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At least 541 records · Page 30Linked to original sources
PubMed1999

Goal-specific influences on the representation of spatial perspective.

In two experiments, subjects learned an unfamiliar campus environment, either by studying a map or by navigating. During acquisition, the subjects had one of two spatial goals: to learn the layout of the building (survey goal) or to learn the fastest routes between locations (route goal). Spatial memory was tested with several tasks, some assessing survey perspective processing and some assessing route perspective processing. Results indicate multiple influences on the representation of spatial perspective. Learning condition influenced performance. Individuals studying maps gave more accurate responses to some survey perspective tasks, whereas individuals navigating gave more accurate responses to some route perspective tasks. Spatial goals also influenced performance. Having a route goal enhanced performance on route perspective tasks; having a survey goal enhanced performance on survey perspective tasks. These findings are discussed in the context of research indicating flexibility when processing spatial perspective. Individuals can use spatial information from different perspectives, often doing so in a goal-directed manner.

Goals↗
PubMed2000

[Placebo effects and adverse effects in clinical trials].

BACKGROUND: It is well known that placebos evoke a variety of effects in the human body. It is less known that placebo medication can produce adverse drug reactions (ADRs). METHOD: The efficacy and, as the main topic, the tolerability were investigated from an international clinical data pool on placebo-controlled randomized multicenter studies of 5 different groups of indications. The therapeutic areas analyzed were neuropsychiatry (nimodipine, ipsapirone), cardiology (nisoldipine), metabolism (acarbose) and gastroenterology (hydrotalcit). RESULTS: The placebo efficacy was evident and varied not only in comparison to 5 indication groups analyzed, but also within them. Placebo showed for example hardly an effect on the symptomatology of stroke patients with a severe neurological deficit in comparison to verum while there was a 50% improvement in symptoms following placebo application in patients with a mild stroke. In angina patients exercise tolerance increased under placebo by 10% (time to onset of ST segment depression and symptoms of angina) while verum showed a 22% improvement. In diabetes placebo had no effect as compared to baseline and to a verum on blood glucose and HbA1C. ADRs could be observed under placebo treatment. The frequency and kind of placebo-induced ADRs varied also between the indication groups, i.e. typical CV side-effects were observed in CV controls. The placebo ADR profile was similar to the reference drug also. Some ADRs were reported even more frequently under placebo than under verum, like "dry mouth" in patients with general anxiety status. CONCLUSIONS: Placebo therapy is frequently effective and is not a "non-therapy". Placebo effects can be shown only by direct comparison with a "non-therapy". A placebo therapy is frequently accompanied by adverse drug reactions (ADRs) just as a verum therapy. Placebo ADRs are frequently illness- and verum-specific. Effects and ADRs of placebo therapy must be known, to judge the effect of verum medication in controlled clinical trials. The mechanisms of placebo effects are manifold (e.g. endorphine release, conditioned learning). Since placebo therapy outside of evidence-based medicine (use of drugs without proven efficacy = pseudoplacebos) may potentially also cause serious side effects, the use may not only be useless but also harmful.

Adverse Drug Reaction Reporting Systems↗
PubMed2001

[Effect of the configuration of a route on distance perception].

Numerous studies have been carried out to investigate the knowledge of route distance in environmental space. Evidence suggests that the knowledge of distance is influenced by the environmental features and structures of the route. The purpose of this study was to investigate the factors that affect this knowledge. In particular, the aim was to determine the role of the structure versus that of characteristic environmental features along the route. In two experiments, it was found that the knowledge of distance was not affected by the structure alone. Rather it was determined by the environmental features along the route. Participants seem to infer the environmental distance between two locations indirectly using successively perceived and stored retrievable features. It could be shown in a third experiment that in an intentional learning condition--in contrast to an incidental condition--, the number of environmental features does not seem to influence distance knowledge. In this condition, a direct retrieval of information appears to be possible. The experiments took place in a virtual environment.

Adult↗
PubMed2005

Smart tutor: a pilot study of a novel adaptive simulation environment.

