Threshold Hypothesis: Fact or Artifact?

ERIC Educational Resources Information Center

Karwowski, Maciej; Gralewski, Jacek

2013-01-01

The threshold hypothesis (TH) assumes the existence of complex relations between creative abilities and intelligence: linear associations below 120 points of IQ and weaker or lack of associations above the threshold. However, diverse results have been obtained over the last six decades--some confirmed the hypothesis and some rejected it. In this…

An Investigation of Factors That Influence the Hypothesis Generation Ability of Students in School- Based Agricultural Education Programs When Troubleshooting Small Gasoline Engines

ERIC Educational Resources Information Center

Blackburn, J. Joey; Robinson, J. Shane

2017-01-01

The purpose of this study was to determine if selected factors influenced the ability of students in school-based agricultural education programs to generate a correct hypothesis when troubleshooting small gasoline engines. Variables of interest included students' cognitive style, age, GPA, and content knowledge in small gasoline engines. Kirton's…

Sensory discrimination and intelligence: testing Spearman's other hypothesis.

PubMed

Deary, Ian J; Bell, P Joseph; Bell, Andrew J; Campbell, Mary L; Fazal, Nicola D

2004-01-01

At the centenary of Spearman's seminal 1904 article, his general intelligence hypothesis remains one of the most influential in psychology. Less well known is the article's other hypothesis that there is "a correspondence between what may provisionally be called 'General Discrimination' and 'General Intelligence' which works out with great approximation to one or absoluteness" (Spearman, 1904, p. 284). Studies that do not find high correlations between psychometric intelligence and single sensory discrimination tests do not falsify this hypothesis. This study is the first directly to address Spearman's general intelligence-general sensory discrimination hypothesis. It attempts to replicate his findings with a similar sample of schoolchildren. In a well-fitting structural equation model of the data, general intelligence and general discrimination correlated .92. In a reanalysis of data published byActon and Schroeder (2001), general intelligence and general sensory ability correlated .68 in men and women. One hundred years after its conception, Spearman's other hypothesis achieves some confirmation. The association between general intelligence and general sensory ability remains to be replicated and explained.

The "Eye Avoidance" Hypothesis of Autism Face Processing.

PubMed

Tanaka, James W; Sung, Andrew

2016-05-01

Although a growing body of research indicates that children with autism spectrum disorder (ASD) exhibit selective deficits in their ability to recognize facial identities and expressions, the source of their face impairment is, as yet, undetermined. In this paper, we consider three possible accounts of the autism face deficit: (1) the holistic hypothesis, (2) the local perceptual bias hypothesis and (3) the eye avoidance hypothesis. A review of the literature indicates that contrary to the holistic hypothesis, there is little evidence to suggest that individuals with autism do perceive faces holistically. The local perceptual bias account also fails to explain the selective advantage that ASD individuals demonstrate for objects and their selective disadvantage for faces. The eye avoidance hypothesis provides a plausible explanation of face recognition deficits where individuals with ASD avoid the eye region because it is perceived as socially threatening. Direct eye contact elicits a increased physiological response as indicated by heightened skin conductance and amygdala activity. For individuals with autism, avoiding the eyes is an adaptive strategy, however, this approach interferes with the ability to process facial cues of identity, expressions and intentions, exacerbating the social challenges for persons with ASD.

The “eye avoidance” hypothesis of autism face processing

PubMed Central

Tanaka, James W.; Sung, Andrew

2013-01-01

Although a growing body of research indicates that children with autism spectrum disorder (ASD) exhibit selective deficits in their ability to recognize facial identities and expressions, the source of their face impairment is, as yet, undetermined. In this paper, we consider three possible accounts of the autism face deficit: 1) the holistic hypothesis, 2) the local perceptual bias hypothesis and 3) the eye avoidance hypothesis. A review of the literature indicates that contrary to the holistic hypothesis, there is little evidence to suggest that individuals with autism do not perceive faces holistically. The local perceptual bias account also fails to explain the selective advantage that ASD individuals demonstrate for objects and their selective disadvantage for faces. The eye avoidance hypothesis provides a plausible explanation of face recognition deficits where individuals with ASD avoid the eye region because it is perceived as socially threatening. Direct eye contact elicits a heightened physiological response as indicated by heightened skin conductance and increased amgydala activity. For individuals with autism, avoiding the eyes is an adaptive strategy, however, this approach interferes with the ability to process facial cues of identity, expressions and intentions, The “eye avoidance” strategy has negative effects on the ability to decode facial information about identity, expression, and intentions, exacerbating the social challenges for persons with ASD. PMID:24150885

Teaching Hypothesis Testing by Debunking a Demonstration of Telepathy.

ERIC Educational Resources Information Center

Bates, John A.

1991-01-01

Discusses a lesson designed to demonstrate hypothesis testing to introductory college psychology students. Explains that a psychology instructor demonstrated apparent psychic abilities to students. Reports that students attempted to explain the instructor's demonstrations through hypothesis testing and revision. Provides instructions on performing…

Social learning and evolution: the cultural intelligence hypothesis

PubMed Central

van Schaik, Carel P.; Burkart, Judith M.

2011-01-01

If social learning is more efficient than independent individual exploration, animals should learn vital cultural skills exclusively, and routine skills faster, through social learning, provided they actually use social learning preferentially. Animals with opportunities for social learning indeed do so. Moreover, more frequent opportunities for social learning should boost an individual's repertoire of learned skills. This prediction is confirmed by comparisons among wild great ape populations and by social deprivation and enculturation experiments. These findings shaped the cultural intelligence hypothesis, which complements the traditional benefit hypotheses for the evolution of intelligence by specifying the conditions in which these benefits can be reaped. The evolutionary version of the hypothesis argues that species with frequent opportunities for social learning should more readily respond to selection for a greater number of learned skills. Because improved social learning also improves asocial learning, the hypothesis predicts a positive interspecific correlation between social-learning performance and individual learning ability. Variation among primates supports this prediction. The hypothesis also predicts that more heavily cultural species should be more intelligent. Preliminary tests involving birds and mammals support this prediction too. The cultural intelligence hypothesis can also account for the unusual cognitive abilities of humans, as well as our unique mechanisms of skill transfer. PMID:21357223

Social learning and evolution: the cultural intelligence hypothesis.

PubMed

van Schaik, Carel P; Burkart, Judith M

2011-04-12

If social learning is more efficient than independent individual exploration, animals should learn vital cultural skills exclusively, and routine skills faster, through social learning, provided they actually use social learning preferentially. Animals with opportunities for social learning indeed do so. Moreover, more frequent opportunities for social learning should boost an individual's repertoire of learned skills. This prediction is confirmed by comparisons among wild great ape populations and by social deprivation and enculturation experiments. These findings shaped the cultural intelligence hypothesis, which complements the traditional benefit hypotheses for the evolution of intelligence by specifying the conditions in which these benefits can be reaped. The evolutionary version of the hypothesis argues that species with frequent opportunities for social learning should more readily respond to selection for a greater number of learned skills. Because improved social learning also improves asocial learning, the hypothesis predicts a positive interspecific correlation between social-learning performance and individual learning ability. Variation among primates supports this prediction. The hypothesis also predicts that more heavily cultural species should be more intelligent. Preliminary tests involving birds and mammals support this prediction too. The cultural intelligence hypothesis can also account for the unusual cognitive abilities of humans, as well as our unique mechanisms of skill transfer.

Hypothesis Generation, Evaluation, and Memory Abilities in Adult Human Concept Learning.

ERIC Educational Resources Information Center

Cason, Carolyn L.; And Others

Studies were made between performance on tests of mental abilities and concept learning tasks; it is pointed out that the researcher is usually confronted with administering large batteries of tests of mental abilities and then analyzing his results with one of the factor analytic techniques. An information process analysis of tests of mental…

The Importance of Teaching Power in Statistical Hypothesis Testing

ERIC Educational Resources Information Center

Olinsky, Alan; Schumacher, Phyllis; Quinn, John

2012-01-01

In this paper, we discuss the importance of teaching power considerations in statistical hypothesis testing. Statistical power analysis determines the ability of a study to detect a meaningful effect size, where the effect size is the difference between the hypothesized value of the population parameter under the null hypothesis and the true value…

A comparator-hypothesis account of biased contingency detection.

PubMed

Vadillo, Miguel A; Barberia, Itxaso

2018-02-12

Our ability to detect statistical dependencies between different events in the environment is strongly biased by the number of coincidences between them. Even when there is no true covariation between a cue and an outcome, if the marginal probability of either of them is high, people tend to perceive some degree of statistical contingency between both events. The present paper explores the ability of the Comparator Hypothesis to explain the general pattern of results observed in this literature. Our simulations show that this model can account for the biasing effects of the marginal probabilities of cues and outcomes. Furthermore, the overall fit of the Comparator Hypothesis to a sample of experimental conditions from previous studies is comparable to that of the popular Rescorla-Wagner model. These results should encourage researchers to further explore and put to the test the predictions of the Comparator Hypothesis in the domain of biased contingency detection. Copyright © 2018 Elsevier B.V. All rights reserved.

Generalist genes analysis of DNA markers associated with mathematical ability and disability reveals shared influence across ages and abilities

PubMed Central

2010-01-01

Background The Generalist Genes Hypothesis is based upon quantitative genetic findings which indicate that many of the same genes influence diverse cognitive abilities and disabilities across age. In a recent genome-wide association study of mathematical ability in 10-year-old children, 43 SNP associations were nominated from scans of pooled DNA, 10 of which were validated in an individually genotyped sample. The 4927 children in this genotyped sample have also been studied at 7, 9 and 12 years of age on measures of mathematical ability, as well as on other cognitive and learning abilities. Results Using these data we have explored the Generalist Genes Hypothesis by assessing the association of the available measures of ability at age 10 and other ages with two composite 'SNP-set' scores, formed from the full set of 43 nominated SNPs and the sub-set of 10 SNPs that were previously found to be associated with mathematical ability at age 10. Both SNP sets yielded significant associations with mathematical ability at ages 7, 9 and 12, as well as with reading and general cognitive ability at age 10. Conclusions Although effect sizes are small, our results correspond with those of quantitative genetic research in supporting the Generalist Genes Hypothesis. SNP sets identified on the basis of their associations with mathematical ability at age 10 show associations with mathematical ability at earlier and later ages and show associations of similar magnitude with reading and general cognitive ability. With small effect sizes expected in such complex traits, future studies may be able to capitalise on power by searching for 'generalist genes' using longitudinal and multivariate approaches. PMID:20602751

Memory Abilities in Williams Syndrome: Dissociation or Developmental Delay Hypothesis?

ERIC Educational Resources Information Center

Sampaio, Adriana; Sousa, Nuno; Fernandez, Montse; Henriques, Margarida; Goncalves, Oscar F.

2008-01-01

Williams syndrome (WS) is a neurodevelopmental genetic disorder often described as being characterized by a dissociative cognitive architecture, in which profound impairments of visuo-spatial cognition contrast with relative preservation of linguistic, face recognition and auditory short-memory abilities. This asymmetric and dissociative cognition…

The arsenic exposure hypothesis for Alzheimer disease.

PubMed

Gong, Gordon; OʼBryant, Sid E

2010-01-01

Prior research has shown that arsenic exposure induces changes that coincide with most of the developmental, biochemical, pathologic, and clinical features of Alzheimer disease (AD) and associated disorders. On the basis of this literature, we propose the Arsenic Exposure Hypothesis for AD that is inclusive of and cooperative with the existing hypotheses. Arsenic toxicity induces hyperphosphorylation of protein tau and overtranscription of the amyloid precursor protein, which are involved in the formation of neurofibrillary tangles and brain amyloid plaques, consistent with the amyloid hypothesis of AD. Arsenic exposure has been associated with cardiovascular diseases and associated risk factors, which is in agreement with the vascular hypothesis of AD. Arsenic exposure invokes brain inflammatory responses, which resonates with the inflammatory hypotheses of AD. Arsenic exposure has been linked to reduced memory and intellectual abilities in children and adolescents, which provides a biologic basis for the developmental origin of health and disease hypothesis for AD. Arsenic and its metabolites generate free radicals causing oxidative stress and neuronal death, which fits the existing oxidative stress hypothesis. Taken together, the arsenic exposure hypothesis for AD provides a parsimonious testable hypothesis for the development and progression of this devastating disease at least for some subsets of individuals.

The relationship between learning mathematics and general cognitive ability in primary school.

PubMed

Cowan, Richard; Hurry, Jane; Midouhas, Emily

2018-06-01

Three relationships between learning mathematics and general cognitive ability have been hypothesized: The educational hypothesis that learning mathematics develops general cognitive skills, the psychometric hypothesis that differences in general cognitive ability cause differences in mathematical attainment, and the reciprocal influence hypothesis that developments in mathematical ability and general cognitive ability influence each other. These hypotheses are assessed with a sample of 948 children from the Twins Early Development Study who were assessed at 7, 9, and 10 years on mathematics, English, and general cognitive ability. A cross-lagged path analysis with mathematics and general cognitive ability measures supports the reciprocal influence hypothesis between 7 and 9 and between 9 and 10. A second analysis including English assessments only provides evidence of a reciprocal relationship between 7 and 9. Statement of Contribution What is already known on this subject? The correlations between mathematical attainment, literacy, and measures of general cognitive skills are well established. The role of literacy in developing general cognitive skills is emerging. What the present study adds? Mathematics contributes to the development of general cognitive skills. General cognitive ability contributes to mathematical development between 7 and 10. These findings support the hypothesis of reciprocal influence between mathematics and general cognitive ability, at least between 7 and 9. © 2017 The British Psychological Society.

Questioning the social intelligence hypothesis.

PubMed

Holekamp, Kay E

2007-02-01

The social intelligence hypothesis posits that complex cognition and enlarged "executive brains" evolved in response to challenges that are associated with social complexity. This hypothesis has been well supported, but some recent data are inconsistent with its predictions. It is becoming increasingly clear that multiple selective agents, and non-selective constraints, must have acted to shape cognitive abilities in humans and other animals. The task now is to develop a larger theoretical framework that takes into account both inter-specific differences and similarities in cognition. This new framework should facilitate consideration of how selection pressures that are associated with sociality interact with those that are imposed by non-social forms of environmental complexity, and how both types of functional demands interact with phylogenetic and developmental constraints.

Enriched Imperialist Competitive Algorithm for system identification of magneto-rheological dampers

NASA Astrophysics Data System (ADS)

Talatahari, Siamak; Rahbari, Nima Mohajer

2015-10-01

In the current research, the imperialist competitive algorithm is dramatically enhanced and a new optimization method dubbed as Enriched Imperialist Competitive Algorithm (EICA) is effectively introduced to deal with high non-linear optimization problems. To conduct a close examination of its functionality and efficacy, the proposed metaheuristic optimization approach is actively employed to sort out the parameter identification of two different types of hysteretic Bouc-Wen models which are simulating the non-linear behavior of MR dampers. Two types of experimental data are used for the optimization problems to minutely examine the robustness of the proposed EICA. The obtained results self-evidently demonstrate the high adaptability of EICA to suitably get to the bottom of such non-linear and hysteretic problems.

IQ as moderator of terminal decline in perceptual and motor speed, spatial, and verbal ability: Testing the cognitive reserve hypothesis in a population-based sample followed from age 70 until death.

PubMed

Thorvaldsson, Valgeir; Skoog, Ingmar; Johansson, Boo

2017-03-01

Terminal decline (TD) refers to acceleration in within-person cognitive decline prior to death. The cognitive reserve hypothesis postulates that individuals with higher IQ are able to better tolerate age-related increase in brain pathologies. On average, they will exhibit a later onset of TD, but once they start to decline, their trajectory is steeper relative to those with lower IQ. We tested these predictions using data from initially nondemented individuals (n = 179) in the H70-study repeatedly measured at ages 70, 75, 79, 81, 85, 88, 90, 92, 95, 97, 99, and 100, or until death, on cognitive tests of perceptual-and-motor-speed and spatial and verbal ability. We quantified IQ using the Raven's Coloured Progressive Matrices (RCPM) test administrated at age 70. We fitted random change point TD models to the data, within a Bayesian framework, conditioned on IQ, age of death, education, and sex. In line with predictions, we found that 1 additional standard deviation on the IQ scale was associated with a delay in onset of TD by 1.87 (95% highest density interval [HDI; 0.20, 4.08]) years on speed, 1.96 (95% HDI [0.15, 3.54]) years on verbal ability, but only 0.88 (95% HDI [-0.93, 3.49]) year on spatial ability. Higher IQ was associated with steeper rate of decline within the TD phase on measures of speed and verbal ability, whereas results on spatial ability were nonconclusive. Our findings provide partial support for the cognitive reserve hypothesis and demonstrate that IQ can be a significant moderator of cognitive change trajectories in old age. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

[Dilemma of null hypothesis in ecological hypothesis's experiment test.

PubMed

Li, Ji

2016-06-01

Experimental test is one of the major test methods of ecological hypothesis, though there are many arguments due to null hypothesis. Quinn and Dunham (1983) analyzed the hypothesis deduction model from Platt (1964) and thus stated that there is no null hypothesis in ecology that can be strictly tested by experiments. Fisher's falsificationism and Neyman-Pearson (N-P)'s non-decisivity inhibit statistical null hypothesis from being strictly tested. Moreover, since the null hypothesis H 0 (α=1, β=0) and alternative hypothesis H 1 '(α'=1, β'=0) in ecological progresses are diffe-rent from classic physics, the ecological null hypothesis can neither be strictly tested experimentally. These dilemmas of null hypothesis could be relieved via the reduction of P value, careful selection of null hypothesis, non-centralization of non-null hypothesis, and two-tailed test. However, the statistical null hypothesis significance testing (NHST) should not to be equivalent to the causality logistical test in ecological hypothesis. Hence, the findings and conclusions about methodological studies and experimental tests based on NHST are not always logically reliable.

[Examination of the hypothesis 'the factors and mechanisms of superiority'].

PubMed

Sierra-Fitzgerald, O; Quevedo-Caicedo, J; López-Calderón, M G

INTRODUCTION. The hypothesis of Geschwind and Galaburda suggests that specific cognitive superiority arises as a result of an alteration in development of the nervous system. In this article we review the co existence of superiority and inferiority . PATIENTS AND METHODS. A study was made of six children aged between 6 and 8 years old at the Instituto de Belles Artes Antonio Maria Valencia in Cali,Columbia with an educational level between second and third grade at a primary school and of medium low socio economic status. The children were considered to have superior musical ability by music experts, which is the way in which the concept of superiority was to be tested. The concept of inferiority was tested by neuropsychological tests = 1.5 DE below normal for the same age. We estimated the perinatal neurological risk in each case. Subsequently the children s general intelligence and specific cognitive abilities were evaluated. In the first case the WISC R and MSCA were used. The neuropsychological profiles were obtained by broad evaluation using a verbal fluency test, a test using counters, Boston vocabulary test, the Wechster memory scale, sequential verbal memory test, super imposed figures test, Piaget Head battery, Rey Osterrieth complex figure and the Wisconsin card classification test. The RESULTS showed slight/moderate deficits in practical construction ability and mild defects of memory and concept abilities. In general the results supported the hypothesis tested. The mechanisms of superiority proposed in the classical hypothesis mainly involve the contralateral hemisphere: in this study the ipsilateral mechanism was more important.

L2 Reading Ability: Further Insight into the Short-Circuit Hypothesis.

ERIC Educational Resources Information Center

Taillefer, Gail F.

1996-01-01

Discusses the notion of a language proficiency threshold that short circuits the transfer of reading ability from the native language (L1) to a second language (L2). This study, in which cognitive complexity of tasks and students' L2 proficiency levels vary, focuses on university students in France reading preprofessional English texts. (39…

Hypothesis analysis methods, hypothesis analysis devices, and articles of manufacture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanfilippo, Antonio P; Cowell, Andrew J; Gregory, Michelle L

Hypothesis analysis methods, hypothesis analysis devices, and articles of manufacture are described according to some aspects. In one aspect, a hypothesis analysis method includes providing a hypothesis, providing an indicator which at least one of supports and refutes the hypothesis, using the indicator, associating evidence with the hypothesis, weighting the association of the evidence with the hypothesis, and using the weighting, providing information regarding the accuracy of the hypothesis.

A large scale test of the gaming-enhancement hypothesis.

PubMed

Przybylski, Andrew K; Wang, John C

2016-01-01

A growing research literature suggests that regular electronic game play and game-based training programs may confer practically significant benefits to cognitive functioning. Most evidence supporting this idea, the gaming-enhancement hypothesis , has been collected in small-scale studies of university students and older adults. This research investigated the hypothesis in a general way with a large sample of 1,847 school-aged children. Our aim was to examine the relations between young people's gaming experiences and an objective test of reasoning performance. Using a Bayesian hypothesis testing approach, evidence for the gaming-enhancement and null hypotheses were compared. Results provided no substantive evidence supporting the idea that having preference for or regularly playing commercially available games was positively associated with reasoning ability. Evidence ranged from equivocal to very strong in support for the null hypothesis over what was predicted. The discussion focuses on the value of Bayesian hypothesis testing for investigating electronic gaming effects, the importance of open science practices, and pre-registered designs to improve the quality of future work.

A large scale test of the gaming-enhancement hypothesis

PubMed Central

Wang, John C.

2016-01-01

A growing research literature suggests that regular electronic game play and game-based training programs may confer practically significant benefits to cognitive functioning. Most evidence supporting this idea, the gaming-enhancement hypothesis, has been collected in small-scale studies of university students and older adults. This research investigated the hypothesis in a general way with a large sample of 1,847 school-aged children. Our aim was to examine the relations between young people’s gaming experiences and an objective test of reasoning performance. Using a Bayesian hypothesis testing approach, evidence for the gaming-enhancement and null hypotheses were compared. Results provided no substantive evidence supporting the idea that having preference for or regularly playing commercially available games was positively associated with reasoning ability. Evidence ranged from equivocal to very strong in support for the null hypothesis over what was predicted. The discussion focuses on the value of Bayesian hypothesis testing for investigating electronic gaming effects, the importance of open science practices, and pre-registered designs to improve the quality of future work. PMID:27896035

The Interrelationship of Sex, Visual Spatial Abilities, and Mathematical Problem Solving Ability in Grade Seven. Parts 1, 2, and 3.

ERIC Educational Resources Information Center

Schonberger, Ann Koch

This three-volume report deals with the hypothesis that males are more successful at solving mathematical and spatial problems than females. The general relationship between visual spatial abilities and mathematical problem-solving ability is also investigated. The research sample consisted of seventh graders. Each pupil took five spatial tests…

Examining the "evolution of increased competitive ability" hypothesis in response to parasites and pathogens in the invasive paper wasp Polistes dominula

NASA Astrophysics Data System (ADS)

Manfredini, Fabio; Grozinger, Christina M.; Beani, Laura

2013-03-01

Successful invaders often become established in new ranges by outcompeting native species. The "evolution of increased competitive ability" hypothesis predicts that invasive species are subjected to less predation and parasitization than sympatric native species, and thus can allocate resources from defence and immunity to growth and fecundity, thereby achieving higher fitness. In this study, we examined whether American invasive Polistes dominula paper wasps have reduced immunocompetence. To explore this scenario, we tested their susceptibility towards parasites and pathogens at both the individual (immune defence) and colony levels, i.e. hygienic behaviour (removal of diseased individuals by nestmates). First, we examined the response to the specific coevolved parasite Xenos vesparum (lost after invasion) in terms of individual host susceptibility and hygienic behaviour. Second, we explored the response against general pathogens by quantifying the bacterial clearance in individual wasps after a challenge with Escherichia coli and hygienic behaviour after a challenge with the fungus Beauveria bassiana. Our results show that American invasive P. dominula have a higher response against X. vesparum at the colony level, but at the individual level their susceptibility is not significantly different from conspecifics of the native range. On the other hand, invasive P. dominula display lower response after a challenge with general pathogens at both the individual and colony levels. While supporting the hypothesis of a reduction of immunocompetence towards general pathogens in invasive species, these findings also suggest that the response against coevolved parasites might follow different evolutionary pathways which are not always easily predictable.

Examining the "evolution of increased competitive ability" hypothesis in response to parasites and pathogens in the invasive paper wasp Polistes dominula.

PubMed

Manfredini, Fabio; Beani, Laura; Grozinger, Christina M

2013-03-01

Successful invaders often become established in new ranges by outcompeting native species. The "evolution of increased competitive ability" hypothesis predicts that invasive species are subjected to less predation and parasitization than sympatric native species, and thus can allocate resources from defence and immunity to growth and fecundity, thereby achieving higher fitness. In this study, we examined whether American invasive Polistes dominula paper wasps have reduced immunocompetence. To explore this scenario, we tested their susceptibility towards parasites and pathogens at both the individual (immune defence) and colony levels, i.e. hygienic behaviour (removal of diseased individuals by nestmates). First, we examined the response to the specific coevolved parasite Xenos vesparum (lost after invasion) in terms of individual host susceptibility and hygienic behaviour. Second, we explored the response against general pathogens by quantifying the bacterial clearance in individual wasps after a challenge with Escherichia coli and hygienic behaviour after a challenge with the fungus Beauveria bassiana. Our results show that American invasive P. dominula have a higher response against X. vesparum at the colony level, but at the individual level their susceptibility is not significantly different from conspecifics of the native range. On the other hand, invasive P. dominula display lower response after a challenge with general pathogens at both the individual and colony levels. While supporting the hypothesis of a reduction of immunocompetence towards general pathogens in invasive species, these findings also suggest that the response against coevolved parasites might follow different evolutionary pathways which are not always easily predictable.

Face recognition ability matures late: evidence from individual differences in young adults.

PubMed

Susilo, Tirta; Germine, Laura; Duchaine, Bradley

2013-10-01

Does face recognition ability mature early in childhood (early maturation hypothesis) or does it continue to develop well into adulthood (late maturation hypothesis)? This fundamental issue in face recognition is typically addressed by comparing child and adult participants. However, the interpretation of such studies is complicated by children's inferior test-taking abilities and general cognitive functions. Here we examined the developmental trajectory of face recognition ability in an individual differences study of 18-33 year-olds (n = 2,032), an age interval in which participants are competent test takers with comparable general cognitive functions. We found a positive association between age and face recognition, controlling for nonface visual recognition, verbal memory, sex, and own-race bias. Our study supports the late maturation hypothesis in face recognition, and illustrates how individual differences investigations of young adults can address theoretical issues concerning the development of perceptual and cognitive abilities. PsycINFO Database Record (c) 2013 APA, all rights reserved.

THE BARKER HYPOTHESIS: IMPLICATIONS FOR FUTURE DIRECTIONS IN TOXICOLOGY RESEARCH

EPA Science Inventory

This review covers the past year’s papers germane to the Barker hypothesis. While much of the literature has centered on maternal and developmental nutrition, new findings have emerged on the ability of toxic exposures during development to impact fetal/developmental programming....

Cognitive differences between orang-utan species: a test of the cultural intelligence hypothesis.

PubMed

Forss, Sofia I F; Willems, Erik; Call, Josep; van Schaik, Carel P

2016-07-28

Cultural species can - or even prefer to - learn their skills from conspecifics. According to the cultural intelligence hypothesis, selection on underlying mechanisms not only improves this social learning ability but also the asocial (individual) learning ability. Thus, species with systematically richer opportunities to socially acquire knowledge and skills should over time evolve to become more intelligent. We experimentally compared the problem-solving ability of Sumatran orang-utans (Pongo abelii), which are sociable in the wild, with that of the closely related, but more solitary Bornean orang-utans (P. pygmaeus), under the homogeneous environmental conditions provided by zoos. Our results revealed that Sumatrans showed superior innate problem-solving skills to Borneans, and also showed greater inhibition and a more cautious and less rough exploration style. This pattern is consistent with the cultural intelligence hypothesis, which predicts that the more sociable of two sister species experienced stronger selection on cognitive mechanisms underlying learning.

Testing the implicit processing hypothesis of precognitive dream experience.

PubMed

Valášek, Milan; Watt, Caroline; Hutton, Jenny; Neill, Rebecca; Nuttall, Rachel; Renwick, Grace

2014-08-01

Seemingly precognitive (prophetic) dreams may be a result of one's unconscious processing of environmental cues and having an implicit inference based on these cues manifest itself in one's dreams. We present two studies exploring this implicit processing hypothesis of precognitive dream experience. Study 1 investigated the relationship between implicit learning, transliminality, and precognitive dream belief and experience. Participants completed the Serial Reaction Time task and several questionnaires. We predicted a positive relationship between the variables. With the exception of relationships between transliminality and precognitive dream belief and experience, this prediction was not supported. Study 2 tested the hypothesis that differences in the ability to notice subtle cues explicitly might account for precognitive dream beliefs and experiences. Participants completed a modified version of the flicker paradigm. We predicted a negative relationship between the ability to explicitly detect changes and precognitive dream variables. This relationship was not found. There was also no relationship between precognitive dream belief and experience and implicit change detection. Copyright © 2014 Elsevier Inc. All rights reserved.

Cognitive differences between orang-utan species: a test of the cultural intelligence hypothesis

PubMed Central

Forss, Sofia I. F.; Willems, Erik; Call, Josep; van Schaik, Carel P.

2016-01-01

Cultural species can - or even prefer to - learn their skills from conspecifics. According to the cultural intelligence hypothesis, selection on underlying mechanisms not only improves this social learning ability but also the asocial (individual) learning ability. Thus, species with systematically richer opportunities to socially acquire knowledge and skills should over time evolve to become more intelligent. We experimentally compared the problem-solving ability of Sumatran orang-utans (Pongo abelii), which are sociable in the wild, with that of the closely related, but more solitary Bornean orang-utans (P. pygmaeus), under the homogeneous environmental conditions provided by zoos. Our results revealed that Sumatrans showed superior innate problem-solving skills to Borneans, and also showed greater inhibition and a more cautious and less rough exploration style. This pattern is consistent with the cultural intelligence hypothesis, which predicts that the more sociable of two sister species experienced stronger selection on cognitive mechanisms underlying learning. PMID:27466052

Numerical ability predicts mortgage default

PubMed Central

Gerardi, Kristopher; Goette, Lorenz; Meier, Stephan

2013-01-01

Unprecedented levels of US subprime mortgage defaults precipitated a severe global financial crisis in late 2008, plunging much of the industrialized world into a deep recession. However, the fundamental reasons for why US mortgages defaulted at such spectacular rates remain largely unknown. This paper presents empirical evidence showing that the ability to perform basic mathematical calculations is negatively associated with the propensity to default on one’s mortgage. We measure several aspects of financial literacy and cognitive ability in a survey of subprime mortgage borrowers who took out loans in 2006 and 2007, and match them to objective, detailed administrative data on mortgage characteristics and payment histories. The relationship between numerical ability and mortgage default is robust to controlling for a broad set of sociodemographic variables, and is not driven by other aspects of cognitive ability. We find no support for the hypothesis that numerical ability impacts mortgage outcomes through the choice of the mortgage contract. Rather, our results suggest that individuals with limited numerical ability default on their mortgage due to behavior unrelated to the initial choice of their mortgage. PMID:23798401

Numerical ability predicts mortgage default.

