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Results for “Concept Formation”

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At least 19 recordsLinked to original sources
PubMed1979

Schematic concept formation: psychophysical analysis of early reading skill.

The relation between the perception of class structure and reading skill was studied within the context of a schematic concept-formation task. Computer generation techniques were utilized to construct visual pattern-classification problems with controlled levels of inter-class pattern similarity of class discrimination difficulty. Children with reading problems were less efficient in their ability to assign patterns to classes than were children without reading problems. It was possible to assess reliably individual subjects' reading skill on the basis of their ability to perform the task.

Child↗
PubMed1978

New concepts on formation of Brunn's nests and cysts in urinary tract mucosa.

To the present time, Brunn's nests have been conceived as being the result of pinching off of epithelial nests from urothelial buds. Mucosal cysts were considered to originate from Brunn's nests. In the present study, it was observed that under the influence of a strong stimulus of repair, the urothelial cells in the proximity of the focus of repair undergo numerous mitoses. The underlying connective tissue becomes loose, isolated cells of the lining urothelium "drop off" into the lamina propria in which they migrate as in a culture medium. There they multiply and form nests of cells at a distance from the lining urothelium. These migrating cells frequently have an early tendency to become arranged into cysts. Thus, during this process of repair urothelial cells behave temporarily as malignant cells.

Animals↗
PubMed1979

Influences of an analog of the neuropeptide ACTH 4--9 on mentally retarded adults.

In a double-blind procedure, 24 mentally retarded adults received 0 mg, 5mg, or 20 mg of an analog of the neuropeptide ACTH 4--9. Following treatment with peptide, the subjects were given the Trails B Test (from the Halstead-Reitan Neuropsychological Battery), the Peabody Picture Vocabulary test, the Benton Visual Retention Test, a concept-formation task, and a standard orienting sequence. The results of the behavioral tests suggested that attentional processes were enhanced in subjects treated with the peptide. The present study, in conjunction with another investigation using the neuropeptide ACTH/MSH 4--10 (Sandman, George, Walker, Nolan & Kastin, 1976), indicates that attentional deficits in mentally retarded adults, traditionally assumed to be irreversible, may be influenced by treatment with fragments of the neuropeptides ACTH and MSH.

Adrenocorticotropic Hormone↗
PubMed1977

Adaptive training and individual differences in perception.

Four types of training techniques were compared in the training of a perceptual concept-formation task. Adaptive training, a technique in which one parameter in the learning situation is varied so that the difficulty of a learning task remains constant for that individual, was compared to three intermediate approaches to training (self-adaptive, in which the trainees could control their own pace of learning by indicating when they felt they had mastered the problem, fixed sequence, and fixed task). The relationship between individual trainee's perceptual style and various stages of training was also investigated. Perceptual style was measured by the Hidden Figures Test, the Rod-and-frame Test, a Distracting Context Test, and a Cancellation Test. Results showed a definite (time to perform the task) advantage in favor of the adaptive training method. Fewer errors were committed under the self-adaptive approach, but the task completion time was significantly higher. Further analysis showed that for the adaptive-training group, measures of perceptual style could be used as predictors of future task success. No such relationship was found for other training techniques. In particular, field-independence appears to be important early in training but becomes increasingly less important, and for the final training criterion trials, is not predictive of performance. In contrast, the Distracting Contest Test-II, early in training, is not an important predictor but is an important predictor for the final criterion trials.

Adult↗
PubMedDate not supplied

[Arterosclerosis and its prevention. The problem and its natural controversy].

It scarcely has a glimpse about the knowledge of aterosclerosis nature. About preventive recommendations, it has not yet surpassed hypothetic level, but problem is in force and requires to prove hypothetic and theoretical models that have been proposed. Everything that has been said as preventive recommendations has arisen all kind of opinions that constitute the existent controversy. Discussion is composed by the diametrically adverse points of view, in spite of that they are refered to the same data. Positive aspect that can remain is to centralize the knowledge and to comprehend best the problem nature. Controversy is a part of the collective thinking process about the theme. Obviously no one researcher has the complete solution, neither it is a lonely person work. There are exposed at the work some details of the subjacent process implicit into the term of risk factors. In order to comprehend the controversy, it is necessary to take on account the process that has been followed for the concepts formation, by no one manner it can be taken with frivolity and less to under-value it. Most part of researches on the subject agree that infancy and youthfulness are the best ages to make intervene primary prevention. There are revised these concept's bases and it is concluded that it is necessary at our ambient to acquire own experience about the theme, but we have to be very cautious at the best resources' utilization that are to our disposition.

Age Factors↗
PubMed1977

Drinking practices and cognitive functioning.

The relationships between drinking practices and cognitive functioning were examined in a non-patient sample. Neither the amount of alcohol consumed over a lifetime nor current frequency of drinking occasions was significantly (ps greater than .05) correlated with cognitive test scores. However, the quantity of alcohol consumed per drinking occasion was inversely related to performance on tests of abstraction, adaptive abilities and concept formation. The results suggest that social drinking may have deleterious effects on cognitive processes.

Adult↗
PubMed1978

A model for non-resolvable ambiguities.