Computer-based learning environments create the possibility of dynamic adaptation to address learner capabilities and user performance. Software algorithms, code-named Smart Tutor, for motor skill learning were developed and applied to an abstract environment for laparoscopic surgery (RapidFire). Smart Tutor dynamically adjusts the environment to minimize frustration and optimize learning conditions for all learners. This study compared the first generation RapidFire / Smart Tutor (RF / ST) to the Minimal Invasive Surgery Trainer Virtual Reality (MIST VR) system for laparoscopic performance improvement and level of frustration. Two groups of novice laparoscopic learners were assessed by pre- and post- training paper cutting exercise and subjective surveys. Users of both systems showed improvement of laparoscopic skills as measured by the paper cutting exercises. No differences were shown between groups for level of improvement. However, a significant difference was seen in the subjective ratings on the post-training survey with less frustration for the RF / ST training group. Important information was acquired for refinements of the Smart Tutor algorithms.

Clinical Competence↗
PubMed2006

Learning by operant conditioning as a nonlinear self-organized process.

Responses of individuals have been rewarded in fixed ratio operant conditioning experiments throughout the last 5 years. The long numerical series of performance rates so obtained have been analyzed by using Fourier spectra, obtaining 1/f noise, and wavelet techniques for the analysis of local variability. These techniques reveal that the evolution of data in each individual is nonlinear but it fluctuates showing self-organized patterns in successive time scales, which leads to a long term logarithmic growth. Based on these observations a model has been developed. It can simulate with a great accuracy the rate of response exhibited by our subjects in all time scales.

Conditioning, Operant↗
PubMed1978

[Behavioral approach and community health.].

According to the behavioural approach, man is the product of his interaction with the environment. Normal as well as pathological behaviours are seen as the result of learning. Even individual subjectivity is perceived as a collection of internal behaviours responding to the same laws as overt behaviour. The therapeutic intervention consists therefore in the restructuring of learning conditions so as to eliminate problem behaviours from the individual's repertoire, and to replace them with more adapted behaviours. The approach does not, however, provide a definition of adaptation. The latter is a value judgement, made by society or the interventive agent, with respect to the individual's behaviour. Serious ethical problems can be posed and the interventive agent must take them into consideration. At the level of intervention in community health the behavioural approach suggests the use of milieu ressources to settle individual problems. Therefore the consultant becomes an educator and a planner in resource-utilization rather than a "therapist" in the traditional sense of the term>> This approach provides very powerful methods of action at the level of primary and tertiary prevention and of evaluation of interventive success.

English Abstract↗
PubMed1990

Dynamic infrared functional mapping of the cerebral cortex.

Although many neuroimaging methods (computer tomography, H+ and isotope clearance, [14C]deoxyglucose utilization, potential-sensitive dyes, electroencephalogram and magnetoencephalogram-mapping, nuclear magnetic resonance tomography, single photon emission computer tomography, and positron emission tomography) are now being used to map brain structure and function, there still exists a need for a new approach that is functional, dynamic, remote, and noninvasive, and that also has reasonable sensitivity and spatial and temporal resolution. Such a method is described here. Thermoencephaloscopy (TES), based on thermovision and digital image processing techniques, is a method of neuroimaging consisting of recording through the intact skull the very weak changes in infrared radiation that are connected with brain activity. The parameters of the method are: temperature sensitivity of 0.002 degrees C, instrumental spatial resolution of 70 microns pixel-1, and instrumental temporal resolution of 40 ms (enabling up to twenty-five maps to be produced per second). The distribution over the rat cerebral cortex of local, multiple, and modally and regionally specific thermoresponses to various sensory stimuli, direct cortical stimulation, and associative learning (conditioning), have been studied, as well as the spreading of thermowaves over the brain cortex. The underlying mechanisms which form the basis of the technique of TES, such as joule heating, local changes in brain metabolism and local cerebral blood flow, as well as the formation of thermodipoles, are discussed.

Animals↗
PubMed1978

[Psychotherapy: present state and developmental trends (author's transl)].

Psychotherapeutic theories and techniques are multiplying explosively. However, the newer developments are reducible to a few basic concepts, namely 1. training, learning, conditioning and information, 2. suggestion, 3. persuasion, 4. counselling, 5. insight (making conscious), 6. group-effects, 7. cartharsis, ecstasis and acting-out. In the present situation a therapeutic schedule based entirely on methods and theories is no longer acceptable and has been replaced by a patient-centred approach, i.e. the method is chosen on a pluralistic basis according to optimum fulfilment of the requirements of patient, therapist and institution. Apart from psychotherapy in the narrower sense, a psychotherapeutic attitude is recommended as an essential method of secondary prevention in all health and social services.