PubMed

Gerardi, Kristopher; Goette, Lorenz; Meier, Stephan

2013-07-09

Unprecedented levels of US subprime mortgage defaults precipitated a severe global financial crisis in late 2008, plunging much of the industrialized world into a deep recession. However, the fundamental reasons for why US mortgages defaulted at such spectacular rates remain largely unknown. This paper presents empirical evidence showing that the ability to perform basic mathematical calculations is negatively associated with the propensity to default on one's mortgage. We measure several aspects of financial literacy and cognitive ability in a survey of subprime mortgage borrowers who took out loans in 2006 and 2007, and match them to objective, detailed administrative data on mortgage characteristics and payment histories. The relationship between numerical ability and mortgage default is robust to controlling for a broad set of sociodemographic variables, and is not driven by other aspects of cognitive ability. We find no support for the hypothesis that numerical ability impacts mortgage outcomes through the choice of the mortgage contract. Rather, our results suggest that individuals with limited numerical ability default on their mortgage due to behavior unrelated to the initial choice of their mortgage.

Verbal Ability and Persistent Offending: A Race-Specific Test of Moffitt's Theory

PubMed Central

Bellair, Paul E.; McNulty, Thomas L.; Piquero, Alex R.

2014-01-01

Theoretical questions linger over the applicability of the verbal ability model to African Americans and the social control theory hypothesis that educational failure mediates the effect of verbal ability on offending patterns. Accordingly, this paper investigates whether verbal ability distinguishes between offending groups within the context of Moffitt's developmental taxonomy. Questions are addressed with longitudinal data spanning childhood through young-adulthood from an ongoing national panel, and multinomial and hierarchical Poisson models (over-dispersed). In multinomial models, low verbal ability predicts membership in a life-course-persistent-oriented group relative to an adolescent-limited-oriented group. Hierarchical models indicate that verbal ability is associated with arrest outcomes among White and African American subjects, with effects consistently operating through educational attainment (high school dropout). The results support Moffitt's hypothesis that verbal deficits distinguish adolescent-limited- and life-course-persistent-oriented groups within race as well as the social control model of verbal ability. PMID:26924885

The nest-concealment hypothesis: New insights from a comparative analysis

USGS Publications Warehouse

Borgmann, Kathi L.; Conway, Courtney J.

2015-01-01

Selection of a breeding site is critical for many animals, especially for birds whose offspring are stationary during development. Thus, birds are often assumed to prefer concealed nest sites. However, 74% of studies (n = 106) that have evaluated this relationship for open-cup nesting songbirds in North America failed to support the nest-concealment hypothesis. We conducted a comparative analysis to identify factors that contribute to variation in the ability of researchers to find support for the nest-concealment hypothesis. We found that some of the discrepancy among studies can be explained by interspecific differences in morphological and extrinsic factors that affect nest predation. Moreover, methods that investigators used to estimate concealment affected whether studies found support for the nest-concealment hypothesis; 33% of the studies that used quantitative estimates found support for the nest-concealment hypothesis whereas only 10% of the studies that used qualitative estimates found support. The timing of measurements also explained some of the ambiguity; studies that provided little information regarding the timing of their foliage density estimates were less likely to support the nest-concealment hypothesis. Species with more conspicuous male plumage were less likely to support the nest-concealment hypothesis when we analyzed studies that used visual estimates. Whereas species with more conspicuous female plumage were more likely to support the nest-concealment hypothesis when we analyzed studies that used quantitative measures. Our results demonstrate that support for the nest-concealment hypothesis has been equivocal, but that some of the ambiguity can be explained by morphological traits and methods used to measure concealment.

Do Statistical Segmentation Abilities Predict Lexical-Phonological and Lexical-Semantic Abilities in Children with and without SLI?

ERIC Educational Resources Information Center

Mainela-Arnold, Elina; Evans, Julia L.

2014-01-01

This study tested the predictions of the procedural deficit hypothesis by investigating the relationship between sequential statistical learning and two aspects of lexical ability, lexical-phonological and lexical-semantic, in children with and without specific language impairment (SLI). Participants included forty children (ages 8;5-12;3), twenty…

Cortical Neural Computation by Discrete Results Hypothesis

PubMed Central

Castejon, Carlos; Nuñez, Angel

2016-01-01

One of the most challenging problems we face in neuroscience is to understand how the cortex performs computations. There is increasing evidence that the power of the cortical processing is produced by populations of neurons forming dynamic neuronal ensembles. Theoretical proposals and multineuronal experimental studies have revealed that ensembles of neurons can form emergent functional units. However, how these ensembles are implicated in cortical computations is still a mystery. Although cell ensembles have been associated with brain rhythms, the functional interaction remains largely unclear. It is still unknown how spatially distributed neuronal activity can be temporally integrated to contribute to cortical computations. A theoretical explanation integrating spatial and temporal aspects of cortical processing is still lacking. In this Hypothesis and Theory article, we propose a new functional theoretical framework to explain the computational roles of these ensembles in cortical processing. We suggest that complex neural computations underlying cortical processing could be temporally discrete and that sensory information would need to be quantized to be computed by the cerebral cortex. Accordingly, we propose that cortical processing is produced by the computation of discrete spatio-temporal functional units that we have called “Discrete Results” (Discrete Results Hypothesis). This hypothesis represents a novel functional mechanism by which information processing is computed in the cortex. Furthermore, we propose that precise dynamic sequences of “Discrete Results” is the mechanism used by the cortex to extract, code, memorize and transmit neural information. The novel “Discrete Results” concept has the ability to match the spatial and temporal aspects of cortical processing. We discuss the possible neural underpinnings of these functional computational units and describe the empirical evidence supporting our hypothesis. We propose that fast

Cortical Neural Computation by Discrete Results Hypothesis.

PubMed

Castejon, Carlos; Nuñez, Angel

2016-01-01

One of the most challenging problems we face in neuroscience is to understand how the cortex performs computations. There is increasing evidence that the power of the cortical processing is produced by populations of neurons forming dynamic neuronal ensembles. Theoretical proposals and multineuronal experimental studies have revealed that ensembles of neurons can form emergent functional units. However, how these ensembles are implicated in cortical computations is still a mystery. Although cell ensembles have been associated with brain rhythms, the functional interaction remains largely unclear. It is still unknown how spatially distributed neuronal activity can be temporally integrated to contribute to cortical computations. A theoretical explanation integrating spatial and temporal aspects of cortical processing is still lacking. In this Hypothesis and Theory article, we propose a new functional theoretical framework to explain the computational roles of these ensembles in cortical processing. We suggest that complex neural computations underlying cortical processing could be temporally discrete and that sensory information would need to be quantized to be computed by the cerebral cortex. Accordingly, we propose that cortical processing is produced by the computation of discrete spatio-temporal functional units that we have called "Discrete Results" (Discrete Results Hypothesis). This hypothesis represents a novel functional mechanism by which information processing is computed in the cortex. Furthermore, we propose that precise dynamic sequences of "Discrete Results" is the mechanism used by the cortex to extract, code, memorize and transmit neural information. The novel "Discrete Results" concept has the ability to match the spatial and temporal aspects of cortical processing. We discuss the possible neural underpinnings of these functional computational units and describe the empirical evidence supporting our hypothesis. We propose that fast-spiking (FS

A Theoretical Note on Sex Linkage and Race Differences in Spatial Visualization Ability

ERIC Educational Resources Information Center

Jensen, Arthur R.

1975-01-01

Evidence on the poorer spatial visualization ability in various Negro populations compared to the White populations and on the direction and magnitude of sex differences in spatial ability relative to other abilities suggests the genetic hypothesis that spatial ability is enhanced by a sex-linked recessive gene and that, since the 20-30 percent…

Automatic Ability Attribution after Failure: A Dual Process View of Achievement Attribution

PubMed Central

Sakaki, Michiko; Murayama, Kou

2013-01-01

Causal attribution has been one of the most influential frameworks in the literature of achievement motivation, but previous studies considered achievement attribution as relatively deliberate and effortful processes. In the current study, we tested the hypothesis that people automatically attribute their achievement failure to their ability, but reduce the ability attribution in a controlled manner. To address this hypothesis, we measured participants’ causal attribution belief for their task failure either under the cognitive load (load condition) or with full attention (no-load condition). Across two studies, participants attributed task performance to their ability more in the load than in the no-load condition. The increased ability attribution under cognitive load further affected intrinsic motivation. These results indicate that cognitive resources available after feedback play crucial roles in determining causal attribution belief, as well as achievement motivations. PMID:23667576

Automatic ability attribution after failure: a dual process view of achievement attribution.

PubMed

Sakaki, Michiko; Murayama, Kou

2013-01-01

Causal attribution has been one of the most influential frameworks in the literature of achievement motivation, but previous studies considered achievement attribution as relatively deliberate and effortful processes. In the current study, we tested the hypothesis that people automatically attribute their achievement failure to their ability, but reduce the ability attribution in a controlled manner. To address this hypothesis, we measured participants' causal attribution belief for their task failure either under the cognitive load (load condition) or with full attention (no-load condition). Across two studies, participants attributed task performance to their ability more in the load than in the no-load condition. The increased ability attribution under cognitive load further affected intrinsic motivation. These results indicate that cognitive resources available after feedback play crucial roles in determining causal attribution belief, as well as achievement motivations.

Measurement of latent cognitive abilities involved in concept identification learning.

PubMed

Thomas, Michael L; Brown, Gregory G; Gur, Ruben C; Moore, Tyler M; Patt, Virginie M; Nock, Matthew K; Naifeh, James A; Heeringa, Steven; Ursano, Robert J; Stein, Murray B

2015-01-01

We used cognitive and psychometric modeling techniques to evaluate the construct validity and measurement precision of latent cognitive abilities measured by a test of concept identification learning: the Penn Conditional Exclusion Test (PCET). Item response theory parameters were embedded within classic associative- and hypothesis-based Markov learning models and were fitted to 35,553 Army soldiers' PCET data from the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS). Data were consistent with a hypothesis-testing model with multiple latent abilities-abstraction and set shifting. Latent abstraction ability was positively correlated with number of concepts learned, and latent set-shifting ability was negatively correlated with number of perseverative errors, supporting the construct validity of the two parameters. Abstraction was most precisely assessed for participants with abilities ranging from 1.5 standard deviations below the mean to the mean itself. Measurement of set shifting was acceptably precise only for participants making a high number of perseverative errors. The PCET precisely measures latent abstraction ability in the Army STARRS sample, especially within the range of mildly impaired to average ability. This precision pattern is ideal for a test developed to measure cognitive impairment as opposed to cognitive strength. The PCET also measures latent set-shifting ability, but reliable assessment is limited to the impaired range of ability, reflecting that perseverative errors are rare among cognitively healthy adults. Integrating cognitive and psychometric models can provide information about construct validity and measurement precision within a single analytical framework.

Spatial Abilities of Medical Graduates and Choice of Residency Programs

ERIC Educational Resources Information Center

Langlois, Jean; Wells, George A.; Lecourtois, Marc; Bergeron, Germain; Yetisir, Elizabeth; Martin, Marcel

2015-01-01

Spatial abilities have been related in previous studies to three-dimensional (3D) anatomy knowledge and the performance in technical skills. The objective of this study was to relate spatial abilities to residency programs with different levels of content of 3D anatomy knowledge and technical skills. The hypothesis was that the choice of residency…

Further evidence for the cultural norm hypothesis: positive emotion in depressed and control European American and Asian American women.

PubMed

Chentsova-Dutton, Yulia E; Tsai, Jeanne L; Gotlib, Ian H

2010-04-01

How does culture shape the effects of depression on emotion? A previous study showed that depression dampened negative emotional responses in European Americans, but increased these responses in Asian Americans (Chentsova-Dutton et al., 2007). These findings support the cultural norm hypothesis, which predicts that depression reduces individuals' abilities to react in culturally ideal ways (i.e., disrupting European Americans' abilities to express emotions openly and Asian Americans' abilities to moderate emotions). In the present study, we examined the generalizability of this hypothesis to positive emotion. We measured the emotional reactivity of 35 European Americans (17 depressed) and 31 Asian Americans (15 depressed) to an amusing film. Consistent with the cultural norm hypothesis, European Americans who were depressed showed dampened emotional reactivity (i.e., fewer smiles, less intense reports of positive emotion, lower cardiac activation) compared to control European Americans, whereas Asian Americans who were depressed showed similar (for smiles and reports of positive emotion), and even greater (for higher cardiac activation) emotional reactivity compared to control Asian Americans. These findings suggest that the cultural norm hypothesis generalizes to positive emotion. PsycINFO Database Record (c) 2010 APA, all rights reserved.

Gender Differences in Academic Achievement: Is Writing an Exception to the Gender Similarities Hypothesis?

PubMed

Reynolds, Matthew R; Scheiber, Caroline; Hajovsky, Daniel B; Schwartz, Bryanna; Kaufman, Alan S

2015-01-01

The gender similarities hypothesis by J. S. Hyde ( 2005 ), based on large-scale reviews of studies, concludes that boys and girls are more alike than different on most psychological variables, including academic skills such as reading and math (J. S. Hyde, 2005 ). Writing is an academic skill that may be an exception. The authors investigated gender differences in academic achievement using a large, nationally stratified sample of children and adolescents ranging from ages 7-19 years (N = 2,027). Achievement data were from the conormed sample for the Kaufman intelligence and achievement tests. Multiple-indicator, multiple-cause, and multigroup mean and covariance structure models were used to test for mean differences. Girls had higher latent reading ability and higher scores on a test of math computation, but the effect sizes were consistent with the gender similarities hypothesis. Conversely, girls scored higher on spelling and written expression, with effect sizes inconsistent with the gender similarities hypothesis. The findings remained the same after controlling for cognitive ability. Girls outperform boys on tasks of writing.

Comments on Jeong-Won Lee and Diane Lemonnier Schallert's "The Relative Contribution of L2 Language Proficiency and L1 Reading Ability to L2 Reading Performance: A Test of the Threshold Hypothesis in an EFL Context."

ERIC Educational Resources Information Center

Bamford, Julian; Day, Richard R.; Schallert, Diane Lemonnier; Lee, Jeong-Won

1998-01-01

Provides reactions to an article, "The Relative Contribution of L2 Language Proficiency and L1 Reading Ability to L2 Reading Performance: A Test of the Threshold Hypothesis in an EFL Context" published in an earlier issue of this journal (v31 n4). The authors of the article respond to these reactions. (Author/VWL)

Gender Differences in the Relationship of Nascent Conservation and Reading Abilities.

ERIC Educational Resources Information Center

Day, H. D.; Hollingsworth, Shirley

1983-01-01

Researchers investigated the effects of sex differences on the relationship between conservation ability and the reading and linguistic awareness of five-year-old children. Findings of this study and others consistently support the hypothesis that conservation ability correlates more highly with reading in girls than in boys. (Author/PP)

Life Origination Hydrate Hypothesis (LOH-Hypothesis)

PubMed Central

Ostrovskii, Victor; Kadyshevich, Elena

2012-01-01

The paper develops the Life Origination Hydrate Hypothesis (LOH-hypothesis), according to which living-matter simplest elements (LMSEs, which are N-bases, riboses, nucleosides, nucleotides), DNA- and RNA-like molecules, amino-acids, and proto-cells repeatedly originated on the basis of thermodynamically controlled, natural, and inevitable processes governed by universal physical and chemical laws from CH4, niters, and phosphates under the Earth's surface or seabed within the crystal cavities of the honeycomb methane-hydrate structure at low temperatures; the chemical processes passed slowly through all successive chemical steps in the direction that is determined by a gradual decrease in the Gibbs free energy of reacting systems. The hypothesis formulation method is based on the thermodynamic directedness of natural movement and consists ofan attempt to mentally backtrack on the progression of nature and thus reveal principal milestones alongits route. The changes in Gibbs free energy are estimated for different steps of the living-matter origination process; special attention is paid to the processes of proto-cell formation. Just the occurrence of the gas-hydrate periodic honeycomb matrix filled with LMSEs almost completely in its final state accounts for size limitation in the DNA functional groups and the nonrandom location of N-bases in the DNA chains. The slowness of the low-temperature chemical transformations and their “thermodynamic front” guide the gross process of living matter origination and its successive steps. It is shown that the hypothesis is thermodynamically justified and testable and that many observed natural phenomena count in its favor. PMID:25382120

Teaching a Hypothesis-driven Physical Diagnosis Curriculum to Pulmonary Fellows Improves Performance of First-Year Medical Students.

PubMed

Staitieh, Bashar S; Saghafi, Ramin; Kempker, Jordan A; Schulman, David A

2016-04-01

Hypothesis-driven physical examination emphasizes the role of bedside examination in the refinement of differential diagnoses and improves diagnostic acumen. This approach has not yet been investigated as a tool to improve the ability of higher-level trainees to teach medical students. To assess the effect of teaching hypothesis-driven physical diagnosis to pulmonary fellows on their ability to improve the pulmonary examination skills of first-year medical students. Fellows and students were assessed on teaching and diagnostic skills by self-rating on a Likert scale. One group of fellows received the hypothesis-driven teaching curriculum (the "intervention" group) and another received instruction on head-to-toe examination. Both groups subsequently taught physical diagnosis to a group of first-year medical students. An oral examination was administered to all students after completion of the course. Fellows were comfortable teaching physical diagnosis to students. Students in both groups reported a lack of comfort with the pulmonary examination at the beginning of the course and improvement in their comfort by the end. Students trained by intervention group fellows outperformed students trained by control group fellows in the interpretation of physical findings (P < 0.05). Teaching hypothesis-driven physical examination to higher-level trainees who teach medical students improves the ability of students to interpret physical findings. This benefit should be confirmed using validated testing tools.

Academic Self-Concept, Implicit Theories of Ability, and Self-Regulation Strategies

ERIC Educational Resources Information Center

Ommundsen, Yngvar; Haugen, Richard; Lund, Thorleif

2005-01-01

The purpose of the present study is to explore how academic self-concept and implicit theories of ability are related to four self-regulation strategies--motivation/diligence, concentration, information processing, and self-handicapping. The hypothesis is that academic self-concept and an incremental theory of ability are (1) positively related to…

Engine monitoring display study

NASA Technical Reports Server (NTRS)

Hornsby, Mary E.

1992-01-01

The current study is part of a larger NASA effort to develop displays for an engine-monitoring system to enable the crew to monitor engine parameter trends more effectively. The objective was to evaluate the operational utility of adding three types of information to the basic Boeing Engine Indicating and Crew Alerting System (EICAS) display formats: alphanumeric alerting messages for engine parameters whose values exceed caution or warning limits; alphanumeric messages to monitor engine parameters that deviate from expected values; and a graphic depiction of the range of expected values for current conditions. Ten training and line pilots each flew 15 simulated flight scenarios with five variants of the basic EICAS format; these variants included different combinations of the added information. The pilots detected engine problems more quickly when engine alerting messages were included in the display; adding a graphic depiction of the range of expected values did not affect detection speed. The pilots rated both types of alphanumeric messages (alert and monitor parameter) as more useful and easier to interpret than the graphic depiction. Integrating engine parameter messages into the EICAS alerting system appears to be both useful and preferred.

Perceptual Inference in Chronic Pain: An Investigation Into the Economy of Action Hypothesis.

PubMed

Tabor, Abby; O'Daly, Owen; Gregory, Robert W; Jacobs, Clair; Travers, Warren; Thacker, Michael A; Moseley, Graham Lorimer

2016-07-01

The experience of chronic pain critically alters one's ability to interact with their environment. One fundamental issue that has received little attention, however, is whether chronic pain disrupts how one perceives their environment in the first place. The Economy of Action hypothesis purports that the environment is spatially scaled according to the ability of the observer. Under this hypothesis it has been proposed that the perception of the world is different between those with and without chronic pain. Such a possibility has profound implications for the investigation and treatment of pain. The present investigation tested the application of this hypothesis to a heterogenous chronic pain population. Individuals with chronic pain (36; 27F) and matched pain-free controls were recruited. Each participant was required to judge the distance to a series of target cones, to which they were to subsequently walk. In addition, at each distance, participants used Numerical Rating Scales to indicate their perceived effort and perceived pain associated with the distance presented. Our findings do not support the Economy of Action hypothesis: there were no significant differences in distance estimates between the chronic pain and pain-free groups (F1,60=0.927; P=0.340). In addition, we found no predictive relationship in the chronic pain group between anticipated pain and estimated distance (F1,154=0.122, P=0.727), nor anticipated effort (1.171, P=0.281) and estimated distance (F1,154=1.171, P=0.281). The application of the Economy of Action hypothesis and the notion of spatial perceptual scaling as a means to assess and treat the experience of chronic pain are not supported by the results of this study.

Developing the research hypothesis.

PubMed

Toledo, Alexander H; Flikkema, Robert; Toledo-Pereyra, Luis H

2011-01-01

The research hypothesis is needed for a sound and well-developed research study. The research hypothesis contributes to the solution of the research problem. Types of research hypotheses include inductive and deductive, directional and non-directional, and null and alternative hypotheses. Rejecting the null hypothesis and accepting the alternative hypothesis is the basis for building a good research study. This work reviews the most important aspects of organizing and establishing an efficient and complete hypothesis.

Heuristics and biases: interactions among numeracy, ability, and reflectiveness predict normative responding

PubMed Central

Klaczynski, Paul A.

2014-01-01

In Stanovich's (2009a, 2011) dual-process theory, analytic processing occurs in the algorithmic and reflective minds. Thinking dispositions, indexes of reflective mind functioning, are believed to regulate operations at the algorithmic level, indexed by general cognitive ability. General limitations at the algorithmic level impose constraints on, and affect the adequacy of, specific strategies and abilities (e.g., numeracy). In a study of 216 undergraduates, the hypothesis that thinking dispositions and general ability moderate the relationship between numeracy (understanding of mathematical concepts and attention to numerical information) and normative responses on probabilistic heuristics and biases (HB) problems was tested. Although all three individual difference measures predicted normative responses, the numeracy-normative response association depended on thinking dispositions and general ability. Specifically, numeracy directly affected normative responding only at relatively high levels of thinking dispositions and general ability. At low levels of thinking dispositions, neither general ability nor numeric skills related to normative responses. Discussion focuses on the consistency of these findings with the hypothesis that the implementation of specific skills is constrained by limitations at both the reflective level and the algorithmic level, methodological limitations that prohibit definitive conclusions, and alternative explanations. PMID:25071639

Heuristics and biases: interactions among numeracy, ability, and reflectiveness predict normative responding.

PubMed

Klaczynski, Paul A

2014-01-01

In Stanovich's (2009a, 2011) dual-process theory, analytic processing occurs in the algorithmic and reflective minds. Thinking dispositions, indexes of reflective mind functioning, are believed to regulate operations at the algorithmic level, indexed by general cognitive ability. General limitations at the algorithmic level impose constraints on, and affect the adequacy of, specific strategies and abilities (e.g., numeracy). In a study of 216 undergraduates, the hypothesis that thinking dispositions and general ability moderate the relationship between numeracy (understanding of mathematical concepts and attention to numerical information) and normative responses on probabilistic heuristics and biases (HB) problems was tested. Although all three individual difference measures predicted normative responses, the numeracy-normative response association depended on thinking dispositions and general ability. Specifically, numeracy directly affected normative responding only at relatively high levels of thinking dispositions and general ability. At low levels of thinking dispositions, neither general ability nor numeric skills related to normative responses. Discussion focuses on the consistency of these findings with the hypothesis that the implementation of specific skills is constrained by limitations at both the reflective level and the algorithmic level, methodological limitations that prohibit definitive conclusions, and alternative explanations.

Further Evidence for the Cultural Norm Hypothesis: Positive Emotion in Depressed and Control European American and Asian American Women

PubMed Central

Chentsova-Dutton, Yulia E.; Tsai, Jeanne L.; Gotlib, Ian H.

2010-01-01

How does culture shape the experience and expression of depression? Previously we observed that depression dampened negative emotional responses in European Americans, but increased negative emotional responses in Asian Americans (Chentsova-Dutton et al., 2007). We interpreted these findings as support for the cultural norm hypothesis, which predicts that depression reduces individuals’ abilities to react in culturally normative or ideal ways (i.e., disrupting European Americans’ abilities to express their emotions openly and Asian Americans’ abilities to moderate and control their emotions). In the present study, we examined the generalizability of the cultural norm hypothesis to positive emotion. We measured the emotional reactivity of 35 European Americans (17 depressed, 18 controls) and 31 Asian Americans (15 depressed, 16 controls) to an amusing film clip. Consistent with the cultural norm hypothesis, depressed European Americans showed dampened positive emotional reactivity (i.e., fewer enjoyment and non-enjoyment smiles, less intense reports of positive emotion, lower cardiac activation) compared to control European Americans, whereas depressed Asian Americans showed similar (i.e., smiles, reports of positive emotion), and even greater (i.e., higher cardiac activation) positive emotional reactivity compared to control Asian Americans. These findings suggest that the cultural norm hypothesis generalizes to the experience and expression of positive emotion. PMID:20438167

Size evolution in microorganisms masks trade-offs predicted by the growth rate hypothesis.

PubMed

Gounand, Isabelle; Daufresne, Tanguy; Gravel, Dominique; Bouvier, Corinne; Bouvier, Thierry; Combe, Marine; Gougat-Barbera, Claire; Poly, Franck; Torres-Barceló, Clara; Mouquet, Nicolas

2016-12-28

Adaptation to local resource availability depends on responses in growth rate and nutrient acquisition. The growth rate hypothesis (GRH) suggests that growing fast should impair competitive abilities for phosphorus and nitrogen due to high demand for biosynthesis. However, in microorganisms, size influences both growth and uptake rates, which may mask trade-offs and instead generate a positive relationship between these traits (size hypothesis, SH). Here, we evolved a gradient of maximum growth rate (μ max ) from a single bacterium ancestor to test the relationship among μ max , competitive ability for nutrients and cell size, while controlling for evolutionary history. We found a strong positive correlation between μ max and competitive ability for phosphorus, associated with a trade-off between μ max and cell size: strains selected for high μ max were smaller and better competitors for phosphorus. Our results strongly support the SH, while the trade-offs expected under GRH were not apparent. Beyond plasticity, unicellular populations can respond rapidly to selection pressure through joint evolution of their size and maximum growth rate. Our study stresses that physiological links between these traits tightly shape the evolution of competitive strategies. © 2016 The Author(s).

Teaching a Hypothesis-driven Physical Diagnosis Curriculum to Pulmonary Fellows Improves Performance of First-Year Medical Students

PubMed Central

Saghafi, Ramin; Kempker, Jordan A.; Schulman, David A.

2016-01-01

Rationale: Hypothesis-driven physical examination emphasizes the role of bedside examination in the refinement of differential diagnoses and improves diagnostic acumen. This approach has not yet been investigated as a tool to improve the ability of higher-level trainees to teach medical students. Objectives: To assess the effect of teaching hypothesis-driven physical diagnosis to pulmonary fellows on their ability to improve the pulmonary examination skills of first-year medical students. Methods: Fellows and students were assessed on teaching and diagnostic skills by self-rating on a Likert scale. One group of fellows received the hypothesis-driven teaching curriculum (the “intervention” group) and another received instruction on head-to-toe examination. Both groups subsequently taught physical diagnosis to a group of first-year medical students. An oral examination was administered to all students after completion of the course. Measurements and Main Results: Fellows were comfortable teaching physical diagnosis to students. Students in both groups reported a lack of comfort with the pulmonary examination at the beginning of the course and improvement in their comfort by the end. Students trained by intervention group fellows outperformed students trained by control group fellows in the interpretation of physical findings (P < 0.05). Conclusions: Teaching hypothesis-driven physical examination to higher-level trainees who teach medical students improves the ability of students to interpret physical findings. This benefit should be confirmed using validated testing tools. PMID:26730644

Conceptual Systems Model as a Tool for Hypothesis Generation and Testing in Ecotoxicological Research

EPA Science Inventory

Microarray, proteomic, and metabonomic technologies are becoming increasingly accessible as tools for ecotoxicology research. Effective use of these technologies will depend, at least in part, on the ability to apply these techniques within a paradigm of hypothesis driven researc...

Ability-performance relationships in education and employment settings: critical tests of the more-is-better and the good-enough hypotheses.

PubMed

Arneson, Justin J; Sackett, Paul R; Beatty, Adam S

2011-10-01

The nature of the relationship between ability and performance is of critical importance for admission decisions in the context of higher education and for personnel selection. Although previous research has supported the more-is-better hypothesis by documenting linearity of ability-performance relationships, such research has not been sensitive enough to detect deviations at the top ends of the score distributions. An alternative position receiving considerable attention is the good-enough hypothesis, which suggests that although higher levels of ability may result in better performance up to a threshold, above this threshold greater ability does not translate to better performance. In this study, the nature of the relationship between cognitive ability and performance was examined throughout the score range in four large-scale data sets. Monotonicity was maintained in all instances. Contrary to the good-enough hypothesis, the ability-performance relationship was commonly stronger at the top end of the score distribution than at the bottom end.

Latent ability: grades and test scores systematically underestimate the intellectual ability of negatively stereotyped students.

PubMed

Walton, Gregory M; Spencer, Steven J

2009-09-01

Past research has assumed that group differences in academic performance entirely reflect genuine differences in ability. In contrast, extending research on stereotype threat, we suggest that standard measures of academic performance are biased against non-Asian ethnic minorities and against women in quantitative fields. This bias results not from the content of performance measures, but from the context in which they are assessed-from psychological threats in common academic environments, which depress the performances of people targeted by negative intellectual stereotypes. Like the time of a track star running into a stiff headwind, such performances underestimate the true ability of stereotyped students. Two meta-analyses, combining data from 18,976 students in five countries, tested this latent-ability hypothesis. Both meta-analyses found that, under conditions that reduce psychological threat, stereotyped students performed better than nonstereotyped students at the same level of past performance. We discuss implications for the interpretation of and remedies for achievement gaps.

Darwin's wind hypothesis: does it work for plant dispersal in fragmented habitats?

PubMed

Riba, Miquel; Mayol, Maria; Giles, Barbara E; Ronce, Ophélie; Imbert, Eric; van der Velde, Marco; Chauvet, Stéphanie; Ericson, Lars; Bijlsma, R; Vosman, Ben; Smulders, M J M; Olivieri, Isabelle

2009-08-01

Using the wind-dispersed plant Mycelis muralis, we examined how landscape fragmentation affects variation in seed traits contributing to dispersal. Inverse terminal velocity (Vt(-1)) of field-collected achenes was used as a proxy for individual seed dispersal ability. We related this measure to different metrics of landscape connectivity, at two spatial scales: in a detailed analysis of eight landscapes in Spain and along a latitudinal gradient using 29 landscapes across three European regions. In the highly patchy Spanish landscapes, seed Vt(-1)increased significantly with increasing connectivity. A common garden experiment suggested that differences in Vt(-1) may be in part genetically based. The Vt(-1) was also found to increase with landscape occupancy, a coarser measure of connectivity, on a much broader (European) scale. Finally, Vt(-1)was found to increase along a south-north latitudinal gradient. Our results for M. muralis are consistent with 'Darwin's wind dispersal hypothesis' that high cost of dispersal may select for lower dispersal ability in fragmented landscapes, as well as with the 'leading edge hypothesis' that most recently colonized populations harbour more dispersive phenotypes.

Do the Brain Networks of Scientists Account for Their Superiority in Hypothesis-Generating?

ERIC Educational Resources Information Center

Lee, Jun-Ki

2012-01-01

Where do scientists' superior abilities originate from when generating a creative idea? What different brain functions are activated between scientists and i) general academic high school students and ii) science high school students when generating a biological hypothesis? To reveal brain level explanations for these questions, this paper…

Learning-Related Changes in Adolescents' Neural Networks during Hypothesis-Generating and Hypothesis-Understanding Training

ERIC Educational Resources Information Center

Lee, Jun-Ki; Kwon, Yongju

2012-01-01

Fourteen science high school students participated in this study, which investigated neural-network plasticity associated with hypothesis-generating and hypothesis-understanding in learning. The students were divided into two groups and participated in either hypothesis-generating or hypothesis-understanding type learning programs, which were…

Childhood Mental Ability and Lifetime Psychiatric Contact: A 66-Year Follow-Up Study of the 1932 Scottish Mental Ability Survey.

