of plasma kinins, human angiotensin, reduced and oxidized glutathiones and oligopeptides with the same amino acid residues by capillary-tube isotachophoresis using a potential gradient detector have been established. The potential unit (PU) value is proposed as a qualitative index for capillary-tube isotachophoresis with a potential gradient detector. As it is unaffected by changes in the operating conditions, the PU value permits inter-laboratory comparison of data. The coefficient of variation of this index under the various operating conditions used was less than 1.69%.

Amino Acid Sequence↗

PubMed2001

Sludge dewatering using centrifuge with thermal/polymer conditioning.

Sludge dewatering is preceded by a conditioning operation to enhance water removal efficiency. In the conditioning operation, chemical coagulants or polymers are added to promote sludge particle aggregation for easier dewatering. In this study, an alternative conditioning method for sludge thermal treatment at temperatures up to 80 degrees C was extensively investigated. Dewatering characteristics such as sludge capillary suction time and specific resistance to filtration, sludge viscosity and concentration of solid cakes were examined thoroughly. A good correlation between capillary suction time and specific resistance to filtration was established for sludges from water treatment, but not for biological sludge. Cationic polymer exhibits the best enhancement on sludge moisture removal. The sludge rheogram varies from 60 to 5 cP as temperature changes from 20 to 80 degrees C for sludges from water treatment plant. The dewatering ability of sludge can be greatly enhanced by thermal treatment in conjunction with the use of polymers.

Centrifugation↗

PubMed1978

[Behavior therapy of uncontrolled imbecilic children].

This paper reports the use over a period of five months of operant conditioning methods, which consisted above all in the withdrawal of privileges, in the case of ten preschool-age problem children. In all of the patients, the program of behavioral therapy resulted in a considerable reduction of the rate of occupational malbehavior. "Good conduct" showed a slight decrease as the challenging character of recompense grew smaller, but was still above the initial level. Intelligence, extraversion, and emotional lability are related to the results of behavioral therapy and discussed in detail. Operant conditioning appears effective when a clear reaction is required under simple conditions of stimulation. In the case of more complex situations with a variety of behavioral alternatives, imitiative learning should be far more promising.

Behavior Therapy↗

PubMed2003

Demonstration of conditional gate operation using superconducting charge qubits.

Following the demonstration of coherent control of the quantum state of a superconducting charge qubit, a variety of qubits based on Josephson junctions have been implemented. Although such solid-state devices are not currently as advanced as microscopic qubits based on nuclear magnetic resonance and ion trap technologies, the potential scalability of the former systems--together with progress in their coherence times and read-out schemes--makes them strong candidates for the building block of a quantum computer. Recently, coherent oscillations and microwave spectroscopy of capacitively coupled superconducting qubits have been reported; the next challenging step towards quantum computation is the realization of logic gates. Here we demonstrate conditional gate operation using a pair of coupled superconducting charge qubits. Using a pulse technique, we prepare different input states and show that their amplitude can be transformed by controlled-NOT (C-NOT) gate operation, although the phase evolution during the gate operation remains to be clarified.

Journal Article↗

PubMed1991

The amelioration of myopia using biofeedback of accommodation: a review.

The purpose of this review is to give an account of the issues raised by reports that myopia can be treated by operant conditioning or biological feedback. Devices are available that provide auditory feedback of accommodative state such that variation in tone frequency provides a means by which the patient can monitor his or her ability to induce changes in accommodation response, the task thus being to change the pitch of the tone in a direction corresponding to a more distant far point. The aim of a training programme is to reinforce and establish control over the accommodative response by a process akin to operant conditioning and subsequently to transfer the skill to normal visual environments such that a manifest reduction in myopia becomes apparent. Although there are reports that the technique can induce a reduction in myopia by up to 3 D the findings are of limited value owing to the lack of objective data, for example pre- and post-training cycloplegic refraction. The pre- and post-training measures of subjective letter acuity used by many studies are, with repeated trials, particularly vulnerable to individual differences in the ability to learn how to discriminate and interpret blurred images. The review concludes that more comprehensive clinical trials are needed before accommodation biofeedback can qualify as an established method of clinical treatment of myopia. The trials should be designed to encompass the following issues: the characteristics of a feasible physiological model linking accommodation and myopia development; the rationale with regard to patient selection; the technical performance of the optometer employed; the characteristics of the control group used; the criteria for assessment of myopic change; the transfer of training to performance in normal visual environments; the economic viability of the programme of training and equipment; and the skill, training and knowledge of the clinician implementing the training programme.

Accommodation, Ocular↗

PubMed1982

Late post-learning participation of entorhinal cortex in memory processes.

Mice of the BALB/c strain were bilaterally implanted with electrodes in the lateral entorhinal cortex (EC) in order to study the influence of post-trial EC stimulation on memory. The learning task was a food reinforced operant conditioning. At one of several time intervals after a first learning session, the experimental groups were stimulated for 80 s with subseizure current intensity. Testing was carried out 24 h later. In the first experiment, a continuous reinforcement schedule was used. EC stimulation had no effect when applied at the 30-s or 3-h intervals, but surprisingly a 30-min delayed stimulation greatly improved retention compared to performance of non-stimulated animals. In the second experiment, the same paradigm was used in a discriminative operant conditioning task. The same facilitation on retention was observed only with the 30-min delayed stimulation. Compared to previous data with hippocampal or hypothalamic stimulation, the present results reveal that EC is lately involved in memory processes.

