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PubMed2001

Reward-related neuronal activities in basal ganglia of domestic chicks.

We aimed to reveal what is coded in the basal ganglia of domestic chicks. In the water-reinforced 'go' task, chicks learned to peck selectively at a colored bead in order to obtain a drop of water. Out of 38 units obtained, seven showed excitatory activities specifically during the reward period. In the food-reinforced go/no-go task, chicks learned to discriminate two colors to obtain mash food after a delay period. They also learned to ignore another color, which was not associated with a reward. Out of 27 units obtained, four showed excitatory activities during the cue period, specifically when a food reward was anticipated. LPO neurons may code qualities of the obtained rewards, and also chick's anticipation of the forthcoming rewards.

Action Potentials↗
PubMed1994

Reinforcement effects of Boschniakia rossica on discrimination learning in cholinergic lesions of rats.

The dried herb or stem of Boschniakia rossica (Boschniakiae Herba) has been used as an antisenile agent in the Jilin Province of China. To elucidate the effects of Boschniakiae Herba on decreased learning ability and memory weakness, a 50% ethanol extract of Boschniakiae Herba was administered to rats whose nucleus basalis of Meynert had been destroyed by the injection of ibotenic acid. This administration showed a significant improvement in the decrease of the ratio of correct responses caused by destruction of the nucleus basalis of Meynert. These results suggest that B. rossica would be therapeutic in senility.

Animals↗
PubMed2004

Practicing effectively in today's health system: teaching systems-based care.

BACKGROUND AND OBJECTIVES: The Institute of Medicine and the new Accreditation Council for Graduate Medical Education General Essentials have focused attention on the Undergraduate Medical Education for the 21st Century (UME-21) core content area of systems-based care. Through teaching systems-based care, medical students can learn how physicians effectively deliver and coordinate care within the health system. While medical students can be introduced to the organization, financing, and delivery of the health care system through lectures, the principles and practice of systems-based care must be reinforced through structured learning experiences during the clinical (ie, third and fourth) years. The purpose of this article is to define the undergraduate clinical content and experiences in systems-based care offered by the eight UME-21 partner schools. METHODS: The eight partner UME-21 schools exposed third- and fourth-year medical students to a variety of clinical experiences outside the traditional teaching hospital in such settings as physician offices, skilled nursing facilities, the patient's home, hospice, and public health departments. They also taught systems-based care skills such as care coordination, performance assessment, and quality improvement. RESULTS: Based on surveys of graduating students, the UME-21 programs were successful in exposing students to the aforementioned topics, though there was variability among schools. DISCUSSION: The experiences of the UME-21 schools in teaching about systems-based care, as discussed in this paper, may be useful to those involved in medical school curricula planning.

Clinical Clerkship↗
PubMed2000

Dorsal hippocampal function in unreinforced spatial learning.

This study examined learning about the spatial environment by rats during a single 10 min period of exploration on an eight-arm radial maze. Because no specific behaviors were learned during this procedure, the existence of learned spatial information was inferred from its retarding effect on subsequent conditioned cue preference (CCP) learning on the same maze. Previous experiments have shown that this form of spatial learning, measured in this way, requires an intact fimbriafornix and functional N-methyl-D-aspartate receptors. However, in the present experiments, large neurotoxic lesions of the dorsal hippocampus that impaired win-shift learning failed to eliminate the retarding effect of exploration on CCP learning. This result was obtained in three independent replications. These findings fail to confirm the hypothesis that the hippocampus is involved in spatial learning when that learning occurs in the absence of reinforcers and does not produce any specific learned behaviors. Previous work showed that this form of "pure" spatial learning requires an intact fimbria-fornix for acquisition but not for expression; the present findings suggest that the hippocampus is not required for either of these processes. The fimbria-fornix may interact with other temporal lobe structures in mediating this form of learning. The function of the hippocampus may be limited in some way to situations that involve reinforcers and/or situations in which specific behaviors are learned.

Animals↗
PubMed1995

Making a place for teaching about family violence in medical school.

Although family violence is a common cause of patients' problems, it has not yet received sufficient attention in medical school curricula. There are several possible reasons for this delay, including the fact that teaching about family violence is complicated because there are no "quick fix" interventions, the approaches are often complex and multidisciplinary, and there may be limited resources for response in many communities. The author offers a variety of suggestions for incorporating family violence topics in the medical school curriculum, such as: (1) expose students to information about family violence in their preclinical training, and integrate family violence issues into clinical instruction (several examples are given); (2) use problem-based teaching formats when possible, since these lend themselves well to the integration of family violence issues into case presentations; (3) enrich the curriculum by the participation of a variety of non-MD experts who deal with family violence issues, and take students out of the classroom to shelters and other relevant locations; (4) teach a prevention-oriented approach, just as is taught for the areas of smoking, seat belt use, weight control, etc.; (5) use standardized patients, interactive computer-based learning, and other innovative methodologies to help preclinical students perfect their interviewing and examination skills; (6) during the clinical years, include violence as part of the differential diagnosis of common medical complaints; (7) give attention to the education of residents for consistent teaching and reinforcement of principles learned in medical school, and integrate family violence education into the entire continuum of physicians' education; (8) build appropriate expectations into accreditation requirements and into medical licensing and specialty certifying examinations.(ABSTRACT TRUNCATED AT 250 WORDS)

Accreditation↗
PubMedDate not supplied

[Excess dietary arginine inhibits the development of the food-acquisition habit in white rats].