ERIC Educational Resources Information Center

Walker, Nicholas P.; McConville, Pauline M; Hunter, David; Deary, Ian J.; Whalley, Lawrence J.

2002-01-01

Tested the hypothesis that intelligence is related to the risk of mental illness by linking childhood mental ability data to registers of psychiatric contact in a stable population of 4,199 adults in Scotland. Findings show intelligence to be an independent predictor of psychiatric contact, with each standard deviation decrease in IQ resulting in…

The Flexibility Hypothesis of Healing.

PubMed

Hinton, Devon E; Kirmayer, Laurence J

2017-03-01

Theories of healing have attempted to identify general mechanisms that may work across different modalities. These include altering expectations, remoralization, and instilling hope. In this paper, we argue that many forms of healing and psychotherapy may work by inducing positive psychological states marked by flexibility or an enhanced ability to shift cognitive sets. Healing practices may induce these states of cognitive and emotional flexibility through specific symbolic interventions we term "flexibility primers" that can include images, metaphors, music, and other media. The flexibility hypothesis suggests that cognitive and emotional flexibility is represented, elicited, and enacted through multiple modalities in healing rituals. Identifying psychological processes and cultural forms that evoke and support cognitive and emotional flexibility provides a way to understand the cultural specificity and potential efficacy of particular healing practices and can guide the design of interventions that promote resilience and well-being.

Who Benefits from Learning with 3D Models?: The Case of Spatial Ability

ERIC Educational Resources Information Center

Huk, T.

2006-01-01

Empirical studies that focus on the impact of three-dimensional (3D) visualizations on learning are to date rare and inconsistent. According to the ability-as-enhancer hypothesis, high spatial ability learners should benefit particularly as they have enough cognitive capacity left for mental model construction. In contrast, the…

Physiopathological Hypothesis of Cellulite

PubMed Central

de Godoy, José Maria Pereira; de Godoy, Maria de Fátima Guerreiro

2009-01-01

A series of questions are asked concerning this condition including as regards to its name, the consensus about the histopathological findings, physiological hypothesis and treatment of the disease. We established a hypothesis for cellulite and confirmed that the clinical response is compatible with this hypothesis. Hence this novel approach brings a modern physiological concept with physiopathologic basis and clinical proof of the hypothesis. We emphasize that the choice of patient, correct diagnosis of cellulite and the technique employed are fundamental to success. PMID:19756187

Modeling Differentiation of Cognitive Abilities within the Higher-Order Factor Model Using Moderated Factor Analysis

ERIC Educational Resources Information Center

Molenaar, Dylan; Dolan, Conor V.; Wicherts, Jelte M.; van der Maas, Han L. J.

2010-01-01

The general differentiation hypothesis states that the strength of the correlations among a set of IQ subtests varies with a given variable. Instances of the general differentiation hypothesis that have been considered in the literature include age and ability differentiation. Traditionally, the differentiation effect is attributed to the varying…

Mentalizing Abilities in Preadolescents' and Their Mothers' Autobiographical Narratives

ERIC Educational Resources Information Center

Scopesi, Alda M.; Rosso, Anna Maria; Viterbori, Paola; Panchieri, Erika

2015-01-01

This study aims to investigate the association between the mental state talk of mothers and their preadolescent children, with the hypothesis that an intergenerational transmission of mentalizing abilities may extend beyond early childhood. The participants were 41 mother-preadolescent child nonclinical dyads. The Adult Attachment Interview (AAI)…

Is the hypothesis of preimplantation genetic screening (PGS) still supportable? A review.

PubMed

Gleicher, Norbert; Orvieto, Raoul

2017-03-27

The hypothesis of preimplantation genetic diagnosis (PGS) was first proposed 20 years ago, suggesting that elimination of aneuploid embryos prior to transfer will improve implantation rates of remaining embryos during in vitro fertilization (IVF), increase pregnancy and live birth rates and reduce miscarriages. The aforementioned improved outcome was based on 5 essential assumptions: (i) Most IVF cycles fail because of aneuploid embryos. (ii) Their elimination prior to embryo transfer will improve IVF outcomes. (iii) A single trophectoderm biopsy (TEB) at blastocyst stage is representative of the whole TE. (iv) TE ploidy reliably represents the inner cell mass (ICM). (v) Ploidy does not change (i.e., self-correct) downstream from blastocyst stage. We aim to offer a review of the aforementioned assumptions and challenge the general hypothesis of PGS. We reviewed 455 publications, which as of January 20, 2017 were listed in PubMed under the search phrase < preimplantation genetic screening (PGS) for aneuploidy>. The literature review was performed by both authors who agreed on the final 55 references. Various reports over the last 18 months have raised significant questions not only about the basic clinical utility of PGS but the biological underpinnings of the hypothesis, the technical ability of a single trophectoderm (TE) biopsy to accurately assess an embryo's ploidy, and suggested that PGS actually negatively affects IVF outcomes while not affecting miscarriage rates. Moreover, due to high rates of false positive diagnoses as a consequence of high mosaicism rates in TE, PGS leads to the discarding of large numbers of normal embryos with potential for normal euploid pregnancies if transferred rather than disposed of. We found all 5 basic assumptions underlying the hypothesis of PGS to be unsupported: (i) The association of embryo aneuploidy with IVF failure has to be reevaluated in view how much more common TE mosaicism is than has until recently been

Pasture succession in the Neotropics: extending the nucleation hypothesis into a matrix discontinuity hypothesis.

PubMed

Peterson, Chris J; Dosch, Jerald J; Carson, Walter P

2014-08-01

The nucleation hypothesis appears to explain widespread patterns of succession in tropical pastures, specifically the tendency for isolated trees to promote woody species recruitment. Still, the nucleation hypothesis has usually been tested explicitly for only short durations and in some cases isolated trees fail to promote woody recruitment. Moreover, at times, nucleation occurs in other key habitat patches. Thus, we propose an extension, the matrix discontinuity hypothesis: woody colonization will occur in focal patches that function to mitigate the herbaceous vegetation effects, thus providing safe sites or regeneration niches. We tested predictions of the classical nucleation hypothesis, the matrix discontinuity hypothesis, and a distance from forest edge hypothesis, in five abandoned pastures in Costa Rica, across the first 11 years of succession. Our findings confirmed the matrix discontinuity hypothesis: specifically, rotting logs and steep slopes significantly enhanced woody colonization. Surprisingly, isolated trees did not consistently significantly enhance recruitment; only larger trees did so. Finally, woody recruitment consistently decreased with distance from forest. Our results as well as results from others suggest that the nucleation hypothesis needs to be broadened beyond its historical focus on isolated trees or patches; the matrix discontinuity hypothesis focuses attention on a suite of key patch types or microsites that promote woody species recruitment. We argue that any habitat discontinuities that ameliorate the inhibition by dense graminoid layers will be foci for recruitment. Such patches could easily be manipulated to speed the transition of pastures to closed canopy forests.

Hypothesis driven development of new adjuvants: short peptides as immunomodulators.

PubMed

Dong, Jessica C; Kobinger, Gary P

2013-04-01

To date, vaccinations have been one of the key strategies in the prevention and protection against infectious pathogens. Traditional vaccines have well-known limitations such as safety and efficacy issues, which consequently deems it inappropriate for particular populations and may not be an effective strategy against all pathogens. This evidence highlights the need to develop more efficacious vaccination regiments. Higher levels of protection can be achieved by the addition of immunostimulating adjuvants. Many adjuvants elicit strong, undefined inflammation, which produces increased immunogenicity but may also lead to undesirable effects. Hypothesis driven development of adjuvants is needed to achieve a more specific and directed immune response required for optimal and safe vaccine-induced immune protection. An example of such hypothesis driven development includes the use of short immunomodulating peptides as adjuvants. These peptides have the ability to influence the immune response and can be extrapolated for adjuvant use, but requires further investigation.

Approximate numerical abilities and mathematics: Insight from correlational and experimental training studies.

PubMed

Hyde, D C; Berteletti, I; Mou, Y

2016-01-01

Humans have the ability to nonverbally represent the approximate numerosity of sets of objects. The cognitive system that supports this ability, often referred to as the approximate number system (ANS), is present in early infancy and continues to develop in precision over the life span. It has been proposed that the ANS forms a foundation for uniquely human symbolic number and mathematics learning. Recent work has brought two types of evidence to bear on the relationship between the ANS and human mathematics: correlational studies showing individual differences in approximate numerical abilities correlate with individual differences in mathematics achievement and experimental studies showing enhancing effects of nonsymbolic approximate numerical training on exact, symbolic mathematical abilities. From this work, at least two accounts can be derived from these empirical data. It may be the case that the ANS and mathematics are related because the cognitive and brain processes responsible for representing numerical quantity in each format overlap, the Representational Overlap Hypothesis, or because of commonalities in the cognitive operations involved in mentally manipulating the representations of each format, the Operational Overlap hypothesis. The two hypotheses make distinct predictions for future work to test. © 2016 Elsevier B.V. All rights reserved.

Generalist genes and the Internet generation: etiology of learning abilities by web testing at age 10.

PubMed

Davis, O S P; Kovas, Y; Harlaar, N; Busfield, P; McMillan, A; Frances, J; Petrill, S A; Dale, P S; Plomin, R

2008-06-01

A key translational issue for neuroscience is to understand how genes affect individual differences in brain function. Although it is reasonable to suppose that genetic effects on specific learning abilities, such as reading and mathematics, as well as general cognitive ability (g), will overlap very little, the counterintuitive finding emerging from multivariate genetic studies is that the same genes affect these diverse learning abilities: a Generalist Genes hypothesis. To conclusively test this hypothesis, we exploited the widespread access to inexpensive and fast Internet connections in the UK to assess 2541 pairs of 10-year-old twins for reading, mathematics and g, using a web-based test battery. Heritabilities were 0.38 for reading, 0.49 for mathematics and 0.44 for g. Multivariate genetic analysis showed substantial genetic correlations between learning abilities: 0.57 between reading and mathematics, 0.61 between reading and g, and 0.75 between mathematics and g, providing strong support for the Generalist Genes hypothesis. If genetic effects on cognition are so general, the effects of these genes on the brain are also likely to be general. In this way, generalist genes may prove invaluable in integrating top-down and bottom-up approaches to the systems biology of the brain.

Differentiation of Cognitive Abilities as a Function of Neuroticism Level: A Measurement Equivalence/Invariance Analysis

ERIC Educational Resources Information Center

Bonaccio, Silvia; Reeve, Charlie L.

2006-01-01

This paper investigates the differentiation of cognitive abilities as a function of neuroticism. Specifically, we examine Eysenck and White's [Eysenck, H. J., and White, P. O. (1964). Personality and the measurement of intelligence. British Journal of Educational Psychology, 24, 197-201.] hypothesis that cognitive abilities are less differentiated…

Varieties of numerical abilities.

PubMed

Dehaene, S

1992-08-01

This paper provides a tutorial introduction to numerical cognition, with a review of essential findings and current points of debate. A tacit hypothesis in cognitive arithmetic is that numerical abilities derive from human linguistic competence. One aim of this special issue is to confront this hypothesis with current knowledge of number representations in animals, infants, normal and gifted adults, and brain-lesioned patients. First, the historical evolution of number notations is presented, together with the mental processes for calculating and transcoding from one notation to another. While these domains are well described by formal symbol-processing models, this paper argues that such is not the case for two other domains of numerical competence: quantification and approximation. The evidence for counting, subitizing and numerosity estimation in infants, children, adults and animals is critically examined. Data are also presented which suggest a specialization for processing approximate numerical quantities in animals and humans. A synthesis of these findings is proposed in the form of a triple-code model, which assumes that numbers are mentally manipulated in an arabic, verbal or analogical magnitude code depending on the requested mental operation. Only the analogical magnitude representation seems available to animals and preverbal infants.

Modeling Reader and Text Interactions during Narrative Comprehension: A Test of the Lexical Quality Hypothesis

ERIC Educational Resources Information Center

Hamilton, Stephen T.; Freed, Erin M.; Long, Debra L.

2013-01-01

The goal of this study was to examine predictions derived from the Lexical Quality Hypothesis regarding relations among word decoding, working-memory capacity, and the ability to integrate new concepts into a developing discourse representation. Hierarchical Linear Modeling was used to quantify the effects of three text properties (length,…

Number sense in infancy predicts mathematical abilities in childhood.

PubMed

Starr, Ariel; Libertus, Melissa E; Brannon, Elizabeth M

2013-11-05

Human infants in the first year of life possess an intuitive sense of number. This preverbal number sense may serve as a developmental building block for the uniquely human capacity for mathematics. In support of this idea, several studies have demonstrated that nonverbal number sense is correlated with mathematical abilities in children and adults. However, there has been no direct evidence that infant numerical abilities are related to mathematical abilities later in childhood. Here, we provide evidence that preverbal number sense in infancy predicts mathematical abilities in preschool-aged children. Numerical preference scores at 6 months of age correlated with both standardized math test scores and nonsymbolic number comparison scores at 3.5 years of age, suggesting that preverbal number sense facilitates the acquisition of numerical symbols and mathematical abilities. This relationship held even after controlling for general intelligence, indicating that preverbal number sense imparts a unique contribution to mathematical ability. These results validate the many prior studies purporting to show number sense in infancy and support the hypothesis that mathematics is built upon an intuitive sense of number that predates language.

A specific hygiene hypothesis.

PubMed

Shunsheng Han, Cliff

2016-08-01

Allergic diseases have reached epidemic proportions in Western populations in the last several decades. The hygiene hypothesis proposed more than twenty years ago has helped us to understand the epidemic and has been verified with numerous studies. However, translational measures deduced from these studies to prevent allergic diseases have not proven effective. Recent studies on immigrants' allergies and any potential association between oral infection and allergic diseases prompt me to propose a specific hygiene hypothesis to explain how oral hygiene practices might have contributed to the uprising of hay fever, the most common allergic disease. The historic oral hygiene level in US is closely associated with the emerging allergic epidemic. Future studies to test the hypothesis are needed and verification of the hypothesis can potentially yield highly effective measures to prevent allergic diseases. Published by Elsevier Ltd.

Intact action segmentation in Parkinson's disease: Hypothesis testing using a novel computational approach.

PubMed

Schiffer, Anne-Marike; Nevado-Holgado, Alejo J; Johnen, Andreas; Schönberger, Anna R; Fink, Gereon R; Schubotz, Ricarda I

2015-11-01

Action observation is known to trigger predictions of the ongoing course of action and thus considered a hallmark example for predictive perception. A related task, which explicitly taps into the ability to predict actions based on their internal representations, is action segmentation; the task requires participants to demarcate where one action step is completed and another one begins. It thus benefits from a temporally precise prediction of the current action. Formation and exploitation of these temporal predictions of external events is now closely associated with a network including the basal ganglia and prefrontal cortex. Because decline of dopaminergic innervation leads to impaired function of the basal ganglia and prefrontal cortex in Parkinson's disease (PD), we hypothesised that PD patients would show increased temporal variability in the action segmentation task, especially under medication withdrawal (hypothesis 1). Another crucial aspect of action segmentation is its reliance on a semantic representation of actions. There is no evidence to suggest that action representations are substantially altered, or cannot be accessed, in non-demented PD patients. We therefore expected action segmentation judgments to follow the same overall patterns in PD patients and healthy controls (hypothesis 2), resulting in comparable segmentation profiles. Both hypotheses were tested with a novel classification approach. We present evidence for both hypotheses in the present study: classifier performance was slightly decreased when it was tested for its ability to predict the identity of movies segmented by PD patients, and a measure of normativity of response behaviour was decreased when patients segmented movies under medication-withdrawal without access to an episodic memory of the sequence. This pattern of results is consistent with hypothesis 1. However, the classifier analysis also revealed that responses given by patients and controls create very similar action

Scientific reasoning in early and middle childhood: the development of domain-general evidence evaluation, experimentation, and hypothesis generation skills.

PubMed

Piekny, Jeanette; Maehler, Claudia

2013-06-01

According to Klahr's (2000, 2005; Klahr & Dunbar, 1988) Scientific Discovery as Dual Search model, inquiry processes require three cognitive components: hypothesis generation, experimentation, and evidence evaluation. The aim of the present study was to investigate (a) when the ability to evaluate perfect covariation, imperfect covariation, and non-covariation evidence emerges, (b) when experimentation emerges, (c) when hypothesis generation skills emerge, and (d), whether these abilities develop synchronously during childhood. We administered three scientific reasoning tasks referring to the three components to 223 children of five age groups (from age 4.0 to 13.5 years). Our results show that the three cognitive components of domain-general scientific reasoning emerge asynchronously. The development of domain-general scientific reasoning begins with the ability to handle unambiguous data, progresses to the interpretation of ambiguous data, and leads to a flexible adaptation of hypotheses according to the sufficiency of evidence. When children understand the relation between the level of ambiguity of evidence and the level of confidence in hypotheses, the ability to differentiate conclusive from inconclusive experiments accompanies this development. Implications of these results for designing science education concepts for young children are briefly discussed. © 2012 The British Psychological Society.

The fighting hypothesis in combat: how well does the fighting hypothesis explain human left-handed minorities?

PubMed

Groothuis, Ton G G; McManus, I C; Schaafsma, Sara M; Geuze, Reint H

2013-06-01

The strong population bias in hand preference in favor of right-handedness seems to be a typical human trait. An elegant evolutionary hypothesis explaining this trait is the so-called fighting hypothesis that postulates that left-handedness is under frequency-dependent selection. The fighting hypothesis assumes that left-handers, being in the minority because of health issues, are still maintained in the population since they would have a greater chance of winning in fights than right-handers due to a surprise effect. This review critically evaluates the assumptions and evidence for this hypothesis and concludes that some evidence, although consistent with the fighting hypothesis, does not directly support it and may also be interpreted differently. Other supportive data are ambiguous or open for both statistical and theoretical criticism. We conclude that, presently, evidence for the fighting hypothesis is not particularly strong, but that there is little evidence to reject it either. The hypothesis thus remains an intuitively plausible explanation for the persistent left-hand preference in the population. We suggest alternative explanations and several ways forward for obtaining more crucial data for testing this frequently cited hypothesis. © 2013 New York Academy of Sciences.

Approaches to informed consent for hypothesis-testing and hypothesis-generating clinical genomics research.

PubMed

Facio, Flavia M; Sapp, Julie C; Linn, Amy; Biesecker, Leslie G

2012-10-10

Massively-parallel sequencing (MPS) technologies create challenges for informed consent of research participants given the enormous scale of the data and the wide range of potential results. We propose that the consent process in these studies be based on whether they use MPS to test a hypothesis or to generate hypotheses. To demonstrate the differences in these approaches to informed consent, we describe the consent processes for two MPS studies. The purpose of our hypothesis-testing study is to elucidate the etiology of rare phenotypes using MPS. The purpose of our hypothesis-generating study is to test the feasibility of using MPS to generate clinical hypotheses, and to approach the return of results as an experimental manipulation. Issues to consider in both designs include: volume and nature of the potential results, primary versus secondary results, return of individual results, duty to warn, length of interaction, target population, and privacy and confidentiality. The categorization of MPS studies as hypothesis-testing versus hypothesis-generating can help to clarify the issue of so-called incidental or secondary results for the consent process, and aid the communication of the research goals to study participants.

Why would Musical Training Benefit the Neural Encoding of Speech? The OPERA Hypothesis.

PubMed

Patel, Aniruddh D

2011-01-01

Mounting evidence suggests that musical training benefits the neural encoding of speech. This paper offers a hypothesis specifying why such benefits occur. The "OPERA" hypothesis proposes that such benefits are driven by adaptive plasticity in speech-processing networks, and that this plasticity occurs when five conditions are met. These are: (1) Overlap: there is anatomical overlap in the brain networks that process an acoustic feature used in both music and speech (e.g., waveform periodicity, amplitude envelope), (2) Precision: music places higher demands on these shared networks than does speech, in terms of the precision of processing, (3) Emotion: the musical activities that engage this network elicit strong positive emotion, (4) Repetition: the musical activities that engage this network are frequently repeated, and (5) Attention: the musical activities that engage this network are associated with focused attention. According to the OPERA hypothesis, when these conditions are met neural plasticity drives the networks in question to function with higher precision than needed for ordinary speech communication. Yet since speech shares these networks with music, speech processing benefits. The OPERA hypothesis is used to account for the observed superior subcortical encoding of speech in musically trained individuals, and to suggest mechanisms by which musical training might improve linguistic reading abilities.

Personality and Neural Correlates of Mentalizing Ability.

PubMed

Allen, Timothy A; Rueter, Amanda R; Abram, Samantha V; Brown, James S; DeYoung, Colin G

2017-01-01

Theory of mind, or mentalizing , defined as the ability to reason about another's mental states, is a crucial psychological function that is disrupted in some forms of psychopathology, but little is known about how individual differences in this ability relate to personality or brain function. One previous study linked mentalizing ability to individual differences in the personality trait Agreeableness. Agreeableness encompasses two major subdimensions: Compassion reflects tendencies toward empathy, prosocial behavior, and interpersonal concern, whereas Politeness captures tendencies to suppress aggressive and exploitative impulses. We hypothesized that Compassion but not Politeness would be associated with better mentalizing ability. This hypothesis was confirmed in Study 1 ( N = 329) using a theory of mind task that required reasoning about the beliefs of fictional characters. Post hoc analyses indicated that the honesty facet of Agreeableness was negatively associated with mentalizing. In Study 2 ( N = 217), we examined whether individual differences in mentalizing and related traits were associated with patterns of resting-state functional connectivity in the brain. Performance on the theory of mind task was significantly associated with patterns of connectivity between the dorsal medial and core subsystems of the default network, consistent with evidence implicating these regions in mentalization.

Apomorphine and the dopamine hypothesis of schizophrenia: a dilemma?

PubMed Central

Dépatie, L; Lal, S

2001-01-01

The dopamine (DA) hypothesis of schizophrenia implicates an enhancement of DA function in the pathophysiology of the disorder, at least in the genesis of positive symptoms. Accordingly, apomorphine, a directly acting DA receptor agonist, should display psychotomimetic properties. A review of the literature shows little or no evidence that apomorphine, in doses that stimulate postsynaptic DA receptors, induces psychosis in non-schizophrenic subjects or a relapse or exacerbation of psychotic symptoms in patients with schizophrenia. After a detailed review of the literature reporting psychotogenic effects of apomorphine in patients with Parkinson's disease, an interpretation of these data is difficult, in part because of several confounding factors, such as the concomitant use of drugs known to induce psychosis and the advanced state of the progressive neurological disorder. In the context of the DA hypothesis of schizophrenia, the limited ability of apomorphine to induce psychosis, in contrast to indirectly acting DA agonists that increase synaptic DA, may be explained by the relatively weak affinity of apomorphine for the D3 receptor compared with DA. Alternatively, enhancement of DA function, though necessary, may be insufficient by itself to induce psychosis. PMID:11394190

Testing the hypothesis of hierarchical predictability in ecological restoration and succession.

PubMed

Abella, Scott R; Schetter, Timothy A; Walters, Timothy L

2018-02-01

To advance predictive ecology, the hypothesis of hierarchical predictability proposes that community measures for which species are interchangeable (e.g., structure and species richness) are more predictable than measures for which species identity matters (e.g., community composition). Predictability is hypothesized to decrease for response measures in order of the following categories: structure, species richness, function, and species composition. We tested this hypothesis using a 14-year, oak savanna-prairie restoration experiment that removed non-native pine plantations at 24 sites in northwestern Ohio, USA. Based on 24 response measures, the data showed minimal support for the hypothesis, because response measures varied in predictability within categories. Half of response measures had over half their variability modeled using fixed (restoration treatment and year) and random plot effects, and these "predictable" measures occurred in all four categories. Pine basal area, environment (e.g., soil texture), and antecedent vegetation accounted for over half the variation in change within the first three post-restoration years for 77% of response measures. Change between the 3rd and 14th years was less predictable, but most restoration measures increased favorably via sites achieving them in unique ways. We propose that variation will not conform with the hypothesis of hierarchical predictability in ecosystems with vegetation dynamics driven by stochastic processes such as seed dispersal, or where vegetation structure and species richness are influenced by species composition. The ability to predict a community measure may be more driven by the number of combinations of casual factors affecting a measure than by the number of values it can have.

Number sense in infancy predicts mathematical abilities in childhood

PubMed Central

Starr, Ariel; Libertus, Melissa E.; Brannon, Elizabeth M.

2013-01-01

Human infants in the first year of life possess an intuitive sense of number. This preverbal number sense may serve as a developmental building block for the uniquely human capacity for mathematics. In support of this idea, several studies have demonstrated that nonverbal number sense is correlated with mathematical abilities in children and adults. However, there has been no direct evidence that infant numerical abilities are related to mathematical abilities later in childhood. Here, we provide evidence that preverbal number sense in infancy predicts mathematical abilities in preschool-aged children. Numerical preference scores at 6 months of age correlated with both standardized math test scores and nonsymbolic number comparison scores at 3.5 years of age, suggesting that preverbal number sense facilitates the acquisition of numerical symbols and mathematical abilities. This relationship held even after controlling for general intelligence, indicating that preverbal number sense imparts a unique contribution to mathematical ability. These results validate the many prior studies purporting to show number sense in infancy and support the hypothesis that mathematics is built upon an intuitive sense of number that predates language. PMID:24145427

Is the Aluminum Hypothesis Dead?

PubMed Central

2014-01-01

The Aluminum Hypothesis, the idea that aluminum exposure is involved in the etiology of Alzheimer disease, dates back to a 1965 demonstration that aluminum causes neurofibrillary tangles in the brains of rabbits. Initially the focus of intensive research, the Aluminum Hypothesis has gradually been abandoned by most researchers. Yet, despite this current indifference, the Aluminum Hypothesis continues to attract the attention of a small group of scientists and aluminum continues to be viewed with concern by some of the public. This review article discusses reasons that mainstream science has largely abandoned the Aluminum Hypothesis and explores a possible reason for some in the general public continuing to view aluminum with mistrust. PMID:24806729

Testing the prenatal hormone hypothesis of tic-related disorders: gender identity and gender role behavior.

PubMed

Alexander, Gerianne M; Peterson, Bradley S

2004-01-01

The hypothesis that prenatal masculinization of the brain increases risk of tic disorders in postnatal life was tested by measuring gender and gender role behavior in 89 children and adults with a clinical diagnosis of Tourette syndrome or obsessive compulsive disorder and 67 healthy, unaffected children and adults. Consistent with this hypothesis, a tic disorder in females was associated with more gender dysphoria, increased masculine play preferences, and a more typically "masculine" pattern of performance on two sex-typed spatial tasks. Males with tic disorders reported increased masculine play preferences, and the strength of these preferences was positively associated with the severity of tic symptoms. In addition, unlike their female counterparts, males with tic disorders showed a relative impairment in mental rotation ability. These behavioral profiles are consistent with those of children who have verifiable elevations in prenatal androgen levels. These findings therefore support the hypothesis that an altered androgen-dependent process of sexual differentiation during prenatal life may contribute to the development of tic-related disorders.

Revisiting the continuum hypothesis: toward an in-depth exploration of executive functions in korsakoff syndrome.

PubMed

Brion, Mélanie; Pitel, Anne-Lise; Beaunieux, Hélène; Maurage, Pierre

2014-01-01

Korsakoff syndrome (KS) is a neurological state mostly caused by alcohol-dependence and leading to disproportionate episodic memory deficits. KS patients present more severe anterograde amnesia than Alcohol-Dependent Subjects (ADS), which led to the continuum hypothesis postulating a progressive increase in brain and cognitive damages during the evolution from ADS to KS. This hypothesis has been extensively examined for memory but is still debated for other abilities, notably executive functions (EF). EF have up to now been explored by unspecific tasks in KS, and few studies explored their interactions with memory. Exploring EF in KS by specific tasks based on current EF models could thus renew the exploration of the continuum hypothesis. This paper will propose a research program aiming at: (1) clarifying the extent of executive dysfunctions in KS by tasks focusing on specific EF subcomponents; (2) determining the differential EF deficits in ADS and KS; (3) exploring EF-memory interactions in KS with innovative tasks. At the fundamental level, this exploration will test the continuum hypothesis beyond memory. At the clinical level, it will propose new rehabilitation tools focusing on the EF specifically impaired in KS.

Revisiting the Continuum Hypothesis: Toward an In-Depth Exploration of Executive Functions in Korsakoff Syndrome

PubMed Central

Brion, Mélanie; Pitel, Anne-Lise; Beaunieux, Hélène; Maurage, Pierre

2014-01-01

Korsakoff syndrome (KS) is a neurological state mostly caused by alcohol-dependence and leading to disproportionate episodic memory deficits. KS patients present more severe anterograde amnesia than Alcohol-Dependent Subjects (ADS), which led to the continuum hypothesis postulating a progressive increase in brain and cognitive damages during the evolution from ADS to KS. This hypothesis has been extensively examined for memory but is still debated for other abilities, notably executive functions (EF). EF have up to now been explored by unspecific tasks in KS, and few studies explored their interactions with memory. Exploring EF in KS by specific tasks based on current EF models could thus renew the exploration of the continuum hypothesis. This paper will propose a research program aiming at: (1) clarifying the extent of executive dysfunctions in KS by tasks focusing on specific EF subcomponents; (2) determining the differential EF deficits in ADS and KS; (3) exploring EF-memory interactions in KS with innovative tasks. At the fundamental level, this exploration will test the continuum hypothesis beyond memory. At the clinical level, it will propose new rehabilitation tools focusing on the EF specifically impaired in KS. PMID:25071526

Distinguishing between the partial-mapping preparation hypothesis and the failure-to-engage hypothesis of residual switch costs.

PubMed

Lindsen, Job P; de Jong, Ritske

2010-10-01

Lien, Ruthruff, Remington, & Johnston (2005) reported residual switch cost differences between stimulus-response (S-R) pairs and proposed the partial-mapping preparation (PMP) hypothesis, which states that advance preparation will typically be limited to a subset of S-R pairs because of structural capacity limitations, to account for these differences. Alternatively, the failure-to-engage (FTE) hypothesis does not allow for differences in probability of advance preparation between S-R pairs within a set; it accounts for residual switch cost differences by assuming that benefits of advance preparation may differ between S-R pairs. Three Experiments were designed to test between these hypotheses. No capacity limitations of the type assumed by the PMP hypothesis were found for many participants in Experiment 1. In Experiments 2 and 3, no evidence was found for the dependency of residual switch cost differences between S-R pairs on response-stimulus interval that is predicted by the PMP hypothesis. Mixture-model analysis of reaction times distributions in Experiment 3 provided strong support for the FTE hypothesis over the PMP hypothesis. Simulation studies with a computational implementation of the FTE hypothesis showed that it is able to account in great detail for the results of the present study. Together, these results provide strong evidence against the PMP hypothesis and support the FTE hypothesis that advance preparation probabilistically fails or succeeds at the level of the task set. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

Do statistical segmentation abilities predict lexical-phonological and lexical-semantic abilities in children with and without SLI?

PubMed Central

Mainela-Arnold, Elina; Evans, Julia L.