Austria↗
PubMed1987

Effects of word fragment completion on free recall. A selective improvement of older adults.

Younger adults (mean age 20.7 years), 73-year-olds, and 82-year-olds studied words and words with two missing letters that had to be completed (word fragments) under incidental learning conditions. Results from an unexpected free recall test showed that the 82-year-olds recalled significantly more word fragments than words, whereas the 73-year-olds showed a slight improvement in the same direction. The younger adults, on the other hand, did not benefit from the additional encoding activity of the word fragment completion, although they showed a higher level of recall performance than the elderly groups for both encoding conditions. It is suggested that older adults may need the attentional guidance provided by the problem-solving demands of word fragment completion to perform maximally in this situation, whereas younger adults, because of a superior ability for self-initiated recoding operations, are less dependent on this form of cognitive support.

Adult↗
PubMed1979

[Possibilities and limits for palsied children in the general polytechnical school (author's transl)].

Some children with cerebral palsy attend the ten-form general polytechnical school. To this end, several prerequisites have to be fulfilled and other essential arrangements to be developed in cooperation with specially trained teachers. The learning conditions have to be fitted to the improving abilities of children during the educational process. Factors of influence and cooperation modes are discussed.

Adolescent↗
PubMed1993

Laparoscopic antireflux repair and myotomy.

Since 1991, the techniques of endosurgical antireflux repair and myotomy have been developed for the treatment of gastroesophageal reflux disease and esophageal motility disorders. The principles of open surgery for the treatment of these conditions learned over several decades should be incorporated into minimally invasive approaches. Moreover, proper patient evaluation and selection are critical to the success of these procedures. This paper describes the technical aspects of endosurgical antireflux repair and myotomy.

Endoscopes↗
PubMed1995

Xinyinqin: a computer-based heart sound simulator.

"Xinyinqin" is the Chinese phoneticized name of the Heart Sound Simulator (HSS). The "qin" in "Xinyinqin" is the Chinese name of a category of musical instruments, which means that the operation of HSS is very convenient--like playing an electric piano with the keys. HSS is connected to the GAME I/O of an Apple microcomputer. The generation of sound is controlled by a program. Xinyinqin is used as a teaching aid of Diagnostics. It has been applied in teaching for three years. In this demonstration we will introduce the following functions of HSS: 1) The main program has two modules. The first one is the heart auscultation training module. HSS can output a heart sound selected by the student. Another program module is used to test the student's learning condition. The computer can randomly simulate a certain heart sound and ask the student to name it. The computer gives the student's answer an assessment: "correct" or "incorrect." When the answer is incorrect, the computer will output that heart sound again for the student to listen to; this process is repeated until she correctly identifies it. 2) The program is convenient to use and easy to control. By pressing the S key, it is able to output a slow heart rate until the student can clearly identify the rhythm. The heart rate, like the actual rate of a patient, can then be restored by hitting any key. By pressing the SPACE BAR, the heart sound output can be stopped to allow the teacher to explain something to the student. The teacher can resume playing the heart sound again by hitting any key; she can also change the content of the training by hitting RETURN key. In the future, we plan to simulate more heart sounds and incorporate relevant graphs.

Computer Simulation↗
PubMed1976

Behavior modification: a perspective.

Behavior modification is an approach for changing behavior based on a preliminary study of the individual. Behavior change is attempted once the individual's learning characteristics and the identification of the optimal learning conditions for the learner have been analyzed. The ability to analyze systematically and to develop behavior-environment relationships also brings a responsibility to the user to understand and master the principles and procedures of behavior modification. This article basically ignores the issue of selecting broad treatment goals and the authority of clinicians or teachers to work actively toward achieving these goals. The principal focus is to provide a perspective on the evaluation and use of behavior modification programs based on their conceptual and procedural foundations. Criticisms and the misuse of behavior modification programs are included as well as a set of guidelines for evaluating and developing effective ones.

Behavior Therapy↗
PubMedDate not supplied

A comparison of latent inhibition and learned irrelevance pre-exposure effects in rabbit and human eyeblink conditioning.

