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PubMed2006

Opioid receptors in the nucleus accumbens regulate attentional learning in the blocking paradigm.

Fear learning depends on prediction error, or the discrepancy between the actual and expected outcome of a conditioning trial. These experiments used blocking and unblocking designs to study the role of opioid receptors in the nucleus accumbens (Acb) in predictive fear learning. Previous fear conditioning to a context blocked later fear conditioning to a conditioned stimulus (CS) in that context. Fear learning proceeded normally (i.e., unblocking occurred) if the CS signaled a more intense footshock than was used during previous context conditioning. Blocking and unblocking were mediated by Acb opioid receptors. Acb microinjections of a nonselective opioid receptor agonist prevented blocking, whereas a nonselective antagonist prevented unblocking. Examination of the associative mechanism for blocking and unblocking revealed that Acb opioid receptors mediate indirect predictive learning by controlling learned variations in attention. Mu-opioid and kappa-opioid receptors contribute to this learned regulation of attention because Acb microinjections of a mu-opioid receptor agonist impaired, whereas a kappa-opioid receptor agonist facilitated, blocking. Acb microinjections of a mu-opioid receptor antagonist also prevented unblocking. Microinjections of a delta-opioid receptor agonist or antagonist were without effect on blocking and unblocking. Our data show that the Acb mediates attentional selection between competing predictors of motivationally significant events to enable learning about the best predictor of such events at the expense of worse predictors. During fear learning, Acb mu-opioid receptors upregulate attention to conditioned stimuli that are predictive of shock, whereas kappa-opioid receptors downregulate attention to conditioned stimuli that are redundant or noninformative predictors of shock.

Analgesics, Opioid↗
PubMed2006

Description and evaluation of an innovative course on learning and study skills for the first year medical students.

The purpose of this study is to share educational structure and evaluation results of an innovative course on effective learning and study skills for the first year medical students. In Turkey, undergraduate medical education takes six years and each year nearly 5,000 high school graduates start medical schools. However, many students experience frustration and failure because of their lack in the learning and studying strategies. At the Ege University Faculty of Medicine, preclinical curriculum consists of the body function systems-based teaching blocks. Year one has three blocks. We implemented an effective learning and study skills course at the first and third blocks of the 2003-2004 curriculum. We evaluated the course by students' feedbacks derived from block questionnaires and students' homework performance analysis. At the first block questionnaire, out of 297, 163 students (54.8%) clearly stated that the course positively influenced their learning process. Structured analysis of the first block's students' homework showed that an average of 206 students (69.3%) can sufficiently describe their learning and studying approach, while 218 (73.4%) can identify the strengths and weaknesses of the curriculum. The average student scores were 74 +/- 10 and 68 +/- 11 out of 100 for first and third blocks, respectively. We interpreted these results as students enjoyed the course and learned the content. In conclusion, a course on effective learning and study skills is likely to assist first year medical students in improving their learning and adaptation to the school.

Clinical Competence↗
PubMed1996

Place learning and hippocampal synaptic plasticity in streptozotocin-induced diabetic rats.

Moderate impairment of learning and memory has been recognized as a complication of diabetes. The present study examined behavioral and electrophysiological measures of cerebral function in streptozotocin (STZ)-induced diabetic rats. Behavioral testing consisted of a spatial learning task in a water maze. Electrophysiological testing consisted of in vitro assessment of hippocampal long-term potentiation (LTP), an activity-dependent form of synaptic plasticity, which is believed to be related to the cellular mechanisms of learning and memory. Two experiments were performed: the first with severely hyperglycemic rats and the second with moderately hyperglycemic rats. Rats were tested in the water maze 11 weeks after induction of diabetes. Next, LTP was measured in vitro in trained animals. Both spatial learning and LTP expression in the CA1 field of the hippocampus were impaired in severely hyperglycemic rats as compared with nondiabetic controls. In contrast, spatial learning and hippocampal LTP were unaffected in moderately hyperglycemic rats. The association of alterations in hippocampal LTP with specific learning impairments has previously been reported in conditions other than diabetes. Our findings suggest that changes in LTP-like forms of synaptic plasticity in the hippocampus, and possibly in other cerebral structures, are involved in learning deficits in STZ-induced diabetes. The beneficial effect of moderate glycemic control on both place learning and hippocampal LTP supports the significance of the relation between these two parameters and indicates that the development of the observed deficits may be related to the level of glycemic control.