2014-01-01

This study tested the predictions of the procedural deficit hypothesis by investigating the relationship between sequential statistical learning and two aspects of lexical ability, lexical-phonological and lexical-semantic, in children with and without specific language impairment (SLI). Participants included 40 children (ages 8;5–12;3), 20 children with SLI and 20 with typical development. Children completed Saffran’s statistical word segmentation task, a lexical-phonological access task (gating task), and a word definition task. Poor statistical learners were also poor at managing lexical-phonological competition during the gating task. However, statistical learning was not a significant predictor of semantic richness in word definitions. The ability to track statistical sequential regularities may be important for learning the inherently sequential structure of lexical-phonology, but not as important for learning lexical-semantic knowledge. Consistent with the procedural/declarative memory distinction, the brain networks associated with the two types of lexical learning are likely to have different learning properties. PMID:23425593

The Impact of Generic Language about Ability on Children's Achievement Motivation

ERIC Educational Resources Information Center

Cimpian, Andrei

2010-01-01

Nuances in how adults talk about ability may have important consequences for children's sustained involvement and success in an activity. In this study, I tested the hypothesis that children would be less motivated while performing a novel activity if they were told that boys or girls in general are good at this activity (generic language) than if…

The Over-Pruning Hypothesis of Autism

ERIC Educational Resources Information Center

Thomas, Michael S. C.; Davis, Rachael; Karmiloff-Smith, Annette; Knowland, Victoria C. P.; Charman, Tony

2016-01-01

This article outlines the "over-pruning hypothesis" of autism. The hypothesis originates in a neurocomputational model of the regressive sub-type (Thomas, Knowland & Karmiloff-Smith, 2011a, 2011b). Here we develop a more general version of the over-pruning hypothesis to address heterogeneity in the timing of manifestation of ASD,…

Tests of the lunar hypothesis

NASA Technical Reports Server (NTRS)

Taylor, S. R.

1984-01-01

The concept that the Moon was fissioned from the Earth after core separation is the most readily testable hypothesis of lunar origin, since direct comparisons of lunar and terrestrial compositions can be made. Differences found in such comparisons introduce so many ad hoc adjustments to the fission hypothesis that it becomes untestable. Further constraints may be obtained from attempting to date the volatile-refractory element fractionation. The combination of chemical and isotopic problems suggests that the fission hypothesis is no longer viable, and separate terrestrial and lunar accretion from a population of fractionated precursor planetesimals provides a more reasonable explanation.

Introduction: revisiting the "negrito" hypothesis: a transdisciplinary approach to human prehistory in southeast Asia.

PubMed

Endicott, Phillip

2013-01-01

The "negrito" hypothesis predicts that a shared phenotype among various contemporary groups of hunter-gatherers in Southeast Asia--dark skin, short stature, tight curly hair--is due to common descent from a region-wide, pre-Neolithic substrate of humanity. The alternative is that their distinctive phenotype results from convergent evolution. The core issues of the negrito hypothesis are today more relevant than ever to studies of human evolution, including the out-of-Africa migration, admixture with Denisovans, and the effects of environment and ecology on life-history traits. Understanding the current distribution of the negrito phenotype dictates a wide-ranging remit for study, including the articulation of the relationship between foragers and farmers in the present, the development of settled agriculture in the mid-Holocene, and terminal Pleistocene population expansions. The consensus reached by the contributors to this special double issue of Human Biology is that there is not yet conclusive evidence either for or against the negrito hypothesis. Nevertheless, the process of revisiting the problem will benefit the knowledge of the human prehistory of Southeast Asia. Whether the term negrito accurately reflects the all-encompassing nature of the resulting inquiry is in itself questionable, but the publication of this double issue is testament to the enduring ability of this hypothesis to unite disparate academic disciplines in a common purpose. Copyright © 2013 Wayne State University Press, Detroit, Michigan 48201-1309.

Attack of the Killer Fungus: A Hypothesis-Driven Lab Module †

PubMed Central

Sato, Brian K.

2013-01-01

Discovery-driven experiments in undergraduate laboratory courses have been shown to increase student learning and critical thinking abilities. To this end, a lab module involving worm capture by a nematophagous fungus was developed. The goals of this module are to enhance scientific understanding of the regulation of worm capture by soil-dwelling fungi and for students to attain a set of established learning goals, including the ability to develop a testable hypothesis and search for primary literature for data analysis, among others. Students in a ten-week majors lab course completed the lab module and generated novel data as well as data that agrees with the published literature. In addition, learning gains were achieved as seen through a pre-module and post-module test, student self-assessment, class exam, and lab report. Overall, this lab module enables students to become active participants in the scientific method while contributing to the understanding of an ecologically relevant model organism. PMID:24358387

Scientific Reasoning in Early and Middle Childhood: The Development of Domain-General Evidence Evaluation, Experimentation, and Hypothesis Generation Skills

ERIC Educational Resources Information Center

Piekny, Jeanette; Maehler, Claudia

2013-01-01

According to Klahr's (2000, 2005; Klahr & Dunbar, 1988) Scientific Discovery as Dual Search model, inquiry processes require three cognitive components: hypothesis generation, experimentation, and evidence evaluation. The aim of the present study was to investigate (a) when the ability to evaluate perfect covariation, imperfect covariation,…

Functional Neuroanatomical Evidence for the Double-Deficit Hypothesis of Developmental Dyslexia

PubMed Central

Norton, Elizabeth S.; Black, Jessica M.; Stanley, Leanne M.; Tanaka, Hiroko; Gabrieli, John D. E.; Sawyer, Carolyn; Hoeft, Fumiko

2015-01-01

The double-deficit hypothesis of dyslexia posits that both rapid naming and phonological impairments can cause reading difficulties, and that individuals who have both of these deficits show greater reading impairments compared to those with a single deficit. Despite extensive behavioral research, the brain basis of poor reading with a double-deficit has never been investigated. The goal of the study was to evaluate the double-deficit hypothesis using functional MRI. Activation patterns during a printed word rhyme judgment task in 90 children with a wide range of reading abilities showed dissociation between brain regions that were sensitive to phonological awareness (left inferior frontal and inferior parietal regions) and rapid naming (right cerebellar lobule VI). More specifically, the double-deficit group showed less activation in the fronto-parietal reading network compared to children with only a deficit in phonological awareness, who in turn showed less activation than the typically-reading group. On the other hand, the double-deficit group showed less cerebellar activation compared to children with only a rapid naming deficit, who in turn showed less activation than the typically-reading children. Functional connectivity analyses revealed that bilateral prefrontal regions were key for linking brain regions associated with phonological awareness and rapid naming, with the double-deficit group being the most aberrant in their connectivity. Our study provides the first functional neuroanatomical evidence for the double-deficit hypothesis of developmental dyslexia. PMID:24953957

The Early Anthropogenic Hypothesis: Challenges and Responses

NASA Astrophysics Data System (ADS)

Ruddiman, William F.

2007-12-01

Ruddiman (2003) proposed that late Holocene anthropogenic intervention caused CH4 and CO2 increases that kept climate from cooling and that preindustrial pandemics caused CO2 decreases and a small cooling. Every aspect of this early anthropogenic hypothesis has been challenged: the timescale, the issue of stage 11 as a better analog, the ability of human activities to account for the gas anomalies, and the impact of the pandemics. This review finds that the late Holocene gas trends are anomalous in all ice timescales; greenhouse gases decreased during the closest stage 11 insolation analog; disproportionate biomass burning and rice irrigation can explain the methane anomaly; and pandemics explain half of the CO2 decrease since 1000 years ago. Only ˜25% of the CO2 anomaly can, however, be explained by carbon from early deforestation. The remainder must have come from climate system feedbacks, including a Holocene ocean that remained anomalously warm because of anthropogenic intervention.

Personality and problem-solving performance explain competitive ability in the wild.

PubMed

Cole, Ella F; Quinn, John L

2012-03-22

Competitive ability is a major determinant of fitness, but why individuals vary so much in their competitiveness remains only partially understood. One increasingly prevalent view is that realized competitive ability varies because it represents alternative strategies that arise because of the costs associated with competitiveness. Here we use a population of great tits (Parus major) to explore whether individual differences in competitive ability when foraging can be explained by two traits that have previously been linked to alternative behavioural strategies: the personality trait 'exploration behaviour' and a simple cognitive trait, 'innovative problem-solving performance'. We assayed these traits under standardized conditions in captivity and then measured competitive ability at feeders with restricted access in the wild. Competitive ability was repeatable within individual males across days and correlated positively with exploration behaviour, representing the first such demonstration of a link between a personality trait and both competitive ability and food intake in the wild. Competitive ability was also simultaneously negatively correlated with problem-solving performance; individuals who were poor competitors were good at problem-solving. Rather than being the result of variation in 'individual quality', our results support the hypothesis that individual variation in competitive ability can be explained by alternative behavioural strategies.

Personality and problem-solving performance explain competitive ability in the wild

PubMed Central

Cole, Ella F.; Quinn, John L.

2012-01-01

Competitive ability is a major determinant of fitness, but why individuals vary so much in their competitiveness remains only partially understood. One increasingly prevalent view is that realized competitive ability varies because it represents alternative strategies that arise because of the costs associated with competitiveness. Here we use a population of great tits (Parus major) to explore whether individual differences in competitive ability when foraging can be explained by two traits that have previously been linked to alternative behavioural strategies: the personality trait ‘exploration behaviour’ and a simple cognitive trait, ‘innovative problem-solving performance’. We assayed these traits under standardized conditions in captivity and then measured competitive ability at feeders with restricted access in the wild. Competitive ability was repeatable within individual males across days and correlated positively with exploration behaviour, representing the first such demonstration of a link between a personality trait and both competitive ability and food intake in the wild. Competitive ability was also simultaneously negatively correlated with problem-solving performance; individuals who were poor competitors were good at problem-solving. Rather than being the result of variation in ‘individual quality’, our results support the hypothesis that individual variation in competitive ability can be explained by alternative behavioural strategies. PMID:21937498

A Graph-Based Recovery and Decomposition of Swanson’s Hypothesis using Semantic Predications

PubMed Central

Cameron, Delroy; Bodenreider, Olivier; Yalamanchili, Hima; Danh, Tu; Vallabhaneni, Sreeram; Thirunarayan, Krishnaprasad; Sheth, Amit P.; Rindflesch, Thomas C.

2014-01-01

Objectives This paper presents a methodology for recovering and decomposing Swanson’s Raynaud Syndrome–Fish Oil Hypothesis semi-automatically. The methodology leverages the semantics of assertions extracted from biomedical literature (called semantic predications) along with structured background knowledge and graph-based algorithms to semi-automatically capture the informative associations originally discovered manually by Swanson. Demonstrating that Swanson’s manually intensive techniques can be undertaken semi-automatically, paves the way for fully automatic semantics-based hypothesis generation from scientific literature. Methods Semantic predications obtained from biomedical literature allow the construction of labeled directed graphs which contain various associations among concepts from the literature. By aggregating such associations into informative subgraphs, some of the relevant details originally articulated by Swanson has been uncovered. However, by leveraging background knowledge to bridge important knowledge gaps in the literature, a methodology for semi-automatically capturing the detailed associations originally explicated in natural language by Swanson has been developed. Results Our methodology not only recovered the 3 associations commonly recognized as Swanson’s Hypothesis, but also decomposed them into an additional 16 detailed associations, formulated as chains of semantic predications. Altogether, 14 out of the 19 associations that can be attributed to Swanson were retrieved using our approach. To the best of our knowledge, such an in-depth recovery and decomposition of Swanson’s Hypothesis has never been attempted. Conclusion In this work therefore, we presented a methodology for semi- automatically recovering and decomposing Swanson’s RS-DFO Hypothesis using semantic representations and graph algorithms. Our methodology provides new insights into potential prerequisites for semantics-driven Literature-Based Discovery (LBD

Knowledge dimensions in hypothesis test problems

NASA Astrophysics Data System (ADS)

Krishnan, Saras; Idris, Noraini

2012-05-01

The reformation in statistics education over the past two decades has predominantly shifted the focus of statistical teaching and learning from procedural understanding to conceptual understanding. The emphasis of procedural understanding is on the formulas and calculation procedures. Meanwhile, conceptual understanding emphasizes students knowing why they are using a particular formula or executing a specific procedure. In addition, the Revised Bloom's Taxonomy offers a twodimensional framework to describe learning objectives comprising of the six revised cognition levels of original Bloom's taxonomy and four knowledge dimensions. Depending on the level of complexities, the four knowledge dimensions essentially distinguish basic understanding from the more connected understanding. This study identifiesthe factual, procedural and conceptual knowledgedimensions in hypothesis test problems. Hypothesis test being an important tool in making inferences about a population from sample informationis taught in many introductory statistics courses. However, researchers find that students in these courses still have difficulty in understanding the underlying concepts of hypothesis test. Past studies also show that even though students can perform the hypothesis testing procedure, they may not understand the rationale of executing these steps or know how to apply them in novel contexts. Besides knowing the procedural steps in conducting a hypothesis test, students must have fundamental statistical knowledge and deep understanding of the underlying inferential concepts such as sampling distribution and central limit theorem. By identifying the knowledge dimensions of hypothesis test problems in this study, suitable instructional and assessment strategies can be developed in future to enhance students' learning of hypothesis test as a valuable inferential tool.

Development of Planning Abilities in Normal Aging: Differential Effects of Specific Cognitive Demands

ERIC Educational Resources Information Center

Köstering, Lena; Stahl, Christoph; Leonhart, Rainer; Weiller, Cornelius; Kaller, Christoph P.

2014-01-01

In line with the frontal hypothesis of aging, the ability to plan ahead undergoes substantial change during normal aging. Although impairments on the Tower of London planning task were reported earlier, associations between age-related declines and specific cognitive demands on planning have not been studied. Here we investigated the impact of…

Young children's non-numerical ordering ability at the start of formal education longitudinally predicts their symbolic number skills and academic achievement in maths.

PubMed

O'Connor, Patrick A; Morsanyi, Kinga; McCormack, Teresa

2018-01-25

Ordinality is a fundamental feature of numbers and recent studies have highlighted the role that number ordering abilities play in mathematical development (e.g., Lyons et al., ), as well as mature mathematical performance (e.g., Lyons & Beilock, ). The current study tested the novel hypothesis that non-numerical ordering ability, as measured by the ordering of familiar sequences of events, also plays an important role in maths development. Ninety children were tested in their first school year and 87 were followed up at the end of their second school year, to test the hypothesis that ordinal processing, including the ordering of non-numerical materials, would be related to their maths skills both cross-sectionally and longitudinally. The results confirmed this hypothesis. Ordinal processing measures were significantly related to maths both cross-sectionally and longitudinally, and children's non-numerical ordering ability in their first year of school (as measured by order judgements for everyday events and the parents' report of their child's everyday ordering ability) was the strongest longitudinal predictor of maths one year later, when compared to several measures that are traditionally considered to be important predictors of early maths development. Children's everyday ordering ability, as reported by parents, also significantly predicted growth in formal maths ability between Year 1 and Year 2, although this was not the case for the event ordering task. The present study provides strong evidence that domain-general ordering abilities play an important role in the development of children's maths skills at the beginning of formal education. © 2018 John Wiley & Sons Ltd.

An experimental test of the EICA hypothesis in multiple ranges: invasive populations outperform those from the native range independent of insect herbivore suppression

PubMed Central

DeWalt, Saara J.; Zou, Jianwen; Rogers, William E.

2017-01-01

Abstract The success of invasive plants may reflect environmental differences in their native and introduced ranges including both abiotic and biotic conditions, such as release from aboveground herbivory. However, in response to these novel conditions, plants from invasive populations may have higher growth rates and lower defence levels compared with those in the native range. This may contribute to their success in the introduced range but perhaps not in the native range. Here, we grew 1000 Triadica sebifera plants from 14 native and introduced populations in seven common gardens with unmanaged background vegetation for three growing seasons in three geographic venues that varied in T. sebifera status and insect herbivore communities: Texas—T. sebifera is invasive, low levels of generalist herbivory; Hawaii—T. sebifera introduced but not invasive, high levels of generalist herbivory from exotic herbivores; China—native range, both generalist and specialist herbivores. We suppressed aboveground insects with insecticide on half the plants. Aboveground damage in the first growing season was lowest in Texas and insecticide sprays reduced damage in China. At the end of the first growing season, plants were tallest on an average in China and shortest in Hawaii. However, height in later years and mass were the highest on average in Texas and the lowest in Hawaii. However, there was large variation in damage and plant performance among gardens within venues. Our results suggest that more rapid aboveground growth rates contribute to T. sebifera’s success in both the invasive and native ranges independent of aboveground herbivory. However, strong variation among sites indicates that T. sebifera plants from invasive populations only have a strong advantage in a subset of sites in Texas. PMID:28039113

An experimental test of the EICA Hypothesis in multiple ranges: invasive populations outperform those from the native range independent of insect herbivore suppression.

PubMed

Siemann, Evan; DeWalt, Saara J; Zou, Jianwen; Rogers, William E

2016-12-30

The success of invasive plants may reflect environmental differences in their native and introduced ranges including both abiotic and biotic conditions, such as release from aboveground herbivory. However, in response to these novel conditions, plants from invasive populations may have higher growth rates and lower defense levels compared to those in the native range. This may contribute to their success in the introduced range but perhaps not in the native range. Here, we grew 1000 Triadica sebifera plants from 14 native and introduced populations in seven common gardens with unmanaged background vegetation for three growing seasons in three geographic venues that varied in T. sebifera status and insect herbivore communities: Texas -T. sebifera is invasive, low levels of generalist herbivory; Hawaii - T. sebifera introduced but not invasive, high levels of generalist herbivory from exotic herbivores; China - native range, both generalist and specialist herbivores. We suppressed aboveground insects with insecticide on half the plants. Aboveground damage in the first growing season was lowest in Texas and insecticide sprays reduced damage in China. At the end of the first growing season, plants were tallest on average in China and shortest in Hawaii. However, height in later years and mass were highest on average in Texas and lowest in Hawaii. However, there was large variation in damage and plant performance among gardens within venues. Our results suggest that more rapid aboveground growth rates contribute to T. sebifera's success in both the invasive and native ranges independent of aboveground herbivory. However, strong variation among sites indicates that T. sebifera plants from invasive populations only have a strong advantage in a subset of sites in Texas. Published by Oxford University Press on behalf of the Annals of Botany Company.

Specific Relations between Neurodevelopmental Abilities and White Matter Microstructure in Children Born Preterm

ERIC Educational Resources Information Center

Counsell, Serena J.; Edwards, A. David; Chew, Andrew T. M.; Anjari, Mustafa; Dyet, Leigh E.; Srinivasan, Latha; Boardman, James P.; Allsop, Joanna M.; Hajnal, Joseph V.; Rutherford, Mary A.; Cowan, Frances M.

2008-01-01

Survivors of preterm birth have a high incidence of neurodevelopmental impairment which is not explained by currently understood brain abnormalities. The aim of this study was to test the hypothesis that the neurodevelopmental abilities of 2-year-old children who were born preterm and who had no evidence of focal abnormality on conventional MR…

A Lateralization of Function Approach to Sex Differences in Spatial Ability: A Reexamination

ERIC Educational Resources Information Center

Rilea, Stacy L.

2008-01-01

The current study assessed the lateralization of function hypothesis (Rilea, S. L., Roskos-Ewoldsen, B., & Boles, D. (2004). "Sex differences in spatial ability: A lateralization of function approach." "Brain and Cognition," 56, 332-343) which suggested that it was the interaction of brain organization and the type of spatial task that led to sex…

In Defense of the Play-Creativity Hypothesis

ERIC Educational Resources Information Center

Silverman, Irwin W.

2016-01-01

The hypothesis that pretend play facilitates the creative thought process in children has received a great deal of attention. In a literature review, Lillard et al. (2013, p. 8) concluded that the evidence for this hypothesis was "not convincing." This article focuses on experimental and training studies that have tested this hypothesis.…

The gender similarities hypothesis.

PubMed

Hyde, Janet Shibley

2005-09-01

The differences model, which argues that males and females are vastly different psychologically, dominates the popular media. Here, the author advances a very different view, the gender similarities hypothesis, which holds that males and females are similar on most, but not all, psychological variables. Results from a review of 46 meta-analyses support the gender similarities hypothesis. Gender differences can vary substantially in magnitude at different ages and depend on the context in which measurement occurs. Overinflated claims of gender differences carry substantial costs in areas such as the workplace and relationships. Copyright (c) 2005 APA, all rights reserved.

Hypothesis testing in hydrology: Theory and practice

NASA Astrophysics Data System (ADS)

Kirchner, James; Pfister, Laurent

2017-04-01

Well-posed hypothesis tests have spurred major advances in hydrological theory. However, a random sample of recent research papers suggests that in hydrology, as in other fields, hypothesis formulation and testing rarely correspond to the idealized model of the scientific method. Practices such as "p-hacking" or "HARKing" (Hypothesizing After the Results are Known) are major obstacles to more rigorous hypothesis testing in hydrology, along with the well-known problem of confirmation bias - the tendency to value and trust confirmations more than refutations - among both researchers and reviewers. Hypothesis testing is not the only recipe for scientific progress, however: exploratory research, driven by innovations in measurement and observation, has also underlain many key advances. Further improvements in observation and measurement will be vital to both exploratory research and hypothesis testing, and thus to advancing the science of hydrology.

The relation between finger gnosis and mathematical ability: why redeployment of neural circuits best explains the finding.

PubMed

Penner-Wilger, Marcie; Anderson, Michael L

2013-01-01

This paper elaborates a novel hypothesis regarding the observed predictive relation between finger gnosis and mathematical ability. In brief, we suggest that these two cognitive phenomena have overlapping neural substrates, as the result of the re-use ("redeployment") of part of the finger gnosis circuit for the purpose of representing numbers. We offer some background on the relation and current explanations for it; an outline of our alternate hypothesis; some evidence supporting redeployment over current views; and a plan for further research.

Explorations in statistics: hypothesis tests and P values.

PubMed

Curran-Everett, Douglas

2009-06-01

Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This second installment of Explorations in Statistics delves into test statistics and P values, two concepts fundamental to the test of a scientific null hypothesis. The essence of a test statistic is that it compares what we observe in the experiment to what we expect to see if the null hypothesis is true. The P value associated with the magnitude of that test statistic answers this question: if the null hypothesis is true, what proportion of possible values of the test statistic are at least as extreme as the one I got? Although statisticians continue to stress the limitations of hypothesis tests, there are two realities we must acknowledge: hypothesis tests are ingrained within science, and the simple test of a null hypothesis can be useful. As a result, it behooves us to explore the notions of hypothesis tests, test statistics, and P values.

Dynamic adsorption properties of n-alkyl glucopyranosides determine their ability to inhibit cytolysis mediated by acoustic cavitation.

PubMed

Sostaric, Joe Z; Miyoshi, Norio; Cheng, Jason Y; Riesz, Peter

2008-10-09

Suspensions of human leukemia (HL-60) cells readily undergo cytolysis when exposed to ultrasound above the acoustic cavitation threshold. However, n-alkyl glucopyranosides (hexyl, heptyl, and octyl) completely inhibit ultrasound-induced (1057 kHz) cytolysis (Sostaric, et al. Free Radical Biol. Med. 2005, 39, 1539-1548). The efficacy of protection from ultrasound-induced cytolysis was determined by the n-alkyl chain length of the glucopyranosides, indicating that protection efficacy depended on adsorption of n-alkyl glucopyranosides to the gas/solution interface of cavitation bubbles and/or the lipid membrane of cells. The current study tests the hypothesis that "sonoprotection" (i.e., protection of cells from ultrasound-induced cytolysis) in vitro depends on the adsorption of glucopyranosides at the gas/solution interface of cavitation bubbles. To test this hypothesis, the effect of ultrasound frequency (from 42 kHz to 1 MHz) on the ability of a homologous series of n-alkyl glucopyranosides to protect cells from ultrasound-induced cytolysis was investigated. It is expected that ultrasound frequency will affect sonoprotection ability since the nature of the cavitation bubble field will change. This will affect the relative importance of the possible mechanisms for ultrasound-induced cytolysis. Additionally, ultrasound frequency will affect the lifetime and rate of change of the surface area of cavitation bubbles, hence the dynamically controlled adsorption of glucopyranosides to their surface. The data support the hypothesis that sonoprotection efficiency depends on the ability of glucopyranosides to adsorb at the gas/solution interface of cavitation bubbles.

Gender and the hygiene hypothesis.

PubMed

Clough, Sharyn

2011-02-01

The hygiene hypothesis offers an explanation for the correlation, well-established in the industrialized nations of North and West, between increased hygiene and sanitation, and increased rates of asthma and allergies. Recent studies have added to the scope of the hypothesis, showing a link between decreased exposure to certain bacteria and parasitic worms, and increased rates of depression and intestinal auto-immune disorders, respectively. What remains less often discussed in the research on these links is that women have higher rates than men of asthma and allergies, as well as many auto-immune disorders, and also depression. The current paper introduces a feminist understanding of gender socialization to the epidemiological and immunological picture. That standards of cleanliness are generally higher for girls than boys, especially under the age of five when children are more likely to be under close adult supervision, is a robust phenomenon in industrialized nations, and some research points to a cross-cultural pattern. I conclude that, insofar as the hygiene hypothesis successfully identifies standards of hygiene and sanitation as mediators of immune health, then attention to the relevant patterns of gender socialization is important. The review also makes clear that adding a feminist analysis of gender socialization to the hygiene hypothesis helps explain variation in morbidity rates not addressed by other sources and responds to a number of outstanding puzzles in current research. Alternative explanations for the sex differences in the relevant morbidity rates are also discussed (e.g., the effects of estrogens). Finally, new sources of evidence for the hygiene hypothesis are suggested in the form of cross-cultural and other natural experiments. Copyright © 2010 Elsevier Ltd. All rights reserved.

Evolution of limited seed dispersal ability on gypsum islands.

PubMed

Schenk, John J

2013-09-01

Dispersal is a major feature of plant evolution that has many advantages but is not always favored. Wide dispersal, for example, leads to greater seed loss in oceanic-island endemics, and evolution has favored morphologies that limit dispersal. I tested the hypothesis that selection favored limited dispersal on gypsum islands in western North America, where edaphic communities are sparsely vegetated except for a specialized flora that competes poorly with the surrounding flora. • I applied a series of comparative phylogenetic approaches to gypsophilic species of Mentzelia section Bartonia (Loasaceae) to investigate the evolution of limited dispersal function in seed wings, which increase primary dispersal by wind. Through these tests, I determined whether narrowed wings were selected for in gypsophilic species. • Gypsophily was derived four to seven times. Seed area was not significantly correlated with gypsophily or wing area. Wing area was significantly smaller in the derived gypsum endemics, supporting the hypothesis in favor of limited dispersal function. A model-fitting approach identified two trait optima in wing area, with gypsum endemics having a lower optimum. • Evolution into novel ecologies influences morphological evolution. Morphological characters have been selected for limited dispersal following evolution onto gypsum islands. Selection for limited dispersal ability has occurred across animals and plants, both in oceanic and terrestrial systems, which suggests that reduced dispersal ability may be a general process: selection favors limited dispersal if the difference in survival between the habitat of the parent and the surrounding area is great enough.

Hypertext Interchange Using ICA.

ERIC Educational Resources Information Center

Rada, Roy; And Others

1995-01-01

Discusses extended ICA (Integrated Chameleon Architecture), a public domain toolset for generating text-to-hypertext translators. A system called SGML-MUCH has been developed using E-ICA (Extended Integrated Chameleon Architecture) and is presented as a case study with converters for the hypertext systems MUCH, Guide, Hyperties, and Toolbook.…

Nonword repetition ability of children who do and do not stutter and covert repair hypothesis.

PubMed

Bakhtiar, Mehdi; Abad, Ali Dehqan Ahmad; Panahi, Mohammad Sadegh Seif

2007-08-01

Stuttering has a life span incidence and it significantly impacts academic, social, emotional and vocational achievements of patients who stutter. The purpose of the present study was to examine phonological encoding in young children who stutter (CWS) during a non word repetition task and to test the covert repair hypothesis (CRH) and phonological skills in Persian native children. The study was conducted among 12 CWS and 12 children who do not stutter (CWNS) between the ages of 5.1 and 7.10 at the rehabilitation clinics in Tehran. A list of 40 bisyllabic and trisyllabic nonwords was used in a nonword repetition task to collect information about the following dependent variables: (a) reaction times (RTs), (b) the number of phonological errors (PEs) and (c) nonword length. An independent sample T-test was performed to compare means of PEs and RTs between the two groups and a paired t-test for analysis of nonword length impacts. Results indicated that the CWS had a slightly poor performance than CWNS but there was no significant difference between the groups. Also, the differences between bisyllabic and trisyllabic nonwords were significant for phonological errors but not for reaction times. In general, it is concluded that CWS might not have a gross problem in phonological retrieval of the novel phonological context even with increase in syllable length. Also, some predictions of CRH were not supported by this research. However, further research into this possibility may shed light on the emergence and characteristics of childhood stuttering.

The relation between finger gnosis and mathematical ability: why redeployment of neural circuits best explains the finding

PubMed Central

Penner-Wilger, Marcie; Anderson, Michael L.

2013-01-01

This paper elaborates a novel hypothesis regarding the observed predictive relation between finger gnosis and mathematical ability. In brief, we suggest that these two cognitive phenomena have overlapping neural substrates, as the result of the re-use (“redeployment”) of part of the finger gnosis circuit for the purpose of representing numbers. We offer some background on the relation and current explanations for it; an outline of our alternate hypothesis; some evidence supporting redeployment over current views; and a plan for further research. PMID:24367341

Evidence of Shifting Standards in Judgments of Male and Female Parents' Job-Related Ability

ERIC Educational Resources Information Center

Fuegen, Kathleen; Endicott, Nicole F.

2010-01-01

We tested the hypothesis, derived from the shifting standards model of stereotyping, that parenthood would polarize judgments of men's and women's job-related ability. One hundred thirty-five attorneys evaluated the resume of a recent law school graduate. The resume depicted the graduate as male or female and as either single or married with two…

Brain reserve hypothesis in dementia.

PubMed

Fratiglioni, Laura; Wang, Hui-Xin

2007-08-01

The concept of brain reserve refers to the ability to tolerate the age-related changes and the disease related pathology in the brain without developing clear clinical symptoms or signs. A considerable body of biological research has documented that a number of factors including education, work complexity, social network, and leisure activities may contribute to this reserve allowing cognitive function to be maintained in old ages. Epidemiological studies have also related these factors to the development of dementia, suggesting that intellectual challenges experienced across the whole life span may increase the brain reserve and be crucial for the occurrence of dementia symptoms in late life. This paper is a systematic review of the published epidemiological studies on this topic. The availability of numerous epidemiological and biological data investigating the reserve hypothesis in dementia permits some preliminary conclusions. High education, adult-life occupational work complexity, as well as a mentally and socially integrated lifestyle in late life could postpone the onset of clinical dementia and AD. The relevance of physical activity itself remains in debate, as most physical activities include also social and mental stimulation. Leisure activities with all three components--physical, mental and social--seem to have the most beneficial effect. Delaying dementia onset by five years would halve dementia prevalence and substantially decrease the number of dementia cases in the community.

Killing Me Softly: The Fetal Origins Hypothesis*

PubMed Central

Almond, Douglas

2013-01-01

In the epidemiological literature, the fetal origins hypothesis associated with David J. Barker posits that chronic, degenerative conditions of adult health, including heart disease and type 2 diabetes, may be triggered by circumstance decades earlier, in utero nutrition in particular. Economists have expanded on this hypothesis, investigating a broader range of fetal shocks and circumstances and have found a wealth of later-life impacts on outcomes including test scores, educational attainment, and income, along with health. In the process, they have provided some of the most credible observational evidence in support of the hypothesis. The magnitude of the impacts is generally large. Thus, the fetal origins hypothesis has not only survived contact with economics, but has flourished. PMID:25152565

Rejecting the equilibrium-point hypothesis.

