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Results for “Conditioning, Operant”

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PubMed2003

Cooling blocks ITM and LTM formation and preserves memory.

In Lymnaea aerial respiratory behaviour can be operantly conditioned; snails learn not to perform this behaviour. Depending on the training procedure used, snails are competent to form either intermediate-term (ITM; lasting 1-3 h) or long-term (LTM; >4 h) memory. We found that cooling the snails for 1 h immediately after training was sufficient to block either ITM or LTM. Cooling snails for a similar period 10 or 15 min after cessation of training, failed to block ITM and LTM formation, respectively. Finally, we employed the cooling technique to extend both ITM and LTM. That is, cooling could prevent forgetting. Cooling extended LTM that normally persisted for 2 days to at least 8 days. These data are consistent with the hypothesis that forgetting is due to the learning and remembering of interfering events, and thus is an active process.

Animals↗

PubMedDate not supplied

Absolute and relative sensitivity of the scotopic system of rat: electroretinography and behavior.

The goal of the present study was to relate the dark and light-adapted flash sensitivity of the scotopic threshold response (STR) and rod b-wave of the electroretinogram (ERG) to behaviorally measured rod increment threshold responses. Small amplitudes of the dark-adapted STR and b-wave, the latter after application of NMDA, were found to increase in proportion to flash intensity. The value obtained for the sensitivity of the b-wave would be expected if signals from rods were summed linearly by the rod bipolar cell. The sensitivity of the STR could not be accounted for in terms of rod signal convergence as the source of this ERG component is still unknown. Increment threshold responses of rats were measured behaviorally in an operant conditioning chamber. At absolute threshold, on average I in 2400 rods were activated by the test flash. Comparison of the adaptive effects of background lights on behaviorally measured scotopic sensitivity and rod ERG sensitivity suggest that the increment threshold sensitivity of rat is regulated at three different sites in the retina.

Adaptation, Ocular↗

PubMed2001

Muscle learning therapy--efficacy of a biofeedback based protocol in treating work-related upper extremity disorders.

Work-related upper extremity disorders (WRUEDs) continue to present significant treatment and financial challenges to providers, employers, and insurers. This retrospective study reviews outcomes for 309 subjects who, between 1995 and 1999, were referred through the workers' compensation system for treatment of computer keyboard- and mouse-related WRUED injuries. The mean length of time from the recorded date of injury to the date of intake was 12.9 months. Subjects were offered a 12-visit course in muscle learning therapy (MLT). MLT is an operant conditioning program which uses surface electromyography (sEMG) to train injured workers to control their muscles during work activities. Patient response to therapy was obtained by a therapist-administered questionnaire during Visit 8 of 12. A group of 309 subjects, who had failed to respond to a previous course of therapy (typically physical therapy), reported significant improvements of pain in the neck, thorax, and upper extremities. Ninety six percent reported that they felt "more in control," 86% reported feeling "better overall," and 81% reported either "working the same and feeling better" or "working and accomplishing more." This study provides preliminary support for this approach and provides justification for controlled clinical trials in the future.

Adult↗

PubMed2003

Support and coronary heart disease: the importance of significant other responses.

In addition to the recognized benefits of social support, there is evidence across several health-related disorders suggesting that specific types of support can contribute to negative outcomes. Informed by theory and research examining the role of pain-related interpersonal interactions in the perpetuation of chronic pain, this study examined whether specific responses from significant others to expressions of coronary heart disease(CHD) related symptoms and incapacity are associated with level of symptoms, degree of disability, and depressive symptom severity among persons with symptomatic CHD. Forty-nine persons with CHD completed self-report questionnaires of the constructs of interest. Regression analyses revealed that degree of perceived solicitious responding to CHD symptoms was associated with increased symptom severity, disability, and depressive symptoms. Results are consistent with an operant-conditioning model and suggest that positive attention from significant others contingent on expressions of CHD symptoms may unwittingly serve to reinforce symptom occurrence and expression, concomitant disability, and emotional distress.

Activities of Daily Living↗

PubMed1993

Behavioral temperature regulation in the obese Zucker rat.