Behavioural effects of NO precursor L-arginine (Arg) were studied. Arg was shown to impair place learning with food reinforcement in the maze task. Arg was introduced per os immediately after the training session, i.e., 24 hours prior to the next session in doses of 50, 100 and 250 mg/kg. Intake of Arg in the dose of 100 mg/kg induced the most effective learning inhibition. Special tests demonstrated that Arg in the applied doses did not influence food motivation. Analysis of Arg effects suggests that the observed behavioural changes are probably due to the excess NO synthesis from Arg in brain tissues which, in turn, may result in cell damage.

Animals↗
PubMed1999

No evidence for olfactory blocking in honeybee classical conditioning

We use binary odorant compounds to investigate 'blocking' in honeybees which learn to associate an odorant (A-D) with a sucrose reward as the reinforcer (+). 'Blocking' means that learning about a stimulus B is reduced when trained in compound with a stimulus A that has previously been trained alone. Thus, reinforcement of B in these circumstances is not sufficient to induce learning. Such blocking is a frequently observed phenomenon in vertebrate learning and has also recently been reported in honeybee olfactory learning. To explain blocking, current models of conditioning include cognition-like concepts of attention or expectation which, consequently, seem also to apply to honeybees. Here, we first reproduce a blocking-like effect in an experimental design taken from the literature. We identify two confounding variables in that design and experimentally demonstrate their potential to support a blocking-like effect. After eliminating these confounding variables using a series of different training procedures, the blocking-like effect disappeared. Thus, convincing evidence for blocking in honeybee classical conditioning is at present lacking. This casts doubt on the applicability of cognition-like concepts to honeybees.

Journal Article↗
PubMed1976

Comparison of nonretarded and mentally retarded children on tasks involving direct and rule-governed imitation.

The influence of intellectual level and social reinforcement on imitation learning was examined. Tasks involving direct and rule-governed imitation of a mode were presented to 20 mentally retarded and 20 nonretarded children. The children within each group were randomly assigned to either an affective ("good-fine") or an informative ("correct-right") social reinforcement condition. Reinforcement, administered on a fixed ration (FR4) schedule, was contingent on the child's imitative behavior. A multivariate analysis of variance showed that both the Population X Reinforcement Type interaction and the Reinforcement main effect were significant. Univariate follow-up tests showed that only rule-governed imitation contributed significantly to the multivariate effects. Analysis of simple effects indicated that retarded children performed optimally under affective reinforcement, while the nonretarded children performed highest under informative reinforcement.

Adolescent↗
PubMed2003

Acetylcholine actions in the dorsomedial striatum support the flexible shifting of response patterns.

There is accumulating evidence that the dorsomedial striatum plays a significant role in the learning of a new response pattern and the inhibiting of old response patterns when conditions demand a shift in strategies. This paper proposes that activity of cholinergic neurons in the dorsomedial striatum is critical for enabling behavioral flexibility when there is a change in task contingencies. Recent experimental findings are provided supporting this idea. Measuring acetylcholine efflux from the dorsomedial striatum during the acquisition and reversal learning of a spatial discrimination shows that acetylcholine efflux selectively increases during reversal learning as a rat begins to learn a newly reinforced spatial location, but returns to near basal levels when a rat reliably executes the new choice pattern. Experimental findings are also described indicating that the blockade of muscarinic cholinergic receptors in the dorsomedial striatum does not impair acquisition of an egocentric response discrimination, but impairs reversal learning of an egocentric response discrimination. Based on these results, increased cholinergic activity at muscarinic receptors is part of a neurochemical process in the dorsomedial striatum that allows inhibition of a previously relevant response pattern while learning a new response pattern. In situations that demand behavioral flexibility, muscarinic cholinergic activity in the dorsomedial striatum may directly influence corticostriatal plasticity to produce changes in response patterns.

Acetylcholine↗
PubMed2006

Crew resource management: applications in healthcare organizations.

Healthcare organizations continue their struggle to establish a culture of open communication and collaboration. Lessons are learned from the aviation industry, which long ago acknowledged that most errors were the result of poor communication and coordination rather than individual mistakes. The author presents a review of how some healthcare organizations have successfully adopted aviation's curriculum called Crew Resource Management, which promotes and reinforces the conscious, learned team behaviors of cooperation, coordination, and sharing.

Aviation↗
PubMed2006

Effects of dextromethorphan on rats' acquisition of responding with delayed reinforcement.

Separate groups of 16 rats received 0, 40, 60, or 80 mg/kg dextromethorphan prior to a 2-h response-acquisition session during which responses on one lever produced food (reinforcement lever, RL, responses) after a 15-s resetting delay and responses on the other lever cancelled food deliveries earned by RL responses, but otherwise had no programmed consequences. When compared to the 0 mg/kg dose, the 40, 60, and 80 mg/kg doses significantly decreased the latency to the tenth RL response, which has been used previously as an index of response acquisition [Pallares, MA, Nadal, RA, Silvestro, JS, Ferre, NS. Effects of ketamine, a noncompetitive NMDA antagonist, on the acquisition of the lever-press response in rats. Physio Behav 1995; 57:389-392.]. Only the 80 mg/kg dose, however, significantly reduced the total number of food pellets earned, the total number of RL responses, or the total number of rats that met the criterion for response acquisition. The present results indicate that dextromethorphan can disrupt initial response acquisition (i.e., learning) with positive reinforcement, although the dose that did so depended on the measure used to index performance. Moreover, the effects of the drug did not appear to reflect specific learning impairment, but rather more general disruption of behavior.

Analgesics, Opioid↗