PubMed

Gottlieb, G L

1998-01-01

The lambda version of the equilibrium-point (EP) hypothesis as developed by Feldman and colleagues has been widely used and cited with insufficient critical understanding. This article offers a small antidote to that lack. First, the hypothesis implicitly, unrealistically assumes identical transformations of lambda into muscle tension for antagonist muscles. Without that assumption, its definitions of command variables R, C, and lambda are incompatible and an EP is not defined exclusively by R nor is it unaffected by C. Second, the model assumes unrealistic and unphysiological parameters for the damping properties of the muscles and reflexes. Finally, the theory lacks rules for two of its three command variables. A theory of movement should offer insight into why we make movements the way we do and why we activate muscles in particular patterns. The EP hypothesis offers no unique ideas that are helpful in addressing either of these questions.

ON THE SUBJECT OF HYPOTHESIS TESTING

PubMed Central

Ugoni, Antony

1993-01-01

In this paper, the definition of a statistical hypothesis is discussed, and the considerations which need to be addressed when testing a hypothesis. In particular, the p-value, significance level, and power of a test are reviewed. Finally, the often quoted confidence interval is given a brief introduction. PMID:17989768

Hypothesis Testing in Task-Based Interaction

ERIC Educational Resources Information Center

Choi, Yujeong; Kilpatrick, Cynthia

2014-01-01

Whereas studies show that comprehensible output facilitates L2 learning, hypothesis testing has received little attention in Second Language Acquisition (SLA). Following Shehadeh (2003), we focus on hypothesis testing episodes (HTEs) in which learners initiate repair of their own speech in interaction. In the context of a one-way information gap…

On the Weyl curvature hypothesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoica, Ovidiu Cristinel, E-mail: holotronix@gmail.com

2013-11-15

The Weyl curvature hypothesis of Penrose attempts to explain the high homogeneity and isotropy, and the very low entropy of the early universe, by conjecturing the vanishing of the Weyl tensor at the Big-Bang singularity. In previous papers it has been proposed an equivalent form of Einstein’s equation, which extends it and remains valid at an important class of singularities (including in particular the Schwarzschild, FLRW, and isotropic singularities). Here it is shown that if the Big-Bang singularity is from this class, it also satisfies the Weyl curvature hypothesis. As an application, we study a very general example of cosmologicalmore » models, which generalizes the FLRW model by dropping the isotropy and homogeneity constraints. This model also generalizes isotropic singularities, and a class of singularities occurring in Bianchi cosmologies. We show that the Big-Bang singularity of this model is of the type under consideration, and satisfies therefore the Weyl curvature hypothesis. -- Highlights: •The singularities we introduce are described by finite geometric/physical objects. •Our singularities have smooth Riemann and Weyl curvatures. •We show they satisfy Penrose’s Weyl curvature hypothesis (Weyl=0 at singularities). •Examples: FLRW, isotropic singularities, an extension of Schwarzschild’s metric. •Example: a large class of singularities which may be anisotropic and inhomogeneous.« less

Should we stop thinking about inhibition? Searching for individual and age differences in inhibition ability.

PubMed

Rey-Mermet, Alodie; Gade, Miriam; Oberauer, Klaus

2018-04-01

Inhibition is often conceptualized as a unitary construct reflecting the ability to ignore and suppress irrelevant information. At the same time, it has been subdivided into inhibition of prepotent responses (i.e., the ability to stop dominant responses) and resistance to distracter interference (i.e., the ability to ignore distracting information). The present study investigated the unity and diversity of inhibition as a psychometric construct, and tested the hypothesis of an inhibition deficit in older age. We measured inhibition in young and old adults with 11 established laboratory tasks: antisaccade, stop-signal, color Stroop, number Stroop, arrow flanker, letter flanker, Simon, global-local, positive and negative compatibility tasks, and n-2 repetition costs in task switching. In both age groups, the inhibition measures from individual tasks had good reliabilities, but correlated only weakly among each other. Structural equation modeling identified a 2-factor model with factors for inhibition of prepotent responses and resistance to distracter interference. Older adults scored worse in the inhibition of prepotent response, but better in the resistance to distracter interference. However, the model had low explanatory power. Together, these findings call into question inhibition as a psychometric construct and the hypothesis of an inhibition deficit in older age. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Hypothesis Testing in the Real World

ERIC Educational Resources Information Center

Miller, Jeff

2017-01-01

Critics of null hypothesis significance testing suggest that (a) its basic logic is invalid and (b) it addresses a question that is of no interest. In contrast to (a), I argue that the underlying logic of hypothesis testing is actually extremely straightforward and compelling. To substantiate that, I present examples showing that hypothesis…

Leadership and satisfaction in tennis: examination of congruence, gender, and ability.

PubMed

Riemer, H A; Toon, K

2001-09-01

The study investigated: (a) the congruency hypothesis, and (b) the member characteristics hypotheses relating to ability and gender, of Chelladurai's (1978) Multidimensional Model of Leadership. One hundred forty-eight tennis players (77 women) competing at the NCAA Division I and II Tennis Championship level participated in the study. Results indicated athlete satisfaction (Athlete Satisfaction Scale; Riemer & Chelladurai, 1998) was not dependent on the congruence between preferred and perceived leadership behavior. Other results indicated that an athlete's level of ability did affect preferences for leadership behavior. Further, while athlete gender was responsible for some variance in preferences for autocratic behavior and positive feedback behavior, the gender of the athlete's coach had a significant effect on the athlete's preferences for social support behavior.

Sagnac effect and Ritz ballistic hypothesis (Review)

NASA Astrophysics Data System (ADS)

Malykin, G. B.

2010-12-01

It is shown that the Ritz ballistic hypothesis, which is based on the vector summation of the speed of light with the velocity of the radiation source, contradicts the fact of existence of the Sagnac effect. Based on a particular example of a three-mirror ring interferometer, it is shown that the application of the Ritz ballistic hypothesis leads to an obvious calculation error, namely, to the appearance of a difference in the propagation times of counterpropagating waves in the absence of rotation. A review is given of experiments and of results of processing of astronomical observations and discussions devoted to testing the Ritz ballistic hypothesis. A number of other physical phenomena that refute the Ritz ballistic hypothesis are considered.

The over-pruning hypothesis of autism.

PubMed

Thomas, Michael S C; Davis, Rachael; Karmiloff-Smith, Annette; Knowland, Victoria C P; Charman, Tony

2016-03-01

This article outlines the over-pruning hypothesis of autism. The hypothesis originates in a neurocomputational model of the regressive sub-type (Thomas, Knowland & Karmiloff-Smith, 2011a, 2011b). Here we develop a more general version of the over-pruning hypothesis to address heterogeneity in the timing of manifestation of ASD, including new computer simulations which reconcile the different observed developmental trajectories (early onset, late onset, regression) via a single underlying atypical mechanism; and which show how unaffected siblings of individuals with ASD may differ from controls either by inheriting a milder version of the pathological mechanism or by co-inheriting the risk factors without the pathological mechanism. The proposed atypical mechanism involves overly aggressive synaptic pruning in infancy and early childhood, an exaggeration of a normal phase of brain development. We show how the hypothesis generates novel predictions that differ from existing theories of ASD including that (1) the first few months of development in ASD will be indistinguishable from typical, and (2) the earliest atypicalities in ASD will be sensory and motor rather than social. Both predictions gain cautious support from emerging longitudinal studies of infants at-risk of ASD. We review evidence consistent with the over-pruning hypothesis, its relation to other current theories (including C. Frith's under-pruning proposal; C. Frith, 2003, 2004), as well as inconsistent data and current limitations. The hypothesis situates causal accounts of ASD within a framework of protective and risk factors (Newschaffer et al., 2012); clarifies different versions of the broader autism phenotype (i.e. the implication of observed similarities between individuals with autism and their family members); and integrates data from multiple disciplines, including behavioural studies, neuroscience studies, genetics, and intervention studies. © 2015 John Wiley & Sons Ltd.

Action perception as hypothesis testing.

PubMed

Donnarumma, Francesco; Costantini, Marcello; Ambrosini, Ettore; Friston, Karl; Pezzulo, Giovanni

2017-04-01

We present a novel computational model that describes action perception as an active inferential process that combines motor prediction (the reuse of our own motor system to predict perceived movements) and hypothesis testing (the use of eye movements to disambiguate amongst hypotheses). The system uses a generative model of how (arm and hand) actions are performed to generate hypothesis-specific visual predictions, and directs saccades to the most informative places of the visual scene to test these predictions - and underlying hypotheses. We test the model using eye movement data from a human action observation study. In both the human study and our model, saccades are proactive whenever context affords accurate action prediction; but uncertainty induces a more reactive gaze strategy, via tracking the observed movements. Our model offers a novel perspective on action observation that highlights its active nature based on prediction dynamics and hypothesis testing. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

75 FR 68177 - Airworthiness Directives; The Boeing Company Model 757 and 767 Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-05

... and FUEL CONFIG discrete signals from the fuel quantity processor unit, and alerts the flightcrew of a... the FUEL CONFIG discrete signal, which disables both the FUEL CONFIG and LOW FUEL messages. Such... depleted below the minimum of 2,200 pounds. The EICAS receives both the LOW FUEL and FUEL CONFIG discrete...

The Bergschrund Hypothesis Revisited

NASA Astrophysics Data System (ADS)

Sanders, J. W.; Cuffey, K. M.; MacGregor, K. R.

2009-12-01

After Willard Johnson descended into the Lyell Glacier bergschrund nearly 140 years ago, he proposed that the presence of the bergschrund modulated daily air temperature fluctuations and enhanced freeze-thaw processes. He posited that glaciers, through their ability to birth bergschrunds, are thus able to induce rapid cirque headwall retreat. In subsequent years, many researchers challenged the bergschrund hypothesis on grounds that freeze-thaw events did not occur at depth in bergschrunds. We propose a modified version of Johnson’s original hypothesis: that bergschrunds maintain subfreezing temperatures at values that encourage rock fracture via ice lensing because they act as a cold air trap in areas that would otherwise be held near zero by temperate glacial ice. In support of this claim we investigated three sections of the bergschrund at the West Washmawapta Glacier, British Columbia, Canada, which sits in an east-facing cirque. During our bergschrund reconnaissance we installed temperature sensors at multiple elevations, light sensors at depth in 2 of the 3 locations and painted two 1 m2 sections of the headwall. We first emphasize bergschrunds are not wanting for ice: verglas covers significant fractions of the headwall and icicles dangle from the base of bödens or overhanging rocks. If temperature, rather than water availability, is the limiting factor governing ice-lensing rates, our temperature records demonstrate that the bergschrund provides a suitable environment for considerable rock fracture. At the three sites (north, west, and south walls), the average temperature at depth from 9/3/2006 to 8/6/2007 was -3.6, -3.6, and -2.0 °C, respectively. During spring, when we observed vast amounts of snow melt trickle in to the bergschrund, temperatures averaged -3.7, -3.8, and -2.2 °C, respectively. Winter temperatures are even lower: -8.5, -7.3, and -2.4 °C, respectively. Values during the following year were similar. During the fall, diurnal

Plastid genome structure and loss of photosynthetic ability in the parasitic genus Cuscuta.

PubMed

Revill, Meredith J W; Stanley, Susan; Hibberd, Julian M

2005-09-01

The genus Cuscuta (dodder) is composed of parasitic plants, some species of which appear to be losing the ability to photosynthesize. A molecular phylogeny was constructed using 15 species of Cuscuta in order to assess whether changes in photosynthetic ability and alterations in structure of the plastid genome relate to phylogenetic position within the genus. The molecular phylogeny provides evidence for four major clades within Cuscuta. Although DNA blot analysis showed that Cuscuta species have smaller plastid genomes than tobacco, and that plastome size varied significantly even within one Cuscuta clade, dot blot analysis indicated that the dodders possess homologous sequence to 101 genes from the tobacco plastome. Evidence is provided for significant rates of DNA transfer from plastid to nucleus in Cuscuta. Size and structure of Cuscuta plastid genomes, as well as photosynthetic ability, appear to vary independently of position within the phylogeny, thus supporting the hypothesis that within Cuscuta photosynthetic ability and organization of the plastid genome are changing in an unco-ordinated manner.

Musical expertise and the ability to imagine loudness.

PubMed

Bishop, Laura; Bailes, Freya; Dean, Roger T

2013-01-01

Most perceived parameters of sound (e.g. pitch, duration, timbre) can also be imagined in the absence of sound. These parameters are imagined more veridically by expert musicians than non-experts. Evidence for whether loudness is imagined, however, is conflicting. In music, the question of whether loudness is imagined is particularly relevant due to its role as a principal parameter of performance expression. This study addressed the hypothesis that the veridicality of imagined loudness improves with increasing musical expertise. Experts, novices and non-musicians imagined short passages of well-known classical music under two counterbalanced conditions: 1) while adjusting a slider to indicate imagined loudness of the music and 2) while tapping out the rhythm to indicate imagined timing. Subtests assessed music listening abilities and working memory span to determine whether these factors, also hypothesised to improve with increasing musical expertise, could account for imagery task performance. Similarity between each participant's imagined and listening loudness profiles and reference recording intensity profiles was assessed using time series analysis and dynamic time warping. The results suggest a widespread ability to imagine the loudness of familiar music. The veridicality of imagined loudness tended to be greatest for the expert musicians, supporting the predicted relationship between musical expertise and musical imagery ability.

Musical Expertise and the Ability to Imagine Loudness

PubMed Central

Bishop, Laura; Bailes, Freya; Dean, Roger T.

2013-01-01

Most perceived parameters of sound (e.g. pitch, duration, timbre) can also be imagined in the absence of sound. These parameters are imagined more veridically by expert musicians than non-experts. Evidence for whether loudness is imagined, however, is conflicting. In music, the question of whether loudness is imagined is particularly relevant due to its role as a principal parameter of performance expression. This study addressed the hypothesis that the veridicality of imagined loudness improves with increasing musical expertise. Experts, novices and non-musicians imagined short passages of well-known classical music under two counterbalanced conditions: 1) while adjusting a slider to indicate imagined loudness of the music and 2) while tapping out the rhythm to indicate imagined timing. Subtests assessed music listening abilities and working memory span to determine whether these factors, also hypothesised to improve with increasing musical expertise, could account for imagery task performance. Similarity between each participant’s imagined and listening loudness profiles and reference recording intensity profiles was assessed using time series analysis and dynamic time warping. The results suggest a widespread ability to imagine the loudness of familiar music. The veridicality of imagined loudness tended to be greatest for the expert musicians, supporting the predicted relationship between musical expertise and musical imagery ability. PMID:23460791

The Sapir-Whorf hypothesis and inference under uncertainty.

PubMed

Regier, Terry; Xu, Yang

2017-11-01

The Sapir-Whorf hypothesis holds that human thought is shaped by language, leading speakers of different languages to think differently. This hypothesis has sparked both enthusiasm and controversy, but despite its prominence it has only occasionally been addressed in computational terms. Recent developments support a view of the Sapir-Whorf hypothesis in terms of probabilistic inference. This view may resolve some of the controversy surrounding the Sapir-Whorf hypothesis, and may help to normalize the hypothesis by linking it to established principles that also explain other phenomena. On this view, effects of language on nonlinguistic cognition or perception reflect standard principles of inference under uncertainty. WIREs Cogn Sci 2017, 8:e1440. doi: 10.1002/wcs.1440 For further resources related to this article, please visit the WIREs website. © 2017 Wiley Periodicals, Inc.

Multiple sclerosis: a geographical hypothesis.

PubMed

Carlyle, I P

1997-12-01

Multiple sclerosis remains a rare neurological disease of unknown aetiology, with a unique distribution, both geographically and historically. Rare in equatorial regions, it becomes increasingly common in higher latitudes; historically, it was first clinically recognized in the early nineteenth century. A hypothesis, based on geographical reasoning, is here proposed: that the disease is the result of a specific vitamin deficiency. Different individuals suffer the deficiency in separate and often unique ways. Evidence to support the hypothesis exists in cultural considerations, in the global distribution of the disease, and in its historical prevalence.

UV-radiation-induced electron emission by hormones. Hypothesis for specific communication mechanisms

NASA Astrophysics Data System (ADS)

Getoff, Nikola

2009-11-01

The highlights of recently observed electron emission from electronically excited sexual hormones (17β-estradiol, progesterone, testosterone) and the phytohormone genistein in polar media are briefly reviewed. The electron yield, Q(e aq-), dependence from substrate concentration, hormone structure, polarity of solvent, absorbed energy and temperature are discussed. The hormones reactivity with e aq- and efficiency in electron transfer ensure them the ability to communicate with other biological systems in an organism. A hypothesis is presented for the explanation of the mechanisms of the distinct recognition of signals transmitted by electrons, originating from different types of hormones to receiving centres. Biological consequences of the electron emission in respect to cancer are mentioned.

Spatial Abilities in an Elective Course of Applied Anatomy after a Problem-Based Learning Curriculum

ERIC Educational Resources Information Center

Langlois, Jean; Wells, George A.; Lecourtois, Marc; Bergeron, Germain; Yetisir, Elizabeth; Martin, Marcel

2009-01-01

A concern on the level of anatomy knowledge reached after a problem-based learning curriculum has been documented in the literature. Spatial anatomy, arguably the highest level in anatomy knowledge, has been related to spatial abilities. Our first objective was to test the hypothesis that residents are interested in a course of applied anatomy…

Mefloquine use, psychosis, and violence: A retinoid toxicity hypothesis

PubMed Central

Mawson, Anthony R.

2013-01-01

Mefloquine use has been linked to severe gastrointestinal and neuropsychiatric adverse effects, including cognitive disturbances, anxiety, depression, psychosis, and violence. The adverse effects of the drug are thought to result from the secondary consequences of hepatocellular injury; in fact, mefloquine is known to cause a transient, anicteric chemical hepatitis. However, the mechanism of mefloquine-associated liver damage and the associated neuropsychiatric and behavioral effects of the drug are not well understood. Mefloquine and other 8-amino-quinolines are the only antimalarial drugs that target the liver-stage malaria parasites, which selectively absorb vitamin A from the host. Vitamin A is also stored mainly in the liver, in potentially poisonous concentrations. These observations suggest that both the therapeutic effectiveness of mefloquine and its adverse effects are related to the ability of the 8-aminoquinolines to alter the metabolism of retinoids (vitamin A and its congeners). Several lines of evidence support the hypothesis that mefloquine neurotoxicity and other adverse effects reflect an endogenous form of hypervitaminosis A due to a process involving: mefloquine-induced dehydrogenase inhibition; the accumulation of retinoids in the liver; retinoid-induced hepatocellular damage; the spillage of stored retinoids into the circulation; and the transport of these compounds to the gut and brain in toxic concentrations. The retinoid hypothesis could be tested clinically by comparing cases of mefloquine toxicity and untreated controls in terms of retinoid profiles (retinol, retinyl esters, percent retinyl esters, and retinoic acid). Subject to such tests, retinoid profiling could provide an indicator for assessing mefloquine-associated adverse effects. PMID:23852388

Mefloquine use, psychosis, and violence: a retinoid toxicity hypothesis.

PubMed

Mawson, Anthony

2013-07-15

Mefloquine use has been linked to severe gastrointestinal and neuropsychiatric adverse effects, including cognitive disturbances, anxiety, depression, psychosis, and violence. The adverse effects of the drug are thought to result from the secondary consequences of hepatocellular injury; in fact, mefloquine is known to cause a transient, anicteric chemical hepatitis. However, the mechanism of mefloquine-associated liver damage and the associated neuropsychiatric and behavioral effects of the drug are not well understood. Mefloquine and other 8-amino-quinolines are the only antimalarial drugs that target the liver-stage malaria parasites, which selectively absorb vitamin A from the host. Vitamin A is also stored mainly in the liver, in potentially poisonous concentrations. These observations suggest that both the therapeutic effectiveness of mefloquine and its adverse effects are related to the ability of the 8-aminoquinolines to alter the metabolism of retinoids (vitamin A and its congeners). Several lines of evidence support the hypothesis that mefloquine neurotoxicity and other adverse effects reflect an endogenous form of hypervitaminosis A due to a process involving: mefloquine-induced dehydrogenase inhibition; the accumulation of retinoids in the liver; retinoid-induced hepatocellular damage; the spillage of stored retinoids into the circulation; and the transport of these compounds to the gut and brain in toxic concentrations. The retinoid hypothesis could be tested clinically by comparing cases of mefloquine toxicity and untreated controls in terms of retinoid profiles (retinol, retinyl esters, percent retinyl esters, and retinoic acid). Subject to such tests, retinoid profiling could provide an indicator for assessing mefloquine-associated adverse effects.

Jetliner Alert Systems

NASA Technical Reports Server (NTRS)

1983-01-01

NASA research and design has significantly improved crew alert systems. The Engine Indication and Crew Alerting System (EICAS), developed by Psycho-Linguistic Research Associates, is technologically advanced and able to order alerts by priority. Ames has also developed computer controlled voice synthesizers for readouts during difficult landing approaches. This is available to airplane manufacturers.

Hierarchical State-Space Estimation of Leatherback Turtle Navigation Ability

PubMed Central

Mills Flemming, Joanna; Jonsen, Ian D.; Field, Christopher A.

2010-01-01

Remotely sensed tracking technology has revealed remarkable migration patterns that were previously unknown; however, models to optimally use such data have developed more slowly. Here, we present a hierarchical Bayes state-space framework that allows us to combine tracking data from a collection of animals and make inferences at both individual and broader levels. We formulate models that allow the navigation ability of animals to be estimated and demonstrate how information can be combined over many animals to allow improved estimation. We also show how formal hypothesis testing regarding navigation ability can easily be accomplished in this framework. Using Argos satellite tracking data from 14 leatherback turtles, 7 males and 7 females, during their southward migration from Nova Scotia, Canada, we find that the circle of confusion (the radius around an animal's location within which it is unable to determine its location precisely) is approximately 96 km. This estimate suggests that the turtles' navigation does not need to be highly accurate, especially if they are able to use more reliable cues as they near their destination. Moreover, for the 14 turtles examined, there is little evidence to suggest that male and female navigation abilities differ. Because of the minimal assumptions made about the movement process, our approach can be used to estimate and compare navigation ability for many migratory species that are able to carry electronic tracking devices. PMID:21203382

Testing the hypothesis on cognitive evolution of modern humans' learning ability: current status of past-climatic approaches.

NASA Astrophysics Data System (ADS)

Yoneda, Minoru; Abe-Ouchi, Ayako; Kawahata, Hodaka; Yokoyama, Yusuke; Oguchi, Takashi

2014-05-01

The impact of climate change on human evolution is important and debating topic for many years. Since 2010, we have involved in a general joint project entitled "Replacement of Neanderthal by Modern Humans: Testing Evolutional Models of Learning", which based on a theoretical prediction that the cognitive ability related to individual and social learning divide fates of ancient humans in very unstable Late Pleistocene climate. This model predicts that the human populations which experienced a series of environmental changes would have higher rate of individual learners, while detailed reconstructions of global climate change have reported fluent and drastic change based on ice cores and stalagmites. However, we want to understand the difference between anatomically modern human which survived and the other archaic extinct humans including European Neanderthals and Asian Denisovans. For this purpose the global synchronized change is not useful for understanding but the regional difference in the amplitude and impact of climate change is the information required. Hence, we invited a geophysicist busing Global Circulation Model to reconstruct the climatic distribution and temporal change in a continental scale. At the same time, some geochemists and geographers construct a database of local climate changes recorded in different proxies. At last, archaeologists and anthropologists tried to interpret the emergence and disappearance of human species in Europe and Asia on the reconstructed past climate maps using some tools, such as Eco-cultural niche model. Our project will show the regional difference in climate change and related archaeological events and its impact on the evolution of learning ability of modern humans.

Cortical activity patterns predict speech discrimination ability

PubMed Central

Engineer, Crystal T; Perez, Claudia A; Chen, YeTing H; Carraway, Ryan S; Reed, Amanda C; Shetake, Jai A; Jakkamsetti, Vikram; Chang, Kevin Q; Kilgard, Michael P

2010-01-01

Neural activity in the cerebral cortex can explain many aspects of sensory perception. Extensive psychophysical and neurophysiological studies of visual motion and vibrotactile processing show that the firing rate of cortical neurons averaged across 50–500 ms is well correlated with discrimination ability. In this study, we tested the hypothesis that primary auditory cortex (A1) neurons use temporal precision on the order of 1–10 ms to represent speech sounds shifted into the rat hearing range. Neural discrimination was highly correlated with behavioral performance on 11 consonant-discrimination tasks when spike timing was preserved and was not correlated when spike timing was eliminated. This result suggests that spike timing contributes to the auditory cortex representation of consonant sounds. PMID:18425123

Debates—Hypothesis testing in hydrology: Theory and practice

NASA Astrophysics Data System (ADS)

Pfister, Laurent; Kirchner, James W.

2017-03-01

The basic structure of the scientific method—at least in its idealized form—is widely championed as a recipe for scientific progress, but the day-to-day practice may be different. Here, we explore the spectrum of current practice in hypothesis formulation and testing in hydrology, based on a random sample of recent research papers. This analysis suggests that in hydrology, as in other fields, hypothesis formulation and testing rarely correspond to the idealized model of the scientific method. Practices such as "p-hacking" or "HARKing" (Hypothesizing After the Results are Known) are major obstacles to more rigorous hypothesis testing in hydrology, along with the well-known problem of confirmation bias—the tendency to value and trust confirmations more than refutations—among both researchers and reviewers. Nonetheless, as several examples illustrate, hypothesis tests have played an essential role in spurring major advances in hydrological theory. Hypothesis testing is not the only recipe for scientific progress, however. Exploratory research, driven by innovations in measurement and observation, has also underlain many key advances. Further improvements in observation and measurement will be vital to both exploratory research and hypothesis testing, and thus to advancing the science of hydrology.

Genome-wide estimates of inbreeding in unrelated individuals and their association with cognitive ability.

PubMed

Power, Robert A; Nagoshi, Craig; DeFries, John C; Plomin, Robert

2014-03-01

The consequence of reduced cognitive ability from inbreeding has long been investigated, mainly restricted to cousin-cousin marriages. Molecular genetic techniques now allow us to test the relationship between increased ancestral inbreeding and cognitive ability in a population of traditionally unrelated individuals. In a representative UK sample of 2329 individuals, we used genome-wide SNP data to estimate the percentage of the genome covered by runs of homozygous SNPs (ROH). This was tested for association with general cognitive ability, as well as measures of verbal and non-verbal ability. Further, association was tested between these traits and specific ROH. Burden of ROH was not associated with cognitive ability after correction for multiple testing, although burden of ROH was nominally associated with increased non-verbal cognitive ability (P=0.03). Moreover, although no individual ROH was significantly associated with cognitive ability, there was a significant bias towards increased cognitive ability in carriers of ROH (P=0.002). A potential explanation for these results is increased positive assortative mating in spouses with higher cognitive ability, although we found no evidence in support of this hypothesis in a separate sample. Reduced minor allele frequency across the genome was associated with higher cognitive ability, which could contribute to an apparent increase in ROH. This may reflect minor alleles being more likely to be deleterious.

Genome-wide estimates of inbreeding in unrelated individuals and their association with cognitive ability

PubMed Central

Power, Robert A; Nagoshi, Craig; DeFries, John C; Donnelly, Peter; Barroso, Ines; Blackwell, Jenefer M; Bramon, Elvira; Brown, Matthew A; Casas, Juan P; Corvin, Aiden; Deloukas, Panos; Duncanson, Audrey; Jankowski, Janusz; Markus, Hugh S; Mathew, Christopher G; Palmer, Colin NA; Plomin, Robert; Rautanen, Anna; Sawcer, Stephen J; Trembath, Richard C; Viswanathan, Ananth C; Wood, Nicholas W; Spencer, Chris C A; Band, Gavin; Bellenguez, Céline; Freeman, Colin; Hellenthal, Garrett; Giannoulatou, Eleni; Pirinen, Matti; Pearson, Richard; Strange, Amy; Su, Zhan; Vukcevic, Damjan; Donnelly, Peter; Langford, Cordelia; Hunt, Sarah E; Edkins, Sarah; Gwilliam, Rhian; Blackburn, Hannah; Bumpstead, Suzannah J; Dronov, Serge; Gillman, Matthew; Gray, Emma; Hammond, Naomi; Jayakumar, Alagurevathi; McCann, Owen T; Liddle, Jennifer; Potter, Simon C; Ravindrarajah, Radhi; Ricketts, Michelle; Waller, Matthew; Weston, Paul; Widaa, Sara; Whittaker, Pamela; Barroso, Ines; Deloukas, Panos; Mathew, Christopher G; Blackwell, Jenefer M; Brown, Matthew A; Corvin, Aiden; Spencer, Chris C A; Plomin, Robert

2014-01-01

The consequence of reduced cognitive ability from inbreeding has long been investigated, mainly restricted to cousin–cousin marriages. Molecular genetic techniques now allow us to test the relationship between increased ancestral inbreeding and cognitive ability in a population of traditionally unrelated individuals. In a representative UK sample of 2329 individuals, we used genome-wide SNP data to estimate the percentage of the genome covered by runs of homozygous SNPs (ROH). This was tested for association with general cognitive ability, as well as measures of verbal and non-verbal ability. Further, association was tested between these traits and specific ROH. Burden of ROH was not associated with cognitive ability after correction for multiple testing, although burden of ROH was nominally associated with increased non-verbal cognitive ability (P=0.03). Moreover, although no individual ROH was significantly associated with cognitive ability, there was a significant bias towards increased cognitive ability in carriers of ROH (P=0.002). A potential explanation for these results is increased positive assortative mating in spouses with higher cognitive ability, although we found no evidence in support of this hypothesis in a separate sample. Reduced minor allele frequency across the genome was associated with higher cognitive ability, which could contribute to an apparent increase in ROH. This may reflect minor alleles being more likely to be deleterious. PMID:23860046

Biostatistics Series Module 2: Overview of Hypothesis Testing.