The learning of an association between a CS and a US can be retarded by unreinforced presentations of the CS alone (termed latent inhibition or LI) or by un-correlated presentations of the CS and US (termed learned irrelevance or LIRR). In rabbit eyeblink conditioning, there have been some recent failures to replicate LI. LIRR has been hypothesized as producing a stronger retardation effect than LI based on both empirical studies and computational models. In the work presented here, we examined the relative strength of LI and LIRR in eyeblink conditioning in rabbits and humans. In both species, a number of preexposure trials sufficient to produce LIRR failed to produce LI (Experiments 1 & 3). Doubling the number of CS pre-exposures did produce LI in rabbits (Experiment 2), but not in humans (Experiment 4). LI was demonstrated in humans only after manipulations including an increased inter-trial interval or ITI (Experiment 5). Overall, it appears that LIRR is a more easily producible pre-exposure retardation effect than LI for eyeblink conditioning in both rabbits and humans. Several theoretical mechanisms for LI including the conditioned attention theory, stimulus compression, novelty, and the switching theory are discussed as possible explanations for the differences between LIRR and LI. Overall, future work involving testing the neural substrates of pre-exposure effects may benefit from the use of LIRR rather than LI.

Adolescent↗
PubMed1996

Context and Pavlovian conditioning.

Procedurally, learning has to occur in a context. Several lines of evidence suggest that contextual stimuli actively affect learning and expression of the conditional response. The experimental context can become associated with the unconditional stimulus (US), especially when the US is presented in a context in the absence of a discrete conditional stimulus (CS). Moreover, context can modulate CS-US associations. Finally, it appears that context can become associated with the CS when it is presented before the CS-US training. The purpose of the present paper is to review some of the relevant literature that considers the context as an important feature of Pavlovian conditioning and to discuss some of the main learning theories that incorporate the context into their theoretical framework. The paper starts by mentioning historical positions that considered context an important variable in conditioning and then describes how the approach to contextual conditioning changed with the modern study of Pavlovian conditioning. Various forms of measurement of context conditioning are presented and the associative strength attached to context in several experimental paradigms is examined. The possible functions that context may acquire during conditioning are pointed out and related to major learning theories. Moreover, the effect of certain neurological manipulations on context conditioning is presented and these results are discussed in terms of possible functions that the context might acquire during Pavlovian conditioning. It is concluded that contextual stimuli acquire different functions during normal conditioning. A procedure in which animals are exposed to an aversive US immediately after they are placed in the experimental context is suggested as a useful control for the study of context conditioning.

Animals↗
PubMed2000

c-Fos induction in response to saccharin after taste aversion learning depends on conditioning method.

Increases in c-Fos-like immunoreactivity (FLI) in the intermediate nucleus of the solitary tract (iNTS) have been seen consistently as a correlate of the expression of a conditioned taste aversion (CTA) when conditioning occurs using taste delivery through intraoral (I/O) infusions. The present study examined whether a similar FLI response would occur when conditioning was accomplished by presenting the taste solution in a bottle. I/O and bottle methods generated aversions that were comparable, when judged by the behavioral response of solution rejection. However, elevations in FLI were seen only in animals conditioned with the I/O method. This finding adds to evidence that the neural pathways underlying CTA learning differ as a function of the type of conditioning method used.

Administration, Oral↗
PubMed2004

Cooperation in the iterated prisoner's dilemma is learned by operant conditioning mechanisms.

The prisoner's dilemma (PD) is the leading metaphor for the evolution of cooperative behavior in populations of selfish agents. Although cooperation in the iterated prisoner's dilemma (IPD) has been studied for over twenty years, most of this research has been focused on strategies that involve nonlearned behavior. Another approach is to suppose that players' selection of the preferred reply might be enforced in the same way as feeding animals track the best way to feed in changing nonstationary environments. Learning mechanisms such as operant conditioning enable animals to acquire relevant characteristics of their environment in order to get reinforcements and to avoid punishments. In this study, the role of operant conditioning in the learning of cooperation was evaluated in the PD. We found that operant mechanisms allow the learning of IPD play against other strategies. When random moves are allowed in the game, the operant learning model showed low sensitivity. On the basis of this evidence, it is suggested that operant learning might be involved in reciprocal altruism.

Animals↗