Animals↗
PubMed1986

Four-year-old children's visual attention in direct and observational learning.

The study was designed to compare direct learning (learning by performing) with observational learning (learning by observing) on a memory task that assessed 4-year-old children's selective attention. 17 pairs of kindergarteners of the same sex (aged 3 yr., 8 mo. to 4 yr., 4 mo.) participated in a central-incidental memory task. Data from a retention test indicated that the performers' mean central learning score was higher than their mean incidental score, while the observers showed no difference between their central and incidental learning scores, performers had a higher mean central learning score than observers. On the other hand, the frequency of the subjects' overt visual attention to the task in their learning phase was also counted. Both observers and performers showed high frequency of visual attention.

Attention↗
PubMed1990

Taste aversion learning in horses.

The ability of ponies to learn to avoid a relatively novel food associated with illness was tested in three situations: when illness occurred immediately after consuming a feed; when illness occurred 30 min after consuming a feed; and when illness was contingent upon eating one of three feeds offered simultaneously. Apomorphine was used to produce illness. The feeds associated with illness were corn, alfalfa pellets, sweet feed and a complete pelleted feed. The ponies learned to avoid all the fees except the complete feed when apomorphine injection immediately followed consumption of the feed. However, the ponies did not learn to avoid a feed if apomorphine was delayed 30 min after feed consumption. They could learn to avoid alfalfa pellets, but not corn, when these feeds were presented with the familiar "safe foods," oats and soybean meal. Ponies apparently are able to learn a taste aversion, but there were constraints on this learning ability. Under the conditions of this study, they did not learn to avoid a food that made them sick long after consumption of the food, and they had more difficulty learning to avoid highly palatable feeds.

Animal Feed↗
PubMed2005

Spatial context learning in visual search and change detection.

Humans conduct visual search more efficiently when the same display is presented for a second time, showing learning of repeated spatial contexts. In this study, we investigate spatial context learning in two tasks: visual search and change detection. In both tasks, we ask whether subjects learn to associate the target with the entire spatial layout of a repeated display (configural learning) or with individual distractor locations (nonconfigural learning). We show that nonconfigural learning results from visual search tasks, but not from change detection tasks. Furthermore, a spatial layout acquired in visual search tasks does not enhance change detection on the same display, whereas a spatial layout acquired in change detection tasks moderately enhances visual search. We suggest that although spatial context learning occurs in multiple tasks, the content of learning is, in part, task specific.

Adult↗
PubMed2001

When it does hurt to try: adult age differences in the effects of instructions on implicit pattern learning.

Trying to learn sometimes impairs implicit learning of artificial grammars and of control systems. We asked whether such negative effects of trying also occur in implicit learning of subtle sequential regularities and whether such effects vary with adult age. Young (n = 12, age = 20-23) and older (n = 24, age = 60-80) adults completed an alternating serial response time task in which predictable pattern events alternated with random ones in a visual/spatial display. Half of the participants were informed about the pattern and were instructed to try to discover it (intentional instructions), and half were not (incidental instructions). Age-related deficits in implicit learning occurred for both conditions. In addition, for the older group, but not for the younger one, intentional instructions impaired implicit pattern learning. This negative effect of trying to learn demonstrates another similarity among implicit learning tasks, supporting the view that some common processes underlie different forms of implicit learning.

Adolescent↗
PubMed2003

A knowledge-resonance (KRES) model of category learning.