PubMed

Hazra, Avijit; Gogtay, Nithya

2016-01-01

Hypothesis testing (or statistical inference) is one of the major applications of biostatistics. Much of medical research begins with a research question that can be framed as a hypothesis. Inferential statistics begins with a null hypothesis that reflects the conservative position of no change or no difference in comparison to baseline or between groups. Usually, the researcher has reason to believe that there is some effect or some difference which is the alternative hypothesis. The researcher therefore proceeds to study samples and measure outcomes in the hope of generating evidence strong enough for the statistician to be able to reject the null hypothesis. The concept of the P value is almost universally used in hypothesis testing. It denotes the probability of obtaining by chance a result at least as extreme as that observed, even when the null hypothesis is true and no real difference exists. Usually, if P is < 0.05 the null hypothesis is rejected and sample results are deemed statistically significant. With the increasing availability of computers and access to specialized statistical software, the drudgery involved in statistical calculations is now a thing of the past, once the learning curve of the software has been traversed. The life sciences researcher is therefore free to devote oneself to optimally designing the study, carefully selecting the hypothesis tests to be applied, and taking care in conducting the study well. Unfortunately, selecting the right test seems difficult initially. Thinking of the research hypothesis as addressing one of five generic research questions helps in selection of the right hypothesis test. In addition, it is important to be clear about the nature of the variables (e.g., numerical vs. categorical; parametric vs. nonparametric) and the number of groups or data sets being compared (e.g., two or more than two) at a time. The same research question may be explored by more than one type of hypothesis test. While this may be

Biostatistics Series Module 2: Overview of Hypothesis Testing

PubMed Central

Hazra, Avijit; Gogtay, Nithya

2016-01-01

Hypothesis testing (or statistical inference) is one of the major applications of biostatistics. Much of medical research begins with a research question that can be framed as a hypothesis. Inferential statistics begins with a null hypothesis that reflects the conservative position of no change or no difference in comparison to baseline or between groups. Usually, the researcher has reason to believe that there is some effect or some difference which is the alternative hypothesis. The researcher therefore proceeds to study samples and measure outcomes in the hope of generating evidence strong enough for the statistician to be able to reject the null hypothesis. The concept of the P value is almost universally used in hypothesis testing. It denotes the probability of obtaining by chance a result at least as extreme as that observed, even when the null hypothesis is true and no real difference exists. Usually, if P is < 0.05 the null hypothesis is rejected and sample results are deemed statistically significant. With the increasing availability of computers and access to specialized statistical software, the drudgery involved in statistical calculations is now a thing of the past, once the learning curve of the software has been traversed. The life sciences researcher is therefore free to devote oneself to optimally designing the study, carefully selecting the hypothesis tests to be applied, and taking care in conducting the study well. Unfortunately, selecting the right test seems difficult initially. Thinking of the research hypothesis as addressing one of five generic research questions helps in selection of the right hypothesis test. In addition, it is important to be clear about the nature of the variables (e.g., numerical vs. categorical; parametric vs. nonparametric) and the number of groups or data sets being compared (e.g., two or more than two) at a time. The same research question may be explored by more than one type of hypothesis test. While this may be

Fluid cognitive ability is a resource for successful emotion regulation in older and younger adults.

PubMed

Opitz, Philipp C; Lee, Ihno A; Gross, James J; Urry, Heather L

2014-01-01

The Selection, Optimization, and Compensation with Emotion Regulation (SOC-ER) framework suggests that (1) emotion regulation (ER) strategies require resources and that (2) higher levels of relevant resources may increase ER success. In the current experiment, we tested the specific hypothesis that individual differences in one internal class of resources, namely cognitive ability, would contribute to greater success using cognitive reappraisal (CR), a form of ER in which one reinterprets the meaning of emotion-eliciting situations. To test this hypothesis, 60 participants (30 younger and 30 older adults) completed standardized neuropsychological tests that assess fluid and crystallized cognitive ability, as well as a CR task in which participants reinterpreted the meaning of sad pictures in order to alter (increase or decrease) their emotions. In a control condition, they viewed the pictures without trying to change how they felt. Throughout the task, we indexed subjective emotional experience (self-reported ratings of emotional intensity), expressive behavior (corrugator muscle activity), and autonomic physiology (heart rate and electrodermal activity) as measures of emotional responding. Multilevel models were constructed to explain within-subjects variation in emotional responding as a function of ER contrasts comparing increase or decrease conditions with the view control condition and between-subjects variation as a function of cognitive ability and/or age group (older, younger). As predicted, higher fluid cognitive ability-indexed by perceptual reasoning, processing speed, and working memory-was associated with greater success using reappraisal to alter emotional responding. Reappraisal success did not vary as a function of crystallized cognitive ability or age group. Collectively, our results provide support for a key tenet of the SOC-ER framework that higher levels of relevant resources may confer greater success at emotion regulation.

Consideration of "g" as a Common Antecedent for Cognitive Ability Test Performance, Test Motivation, and Perceived Fairness

ERIC Educational Resources Information Center

Reeve, Charlie L.; Lam, Holly

2007-01-01

Several different analyses were used to test the hypothesis that test-taking motivation, perceived test fairness, and actual test performance are correlated only because they share a common antecedent. First, hierarchical regressions reveal that initial test performance has a unique influence on non-ability factors even after controlling for…

Exploring Braak's Hypothesis of Parkinson's Disease.

PubMed

Rietdijk, Carmen D; Perez-Pardo, Paula; Garssen, Johan; van Wezel, Richard J A; Kraneveld, Aletta D

2017-01-01

Parkinson's disease (PD) is a neurodegenerative disorder for which there is no cure. Most patients suffer from sporadic PD, which is likely caused by a combination of genetic and environmental factors. Braak's hypothesis states that sporadic PD is caused by a pathogen that enters the body via the nasal cavity, and subsequently is swallowed and reaches the gut, initiating Lewy pathology (LP) in the nose and the digestive tract. A staging system describing the spread of LP from the peripheral to the central nervous system was also postulated by the same research group. There has been criticism to Braak's hypothesis, in part because not all patients follow the proposed staging system. Here, we review literature that either supports or criticizes Braak's hypothesis, focused on the enteric route, digestive problems in patients, the spread of LP on a tissue and a cellular level, and the toxicity of the protein αSynuclein (αSyn), which is the major constituent of LP. We conclude that Braak's hypothesis is supported by in vitro, in vivo , and clinical evidence. However, we also conclude that the staging system of Braak only describes a specific subset of patients with young onset and long duration of the disease.

Multiple-hypothesis multiple-model line tracking

NASA Astrophysics Data System (ADS)

Pace, Donald W.; Owen, Mark W.; Cox, Henry

2000-07-01

Passive sonar signal processing generally includes tracking of narrowband and/or broadband signature components observed on a Lofargram or on a Bearing-Time-Record (BTR) display. Fielded line tracking approaches to date have been recursive and single-hypthesis-oriented Kalman- or alpha-beta filters, with no mechanism for considering tracking alternatives beyond the most recent scan of measurements. While adaptivity is often built into the filter to handle changing track dynamics, these approaches are still extensions of single target tracking solutions to multiple target tracking environment. This paper describes an application of multiple-hypothesis, multiple target tracking technology to the sonar line tracking problem. A Multiple Hypothesis Line Tracker (MHLT) is developed which retains the recursive minimum-mean-square-error tracking behavior of a Kalman Filter in a maximum-a-posteriori delayed-decision multiple hypothesis context. Multiple line track filter states are developed and maintained using the interacting multiple model (IMM) state representation. Further, the data association and assignment problem is enhanced by considering line attribute information (line bandwidth and SNR) in addition to beam/bearing and frequency fit. MHLT results on real sonar data are presented to demonstrate the benefits of the multiple hypothesis approach. The utility of the system in cluttered environments and particularly in crossing line situations is shown.

[Laughter and depression: hypothesis of pathogenic and therapeutic correlation].

PubMed

Fonzi, Laura; Matteucci, Gabriella; Bersani, Giuseppe

2010-01-01

Laughter is a very common behaviour in everyday life, nevertheless scientific literature is lacking in studies which examine closely its nature. The study aims are: to summarise the present knowledge about laughter and its relation with depression and to make hypotheses on its possible therapeutic function. In the first part of the review the main data existing about encephalic structures involved in laughter genesis, which show participation of cortical and subcortical regions, are reported and the effects of laughter on the organism physiologic equilibrium, particularly on the neuroendocrine and immune systems, are described. In the second part, scientific evidence about the influence of depression on the ability to laugh are referred, which suggests that reduction of laughter frequency is a symptom of the disease and that its increase may be used as a marker of clinical improvement. Finally, the main assumptions supporting the hypothesis of the therapeutic action of laughter on depression are examined: first of all, it has been demonstrated that laughter is able to improve mood directly and to moderate negative consequences of stressful events on psychological well-being; in addition, it is possible that the stimulation of particular cerebral regions, involved in depression pathogenesis, and the normalisation of the hypothalamic pituitary adrenocortical system dysfunctions, both mediated by laughter, can counteract efficiently depressive symptoms; finally, the favourable effects of laughter on social relationships and physical health may have a role in influencing the ability of depressed patients to face the disease.

Whiplash and the compensation hypothesis.

PubMed

Spearing, Natalie M; Connelly, Luke B

2011-12-01

Review article. To explain why the evidence that compensation-related factors lead to worse health outcomes is not compelling, either in general, or in the specific case of whiplash. There is a common view that compensation-related factors lead to worse health outcomes ("the compensation hypothesis"), despite the presence of important, and unresolved sources of bias. The empirical evidence on this question has ramifications for the design of compensation schemes. Using studies on whiplash, this article outlines the methodological problems that impede attempts to confirm or refute the compensation hypothesis. Compensation studies are prone to measurement bias, reverse causation bias, and selection bias. Errors in measurement are largely due to the latent nature of whiplash injuries and health itself, a lack of clarity over the unit of measurement (specific factors, or "compensation"), and a lack of appreciation for the heterogeneous qualities of compensation-related factors and schemes. There has been a failure to acknowledge and empirically address reverse causation bias, or the likelihood that poor health influences the decision to pursue compensation: it is unclear if compensation is a cause or a consequence of poor health, or both. Finally, unresolved selection bias (and hence, confounding) is evident in longitudinal studies and natural experiments. In both cases, between-group differences have not been addressed convincingly. The nature of the relationship between compensation-related factors and health is unclear. Current approaches to testing the compensation hypothesis are prone to several important sources of bias, which compromise the validity of their results. Methods that explicitly test the hypothesis and establish whether or not a causal relationship exists between compensation factors and prolonged whiplash symptoms are needed in future studies.

A Model of the Relative Income Hypothesis

ERIC Educational Resources Information Center

Sanders, Shane

2010-01-01

James Duesenberry's (1949) relative income hypothesis holds substantial empirical credibility, as well as a rich set of implications. Although present in the pages of leading economics journals, the hypothesis has become all but foreign to the blackboards of economics classrooms. To help reintegrate the concept into the undergraduate economics…

Seeking health information on the web: positive hypothesis testing.

PubMed

Kayhan, Varol Onur

2013-04-01

The goal of this study is to investigate positive hypothesis testing among consumers of health information when they search the Web. After demonstrating the extent of positive hypothesis testing using Experiment 1, we conduct Experiment 2 to test the effectiveness of two debiasing techniques. A total of 60 undergraduate students searched a tightly controlled online database developed by the authors to test the validity of a hypothesis. The database had four abstracts that confirmed the hypothesis and three abstracts that disconfirmed it. Findings of Experiment 1 showed that majority of participants (85%) exhibited positive hypothesis testing. In Experiment 2, we found that the recommendation technique was not effective in reducing positive hypothesis testing since none of the participants assigned to this server could retrieve disconfirming evidence. Experiment 2 also showed that the incorporation technique successfully reduced positive hypothesis testing since 75% of the participants could retrieve disconfirming evidence. Positive hypothesis testing on the Web is an understudied topic. More studies are needed to validate the effectiveness of the debiasing techniques discussed in this study and develop new techniques. Search engine developers should consider developing new options for users so that both confirming and disconfirming evidence can be presented in search results as users test hypotheses using search engines. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

The Hypothesis-Driven Physical Examination.

PubMed

Garibaldi, Brian T; Olson, Andrew P J

2018-05-01

The physical examination remains a vital part of the clinical encounter. However, physical examination skills have declined in recent years, in part because of decreased time at the bedside. Many clinicians question the relevance of physical examinations in the age of technology. A hypothesis-driven approach to teaching and practicing the physical examination emphasizes the performance of maneuvers that can alter the likelihood of disease. Likelihood ratios are diagnostic weights that allow clinicians to estimate the post-probability of disease. This hypothesis-driven approach to the physical examination increases its value and efficiency, while preserving its cultural role in the patient-physician relationship. Copyright © 2017 Elsevier Inc. All rights reserved.

Ecosystem Succession and Nutrient Retention: A Hypothesis

ERIC Educational Resources Information Center

Vitousek, Peter M.; Reiners, William A.

1975-01-01

A hypothesis is presented for the regulation of elemental losses from terrestrial ecosystems. Losses of elements are controlled by the net increment of biomass growth and the elemental composition of this net increment. According to this hypothesis, loss rates are highest in early succession and in steady state ecosystems. (Author/EB)

Effect of Power Point Enhanced Teaching (Visual Input) on Iranian Intermediate EFL Learners' Listening Comprehension Ability

ERIC Educational Resources Information Center

Sehati, Samira; Khodabandehlou, Morteza

2017-01-01

The present investigation was an attempt to study on the effect of power point enhanced teaching (visual input) on Iranian Intermediate EFL learners' listening comprehension ability. To that end, a null hypothesis was formulated as power point enhanced teaching (visual input) has no effect on Iranian Intermediate EFL learners' listening…

Diagnostic Utility of WISC-IV General Abilities Index and Cognitive Proficiency Index Difference Scores among Children with ADHD

ERIC Educational Resources Information Center

Devena, Sarah E.; Watkins, Marley W.

2012-01-01

The Wechsler Intelligence Scale for Children-Fourth Edition General Abilities Index and Cognitive Proficiency Index have been advanced as possible diagnostic markers of attention deficit hyperactivity disorder. This hypothesis was tested with a hospital sample with attention deficit hyperactivity disorder (n = 78), a referred but nondiagnosed…

The mechanisms of far transfer from cognitive training: Review and hypothesis.

PubMed

Greenwood, Pamela M; Parasuraman, Raja

2016-09-01

General intelligence is important for success in daily life, fueling interest in developing cognitive training as an intervention to improve fluid ability (Gf). A major obstacle to the design of effective cognitive interventions has been the paucity of hypotheses bearing on mechanisms underlying transfer of cognitive training to Gf. Despite the large amounts of money and time currently being expended on cognitive training, there is little scientific agreement on how, or even whether, Gf can be heightened by such training. We review the relevant strands of evidence on cognitive-training-related changes in (a) cortical mechanisms of distraction suppression, and (b) activation of the dorsal attention network (DAN). We hypothesize that training-related increases in control of attention are important for what is termed far transfer of cognitive training to untrained abilities, notably to Gf. We review the evidence that distraction suppression evident in behavior, neuronal firing, scalp electroencephalography, and hemodynamic change is important for protecting target processing during perception and also for protecting targets held in working memory. Importantly, attentional control also appears to be central to performance on Gf assessments. Consistent with this evidence, forms of cognitive training that increase ability to ignore distractions (e.g., working memory training and perceptual training) not only affect the DAN but also affect transfer to Gf. Our hypothesis is supported by existing evidence. However, to advance the field of cognitive training, it is necessary that competing hypotheses on mechanisms of far transfer of cognitive training be advanced and empirically tested. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

The Alzheimer's Disease Mitochondrial Cascade Hypothesis: Progress and Perspectives

PubMed Central

Swerdlow, Russell H.; Burns, Jeffrey M.; Khan, Shaharyar M.

2013-01-01

Ten years ago we first proposed the Alzheimer's disease (AD) mitochondrial cascade hypothesis. This hypothesis maintains gene inheritance defines an individual's baseline mitochondrial function; inherited and environmental factors determine rates at which mitochondrial function changes over time; and baseline mitochondrial function and mitochondrial change rates influence AD chronology. Our hypothesis unequivocally states in sporadic, late-onset AD, mitochondrial function affects amyloid precursor protein (APP) expression, APP processing, or beta amyloid (Aβ) accumulation and argues if an amyloid cascade truly exists, mitochondrial function triggers it. We now review the state of the mitochondrial cascade hypothesis, and discuss it in the context of recent AD biomarker studies, diagnostic criteria, and clinical trials. Our hypothesis predicts biomarker changes reflect brain aging, new AD definitions clinically stage brain aging, and removing brain Aβ at any point will marginally impact cognitive trajectories. Our hypothesis, therefore, offers unique perspective into what sporadic, late-onset AD is and how to best treat it. PMID:24071439

The intelligence of observation: improving high school students' spatial ability by means of intervention unit

NASA Astrophysics Data System (ADS)

Patkin, Dorit; Dayan, Ester

2013-03-01

This case study of one class versus a control group focused on the impact of an intervention unit, which is not part of the regular curriculum, on the improvement of spatial ability of high school students (forty-six 12th-graders, aged 17-18, both boys and girls) in general as well as from a gender perspective. The study explored three sub-abilities: mental rotation (MR), spatial visualization (VS) and spatial orientation (SO). Findings indicated that the spatial orientation of the experimental group students had considerably improved. The findings also illustrated a significant gender-based advantage in favour of the boys in some of the spatial abilities even before the implementation of the intervention unit. The hypothesis relating to the reduction of the gender differences was not corroborated.

The evolutionary dynamics of receptor binding avidity in influenza A: a mathematical model for a new antigenic drift hypothesis

PubMed Central

Yuan, Hsiang-Yu; Koelle, Katia

2013-01-01

The most salient feature of influenza evolution in humans is its antigenic drift. This process is characterized by structural changes in the virus's B-cell epitopes and ultimately results in the ability of the virus to evade immune recognition and thereby reinfect previously infected hosts. Until recently, amino acid substitutions in epitope regions of the viral haemagglutinin were thought to be positively selected for their ability to reduce antibody binding and therefore were thought to be responsible for driving antigenic drift. However, a recent hypothesis put forward by Hensley and co-workers posits that cellular receptor binding avidity is the dominant phenotype under selection, with antigenic drift being a side effect of these binding avidity changes. Here, we present a mathematical formulation of this new antigenic drift model and use it to show how rates of antigenic drift depend on epidemiological parameters. We further use the model to evaluate how two different vaccination strategies can impact antigenic drift rates and ultimately disease incidence levels. Finally, we discuss the assumptions present in the model formulation, predictions of the model, and future work that needs to be done to determine the consistency of this hypothesis with known patterns of influenza's genetic and antigenic evolution. PMID:23382426

The GABA Hypothesis in Essential Tremor: Lights and Shadows.

PubMed

Gironell, Alexandre

2014-01-01

The gamma-aminobutyric acid (GABA) hypothesis in essential tremor (ET) implies a disturbance of the GABAergic system, especially involving the cerebellum. This review examines the evidence of the GABA hypothesis. The review is based on published data about GABA dysfunction in ET, taking into account studies on cerebrospinal fluid, pathology, electrophysiology, genetics, neuroimaging, experimental animal models, and human drug therapies. Findings from several studies support the GABA hypothesis in ET. The hypothesis follows four steps: 1) cerebellar neurodegeneration with Purkinje cell loss; 2) a decrease in GABA system activity in deep cerebellar neurons; 3) disinhibition in output deep cerebellar neurons with pacemaker activity; and 4) an increase in rhythmic activity of the thalamus and thalamo-cortical circuit, contributing to the generation of tremor. Doubts have been cast on this hypothesis, however, by the fact that it is based on relatively few works, controversial post-mortem findings, and negative genetic studies on the GABA system. Furthermore, GABAergic drug efficacy is low and some GABAergic drugs do not have antitremoric efficacy. The GABA hypothesis continues to be the most robust pathophysiological hypothesis to explain ET. There is light in all GABA hypothesis steps, but a number of shadows cannot be overlooked. We need more studies to clarify the neurodegenerative nature of the disease, to confirm the decrease of GABA activity in the cerebellum, and to test more therapies that enhance the GABA transmission specifically in the cerebellum area.

Pathogenesis of Rushton bodies: A novel hypothesis.

PubMed

Sarode, Gargi S; Sarode, Sachin C; Tupkari, Jagdish V; Deshmukh, Revati; Patil, Shankargouda

2016-08-01

Rushton bodies (RBs) are one of the characteristic features seen in the epithelial lining of odontogenic cysts mainly radicular, dentigerous and odontogenic keratocyst. It has two different histo-morphological appearances; granular and homogeneous. Although widely investigated, the exact pathogenesis and histogenesis of RBs is still an enigma. Many hypotheses were made in the literature but none has explained conceivably the two histo-morphological appearances of RBs and their association with inflammation. In the present paper the various pathogenesis for the formation of RBs proposed till date are discussed along with proposal for a novel hypothesis. The given hypothesis is mainly related to inflammation and its effect on pore size of basement membrane of odontogenic cystic epithelium. It explains RBs association with inflammation as well as existence of two histo-morphological appearances. The proposed hypothesis also justifies the RB's presence inside the lining epithelium of odontogenic cyst despite its hematogenous origin. Future studies are advocated for isolating RBs using laser capture microdissection and subsequent biochemical, histochemical and electron microscopic analysis to substantiate the proposed hypothesis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Autism, Asthma, Inflammation, and the Hygiene Hypothesis

PubMed Central

Becker, Kevin G.

2007-01-01

Inflammation and the genes, molecules, and biological pathways that lead to inflammatory processes influence many important and disparate biological processes and disease states that are quite often not generally considered classical inflammatory or autoimmune disorders. These include development, reproduction, aging, tumor development and tumor rejection, cardiovascular pathologies, metabolic disorders, as well as neurological and psychiatric disorders. This paper compares parallel aspects of autism and inflammatory disorders with an emphasis on asthma. These comparisons include epidemiological, morphometric, molecular, and genetic aspects of both disease types, contributing to a hypothesis of autism in the context of the immune based hygiene hypothesis. This hypothesis is meant to address the apparent rise in the prevalence of autism in the population. PMID:17412520

Autism, asthma, inflammation, and the hygiene hypothesis.

PubMed

Becker, Kevin G

2007-01-01

Inflammation and the genes, molecules, and biological pathways that lead to inflammatory processes influence many important and disparate biological processes and disease states that are quite often not generally considered classical inflammatory or autoimmune disorders. These include development, reproduction, aging, tumor development and tumor rejection, cardiovascular pathologies, metabolic disorders, as well as neurological and psychiatric disorders. This paper compares parallel aspects of autism and inflammatory disorders with an emphasis on asthma. These comparisons include epidemiological, morphometric, molecular, and genetic aspects of both disease types, contributing to a hypothesis of autism in the context of the immune based hygiene hypothesis. This hypothesis is meant to address the apparent rise in the prevalence of autism in the population.

Supporting shared hypothesis testing in the biomedical domain.

PubMed

Agibetov, Asan; Jiménez-Ruiz, Ernesto; Ondrésik, Marta; Solimando, Alessandro; Banerjee, Imon; Guerrini, Giovanna; Catalano, Chiara E; Oliveira, Joaquim M; Patanè, Giuseppe; Reis, Rui L; Spagnuolo, Michela

2018-02-08

Pathogenesis of inflammatory diseases can be tracked by studying the causality relationships among the factors contributing to its development. We could, for instance, hypothesize on the connections of the pathogenesis outcomes to the observed conditions. And to prove such causal hypotheses we would need to have the full understanding of the causal relationships, and we would have to provide all the necessary evidences to support our claims. In practice, however, we might not possess all the background knowledge on the causality relationships, and we might be unable to collect all the evidence to prove our hypotheses. In this work we propose a methodology for the translation of biological knowledge on causality relationships of biological processes and their effects on conditions to a computational framework for hypothesis testing. The methodology consists of two main points: hypothesis graph construction from the formalization of the background knowledge on causality relationships, and confidence measurement in a causality hypothesis as a normalized weighted path computation in the hypothesis graph. In this framework, we can simulate collection of evidences and assess confidence in a causality hypothesis by measuring it proportionally to the amount of available knowledge and collected evidences. We evaluate our methodology on a hypothesis graph that represents both contributing factors which may cause cartilage degradation and the factors which might be caused by the cartilage degradation during osteoarthritis. Hypothesis graph construction has proven to be robust to the addition of potentially contradictory information on the simultaneously positive and negative effects. The obtained confidence measures for the specific causality hypotheses have been validated by our domain experts, and, correspond closely to their subjective assessments of confidences in investigated hypotheses. Overall, our methodology for a shared hypothesis testing framework exhibits

Multiple hypothesis tracking for the cyber domain

NASA Astrophysics Data System (ADS)

Schwoegler, Stefan; Blackman, Sam; Holsopple, Jared; Hirsch, Michael J.

2011-09-01

This paper discusses how methods used for conventional multiple hypothesis tracking (MHT) can be extended to domain-agnostic tracking of entities from non-kinematic constraints such as those imposed by cyber attacks in a potentially dense false alarm background. MHT is widely recognized as the premier method to avoid corrupting tracks with spurious data in the kinematic domain but it has not been extensively applied to other problem domains. The traditional approach is to tightly couple track maintenance (prediction, gating, filtering, probabilistic pruning, and target confirmation) with hypothesis management (clustering, incompatibility maintenance, hypothesis formation, and Nassociation pruning). However, by separating the domain specific track maintenance portion from the domain agnostic hypothesis management piece, we can begin to apply the wealth of knowledge gained from ground and air tracking solutions to the cyber (and other) domains. These realizations led to the creation of Raytheon's Multiple Hypothesis Extensible Tracking Architecture (MHETA). In this paper, we showcase MHETA for the cyber domain, plugging in a well established method, CUBRC's INFormation Engine for Real-time Decision making, (INFERD), for the association portion of the MHT. The result is a CyberMHT. We demonstrate the power of MHETA-INFERD using simulated data. Using metrics from both the tracking and cyber domains, we show that while no tracker is perfect, by applying MHETA-INFERD, advanced nonkinematic tracks can be captured in an automated way, perform better than non-MHT approaches, and decrease analyst response time to cyber threats.

Electron Gyro-Harmonic Effects on Ionospheric Stimulated Brillouin Scatter

DTIC Science & Technology

2014-08-21

27709-2211 Brillouin, SBS, emission lines, pump frequency stepping, cyclotron , EIC, airglow, upper hybrid REPORT DOCUMENTATION PAGE 11. SPONSOR...direction and the background magnetic field vector, the excited electrostatic wave could be either ion acoustic (IA) or electrostatic ion cyclotron (EIC...A. Hedberg, B. Lundborg, P. Stubbe, H. Kopka, and M. T. Rietveld (1989), Stimulated electromagnetic emission near electron cyclotron harmonics in

Revisiting the hypothesis-driven interview in a contemporary context.

PubMed

Holmes, Alex; Singh, Bruce; McColl, Geoff

2011-12-01

The "hypothesis-driven interview" was articulated by George Engel as a method of raising and testing hypotheses in the process of building a biopsychosocial formulation and determining the most likely diagnosis. This interview was a forerunner of the modern medical interview as well as the contemporary psychiatric assessment. The objective of this article is to describe the hypothesis-driven interview and to explore its relationship with the contemporary medical interview. The literature on the medical and hypothesis-driven interview was reviewed. Key features of each were identified. The hypothesis-driven interview shares much with the contemporary medical interview. In addition, it enhances the application of communication skills and allows the interviewer to develop a formulation during the course of the assessment. The hypothesis-driven interview is well suited to the aims of a contemporary psychiatric assessment.

Universality hypothesis breakdown at one-loop order

NASA Astrophysics Data System (ADS)

Carvalho, P. R. S.

2018-05-01

We probe the universality hypothesis by analytically computing the at least two-loop corrections to the critical exponents for q -deformed O (N ) self-interacting λ ϕ4 scalar field theories through six distinct and independent field-theoretic renormalization group methods and ɛ -expansion techniques. We show that the effect of q deformation on the one-loop corrections to the q -deformed critical exponents is null, so the universality hypothesis is broken down at this loop order. Such an effect emerges only at the two-loop and higher levels, and the validity of the universality hypothesis is restored. The q -deformed critical exponents obtained through the six methods are the same and, furthermore, reduce to their nondeformed values in the appropriated limit.

Null but not void: considerations for hypothesis testing.

PubMed

Shaw, Pamela A; Proschan, Michael A

2013-01-30

Standard statistical theory teaches us that once the null and alternative hypotheses have been defined for a parameter, the choice of the statistical test is clear. Standard theory does not teach us how to choose the null or alternative hypothesis appropriate to the scientific question of interest. Neither does it tell us that in some cases, depending on which alternatives are realistic, we may want to define our null hypothesis differently. Problems in statistical practice are frequently not as pristinely summarized as the classic theory in our textbooks. In this article, we present examples in statistical hypothesis testing in which seemingly simple choices are in fact rich with nuance that, when given full consideration, make the choice of the right hypothesis test much less straightforward. Published 2012. This article is a US Government work and is in the public domain in the USA.

Laparoscopic baseline ability assessment by virtual reality.

PubMed

Madan, Atul K; Frantzides, Constantine T; Sasso, Lisa M

2005-02-01

Assessment of any surgical skill is time-consuming and difficult. Currently, there are no accepted metrics for most surgical skills, especially laparoscopic skills. Virtual reality has been utilized for laparoscopic training of surgical residents. Our hypothesis is that this technology can be utilized for laparoscopic ability metrics. This study involved medical students with no previous laparoscopic experience. All students were taken into a porcine laboratory in order to assess two operative tasks (measuring a piece of bowel and placing a piece of bowel into a laparoscopic bag). Then they were taken into an inanimate lab with a Minimally Invasive Surgery Trainer-Virtual Reality (MIST-VR). Each student repeatedly performed one task (placing a virtual reality ball into a receptacle). The students' scores and times from the animate lab were compared with average economy of movement and times from the MIST-VR. The MIST-VR scored both hands individually. Thirty-two first- and second-year medical students were included in the study. There was statistically significant (P < 0.05) correlation between 11 of 16 possible relationships between the virtual reality trainer and operative tasks. While not all of the possible relationships demonstrated statistically significant correlation, the majority of the possible relationships demonstrated statistically significant correlation. Virtual reality may be an avenue for measuring laparoscopic surgical ability.

Neural basis of major depressive disorder: Beyond monoamine hypothesis.

PubMed

Boku, Shuken; Nakagawa, Shin; Toda, Hiroyuki; Hishimoto, Akitoyo

2018-01-01

The monoamine hypothesis has been accepted as the most common hypothesis of major depressive disorder (MDD) for a long period because of its simplicity and understandability. Actually, most currently used antidepressants have been considered to act based on the monoamine hypothesis. However, an important problem of the monoamine hypothesis has been pointed out as follows: it fails to explain the latency of response to antidepressants. In addition, many patients with MDD have remained refractory to currently used antidepressants. Therefore, monoamine-alternate hypotheses are required to explain the latency of response to antidepressants. Such hypotheses have been expected to contribute to identifying hopeful new therapeutic targets for MDD. Past studies have revealed that the volume of the hippocampus is decreased in patients with MDD, which is likely caused by the failure of the hypothalamic-pituitary-adrenal axis and following elevation of glucocorticoids. Two hypotheses have been proposed to explain the volume of the hippocampus: (i) the neuroplasticity hypothesis; and (ii) the neurogenesis hypothesis. The neuroplasticity hypothesis explains how the hippocampal volume is decreased by the morphological changes of hippocampal neurons, such as the shortening length of dendrites and the decreased number and density of spines. The neurogenesis hypothesis explains how the hippocampal volume is decreased by the decrease of neurogenesis in the hippocampal dentate gyrus. These hypotheses are able to explain the latency of response to antidepressants. In this review, we first overview how the neuroplasticity and neurogenesis hypotheses have been developed. We then describe the details of these hypotheses. © 2017 The Authors. Psychiatry and Clinical Neurosciences © 2017 Japanese Society of Psychiatry and Neurology.

A Dopamine Hypothesis of Autism Spectrum Disorder.