The behavioral thermoregulatory capability of lean (Fa/?) and obese (fa/fa) Zucker rats was investigated in an operant conditioning apparatus. Obese rats exposed to -9 degrees C leverpressed for heat significantly more than lean rats, and consequently received more exogenous heat. Despite this increased heat intake, obese and lean animals demonstrated equivalent increases in core temperature. These results suggest that the obese (fa/fa) Zucker rat is not acting on a lowered thermoregulatory set point and is capable of behaviorally thermoregulating to compensate for poor heat absorption and/or a defect in metabolic heat production.

Animals↗

PubMed1983

Behavior of rhesus monkeys during 28-day cycles of estrogen treatment.

Sixteen ovariectomized rhesus monkeys were paired, each with two males, during thirty-two 28-day periods during which they received one or more of the following schedules of daily injections: (a) different mixtures of estradiol benzoate, progesterone, and testosterone propionate (artificial menstrual cycles), (b) the doses of estradiol benzoate given in artificial cycles but without the other hormones (cyclic estradiol regimens), and (c) appropriate control treatments (625 one-hour behavioral tests). Hormone doses were adjusted to give plasma levels in the physiological range (335 blood samples). Measures of male sexual activity during artificial cycles and during cyclic estradiol regimens showed significant cyclic changes, but these changes were indistinguishable from each other. In four females studied in an operant conditioning paradigm, there was a midcycle dip in the times taken to obtain access to males during the cyclic estradiol regimens. The data indicated that the estrogen state of the female plays a preponderant role in determining the cyclic changes in the behavioral interactions of the pair independently of the effects of other ovarian hormones.

Animals↗

PubMed1997

Sex differences in effects of predictable and unpredictable footshock on fentanyl self-administration in rats.

An operant conditioning paradigm was used to examine effects of predictable and unpredictable footshock on oral fentanyl (50 micrograms/ml self-administration (SA) in 12 female and 12 male Wistar rats (Rattus norvegicus). Rats were tested for drug SA under a progressive ratio schedule with and without repeated predictable or unpredictable footshock over 8 weeks. Female rats consumed greater amounts of fentanyl than did male rats. Male rats exhibited greater withdrawal behaviors following naloxone challenge. Predictable footshock with repeated exposure (i.e., chronic stress) was accompanied by greater fentanyl SA than was unpredictable footshock, particularly for female rats. Corticosterone levels were positively correlated with fentanyl SA. Predictability of the stressor also had a greater effect on maintenance of fentanyl SA than it did on relapse to fentanyl SA. Results suggest that sex plays an important role in drug-taking behavior by rats.

Analgesics, Opioid↗

PubMed2003

Interval timing as an emergent learning property.

Interval timing in operant conditioning is the learned covariation of a temporal dependent measure such as wait time with a temporal independent variable such as fixed-interval duration. The dominant theories of interval timing all incorporate an explicit internal clock, or "pacemaker," despite its lack of independent evidence. The authors propose an alternative, pacemaker-free view that demonstrates that temporal discrimination can be explained by using only 2 assumptions: (a) variation and selection of responses through competition between reinforced behavior and all other, elicited, behaviors and (b) modulation of the strength of response competition by the memory for recent reinforcement. The model departs radically from existing timing models: It shows that temporal learning can emerge from a simple dynamic process that lacks a periodic time reference such as a pacemaker.

Conditioning, Operant↗

PubMed1987

Perceptual organization of acoustic stimuli by budgerigars (Melopsittacus undulatus): I. Pure tones.

A new combination of operant conditioning and psychophysical scaling procedures was used to study auditory perception in a small bird. In a same-different discrimination task, budgerigars learned to discriminate among pure tones that varied along one or more acoustic dimensions. Response latencies were used to generate a matrix of interstimulus similarities. Multidimensional scaling procedures were used to arrange these acoustic stimuli in a multidimensional space that supposedly reflects the bird's perceptual organization. For tones that varied in intensity, duration, and frequency simultaneously, budgerigars were much more sensitive to frequency changes. From a set of tones that varied only in intensity, it was possible to calculate the growth of loudness with intensity for the budgerigar. For tones that varied only in frequency, budgerigars showed evidence of an "acoustic fovea" for frequency change in the spectral region of 2-4 kHz. Budgerigars and humans also differed in their perceptual grouping of tone sequences that rise, fall, or remain constant in pitch. Surprisingly, budgerigars were much less responsive to pitch contour than were humans.