This article introduces a connectionist model of category learning that takes into account the prior knowledge that people bring to new learning situations. In contrast to connectionist learning models that assume a feedforward network and learn by the delta rule or backpropagation, this model, the knowledge-resonance model, or KRES, employs a recurrent network with bidirectional symmetric connection whose weights are updated according to a contrastive Hebbian learning rule. We demonstrate that when prior knowledge is represented in the network, KRES accounts for a considerable range of empirical results regarding the effects of prior knowledge on category learning, including (1) the accelerated learning that occurs in the presence of knowledge, (2) the better learning in the presence of knowledge of category features that are not related to prior knowledge, (3) the reinterpretation of features with ambiguous interpretations in light of error-corrective feedback, and (4) the unlearning of prior knowledge when that knowledge is inappropriate in the context of a particular category.

Animals↗
PubMed2000

A functional relation between learning and organization in free recall.

It is well known that multitrial free recall is accompanied by increased organization of output over learning trials, even when the order of presentation is randomized. We compared the relation between learning and organization in 30 young and 30 older adults as they learned categorized materials to a criterion of 100% recall. The importance of this age manipulation was that it allowed us to examine, using two groups that differ significantly in their learning ability, whether organization and learning follow the same function. As was expected, older adults showed less organization on any given learning trial. However, when equated for degree of learning, the older adults showed approximately the same level of organization as the young. This finding suggests that the organization-learning relation remains invariant in the face of significant differences in participants' mnemonic abilities.

Adult↗
PubMed1993

Preferred learning styles and study strategies in a linguistically diverse baccalaureate nursing student population.

This study examined learning styles, learning and study strategies, and specific background variables (primary language, ethnic background, and length of time in the United States) in a multicultural and linguistically diverse baccalaureate nursing student population. Results revealed positive associations between English as a primary language and the learning strategy of self-study and negative associations with high anxiety levels. Length of time in the United States was positively correlated with the learning strategy of information-processing. Lower GPA scores reflected lower mean ratings on the composite scales of the Learning Styles Inventory (LSI) and Learning and Study Strategies Inventory (LASSI). The main predictor variables for GPA were English as a primary language, the learning strategies of information-processing and selecting main ideas, and the learning style of group study.

Adult↗
PubMed2005

The effect of a metacognitive intervention on approach to and self-regulation of learning in baccalaureate nursing students.

There is little empirical support in the nursing education literature related to the process of learning. This quasi-experimental study examined the effect of a metacognitive intervention (concept mapping) on approach to learning and self-regulation of learning in a sample of baccalaureate nursing students. Significant group differences were found in the concept mapping group, with an increase in deep approach to learning and adaptive control belief mean scores at the end of the semester. Students in the control group experienced a decrease in the deep approach to learning mean score and an increase in the surface approach to learning mean score at the end of the semester. Therefore, students who used concept mapping demonstrated an increase in deep approach to learning and the self-regulation of that learning, compared with students who did not use concept mapping. The results of this study provide empirical support for the use of concept mapping as a metacognitive intervention.

Adult↗
PubMed2003

[Social learning as an uncertainty-reduction strategy: an adaptationist approach].

Social learning is an effective mechanism to reduce uncertainty about environmental knowledge, helping individuals adopt an adaptive behavior in the environment at small cost. Although this is evident for learning about temporally stable targets (e.g., acquiring avoidance of toxic foods culturally), the functional value of social learning in a temporally unstable environment is less clear; knowledge acquired by social learning may be outdated. This paper addressed adaptive values of social learning in a non-stationary environment empirically. When individual learning about the non-stationary environment is costly, a hawk-dove-game-like equilibrium is expected to emerge in the population, where members who engage in costly individual learning and members who skip the information search and free-ride on other members' search efforts coexist at a stable ratio. Such a "producer-scrounger" structure should qualify effectiveness of social/cultural learning severely, especially "conformity bias" when using social information (Boyd & Richerson, 1985). We tested these predictions by an experiment implementing a non-stationary uncertain environment in a laboratory. The results supported our thesis. Implications of these findings and some future directions were discussed.