PubMed

Pavăl, Denis

2017-01-01

Autism spectrum disorder (ASD) comprises a group of neurodevelopmental disorders characterized by social deficits and stereotyped behaviors. While several theories have emerged, the pathogenesis of ASD remains unknown. Although studies report dopamine signaling abnormalities in autistic patients, a coherent dopamine hypothesis which could link neurobiology to behavior in ASD is currently lacking. In this paper, we present such a hypothesis by proposing that autistic behavior arises from dysfunctions in the midbrain dopaminergic system. We hypothesize that a dysfunction of the mesocorticolimbic circuit leads to social deficits, while a dysfunction of the nigrostriatal circuit leads to stereotyped behaviors. Furthermore, we discuss 2 key predictions of our hypothesis, with emphasis on clinical and therapeutic aspects. First, we argue that dopaminergic dysfunctions in the same circuits should associate with autistic-like behavior in nonautistic subjects. Concerning this, we discuss the case of PANDAS (pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections) which displays behaviors similar to those of ASD, presumed to arise from dopaminergic dysfunctions. Second, we argue that providing dopamine modulators to autistic subjects should lead to a behavioral improvement. Regarding this, we present clinical studies of dopamine antagonists which seem to have improving effects on autistic behavior. Furthermore, we explore the means of testing our hypothesis by using neuroreceptor imaging, which could provide comprehensive evidence for dopamine signaling dysfunctions in autistic subjects. Lastly, we discuss the limitations of our hypothesis. Along these lines, we aim to provide a dopaminergic model of ASD which might lead to a better understanding of the ASD pathogenesis. © 2017 S. Karger AG, Basel.

Associations of physical activity with driving-related cognitive abilities in older drivers: an exploratory study.

PubMed

Marmeleira, José; Ferreira, Inês; Melo, Filipe; Godinho, Mário

2012-10-01

The purpose of this study was to examine the associations between hysical activity and driving-related cognitive abilities of older drivers. Thirty-eight female and male drivers ages 61 to 81 years (M = 70.2, SD = 5.0) responded to the International Physical Activity Questionnaire and were assessed on a battery of neuropsychological tests, which included measures of visual attention, executive functioning, mental status, visuospatial ability, and memory. A higher amount of reported physical activity was significantly correlated with better scores on tests of visual processing speed and divided visual attention. Higher amounts of physical activity was significantly associated with a better composite score for visual attention, but its correlation with the composite score for executive functioning was not significant. These findings support the hypothesis that pzhysical activity is associated with preservation of specific driving-related cognitive abilities of older adults.

Understanding suicide terrorism: premature dismissal of the religious-belief hypothesis.

PubMed

Liddle, James R; Machluf, Karin; Shackelford, Todd K

2010-07-06

We comment on work by Ginges, Hansen, and Norenzayan (2009), in which they compare two hypotheses for predicting individual support for suicide terrorism: the religious-belief hypothesis and the coalitional-commitment hypothesis. Although we appreciate the evidence provided in support of the coalitional-commitment hypothesis, we argue that their method of testing the religious-belief hypothesis is conceptually flawed, thus calling into question their conclusion that the religious-belief hypothesis has been disconfirmed. In addition to critiquing the methodology implemented by Ginges et al., we provide suggestions on how the religious-belief hypothesis may be properly tested. It is possible that the premature and unwarranted conclusions reached by Ginges et al. may deter researchers from examining the effect of specific religious beliefs on support for terrorism, and we hope that our comments can mitigate this possibility.

Bayesian Hypothesis Testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andrews, Stephen A.; Sigeti, David E.

These are a set of slides about Bayesian hypothesis testing, where many hypotheses are tested. The conclusions are the following: The value of the Bayes factor obtained when using the median of the posterior marginal is almost the minimum value of the Bayes factor. The value of τ 2 which minimizes the Bayes factor is a reasonable choice for this parameter. This allows a likelihood ratio to be computed with is the least favorable to H 0.

The Gender Similarities Hypothesis

ERIC Educational Resources Information Center

Hyde, Janet Shibley

2005-01-01

The differences model, which argues that males and females are vastly different psychologically, dominates the popular media. Here, the author advances a very different view, the gender similarities hypothesis, which holds that males and females are similar on most, but not all, psychological variables. Results from a review of 46 meta-analyses…

Brain size predicts problem-solving ability in mammalian carnivores

PubMed Central

Benson-Amram, Sarah; Dantzer, Ben; Stricker, Gregory; Swanson, Eli M.; Holekamp, Kay E.

2016-01-01

Despite considerable interest in the forces shaping the relationship between brain size and cognitive abilities, it remains controversial whether larger-brained animals are, indeed, better problem-solvers. Recently, several comparative studies have revealed correlations between brain size and traits thought to require advanced cognitive abilities, such as innovation, behavioral flexibility, invasion success, and self-control. However, the general assumption that animals with larger brains have superior cognitive abilities has been heavily criticized, primarily because of the lack of experimental support for it. Here, we designed an experiment to inquire whether specific neuroanatomical or socioecological measures predict success at solving a novel technical problem among species in the mammalian order Carnivora. We presented puzzle boxes, baited with food and scaled to accommodate body size, to members of 39 carnivore species from nine families housed in multiple North American zoos. We found that species with larger brains relative to their body mass were more successful at opening the boxes. In a subset of species, we also used virtual brain endocasts to measure volumes of four gross brain regions and show that some of these regions improve model prediction of success at opening the boxes when included with total brain size and body mass. Socioecological variables, including measures of social complexity and manual dexterity, failed to predict success at opening the boxes. Our results, thus, fail to support the social brain hypothesis but provide important empirical support for the relationship between relative brain size and the ability to solve this novel technical problem. PMID:26811470

Brain size predicts problem-solving ability in mammalian carnivores.

PubMed

Benson-Amram, Sarah; Dantzer, Ben; Stricker, Gregory; Swanson, Eli M; Holekamp, Kay E

2016-03-01

Despite considerable interest in the forces shaping the relationship between brain size and cognitive abilities, it remains controversial whether larger-brained animals are, indeed, better problem-solvers. Recently, several comparative studies have revealed correlations between brain size and traits thought to require advanced cognitive abilities, such as innovation, behavioral flexibility, invasion success, and self-control. However, the general assumption that animals with larger brains have superior cognitive abilities has been heavily criticized, primarily because of the lack of experimental support for it. Here, we designed an experiment to inquire whether specific neuroanatomical or socioecological measures predict success at solving a novel technical problem among species in the mammalian order Carnivora. We presented puzzle boxes, baited with food and scaled to accommodate body size, to members of 39 carnivore species from nine families housed in multiple North American zoos. We found that species with larger brains relative to their body mass were more successful at opening the boxes. In a subset of species, we also used virtual brain endocasts to measure volumes of four gross brain regions and show that some of these regions improve model prediction of success at opening the boxes when included with total brain size and body mass. Socioecological variables, including measures of social complexity and manual dexterity, failed to predict success at opening the boxes. Our results, thus, fail to support the social brain hypothesis but provide important empirical support for the relationship between relative brain size and the ability to solve this novel technical problem.

Song learning and cognitive ability are not consistently related in a songbird.

PubMed

Anderson, Rindy C; Searcy, William A; Peters, Susan; Hughes, Melissa; DuBois, Adrienne L; Nowicki, Stephen

2017-03-01

Learned aspects of song have been hypothesized to signal cognitive ability in songbirds. We tested this hypothesis in hand-reared song sparrows (Melospiza melodia) that were tutored with playback of adult songs during the critical period for song learning. The songs developed by the 19 male subjects were compared to the model songs to produce two measures of song learning: the proportion of notes copied from models and the average spectrogram cross-correlation between copied notes and model notes. Song repertoire size, which reflects song complexity, was also measured. At 1 year of age, subjects were given a battery of five cognitive tests that measured speed of learning in the context of a novel foraging task, color association, color reversal, detour-reaching, and spatial learning. Bivariate correlations between the three song measures and the five cognitive measures revealed no significant associations. As in other studies of avian cognition, different cognitive measures were for the most part not correlated with each other, and this result remained true when 22 hand-reared female song sparrows were added to the analysis. General linear mixed models controlling for effects of neophobia and nest of origin indicated that all three song measures were associated with better performance on color reversal and spatial learning but were associated with worse performance on novel foraging and detour-reaching. Overall, the results do not support the hypothesis that learned aspects of song signal cognitive ability.

Selective Methylation: an Incorrect Hypothesis

PubMed Central

Shugart, Lee

1976-01-01

“Selective methylation,” a hypothesis proposed to explain the discrepancy found in the degree of methyl deficiency of transfer ribonucleic acid, cannot be explained on the basis of some biological phenomenon. PMID:770445

Evaluating the Stage Learning Hypothesis.

ERIC Educational Resources Information Center

Thomas, Hoben

1980-01-01

A procedure for evaluating the Genevan stage learning hypothesis is illustrated by analyzing Inhelder, Sinclair, and Bovet's guided learning experiments (in "Learning and the Development of Cognition." Cambridge: Harvard University Press, 1974). (Author/MP)

Fluid cognitive ability is a resource for successful emotion regulation in older and younger adults

PubMed Central

Opitz, Philipp C.; Lee, Ihno A.; Gross, James J.; Urry, Heather L.

2014-01-01

The Selection, Optimization, and Compensation with Emotion Regulation (SOC-ER) framework suggests that (1) emotion regulation (ER) strategies require resources and that (2) higher levels of relevant resources may increase ER success. In the current experiment, we tested the specific hypothesis that individual differences in one internal class of resources, namely cognitive ability, would contribute to greater success using cognitive reappraisal (CR), a form of ER in which one reinterprets the meaning of emotion-eliciting situations. To test this hypothesis, 60 participants (30 younger and 30 older adults) completed standardized neuropsychological tests that assess fluid and crystallized cognitive ability, as well as a CR task in which participants reinterpreted the meaning of sad pictures in order to alter (increase or decrease) their emotions. In a control condition, they viewed the pictures without trying to change how they felt. Throughout the task, we indexed subjective emotional experience (self-reported ratings of emotional intensity), expressive behavior (corrugator muscle activity), and autonomic physiology (heart rate and electrodermal activity) as measures of emotional responding. Multilevel models were constructed to explain within-subjects variation in emotional responding as a function of ER contrasts comparing increase or decrease conditions with the view control condition and between-subjects variation as a function of cognitive ability and/or age group (older, younger). As predicted, higher fluid cognitive ability—indexed by perceptual reasoning, processing speed, and working memory—was associated with greater success using reappraisal to alter emotional responding. Reappraisal success did not vary as a function of crystallized cognitive ability or age group. Collectively, our results provide support for a key tenet of the SOC-ER framework that higher levels of relevant resources may confer greater success at emotion regulation. PMID:24987387

[Dinitrosyl iron complexes are endogenous signaling agents in animal and human cells and tissues (a hypothesis)].

PubMed

Vanin, A F

2004-01-01

The hypothesis was advanced that dinitrosyl iron complexes generated in animal and human cells and tissues producing nitric oxide can function as endogenous universal regulators of biochemical and physiological processes. This function is realized by the ability of dinitrosyl iron complexes to act as donors of free nitric oxide molecules interacting with the heme groups of proteins, nitrosonium ions, or Fe+(NO+)2 interacting with the thiol groups of proteins. The effect of dinitrosyl iron complexes on the activity of some enzymes and the expression of the genome at the translation and transcription levels was considered.

Does the heritability of cognitive abilities vary as a function of parental education? Evidence from a German twin sample.

PubMed

Spengler, Marion; Gottschling, Juliana; Hahn, Elisabeth; Tucker-Drob, Elliot M; Harzer, Claudia; Spinath, Frank M

2018-01-01

A well-known hypothesis in the behavioral genetic literature predicts that the heritability of cognitive abilities is higher in the presence of higher socioeconomic contexts. However, studies suggest that the effect of socioeconomic status (SES) on the heritability of cognitive ability may not be universal, as it has mostly been demonstrated in the United States, but not in other Western nations. In the present study we tested whether the importance of genetic and environmental effects on cognitive abilities varies as a function of parental education in a German twin sample. Cognitive ability scores (general, verbal, and nonverbal) were obtained on 531 German twin pairs (192 monozygotic, 339 dizygotic, ranging from 7 to 14 years of age; Mage = 10.25, SD = 1.83). Data on parental education were available from mothers and fathers. Results for general cognitive ability and nonverbal ability indicated no significant gene x parental education interaction effect. For verbal ability, a significant nonshared environment (E) x parental education interaction was found in the direction of greater nonshared environmental influences on verbal abilities among children raised by more educated parents.

Ontological confusions but not mentalizing abilities predict religious belief, paranormal belief, and belief in supernatural purpose.

PubMed

Lindeman, Marjaana; Svedholm-Häkkinen, Annika M; Lipsanen, Jari

2015-01-01

The current research tested the hypothesis that the abilities for understanding other people's minds give rise to the cognitive biases that underlie supernatural beliefs. We used structural equation modeling (N=2789) to determine the roles of various mentalizing tendencies, namely self-reported affective and cognitive empathy (i.e., mind reading), actual cognitive and affective empathic abilities, hyper-empathizing, and two cognitive biases (core ontological confusions and promiscuous teleology) in giving rise to supernatural beliefs. Support for a path from mentalizing abilities through cognitive biases to supernatural beliefs was weak. The relationships of mentalizing abilities with supernatural beliefs were also weak, and these relationships were not substantially mediated by cognitive biases. Core ontological confusions emerged as the best predictor, while promiscuous teleology predicted only a small proportion of variance. The results were similar for religious beliefs, paranormal beliefs, and for belief in supernatural purpose. Copyright © 2014 Elsevier B.V. All rights reserved.

Variation in the X-Linked EFHC2 Gene Is Associated with Social Cognitive Abilities in Males

PubMed Central

Startin, Carla M.; Fiorentini, Chiara; de Haan, Michelle; Skuse, David H.

2015-01-01

Females outperform males on many social cognitive tasks. X-linked genes may contribute to this sex difference. Males possess one X chromosome, while females possess two X chromosomes. Functional variations in X-linked genes are therefore likely to impact more on males than females. Previous studies of X-monosomic women with Turner syndrome suggest a genetic association with facial fear recognition abilities at Xp11.3, specifically at a single nucleotide polymorphism (SNP rs7055196) within the EFHC2 gene. Based on a strong hypothesis, we investigated an association between variation at SNP rs7055196 and facial fear recognition and theory of mind abilities in males. As predicted, males possessing the G allele had significantly poorer facial fear detection accuracy and theory of mind abilities than males possessing the A allele (with SNP variant accounting for up to 4.6% of variance). Variation in the X-linked EFHC2 gene at SNP rs7055196 is therefore associated with social cognitive abilities in males. PMID:26107779

Amyloid pore-channel hypothesis: effect of ethanol on aggregation state using frog oocytes for an Alzheimer's disease study.

PubMed

Parodi, Jorge; Ormeño, David; Ochoa-de la Paz, Lenin D

2015-01-01

Alzheimer's disease severely compromises cognitive function. One of the mechanisms to explain the pathology of Alzheimer's disease has been the hypotheses of amyloid-pore/channel formation by complex Aβ-aggregates. Clinical studies suggested the moderate alcohol consumption can reduces probability developing neurodegenerative pathologies. A recent report explored the ability of ethanol to disrupt the generation of complex Aβ in vitro and reduce the toxicity in two cell lines. Molecular dynamics simulations were applied to understand how ethanol blocks the aggregation of amyloid. On the other hand, the in silico modeling showed ethanol effect over the dynamics assembling for complex Aβ-aggregates mediated by break the hydrosaline bridges between Asp 23 and Lys 28, was are key element for amyloid dimerization. The amyloid pore/channel hypothesis has been explored only in neuronal models, however recently experiments suggested the frog oocytes such an excellent model to explore the mechanism of the amyloid pore/channel hypothesis. So, the used of frog oocytes to explored the mechanism of amyloid aggregates is new, mainly for amyloid/pore hypothesis. Therefore, this experimental model is a powerful tool to explore the mechanism implicates in the Alzheimer's disease pathology and also suggests a model to prevent the Alzheimer's disease pathology.

Rhythmic abilities and musical training in Parkinson's disease: do they help?

PubMed

Cochen De Cock, V; Dotov, D G; Ihalainen, P; Bégel, V; Galtier, F; Lebrun, C; Picot, M C; Driss, V; Landragin, N; Geny, C; Bardy, B; Dalla Bella, S

2018-01-01

Rhythmic auditory cues can immediately improve gait in Parkinson's disease. However, this effect varies considerably across patients. The factors associated with this individual variability are not known to date. Patients' rhythmic abilities and musicality (e.g., perceptual and singing abilities, emotional response to music, and musical training) may foster a positive response to rhythmic cues. To examine this hypothesis, we measured gait at baseline and with rhythmic cues in 39 non-demented patients with Parkinson's disease and 39 matched healthy controls. Cognition, rhythmic abilities and general musicality were assessed. A response to cueing was qualified as positive when the stimulation led to a clinically meaningful increase in gait speed. We observed that patients with positive response to cueing ( n  = 17) were more musically trained, aligned more often their steps to the rhythmic cues while walking, and showed better music perception as well as poorer cognitive flexibility than patients with non-positive response ( n  = 22). Gait performance with rhythmic cues worsened in six patients. We concluded that rhythmic and musical skills, which can be modulated by musical training, may increase beneficial effects of rhythmic auditory cueing in Parkinson's disease. Screening patients in terms of musical/rhythmic abilities and musical training may allow teasing apart patients who are likely to benefit from cueing from those who may worsen their performance due to the stimulation.

Age Dedifferentiation Hypothesis: Evidence form the WAIS III.

ERIC Educational Resources Information Center

Juan-Espinosa, Manuel; Garcia, Luis F.; Escorial, Sergio; Rebollo, Irene; Colom, Roberto; Abad, Francisco J.

2002-01-01

Used the Spanish standardization of the Wechsler Adult Intelligence Scale III (WAIS III) (n=1,369) to test the age dedifferentiation hypothesis. Results show no changes in the percentage of variance accounted for by "g" and four group factors when restriction of range is controlled. Discusses an age indifferentation hypothesis. (SLD)

Recognition of facial expressions of emotion by adults with intellectual disability: Is there evidence for the emotion specificity hypothesis?

PubMed

Scotland, Jennifer L; McKenzie, Karen; Cossar, Jill; Murray, Aja; Michie, Amanda

2016-01-01

This study aimed to evaluate the emotion recognition abilities of adults (n=23) with an intellectual disability (ID) compared with a control group of children (n=23) without ID matched for estimated cognitive ability. The study examined the impact of: task paradigm, stimulus type and preferred processing style (global/local) on accuracy. We found that, after controlling for estimated cognitive ability, the control group performed significantly better than the individuals with ID. This provides some support for the emotion specificity hypothesis. Having a more local processing style did not significantly mediate the relation between having ID and emotion recognition, but did significantly predict emotion recognition ability after controlling for group. This suggests that processing style is related to emotion recognition independently of having ID. The availability of contextual information improved emotion recognition for people with ID when compared with line drawing stimuli, and identifying a target emotion from a choice of two was relatively easier for individuals with ID, compared with the other task paradigms. The results of the study are considered in the context of current theories of emotion recognition deficits in individuals with ID. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Double-Deficit Hypothesis: A Comprehensive Analysis of the Evidence

ERIC Educational Resources Information Center

Vukovic, Rose K.; Siegel, Linda S.

2006-01-01

The double-deficit hypothesis of developmental dyslexia proposes that deficits in phonological processing and naming speed represent independent sources of dysfunction in dyslexia. The present article is a review of the evidence for the double-deficit hypothesis, including a discussion of recent findings related to the hypothesis. Studies in this…

New methods of testing nonlinear hypothesis using iterative NLLS estimator

NASA Astrophysics Data System (ADS)

Mahaboob, B.; Venkateswarlu, B.; Mokeshrayalu, G.; Balasiddamuni, P.

2017-11-01

This research paper discusses the method of testing nonlinear hypothesis using iterative Nonlinear Least Squares (NLLS) estimator. Takeshi Amemiya [1] explained this method. However in the present research paper, a modified Wald test statistic due to Engle, Robert [6] is proposed to test the nonlinear hypothesis using iterative NLLS estimator. An alternative method for testing nonlinear hypothesis using iterative NLLS estimator based on nonlinear hypothesis using iterative NLLS estimator based on nonlinear studentized residuals has been proposed. In this research article an innovative method of testing nonlinear hypothesis using iterative restricted NLLS estimator is derived. Pesaran and Deaton [10] explained the methods of testing nonlinear hypothesis. This paper uses asymptotic properties of nonlinear least squares estimator proposed by Jenrich [8]. The main purpose of this paper is to provide very innovative methods of testing nonlinear hypothesis using iterative NLLS estimator, iterative NLLS estimator based on nonlinear studentized residuals and iterative restricted NLLS estimator. Eakambaram et al. [12] discussed least absolute deviation estimations versus nonlinear regression model with heteroscedastic errors and also they studied the problem of heteroscedasticity with reference to nonlinear regression models with suitable illustration. William Grene [13] examined the interaction effect in nonlinear models disused by Ai and Norton [14] and suggested ways to examine the effects that do not involve statistical testing. Peter [15] provided guidelines for identifying composite hypothesis and addressing the probability of false rejection for multiple hypotheses.

Enriching plausible new hypothesis generation in PubMed.

PubMed

Baek, Seung Han; Lee, Dahee; Kim, Minjoo; Lee, Jong Ho; Song, Min

2017-01-01

Most of earlier studies in the field of literature-based discovery have adopted Swanson's ABC model that links pieces of knowledge entailed in disjoint literatures. However, the issue concerning their practicability remains to be solved since most of them did not deal with the context surrounding the discovered associations and usually not accompanied with clinical confirmation. In this study, we aim to propose a method that expands and elaborates the existing hypothesis by advanced text mining techniques for capturing contexts. We extend ABC model to allow for multiple B terms with various biological types. We were able to concretize a specific, metabolite-related hypothesis with abundant contextual information by using the proposed method. Starting from explaining the relationship between lactosylceramide and arterial stiffness, the hypothesis was extended to suggest a potential pathway consisting of lactosylceramide, nitric oxide, malondialdehyde, and arterial stiffness. The experiment by domain experts showed that it is clinically valid. The proposed method is designed to provide plausible candidates of the concretized hypothesis, which are based on extracted heterogeneous entities and detailed relation information, along with a reliable ranking criterion. Statistical tests collaboratively conducted with biomedical experts provide the validity and practical usefulness of the method unlike previous studies. Applying the proposed method to other cases, it would be helpful for biologists to support the existing hypothesis and easily expect the logical process within it.

Are sick individuals weak competitors? Competitive ability of snails parasitized by a gigantism-inducing trematode.

PubMed

Seppälä, Otto; Karvonen, Anssi; Kuosa, Marja; Haataja, Maarit; Jokela, Jukka

2013-01-01

Parasitized individuals are often expected to be poor competitors because they are weakened by infections. Many trematode species, however, although extensively exploiting their mollusc hosts, also induce gigantism (increased host size) by diverting host resources towards growth instead of reproduction. In such systems, alternatively to reduced competitive ability due to negative effects of parasitism on host performance, larger size could allow more efficient resource acquisition and thus increase the relative competitive ability of host individuals. We addressed this hypothesis by testing the effect of a trematode parasite Diplostomum pseudospathaceum on the competitive ability of its snail host Lymnaea stagnalis. We experimentally examined the growth of snails kept in pairs in relation to their infection status and intensity of resource competition (i.e. food availability). We found that parasitized snails grew faster and their reproduction was reduced compared to unparasitized individuals indicating parasite-induced gigantism. However, growth of the snails was faster when competing with parasitized individuals compared to unparasitized snails indicating reduced competitive ability due to parasitism. The latter effect, however, was relatively weak suggesting that the effects of the parasite on snail physiology may partly override each other in determining competitive ability.

Are Sick Individuals Weak Competitors? Competitive Ability of Snails Parasitized by a Gigantism-Inducing Trematode

PubMed Central

Seppälä, Otto; Karvonen, Anssi; Kuosa, Marja; Haataja, Maarit; Jokela, Jukka

2013-01-01

Parasitized individuals are often expected to be poor competitors because they are weakened by infections. Many trematode species, however, although extensively exploiting their mollusc hosts, also induce gigantism (increased host size) by diverting host resources towards growth instead of reproduction. In such systems, alternatively to reduced competitive ability due to negative effects of parasitism on host performance, larger size could allow more efficient resource acquisition and thus increase the relative competitive ability of host individuals. We addressed this hypothesis by testing the effect of a trematode parasite Diplostomum pseudospathaceum on the competitive ability of its snail host Lymnaea stagnalis. We experimentally examined the growth of snails kept in pairs in relation to their infection status and intensity of resource competition (i.e. food availability). We found that parasitized snails grew faster and their reproduction was reduced compared to unparasitized individuals indicating parasite-induced gigantism. However, growth of the snails was faster when competing with parasitized individuals compared to unparasitized snails indicating reduced competitive ability due to parasitism. The latter effect, however, was relatively weak suggesting that the effects of the parasite on snail physiology may partly override each other in determining competitive ability. PMID:24205383

A Hypothesis-Driven Approach to Site Investigation

NASA Astrophysics Data System (ADS)

Nowak, W.

2008-12-01

Variability of subsurface formations and the scarcity of data lead to the notion of aquifer parameters as geostatistical random variables. Given an information need and limited resources for field campaigns, site investigation is often put into the context of optimal design. In optimal design, the types, numbers and positions of samples are optimized under case-specific objectives to meet the information needs. Past studies feature optimal data worth (balancing maximum financial profit in an engineering task versus the cost of additional sampling), or aim at a minimum prediction uncertainty of stochastic models for a prescribed investigation budget. Recent studies also account for other sources of uncertainty outside the hydrogeological range, such as uncertain toxicity, ingestion and behavioral parameters of the affected population when predicting the human health risk from groundwater contaminations. The current study looks at optimal site investigation from a new angle. Answering a yes/no question under uncertainty directly requires recasting the original question as a hypothesis test. Otherwise, false confidence in the resulting answer would be pretended. A straightforward example is whether a recent contaminant spill will cause contaminant concentrations in excess of a legal limit at a nearby drinking water well. This question can only be answered down to a specified chance of error, i.e., based on the significance level used in hypothesis tests. Optimal design is placed into the hypothesis-driven context by using the chance of providing a false yes/no answer as new criterion to be minimized. Different configurations apply for one-sided and two-sided hypothesis tests. If a false answer entails financial liability, the hypothesis-driven context can be re-cast in the context of data worth. The remaining difference is that failure is a hard constraint in the data worth context versus a monetary punishment term in the hypothesis-driven context. The basic principle

The (not so) immortal strand hypothesis.

PubMed

Tomasetti, Cristian; Bozic, Ivana

2015-03-01

Non-random segregation of DNA strands during stem cell replication has been proposed as a mechanism to minimize accumulated genetic errors in stem cells of rapidly dividing tissues. According to this hypothesis, an "immortal" DNA strand is passed to the stem cell daughter and not the more differentiated cell, keeping the stem cell lineage replication error-free. After it was introduced, experimental evidence both in favor and against the hypothesis has been presented. Using a novel methodology that utilizes cancer sequencing data we are able to estimate the rate of accumulation of mutations in healthy stem cells of the colon, blood and head and neck tissues. We find that in these tissues mutations in stem cells accumulate at rates strikingly similar to those expected without the protection from the immortal strand mechanism. Utilizing an approach that is fundamentally different from previous efforts to confirm or refute the immortal strand hypothesis, we provide evidence against non-random segregation of DNA during stem cell replication. Our results strongly suggest that parental DNA is passed randomly to stem cell daughters and provides new insight into the mechanism of DNA replication in stem cells. Copyright © 2015. Published by Elsevier B.V.

The (not so) Immortal Strand Hypothesis

PubMed Central

Tomasetti, Cristian; Bozic, Ivana

2015-01-01

Background Non-random segregation of DNA strands during stem cell replication has been proposed as a mechanism to minimize accumulated genetic errors in stem cells of rapidly dividing tissues. According to this hypothesis, an “immortal” DNA strand is passed to the stem cell daughter and not the more differentiated cell, keeping the stem cell lineage replication error-free. After it was introduced, experimental evidence both in favor and against the hypothesis has been presented. Principal Findings Using a novel methodology that utilizes cancer sequencing data we are able to estimate the rate of accumulation of mutations in healthy stem cells of the colon, blood and head and neck tissues. We to find that in these tissues mutations in stem cells accumulate at rates strikingly similar to those expected without the protection from the immortal strand mechanism. Significance Utilizing an approach that is fundamentally different from previous efforts to confirm or refute the immortal strand hypothesis, we provide strong evidence against non-random segregation of DNA during stem cell replication. Our results strongly suggest that parental DNA is passed randomly to stem cell daughters and provides new insight into the mechanism of DNA replication in stem cells. PMID:25700960

Hypothesis driven assessment of an NMR curriculum

NASA Astrophysics Data System (ADS)

Cossey, Kimberly

The goal of this project was to develop a battery of assessments to evaluate an undergraduate NMR curriculum at Penn State University. As a chemical education project, we sought to approach the problem of curriculum assessment from a scientific perspective, while remaining grounded in the education research literature and practices. We chose the phrase hypothesis driven assessment to convey this process of relating the scientific method to the study of educational methods, modules, and curricula. We began from a hypothesis, that deeper understanding of one particular analytical technique (NMR) will increase undergraduate students' abilities to solve chemical problems. We designed an experiment to investigate this hypothesis, and data collected were analyzed and interpreted in light of the hypothesis and several related research questions. The expansion of the NMR curriculum at Penn State was funded through the NSF's Course, Curriculum, and Laboratory Improvement (CCLI) program, and assessment was required. The goal of this project, as stated in the grant proposal, was to provide NMR content in greater depth by integrating NMR modules throughout the curriculum in physical chemistry, instrumental, and organic chemistry laboratory courses. Hands-on contact with the NMR spectrometer and NMR data and repeated exposure of the analytical technique within different contexts (courses) were unique factors of this curriculum. Therefore, we maintained a focus on these aspects throughout the evaluation process. The most challenging and time-consuming aspect of any assessment is the development of testing instruments and methods to provide useful data. After key variables were defined, testing instruments were designed to measure these variables based on educational literature (Chapter 2). The primary variables measured in this assessment were: depth of understanding of NMR, basic NMR knowledge, problem solving skills (HETCOR problem), confidence for skills used in class (within

Rayleigh's hypothesis and the geometrical optics limit.

PubMed

Elfouhaily, Tanos; Hahn, Thomas

2006-09-22

The Rayleigh hypothesis (RH) is often invoked in the theoretical and numerical treatment of rough surface scattering in order to decouple the analytical form of the scattered field. The hypothesis stipulates that the scattered field away from the surface can be extended down onto the rough surface even though it is formed by solely up-going waves. Traditionally this hypothesis is systematically used to derive the Volterra series under the small perturbation method which is equivalent to the low-frequency limit. In this Letter we demonstrate that the RH also carries the high-frequency or the geometrical optics limit, at least to first order. This finding has never been explicitly derived in the literature. Our result comforts the idea that the RH might be an exact solution under some constraints in the general case of random rough surfaces and not only in the case of small-slope deterministic periodic gratings.

The GSK3 hypothesis of Alzheimer's disease

PubMed Central

Hooper, Claudie; Killick, Richard; Lovestone, Simon

2008-01-01

Glycogen synthase kinase 3 (GSK3) is a constitutively active, proline-directed serine/threonine kinase that plays a part in a number of physiological processes ranging from glycogen metabolism to gene transcription. GSK3 also plays a pivotal and central role in the pathogenesis of both sporadic and familial forms of Alzheimer's disease (AD), an observation that has led us to coin the ‘GSK3 hypothesis of AD’. According to this hypothesis, over-activity of GSK3 accounts for memory impairment, tau hyper-phosphorylation, increased β-amyloid production and local plaque-associated microglial-mediated inflammatory responses; all of which are hallmark characteristics of AD. If our ‘GSK3 hypothesis of AD’ is substantiated and GSK3 is indeed a causal mediator of AD then inhibitors of GSK3 would provide a novel avenue for therapeutic intervention in this devastating disorder. PMID:18088381

Botulinum toxin and the facial feedback hypothesis: can looking better make you feel happier?