The dynamical behavior of the perception of ambiguous figures arising from the essentially nonresolvable ambiguity built in the figures themselves is analysed. Two main features of it are explored, the initial transient and the rhythmic alternation of inversions of perspective following it. The initial transient is envisaged in terms of a symmetry breaking disorder-order transformation induced by the "attention" of the observer. The rhythmic inversions of the ordered structures are classified by a model based on an ideally non linear decision equation for binary systems originally proposed to schematize the observed behavior of neurons. Finally it is suggested that the phenomena relative to the perception of ambiguous figures could represent the simplest ones among more complex situations arising in perception, in concept formation, in the sensing of emotion and in communication in general.

Humans↗
PubMed1979

Effects of amount of helplessness training and internal-external locus of control on mood and performance.

Based on Wortman and Brehm's integration of reactance theory with Seligman's model of learned helplessness, an investigation was conducted to examine the effects of amount of helplessness training and internal--external locus of control on subsequent task performance and on self-ratings of mood. Subjects were divided into "internal" and "external" groups and were then given either high, low, or no helplessness training on a series of concept-formation problems. After completing a mood checklist, all subjects worked on an anagram task presented as a second experiment by a second experimenter. The results revealed that internals exhibited greater performance decrements and reported greater depression under high helplessness than did externals. In the low helplessness conditions, internals tended to perform better than control subjects, while externals tended to perform worse than control subjects; low helplessness subjects also reported the highest levels of hostility. The results are discussed within the context of Wortman and Brehm's integration of reactance and learned helplessness theories.

Adjustment Disorders↗
PubMed1979

Visual classes and natural categories in the pigeon.

After being trained on an oak leaf pattern, pigeons responded to other oak leaf patterns but not to leaf patterns of other species. Thus, graphic variation among the instances of a species is "transparent" to the visual system. At this taxonomic level, concept formation is spontaneous rather than inductive. It is argued that such immediate generalization may be critical to the survival of the organism.

Animals↗
PubMed2026

Cognitive impairment as a manifestation of SPG7: case report.

Hereditary spastic paraplegia (HSP) is a group of genetic disorders caused by >80 genes that can be described as either pure or complex forms.We report a case of a patient with a complex form of SPG7 with significant cognitive impairment.A 42-year-old man presented with a 10-year history of dysarthria, 5 years of gait difficulties, and 3 years of cognitive symptoms. Neuropsychological analysis showed deficits involving speed of information processing, mental flexibility, ideational fluency, verbal concept formation, visual working memory, and visual-spatial perception. Next-generation sequencing on whole blood revealed 2 heterozygous pathogenic variants in SPG7 (c. 1049_1077del, p. Pro350Glnfs*36 and c. 1529C>T, p. Ala510Val).There are emerging reports of complex forms of SPG7 presenting with impairments in memory, executive dysfunction, language, visuospatial processing, social functioning, and emotional communication. In this report, we describe a complex SPG7 patient who underwent formal neuropsychological testing to assess cognitive status in depth. This revealed deficits in speed of processing, visuospatial working memory and perception, impaired non-verbal intellect, and overall lack of insight, which have not yet been described in the literature.

Cognitive impairment↗
PubMed1976

New concepts in the formation, regulation of release, and metabolism of parathyroid hormone.

New information has elucidated many of the biochemical pathways in the formation, release and metabolism of parathyroid hormone (PTH). The hormone is biosynthesized in the parathyroid cells from two distinct precursors, or prohormones, that are modified by specific enzymic cleavages during the synthesis and intracellular transport of the hormonal polypeptide. Release of the hormone from the gland inversely depends on the extracellular calcium concentration, but is regulated over a much narrower range of calcium concentration than was realized previously. This new information points to a pattern of regulation that is more appropriate for homeostasis than was the pattern indicated by earlier studies. The persistence of a basal level of PTH secretion, despite sustained hypercalcaemia, suggests a possible mechanism for the abnormal secretion seen in states of hyperparathyroidism. The discovery of a calium-dependent degradative pathway for PTH in the parathyroid cell indicates that changes in the turnover of PTH may be one means by which calcium regulates the amount of hormone available for secretion. Of the multiple immunoreactive forms of PTH present in the circulation of man and animals, the predominant form in blood appears to be a large biologically-inactive fragment consisting of the middle and carboxy two-thirds of the hormone sequence. At times, smaller biologically-active fragments of PTH may also appear in blood. Most circulating fragments of PTH probably arise from peripheral cleavage of the intact, secreted hormone in kidney and liver, but some forms of the hormone, including prohormones, may also be secreted from the parathyroid gland. The heterogeneity of circulating PTH and the concomitant uncertainties regarding its precise character have introduced difficulties in the interpretation of immunoassay measurements. A further delineation of the pathways and regulation of PTH biosynthesis, secretion and metabolism should lead to the development of more-specific immuno-assays and result in improved diagnosis and management of patients with disorders of the parathyroid glands.

Amino Acid Sequence↗
PubMedDate not supplied

The cerebrospinal fluid: current concepts of its formation.

Until recently it has been generally accepted that the choroid plexuses are the major source of the cerebrospinal fluid (CSF). However, data now indicate that significant contributions to the CSF are made at extrachoroidal sites. CSF production studies and 24Na transport studies in normal and plexectomized rhesus monkeys supportive of substantial extrachoroidal CSF formation will be presented. Although the exact mechanisms of CSF formation remain to be defined, ultrafiltration is probably involved to a considerable extent. Data indicative of a lymphatic-like role for the CSF will be considered.

Animals↗