Adaptation, Psychological↗
PubMedDate not supplied

Learning styles and outcomes in clinical laboratory science.

OBJECTIVE: To compare two learning styles--reflective observation versus active experimentation--in terms of learning outcomes. DESIGN: The independent variable, student learning styles, was generally defined as styles determined by use of the Kolb's Learning Style Inventory. The styles were identified as either active experimentation or reflective observation. The dependent variables were learning outcomes that were determined by two methods: the average score on eight posttests scheduled at periodic intervals and a national certification examination score. SETTING: Clinical laboratory science education program at the University of Nebraska Medical Center in Omaha and at six clinical sites in other cities across Nebraska. PARTICIPANTS: Forty senior clinical laboratory science students enrolled in a baccalaureate degree program. MAIN OUTCOME MEASURES: Data analysis consisted of descriptive statistics, two-way analysis of variance, two-way analysis of covariance, and repeated measures analysis of variance. RESULTS: Results showed no significant difference between the students' examination scores based on learning styles. There was no significant difference in the pattern of the examination scores over the semester of learners who were active experimenters versus reflective observers. CONCLUSION: Results of the study generally did not support the conclusions of the earlier research; students' learning styles did not affect their examination scores. No pattern in the examination scored exists in the learning style groups.

Clinical Laboratory Techniques↗
PubMedDate not supplied

Sensorimotor skill learning in amnesia: additional evidence for the neural basis of nondeclarative memory.

We investigated sensorimotor skill learning, a form of nondeclarative (implicit) memory, in 28 subjects with declarative (explicit) memory defects caused by either mesial temporal (n = 15) or basal forebrain (n = 13) damage and in 66 normal control subjects. All 28 amnesics had normal learning of a rotor pursuit task. We also studied in detail the sensorimotor skill learning of patient Boswell. As a result of bilateral damage to both mesial and lateral aspects of the temporal lobes and to the basal forebrain, Boswell has one of the most severe impairments ever reported for learning of all types of declarative knowledge. Compared to matched controls, Boswell acquired and retained normally the skills associated with performing motor tasks. We conducted a long-term (2-year) followup study of Boswell's retention of the rotor pursuit task, and we found that he retained the skill as well as normal controls. Our study builds on previous work in the following respects: (1) It provides evidence, for the first time, that skill learning is normal in basal forebrain amnesics; (2) it shows that patient Boswell has normal learning and long-term retention of sensorimotor skills, in spite of his extensive damage; and (3) it offers additional evidence that mesial temporal lobe damage spares skill learning. These findings demonstrate unequivocally that sensorimotor skill learning does not require structures in mesial and lateral temporal regions nor in basal forebrain.

Adult↗
PubMed2000

Learning of visuomotor transformations for vectorial planning of reaching trajectories.

The planning of visually guided reaches is accomplished by independent specification of extent and direction. We investigated whether this separation of extent and direction planning for well practiced movements could be explained by differences in the adaptation to extent and directional errors during motor learning. We compared the time course and generalization of adaptation with two types of screen cursor transformation that altered the relationship between hand space and screen space. The first was a gain change that induced extent errors and required subjects to learn a new scaling factor. The second was a screen cursor rotation that induced directional errors and required subjects to learn new reference axes. Subjects learned a new scaling factor at the same rate when training with one or multiple target distances, whereas learning new reference axes took longer and was less complete when training with multiple compared with one target direction. After training to a single target, subjects were able to transfer learning of a new scaling factor to previously unvisited distances and directions. In contrast, generalization of rotation adaptation was incomplete; there was transfer across distances and arm configurations but not across directions. Learning a rotated reference frame only occurred after multiple target directions were sampled during training. These results suggest the separate processing of extent and directional errors by the brain and support the idea that reaching movements are planned as a hand-centered vector whose extent and direction are established via learning a scaling factor and reference axes.