Animals↗

PubMed1987

Perceptual organization of acoustic stimuli by budgerigars (Melopsittacus undulatus): II. Vocal signals.

Operant conditioning and multidimensional scaling procedures were used to study auditory perception of complex sounds in the budgerigar. In a same-different discrimination task, budgerigars learned to discriminate among natural vocal signals. Multidimensional scaling procedures were used to arrange these complex acoustic stimuli in a two-dimensional space reflecting perceptual organization. Results show that budgerigars group vocal stimuli according to functional and acoustical categories. Studies with only contact calls show that birds also make within-category discriminations. The acoustic cues in contact calls most salient to budgerigars appear to be quite complex. There is a suggestion that the sex of the signaler may also be encoded in these calls. The results from budgerigars were compared with the results from humans tested on some of the same sets of complex sounds.

Animals↗

PubMed1993

Conspecific song perception in zebra finches (Taeniopygia guttata).

Adult male and female zebra finches (Taeniopygia guttata), previously trained with operant conditioning to discriminate between conspecific songs, were tested to determine their dependence on 2 properties of songs, the presence of song syllables and the temporal order of songs. The removal of song syllables disrupted discrimination performance but usually only if the stimulus was the bird's own song. All birds initially failed to identify reversed songs correctly, but males relearned discriminations with reversed songs in fewer trials than did females. The results suggest that there are 3 levels of song perception: a bird's own song, other males' songs as processed by males, and songs as processed by females. Each of these levels correlates with the known electrophysiological and neuroanatomical properties of the song system and with the natural history of song.

Animals↗

PubMed2000

Auditory scene analysis in estrildid finches (Taeniopygia guttata and Lonchura striata domestica): a species advantage for detection of conspecific song.

Operant-conditioning techniques were used to investigate the ability of zebra finches (Taeniopygia guttata) and Bengalese finches (Lonchura striata domestica) to detect a zebra finch or a Bengalese finch target song intermixed with other birdsongs. Sixteen birds were trained to respond to the presence of a particular target song, either of their own species (n = 8) or of another species (n = 8). The birds were able to learn a discrimination between song mixtures that contained a target song and song mixtures that did not, and they were able to maintain their response to the target song when it was mixed with novel songs. Zebra finches, but not Bengalese finches, learned the discrimination with a conspecific target more quickly and were worse at detecting a Bengalese finch in the presence of a conspecific song. The results indicate that selective attention to birdsongs within an auditory scene is related to their biological relevance.

Animals↗

PubMed2003

A gray seal's (Halichoerus grypus) responses to experimenter-given pointing and directional cues.

A gray seal (Halichoerus grypus) was trained to touch a target on its left or right by responding to pointing signals. The authors then tested whether the seal would be able to generalize spontaneously to altered signals. It responded correctly to center pointing and head turning, center upper body turning, and off-center pointing but not to head turning and eye movements alone. The seal also responded correctly to brief ipsilateral and contralateral points from center and lateral positions. Pointing gestures did not cause the seal to select an object placed centrally behind it. Like many animals in similar studies, this gray seal probably did not understand the referential character of these gestures but rather used signal generalization and experience from initial operant conditioning to solve these tasks.

Animals↗

PubMed2005

Characteristics of sound discrimination enhancement after sound exposure in adult rats.

The auditory perceptual capacity of adult rats was assessed with regard to performance during 2-sound-discriminative operant conditioning. If the animals were passively exposed to a sound stimulus before the conditioning, performance was improved (sound-exposure-enhanced discrimination [SED]). SED had a stimulus specificity that could not be predicted in terms of the cochleotopy. SED was obstructed by D-2-amino-5-phosphonovaleric acid, an antagonist of N-methyl-D-aspartate receptors, infused into the auditory cortex (AC). No evidence supported the hypothesis that SED was due to a change of attention or motivation or to interference in the association process (e.g., latent inhibition). These findings suggest that passive auditory experience can enhance the perceptual capacity of an adult rat's AC.