Animals↗

PubMed2005

Simultaneous intra-accumbens remifentanil and dopamine kinetics suggest that neither determines within-session operant responding.

RATIONALE: The ultra-short-acting mu opioid agonist analgesic/anesthetic remifentanil (RMF) is extremely rapidly eliminated from blood (half-life in rats, 0.3-0.7 min). This extremely fast elimination is thought to be the main reason why RMF maintains such high rates of responding in animal operant-conditioning models of drug addiction. OBJECTIVE: The present study investigated if such a fast elimination of RMF also occurs in the extracellular space of the brain, i.e., in the pharmacokinetic compartment that is thought to be ultimately mediating the reinforcing effect, and hence, the abuse liability of drugs. METHODS: Nucleus accumbens (NAC) RMF and dopamine (DA) were simultaneously quantified by in vivo microdialysis followed by tandem mass spectrometry both in rats that traversed an alley to receive intravenous injections of 0.032 mg kg(-1) RMF in an operant runway procedure (contingent RMF) and in rats that passively received RMF in the runway (noncontingent RMF). RESULTS: Regardless of the mode of administration (i.e., contingent or noncontingent), intra-accumbens RMF peaked in the first 10-min sample and decreased exponentially with a t(1/2) of 10.0+/-1.2 min (N=31). RMF-stimulated DA peaked in the 10-min sample immediately after the RMF peak and decreased with a time course very similar to that of RMF. Crosscorrelation of the NAC RMF and NAC DA curves showed them to be tightly synchronized. Noncontingent single-dose RMF was eliminated from the whole brain with a half-life of 1.1+/-0.2 min and from blood with a half-life of 0.3 min or less. The comparison of blood-vs-brain RMF pharmacokinetics with rat RMF self-administration behavior, either in operant runway (present study) or in lever-press-based operant-conditioning procedures, suggests that titration of blood RMF, whole-brain RMF, intra-accumbens RMF, or accumbal DA levels (assessed with the limited temporal resolution of in vivo microdialysis) does not determine a rat's decision to reemit a response during a multiple-injection drug self-administration session.

Anesthetics, Intravenous↗

PubMed1980

Temporally spaced responding for food in adult rats after undernutrition early in life.

Rats were undernourished during the suckling and early post-weaning periods and were then fed a good quality diet ad libitum from 43 to 300 days when behavioural testing was begun. Male previously undernourished and control rats were tested on three operant conditioning schedules in which low rates of bar-pressing were rewarded with food (differential reinforcement of low rate or DRL schedules). These were DRL 5 sec, DRL 10 sec and DRL 30 sec. On each schedule the response rates of both groups of animals declined over several sessions and their efficiency at obtaining the food rewards increased. However, there were no significant differences between the two groups on either of these measures. This finding indicates that, despite being hyper-responsive in many situations, including some operant conditioning schedules, previously undernourished rats are as capable as controls of withholding responding when necessary.

Animals↗

PubMed1980

Biofeedback therapy for fecal incontinence.

Operant conditioning offers a new therapeutic modality for fecal incontinence. Our experience with biofeedback therapy in six male and six female patients (ages 12-78 years) is presented. Incontinence was associated with a surgical procedure in six patients and with a medical condition in six patients. Rectosphincteric manometry was performed using a three balloon technic, with one balloon positioned in the rectum as a distending stimulus and the others at the internal and external sphinchters. Pressure responses to measured volumes of rectal distention were displayed on a polygraph. Rectosphincteric reflexes and sensory thresholds for rectal distention were determined. Patients were then encouraged to elevate sphinchter pressures while observing their manometric responses. Follow-up of 10-96 weeks showed ten patients had good responses, with complete continence in six patients. Nine of 10 responders required only one treatment session. Operant conditioning is a valuable technic in properly selected patients with an 80% probability of success.

Adolescent↗

PubMed2000

Self regulation of electrocortical activity in schizophrenia and schizotypy: a review.

Contrary to the belief that schizophrenic patients will be unable to learn self control of electrocortical activity due to attentional and motivational deficits, the two studies which have investigated this, both involving operant conditioning of slow cortical potentials, have demonstrated that self regulation can take place. This was particularly true of a study of interhemispheric control. Learning difficulties were found to be more to do with sustaining motivation towards the end of sessions or training programs, rather than in initial learning. Schizotypical features in the normal population have in the case of anhedonia been associated with slower learning, while withdrawn introversion has been associated with faster learning. In view of the affirmative evidence and advances in understanding the functional significance of electroencephalographic (EEG) rhythms, the undertaking of therepeutic regimens with electrocortical operant conditioning is warranted in the schizophrenia spectrum.

Attention↗