Adaptation, Physiological↗
PubMed2001

Long-lasting cholinergic modulation underlies rule learning in rats.

We studied the role of acetylcholine (ACh) in creating learning-related long-lasting modifications in the rat cortex. Rats were trained to discriminate positive and negative cues in pairs of odors, until they demonstrated rule learning and entered a mode of high capability for learning of additional odors. We have previously reported that pyramidal neurons in olfactory (piriform) cortex from trained rats had reduced spike afterhyperpolarization (AHP) for 3 d after rule learning. In the present study we examined the mechanism underlying this long-lasting modification. The cholinergic agonist carbachol reduced both slow AHP and firing adaptation in neurons from pseudotrained rats, but had no effect on neurons from trained rats, suggesting pre-existing cholinergic effect. Intracellular application of the calcium chelator BAPTA abolished the difference in slow AHP and in adaptation between groups, suggesting that the difference resulted from reduction in the ACh-sensitive, Ca(2+)-dependent potassium current, I(AHP). At the behavioral level, application of the muscarinic blocker scopolamine before each training session delayed rule learning but had no effect on further acquisition of odor memory. We suggest that intense ACh activity during rule learning enhances neuronal excitability in the piriform cortex by reducing I(AHP) and that the effect outlasts the stage of rule learning, so that ACh activity is not crucial for further odor learning.

Acetylcholine↗
PubMed2001

Invariant object recognition in the visual system with error correction and temporal difference learning.

It has been proposed that invariant pattern recognition might be implemented using a learning rule that utilizes a trace of previous neural activity which, given the spatio-temporal continuity of the statistics of sensory input, is likely to be about the same object though with differing transforms in the short time scale. Recently, it has been demonstrated that a modified Hebbian rule which incorporates a trace of previous activity but no contribution from the current activity can offer substantially improved performance. In this paper we show how this rule can be related to error correction rules, and explore a number of error correction rules that can be applied to and can produce good invariant pattern recognition. An explicit relationship to temporal difference learning is then demonstrated, and from this further learning rules related to temporal difference learning are developed. This relationship to temporal difference learning allows us to begin to exploit established analyses of temporal difference learning to provide a theoretical framework for better understanding the operation and convergence properties of these learning rules, and more generally, of rules useful for learning invariant representations. The efficacy of these different rules for invariant object recognition is compared using VisNet, a hierarchical competitive network model of the operation of the visual system.

Learning↗
PubMed2001

Linking teaching approaches and learning styles: how can it help students?

Although limited, one study revealed that the preferred learning style for paramedic students is that of assimilator. Assimilators prefer a more passive/reflective role in the learning situation and tend to favor lectures with an emphasis on concepts, assigned readings, exams and assigned tasks. By increasing complexity and requiring more self-directed activities in your teaching approach, you are encouraging students (particularly the assimilators) to move from a role of dependence on you for facts and direction to a role in which they begin to 1) seek some knowledge on their own; 2) assume responsibility for analyzing potential solutions to problems; and 3) justify decisions. You should be able to document their progress toward independence through clinical and field evaluations by preceptors. Students should reach the point of competently assuming control of patient care for the majority of patients they encounter by the end of their field internship. Instructors should keep in mind that there is currently no consensus on a definition of learning styles, and different indicators identify different factors. Learning style inventory results, regardless of the instrument used, should not be a primary factor in decisions to alter curriculum approaches. However, although there is inconsistency in the data on its reliability and validity, and Kolb's LSI measures only certain factors, the results that are available seem significant enough to at least consider learning styles as one resource for adapting and sequencing our teaching methodologies. A learning-styles inventory administered to students at the beginning of a training program would provide faculty with the knowledge of the preferred learning style of that class. This knowledge could prove extremely helpful, not only in planning classroom activities, but also in developing approaches for remediating students experiencing difficulty in mastering the curriculum content. The more knowledge we have about our students, the greater our likelihood of success in reaching our ultimate goal of providing the best possible learning experience.

Emergency Medical Technicians↗

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