2-Amino-5-phosphonovalerate↗

PubMed1975

Escalation of aggression: experimental studies.

A finding commonly obtained in research using the Buss "aggression machine" is a main effect for trail blocks, indicating an escalation in shock intensity over trails. Theoretical explanations for this effect were tested in a modified verbal operant-conditioning situation. In Experiment 1, subjects could administer any of 10 levels of positive reinforcement to a "learner" for correct verbal responses or any of 10 levels of negative reinforcement to a learner for incorrect responses. Half of the subjects were required to begin with weak, half with strong, reinforcements. Results indicated that, regardless of condition, subjects gave more intense reinforcements as the learning trails progressed. Those who administered negative reinforcements devalued the learner relative to those who administered positive reinforcements. In Experiment 2, a role-playing procedure was used in which subjects administered either positive or negative reinforcements to a learner whose performance either did or did not improve over trials. Again, in all experimental groups, subjects administered increasingly intense reinforcements over trials. The results are interpreted as supporting a disinhibition theory of anti- and prosocial behavior.

Aggression↗

PubMed1980

Auditory intensity discrimination in blackbirds and pigeons.

Redwing blackbirds, brown-headed cowbirds, and pigeons were trained with operant conditioning techniques to respond to small increases in the intensity of pulsed tone trains at three frequencies: .5, 1.0, and 2.0 kHz. All three species produced similar intensity difference limens (DLs) at the frequencies tested. Intensity DLs decreased as sensation level (intensity level above absolute threshold) increased at all three frequencies, with the slopes of these sensation level functions being greatest at 2.0 kHz . The median intensity DLs at 50 dB sensation level were 3.3, 2.7, and 2.9 dB at .5, 1.0, and 2.0 kHz, respectively, averaged over the three species. Some subjects were also required to detect decreases in intensity. They produced intensity DLs two to three times larger than the DLs obtained when these same subjects were required to detect increases in intensity. Avian intensity DLs generally appear to be 1-2 dB higher than the DLs of those mammals that have been tested (rat, cat, monkey, humans).

Animals↗

PubMed1981

Amnesia for discrete events in rats with fornicotomies: effects of interference on spatial alternation performance.

Rats, one groups with fornicotomies, and another group with control operations, were trained in several versions of a bar-press, spatial alternation task. In free operant conditions the fornicotomized rats showed adequate alternation performance when the bars were relatively separated by placement either at the ends of an alley or at the ends of the arms of a T-maze, but they were impaired when the bars were adjacent. Also, the fornicotomized rats failed to alternate after interpolation of either baffles or a 10-sec delay in the stem, both of which manipulations resulted in intervening turning responses before each choice. A failure to discriminate memories of relevant, discrete events from those of similar, intervening events appears best to account for the results.

Animals↗

PubMed1975

Scotopic sensitivity in coyotes (Canis latrans).

The absolute scotopic limen for light intensity was measured for three 10-mo-old female coyotes. The methodology was similar to that used by Blough in determining psychophysical thresholds in pigeons. Three coyotes were operantly conditioned to depress one of two foot treadles, left or right, depending on the condition of the stimulus light. Scotopic adaptation curves for each coyote were generated. Nonlinear regression curves were then fitted to the raw data. The mean scotopic thresholds did not differ significantly. However, time to the curves' asymptotes did differ significantly for one of the coyotes. The adaptation curves showed a distinct rod-cone "break," and retinal histology confirmed that the coyote has a duplex retina with a preponderance of rods. In addition, electroretinographic analysis showed the relative contributions of rods and cones at various light intensities and indicated a rod-cone break at approximately 15 min. Scotopic spectral sensitivity curves were also generated. The coyotes' scotopic visual threshold is exceeded by the natural illumination available under many nocturnal conditions. The results are discussed in relation to the ecology of the species.

Animals↗