PubMed

Alam, Murad; Barrett, Karen C; Hodapp, Robert M; Arndt, Kenneth A

2008-06-01

The facial feedback hypothesis suggests that muscular manipulations which result in more positive facial expressions may lead to more positive emotional states in affected individuals. In this essay, we hypothesize that the injection of botulinum toxin for upper face dynamic creases might induce positive emotional states by reducing the ability to frown and create other negative facial expressions. The use of botulinum toxin to pharmacologically alter upper face muscular expressiveness may curtail the appearance of negative emotions, most notably anger, but also fear and sadness. This occurs via the relaxation of the corrugator supercilii and the procerus, which are responsible for brow furrowing, and to a lesser extent, because of the relaxation of the frontalis. Concurrently, botulinum toxin may dampen some positive expressions like the true smile, which requires activity of the orbicularis oculi, a muscle also relaxed after toxin injections. On balance, the evidence suggests that botulinum toxin injections for upper face dynamic creases may reduce negative facial expressions more than they reduce positive facial expressions. Based on the facial feedback hypothesis, this net change in facial expression may potentially have the secondary effect of reducing the internal experience of negative emotions, thus making patients feel less angry, sad, and fearful.

A test of the reward-value hypothesis.

PubMed

Smith, Alexandra E; Dalecki, Stefan J; Crystal, Jonathon D

2017-03-01

Rats retain source memory (memory for the origin of information) over a retention interval of at least 1 week, whereas their spatial working memory (radial maze locations) decays within approximately 1 day. We have argued that different forgetting functions dissociate memory systems. However, the two tasks, in our previous work, used different reward values. The source memory task used multiple pellets of a preferred food flavor (chocolate), whereas the spatial working memory task provided access to a single pellet of standard chow-flavored food at each location. Thus, according to the reward-value hypothesis, enhanced performance in the source memory task stems from enhanced encoding/memory of a preferred reward. We tested the reward-value hypothesis by using a standard 8-arm radial maze task to compare spatial working memory accuracy of rats rewarded with either multiple chocolate or chow pellets at each location using a between-subjects design. The reward-value hypothesis predicts superior accuracy for high-valued rewards. We documented equivalent spatial memory accuracy for high- and low-value rewards. Importantly, a 24-h retention interval produced equivalent spatial working memory accuracy for both flavors. These data are inconsistent with the reward-value hypothesis and suggest that reward value does not explain our earlier findings that source memory survives unusually long retention intervals.

Nature versus Nurture in Determining Athletic Ability.

PubMed

Yan, Xu; Papadimitriou, Ioannis; Lidor, Ronnie; Eynon, Nir

2016-01-01

This overview provides a general discussion of the roles of nature and nurture in determining human athletic ability. On the nature (genetics) side, a review is provided with emphasis on the historical research and on several areas which are likely to be important for future research, including next-generation sequencing technologies. In addition, a number of well-designed training studies that could possibly reveal the biological mechanism ('cause') behind the association between gene variants and athletic ability are discussed. On the nurture (environment) side, we discuss common environmental variables including deliberate practice, family support, and the birthplace effect, which may be important in becoming an elite athlete. Developmental effects are difficult to disassociate with genetic effects, because the early life environment may have long-lasting effects in adulthood. With this in mind, the fetal programming hypothesis is also briefly reviewed, as fetal programming provides an excellent example of how the environment interacts with genetics. We conclude that the traditional argument of nature versus nurture is no longer relevant, as it has been clearly established that both are important factors in the road to becoming an elite athlete. With the availability of the next-generation genetics (sequencing) techniques, it is hoped that future studies will reveal the relevant genes influencing performance, as well as the interaction between those genes and environmental (nurture) factors. © 2016 S. Karger AG, Basel.

Relationships between visual-motor and cognitive abilities in intellectual disabilities.

PubMed

Di Blasi, Francesco D; Elia, Flaviana; Buono, Serafino; Ramakers, Ger J A; Di Nuovo, Santo F

2007-06-01

The neurobiological hypothesis supports the relevance of studying visual-perceptual and visual-motor skills in relation to cognitive abilities in intellectual disabilities because the defective intellectual functioning in intellectual disabilities is not restricted to higher cognitive functions but also to more basic functions. The sample was 102 children 6 to 16 years old and with different severities of intellectual disabilities. Children were administered the Wechsler Intelligence Scale for Children, the Bender Visual Motor Gestalt Test, and the Developmental Test of Visual Perception, and data were also analysed according to the presence or absence of organic anomalies, which are etiologically relevant for mental disabilities. Children with intellectual disabilities had deficits in perceptual organisation which correlated with the severity of intellectual disabilities. Higher correlations between the spatial subtests of the Developmental Test of Visual Perception and the Performance subtests of the Wechsler Intelligence Scale for Children suggested that the spatial skills and cognitive performance may have a similar basis in information processing. Need to differentiate protocols for rehabilitation and intervention for recovery of perceptual abilities from general programs of cognitive stimulations is suggested.

Motor Synergies and the Equilibrium-Point Hypothesis

PubMed Central

Latash, Mark L.

2010-01-01

The article offers a way to unite three recent developments in the field of motor control and coordination: (1) The notion of synergies is introduced based on the principle of motor abundance; (2) The uncontrolled manifold hypothesis is described as offering a computational framework to identify and quantify synergies; and (3) The equilibrium-point hypothesis is described for a single muscle, single joint, and multi-joint systems. Merging these concepts into a single coherent scheme requires focusing on control variables rather than performance variables. The principle of minimal final action is formulated as the guiding principle within the referent configuration hypothesis. Motor actions are associated with setting two types of variables by a controller, those that ultimately define average performance patterns and those that define associated synergies. Predictions of the suggested scheme are reviewed, such as the phenomenon of anticipatory synergy adjustments, quick actions without changes in synergies, atypical synergies, and changes in synergies with practice. A few models are briefly reviewed. PMID:20702893

Motor synergies and the equilibrium-point hypothesis.

PubMed

Latash, Mark L

2010-07-01

The article offers a way to unite three recent developments in the field of motor control and coordination: (1) The notion of synergies is introduced based on the principle of motor abundance; (2) The uncontrolled manifold hypothesis is described as offering a computational framework to identify and quantify synergies; and (3) The equilibrium-point hypothesis is described for a single muscle, single joint, and multijoint systems. Merging these concepts into a single coherent scheme requires focusing on control variables rather than performance variables. The principle of minimal final action is formulated as the guiding principle within the referent configuration hypothesis. Motor actions are associated with setting two types of variables by a controller, those that ultimately define average performance patterns and those that define associated synergies. Predictions of the suggested scheme are reviewed, such as the phenomenon of anticipatory synergy adjustments, quick actions without changes in synergies, atypical synergies, and changes in synergies with practice. A few models are briefly reviewed.

Auditory-motor entrainment and phonological skills: precise auditory timing hypothesis (PATH).

PubMed

Tierney, Adam; Kraus, Nina

2014-01-01

Phonological skills are enhanced by music training, but the mechanisms enabling this cross-domain enhancement remain unknown. To explain this cross-domain transfer, we propose a precise auditory timing hypothesis (PATH) whereby entrainment practice is the core mechanism underlying enhanced phonological abilities in musicians. Both rhythmic synchronization and language skills such as consonant discrimination, detection of word and phrase boundaries, and conversational turn-taking rely on the perception of extremely fine-grained timing details in sound. Auditory-motor timing is an acoustic feature which meets all five of the pre-conditions necessary for cross-domain enhancement to occur (Patel, 2011, 2012, 2014). There is overlap between the neural networks that process timing in the context of both music and language. Entrainment to music demands more precise timing sensitivity than does language processing. Moreover, auditory-motor timing integration captures the emotion of the trainee, is repeatedly practiced, and demands focused attention. The PATH predicts that musical training emphasizing entrainment will be particularly effective in enhancing phonological skills.

Towards a glutamate hypothesis of depression

PubMed Central

Sanacora, Gerard; Treccani, Giulia; Popoli, Maurizio

2011-01-01

Half a century after the first formulation of the monoamine hypothesis, compelling evidence implies that long-term changes in an array of brain areas and circuits mediating complex cognitive-emotional behaviors represent the biological underpinnings of mood/anxiety disorders. A large number of clinical studies suggest that pathophysiology is associated with dysfunction of the predominant glutamatergic system, malfunction in the mechanisms regulating clearance and metabolism of glutamate, and cytoarchitectural/morphological maladaptive changes in a number of brain areas mediating cognitive-emotional behaviors. Concurrently, a wealth of data from animal models have shown that different types of environmental stress enhance glutamate release/transmission in limbic/cortical areas and exert powerful structural effects, inducing dendritic remodeling, reduction of synapses and possibly volumetric reductions resembling those observed in depressed patients. Because a vast majority of neurons and synapses in these areas and circuits use glutamate as neurotransmitter, it would be limiting to maintain that glutamate is in some way ‘involved’ in mood/anxiety disorders; rather it should be recognized that the glutamatergic system is a primary mediator of psychiatric pathology and, potentially, also a final common pathway for the therapeutic action of antidepressant agents. A paradigm shift from a monoamine hypothesis of depression to a neuroplasticity hypothesis focused on glutamate may represent a substantial advancement in the working hypothesis that drives research for new drugs and therapies. Importantly, despite the availability of multiple classes of drugs with monoamine-based mechanisms of action, there remains a large percentage of patients who fail to achieve a sustained remission of depressive symptoms. The unmet need for improved pharmacotherapies for treatment-resistant depression means there is a large space for the development of new compounds with novel

Mars' Oceanus Borealis, Ancient Glaciers, and the MEGAOUTFLO Hypothesis

NASA Technical Reports Server (NTRS)

Baker, V. R.; Strom, R. G.; Dohm, J. M.; Gulick, V. C.; Kargel, J. S.; Komatsu, G.; Ori, G. G.; Rice, J. W., Jr.

2000-01-01

Recent results from Global Surveyor corroborate the hypothesis that episodes of outburst flooding produced ponded water and climate change on Mars. This hypothesis colligates diverse facts concerning the Martian landscape and its history into a unified genetic system.

[Survival of Vibrio cholerae 01 in freshwater surface and endemic cholera: a geological hypothesis].

PubMed

Borroto, R J

1998-12-01

The danger that cholera is becoming endemic in Latin America makes it imperative to know the geographic location of aquatic environments where ecological conditions favor long-term survival of the toxigenic Vibrio cholerae O1 El Tor biotype, and such aquatic environments should be sampled to determine if they harbor this microorganism. For efficient and effective sampling, it would be useful to know what kinds of waters are ecologically suitable for the survival of this pathogen during periods between epidemics, and where these bodies of water are located. This paper presents the hypothesis that toxigenic V. cholerae O1's ability to survive in surface freshwaters tends to be inversely related to the altitude above sea level of these freshwaters.

Amyloid pore-channel hypothesis: effect of ethanol on aggregation state using frog oocytes for an Alzheimer’s disease study

PubMed Central

Parodi, Jorge; Ormeño, David; la Paz, Lenin D. Ochoa-de

2015-01-01

Alzheimer's disease severely compromises cognitive function. One of the mechanisms to explain the pathology of Alzheimer’s disease has been the hypotheses of amyloid-pore/channel formation by complex Aβ-aggregates. Clinical studies suggested the moderate alcohol consumption can reduces probability developing neurodegenerative pathologies. A recent report explored the ability of ethanol to disrupt the generation of complex Aβ in vitro and reduce the toxicity in two cell lines. Molecular dynamics simulations were applied to understand how ethanol blocks the aggregation of amyloid. On the other hand, the in silico modeling showed ethanol effect over the dynamics assembling for complex Aβ-aggregates mediated by break the hydrosaline bridges between Asp 23 and Lys 28, was are key element for amyloid dimerization. The amyloid pore/channel hypothesis has been explored only in neuronal models, however recently experiments suggested the frog oocytes such an excellent model to explore the mechanism of the amyloid pore/channel hypothesis. So, the used of frog oocytes to explored the mechanism of amyloid aggregates is new, mainly for amyloid/pore hypothesis. Therefore, this experimental model is a powerful tool to explore the mechanism implicates in the Alzheimer’s disease pathology and also suggests a model to prevent the Alzheimer’s disease pathology. [BMB Reports 2015; 48(1): 13-18] PMID:25047445

On the nature and nurture of intelligence and specific cognitive abilities: the more heritable, the more culture dependent.

PubMed

Kan, Kees-Jan; Wicherts, Jelte M; Dolan, Conor V; van der Maas, Han L J

2013-12-01

To further knowledge concerning the nature and nurture of intelligence, we scrutinized how heritability coefficients vary across specific cognitive abilities both theoretically and empirically. Data from 23 twin studies (combined N = 7,852) showed that (a) in adult samples, culture-loaded subtests tend to demonstrate greater heritability coefficients than do culture-reduced subtests; and (b) in samples of both adults and children, a subtest's proportion of variance shared with general intelligence is a function of its cultural load. These findings require an explanation because they do not follow from mainstream theories of intelligence. The findings are consistent with our hypothesis that heritability coefficients differ across cognitive abilities as a result of differences in the contribution of genotype-environment covariance. The counterintuitive finding that the most heritable abilities are the most culture-dependent abilities sheds a new light on the long-standing nature-nurture debate of intelligence.

Tests of the Giant Impact Hypothesis

NASA Technical Reports Server (NTRS)

Jones, J. H.

1998-01-01

The giant impact hypothesis has gained popularity as a means of explaining a volatile-depleted Moon that still has a chemical affinity to the Earth. As Taylor's Axiom decrees, the best models of lunar origin are testable, but this is difficult with the giant impact model. The energy associated with the impact would be sufficient to totally melt and partially vaporize the Earth. And this means that there should he no geological vestige of Barber times. Accordingly, it is important to devise tests that may be used to evaluate the giant impact hypothesis. Three such tests are discussed here. None of these is supportive of the giant impact model, but neither do they disprove it.

Testing the null hypothesis: the forgotten legacy of Karl Popper?

PubMed

Wilkinson, Mick

2013-01-01

Testing of the null hypothesis is a fundamental aspect of the scientific method and has its basis in the falsification theory of Karl Popper. Null hypothesis testing makes use of deductive reasoning to ensure that the truth of conclusions is irrefutable. In contrast, attempting to demonstrate the new facts on the basis of testing the experimental or research hypothesis makes use of inductive reasoning and is prone to the problem of the Uniformity of Nature assumption described by David Hume in the eighteenth century. Despite this issue and the well documented solution provided by Popper's falsification theory, the majority of publications are still written such that they suggest the research hypothesis is being tested. This is contrary to accepted scientific convention and possibly highlights a poor understanding of the application of conventional significance-based data analysis approaches. Our work should remain driven by conjecture and attempted falsification such that it is always the null hypothesis that is tested. The write up of our studies should make it clear that we are indeed testing the null hypothesis and conforming to the established and accepted philosophical conventions of the scientific method.

Investigation of predictors affecting food mixing ability in mandibulectomy and/or glossectomy patients.

PubMed

Otomaru, Takafumi; Sumita, Yuka I; Chang, Qingan; Fueki, Kenji; Igarashi, Yoshimasa; Taniguchi, Hisashi

2009-07-01

Several previous reports have described factors that affect masticatory function. However, there are no known predictors that affect the food mixing ability of the masticatory function, and it has been impossible to predict masticatory function in mandibulectomy and/or glossectomy patients. The purpose of the present study was to develop a numerical formula that could predict the food mixing ability of the masticatory function among mandibulectomy and/or glossectomy patients. The null hypothesis of the study was that five predictors, namely mandibulectomy, mandibular continuity, number of residual mandibular teeth, occlusal units and tongue movement score, were unable to account for the mixing ability index (MAI) in mandibulectomy and/or glossectomy patients. The subjects were 20 patients who had undergone mandibulectomy and/or glossectomy. The above-described five predictors were assessed. Tongue movement was evaluated with a tongue movement test and the MAI was evaluated with a mixing ability test. Multiple regression analysis was used to examine whether the five predictors affected the MAI after prosthetic treatment. A regression equation was determined for the five predictors (R(2)=0.83; adjusted R(2)=0.77; p<0.001). The obtained regression equation could successfully account for the MAI in mandibulectomy and/or glossectomy patients.

Sibship size and educational attainment. A joint test of the Confluence Model and the Resource Dilution Hypothesis

PubMed Central

Jæger, Mads Meier

2012-01-01

Studies on family background often explain the negative effect of sibship size on educational attainment by one of two theories: the Confluence Model (CM) or the Resource Dilution Hypothesis (RDH). However, as both theories – for substantively different reasons – predict that sibship size should have a negative effect on educational attainment most studies cannot distinguish empirically between the CM and the RDH. In this paper, I use the different theoretical predictions in the CM and RDH on the role of cognitive ability as a partial or complete mediator of the effect of sibship size to distinguish the two theories and to identify a unique RDH effect on educational attainment. Using sibling data from the Wisconsin Longitudinal Study (WLS) and a random effect Instrumental Variable model I find that, in addition to a negative effect on cognitive ability, sibship size also has a strong negative effect on educational attainment which is uniquely explained by the RDH. PMID:22468016

White Matter Maturation Supports the Development of Reasoning Ability Through its Influence on Processing Speed

PubMed Central

Ferrer, E.; Whitaker, K.J.; Steele, J.; Green, C.T.; Wendelken, C.; Bunge, S.A.

2013-01-01

The structure of the human brain changes in several ways throughout childhood and adolescence. Perhaps the most salient of these changes is the strengthening of white matter tracts that enable distal brain regions to communicate with one another more quickly and efficiently. Here, we sought to understand whether and how white matter changes contribute to improved reasoning ability over development. In particular, we sought to understand whether previously reported relationships between white matter microstructure and reasoning are mediated by processing speed. To this end, we analyzed diffusion tensor imaging data as well as data from standard psychometric tests of cognitive abilities from 103 individuals between the ages of 6 and 18. We used structural equation modeling to investigate the network of relationships between brain and behavior variables. Our analyses provide support for the hypothesis that white matter maturation (as indexed either by microstructural organization or volume) supports improved processing speed, which, in turn, supports improved reasoning ability. PMID:24118718

Affective Feedback from Computers and its Effect on Perceived Ability and Affect: A Test of the Computers as Social Actor Hypothesis

ERIC Educational Resources Information Center

Mishra, Punya

2006-01-01

We report an experimental study that examined two questions: (a) The effect of affective feedback from computers on participants' motivation and self-perception of ability; and (b) whether people respond similarly to computer feedback as they do to human feedback. This study, framed within the Computers As Social Actors (CASA) framework,…

Toe spreading ability in men with chronic pelvic pain syndrome

PubMed Central

Yilmaz, Ugur; Rothman, Ivan; Ciol, Marcia A; Yang, Claire C; Berger, Richard E

2005-01-01

Background We examined toe-spreading ability in subjects with chronic pelvic pain syndrome (CPPS) to test the hypothesis that subjects with CPPS could have deficiencies in lower extremity functions innervated by sacral spinal roots. Methods Seventy two subjects with CPPS and 98 volunteer controls were examined as part of a larger study on CPPS. All the subjects underwent a detailed urologic and neurological examination including a toe-spreading examination with a quantitative scoring system. We compared the groups in terms of ability of toe-spreading as either "complete" (all toes spreading) or "incomplete" (at least one interdigital space not spreading) and also by comparing the number of interdigital spaces. For CPPS subjects only, we also analyzed the variation of the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) scales by toe-spreading categories. Results CPPS subjects were less often able to spread all toes than subjects without CPPS (p = 0.005). None of the NIH-CPSI sub-scales (pain, urinary symptoms, and quality of life), nor the total score showed an association with toe spreading ability. Conclusion We found toe spreading to be diminished in subjects with CPPS. We hypothesize that incomplete toe spreading in subjects with CPPS may be related to subtle deficits involving the most caudal part of the spinal segments. PMID:15949041

Unscaled Bayes factors for multiple hypothesis testing in microarray experiments.

PubMed

Bertolino, Francesco; Cabras, Stefano; Castellanos, Maria Eugenia; Racugno, Walter

2015-12-01

Multiple hypothesis testing collects a series of techniques usually based on p-values as a summary of the available evidence from many statistical tests. In hypothesis testing, under a Bayesian perspective, the evidence for a specified hypothesis against an alternative, conditionally on data, is given by the Bayes factor. In this study, we approach multiple hypothesis testing based on both Bayes factors and p-values, regarding multiple hypothesis testing as a multiple model selection problem. To obtain the Bayes factors we assume default priors that are typically improper. In this case, the Bayes factor is usually undetermined due to the ratio of prior pseudo-constants. We show that ignoring prior pseudo-constants leads to unscaled Bayes factor which do not invalidate the inferential procedure in multiple hypothesis testing, because they are used within a comparative scheme. In fact, using partial information from the p-values, we are able to approximate the sampling null distribution of the unscaled Bayes factor and use it within Efron's multiple testing procedure. The simulation study suggests that under normal sampling model and even with small sample sizes, our approach provides false positive and false negative proportions that are less than other common multiple hypothesis testing approaches based only on p-values. The proposed procedure is illustrated in two simulation studies, and the advantages of its use are showed in the analysis of two microarray experiments. © The Author(s) 2011.

Testing of Hypothesis in Equivalence and Non Inferiority Trials-A Concept.

PubMed

Juneja, Atul; Aggarwal, Abha R; Adhikari, Tulsi; Pandey, Arvind

2016-04-01

Establishing the appropriate hypothesis is one of the important steps for carrying out the statistical tests/analysis. Its understanding is important for interpreting the results of statistical analysis. The current communication attempts to provide the concept of testing of hypothesis in non inferiority and equivalence trials, where the null hypothesis is just reverse of what is set up for conventional superiority trials. It is similarly looked for rejection for establishing the fact the researcher is intending to prove. It is important to mention that equivalence or non inferiority cannot be proved by accepting the null hypothesis of no difference. Hence, establishing the appropriate statistical hypothesis is extremely important to arrive at meaningful conclusion for the set objectives in research.

Longitudinal Dimensionality of Adolescent Psychopathology: Testing the Differentiation Hypothesis

ERIC Educational Resources Information Center

Sterba, Sonya K.; Copeland, William; Egger, Helen L.; Costello, E. Jane; Erkanli, Alaattin; Angold, Adrian

2010-01-01

Background: The differentiation hypothesis posits that the underlying liability distribution for psychopathology is of low dimensionality in young children, inflating diagnostic comorbidity rates, but increases in dimensionality with age as latent syndromes become less correlated. This hypothesis has not been adequately tested with longitudinal…

About the structure of cellulose: debating the Lindman hypothesis

USDA-ARS?s Scientific Manuscript database

The hypothesis advanced in this issue of Cellulose, that the solubility or insolubility characteristics of cellulose are significantly based upon amphiphilic and hydrophobic molecular interactions, is bound to shake the roots of (some of) our textbook wisdom. The hypothesis is based on the considera...

Are non-human primates capable of rhythmic entrainment? Evidence for the gradual audiomotor evolution hypothesis.

PubMed

Merchant, Hugo; Honing, Henkjan

2013-01-01

We propose a decomposition of the neurocognitive mechanisms that might underlie interval-based timing and rhythmic entrainment. Next to reviewing the concepts central to the definition of rhythmic entrainment, we discuss recent studies that suggest rhythmic entrainment to be specific to humans and a selected group of bird species, but, surprisingly, is not obvious in non-human primates. On the basis of these studies we propose the gradual audiomotor evolution hypothesis that suggests that humans fully share interval-based timing with other primates, but only partially share the ability of rhythmic entrainment (or beat-based timing). This hypothesis accommodates the fact that non-human primates (i.e., macaques) performance is comparable to humans in single interval tasks (such as interval reproduction, categorization, and interception), but show differences in multiple interval tasks (such as rhythmic entrainment, synchronization, and continuation). Furthermore, it is in line with the observation that macaques can, apparently, synchronize in the visual domain, but show less sensitivity in the auditory domain. And finally, while macaques are sensitive to interval-based timing and rhythmic grouping, the absence of a strong coupling between the auditory and motor system of non-human primates might be the reason why macaques cannot rhythmically entrain in the way humans do.

Knudson's hypothesis revisited in Indian retinoblastoma patients.

PubMed

Gaikwad, Namrata; Vanniarajan, Ayyasamy; Husain, Akram; Jeyaram, Illaiyaraja; Thirumalairaj, Kannan; Santhi, Radhakrishnan; Muthukkaruppan, Veerappan; Kim, Usha

2015-12-01

Retinoblastoma (RB) is the most common primary intraocular malignancy affecting children under 5 years of age. This study aims to correlate the clinical parameters with RB1 mutation in the light of Knudson's two-hit hypothesis in Indian RB patients. We analyzed the clinical details of 73 RB patients visiting Aravind Eye Hospital, Madurai, India, between January and October 2012. Data on gender, presenting age and sign, laterality, number of tumors in each eye and family history were collected. A semi log plot was derived based on Knudson's two-hit hypothesis. Genetic analysis of RB1 was carried out to identify the two hits. The mean age at diagnosis for unilateral and bilateral cases was 24.0 ± 15.1 and 9.8 ± 11.5 months, respectively. Familial RB was seen in 13 (17.8%) patients of whom 11 were bilateral. Multiple tumors were observed more frequently in bilateral than in unilateral cases. All unilateral and bilateral patients followed the two-hit and one-hit curves, respectively, confirming Knudson's hypothesis in Indian patients. Genetic analysis identified two somatic mutations in tumor samples of sporadic unilateral cases. Among the two bilateral patients, one received the first hit from her father and the other patient developed a de novo germline mutation during early development. The two-hit hypothesis has been reestablished in Indian patients. Genetic analysis of tumor samples has also complemented the statistical analysis to reaffirm the two hits in tumor development. © 2015 Wiley Publishing Asia Pty Ltd.

Surgical simulation tasks challenge visual working memory and visual-spatial ability differently.

PubMed

Schlickum, Marcus; Hedman, Leif; Enochsson, Lars; Henningsohn, Lars; Kjellin, Ann; Felländer-Tsai, Li

2011-04-01

New strategies for selection and training of physicians are emerging. Previous studies have demonstrated a correlation between visual-spatial ability and visual working memory with surgical simulator performance. The aim of this study was to perform a detailed analysis on how these abilities are associated with metrics in simulator performance with different task content. The hypothesis is that the importance of visual-spatial ability and visual working memory varies with different task contents. Twenty-five medical students participated in the study that involved testing visual-spatial ability using the MRT-A test and visual working memory using the RoboMemo computer program. Subjects were also trained and tested for performance in three different surgical simulators. The scores from the psychometric tests and the performance metrics were then correlated using multivariate analysis. MRT-A score correlated significantly with the performance metrics Efficiency of screening (p = 0.006) and Total time (p = 0.01) in the GI Mentor II task and Total score (p = 0.02) in the MIST-VR simulator task. In the Uro Mentor task, both the MRT-A score and the visual working memory 3-D cube test score as presented in the RoboMemo program (p = 0.02) correlated with Total score (p = 0.004). In this study we have shown that some differences exist regarding the impact of visual abilities and task content on simulator performance. When designing future cognitive training programs and testing regimes, one might have to consider that the design must be adjusted in accordance with the specific surgical task to be trained in mind.

SIDS-CDF Hypothesis Revisited: Cause vs. Contributing Factors.

PubMed

Siren, Pontus M A

2016-01-01

The sudden infant death syndrome (SIDS)-critical diaphragm failure (CDF) hypothesis was first published by Siren and Siren in 2011 (1). Since its publication, the hypothesis has continued to generate interest and several colleagues have contributed perspectives and insights to it (2-5). The basic premise of the hypothesis is that the diaphragm is a vital organ that must continuously generate adequate force to maintain ventilation, and that CDF is a terminal event and the cause of death in SIDS. I have argued in two follow-up articles that all SIDS factors either increase the workload of the respiratory muscles, the diaphragm being the primary muscle affected, or reduce its force generating capacity (6, 7). The SIDS-CDF hypothesis posits that SIDS has many contributing factors but only one cause, namely, the failure of the vital respiratory pump. There are several known SIDS factors, such as the prone sleeping position, non-lethal infections, deep sleep, gestational prematurity, low birth weight, cigarette smoke, male gender, and altitude, but of these, some such as the prone sleeping position more significantly both impact diaphragm function and correlate with SIDS. However, SIDS cases are multifactorial and as such can be caused by different combinations of factors. An infection combined with a prone sleeping position and elevated room temperature could lead to SIDS, whereas in other circumstances, low birth weight, cigarette smoke, prone sleeping position, and altitude could result in CDF and SIDS. The SIDS-CDF hypothesis also posits that SIDS does not have a congenital or genetic origin, and that efforts to identify significant genetic anomalies in SIDS victims are unlikely to be successful (8-11).

On the Hypothesis of Control of the Universe

NASA Astrophysics Data System (ADS)

Kalanov, Temur Z.

2007-04-01

The problem of the SETI is not solved till now because idea of the SETI represents a methodological error in cosmology and astrophysics. This fact means that one should prove existence of Supreme Intelligence in a correct way. In this connection, the hypothesis of control of the Universe is proposed. The hypothesis is based on the new point of view [1] according to which information is essence of the Universe, and material objects are manifestation of the essence. The hypothesis is formulated as follows: (1) the Universe represents the cybernetic system; (2) the cybernetic system is a set of mutual connected elements which receive, memorize, process, and transmit information; (3) each material element (for example, atom, molecule, man, the Earth, the Sun) is a unity of opposites: the controlling aspect and the controllable aspect; (4) the Universe as a system is a unity of opposites: the controlling aspect and the controllable aspect. Consequently, the Universe is controlled by the certain object. Thus, the problem of definition of the controlling object arises. Correct solution of this problem is the key to exploration of the Universe. Ref.: [1] T.Z. Kalanov, ``On the hypothesis of Universe's ``system block'' ''. Bulletin of the APS, Vol. 51, No. 2 (2006), p. 61.

Almost-Quantum Correlations Violate the No-Restriction Hypothesis

NASA Astrophysics Data System (ADS)

Sainz, Ana Belén; Guryanova, Yelena; Acín, Antonio; Navascués, Miguel

2018-05-01

To identify which principles characterize quantum correlations, it is essential to understand in which sense this set of correlations differs from that of almost-quantum correlations. We solve this problem by invoking the so-called no-restriction hypothesis, an explicit and natural axiom in many reconstructions of quantum theory stating that the set of possible measurements is the dual of the set of states. We prove that, contrary to quantum correlations, no generalized probabilistic theory satisfying the no-restriction hypothesis is able to reproduce the set of almost-quantum correlations. Therefore, any theory whose correlations are exactly, or very close to, the almost-quantum correlations necessarily requires a rule limiting the possible measurements. Our results suggest that the no-restriction hypothesis may play a fundamental role in singling out the set of quantum correlations among other nonsignaling ones.

Almost-Quantum Correlations Violate the No-Restriction Hypothesis.

PubMed

Sainz, Ana Belén; Guryanova, Yelena; Acín, Antonio; Navascués, Miguel

2018-05-18

To identify which principles characterize quantum correlations, it is essential to understand in which sense this set of correlations differs from that of almost-quantum correlations. We solve this problem by invoking the so-called no-restriction hypothesis, an explicit and natural axiom in many reconstructions of quantum theory stating that the set of possible measurements is the dual of the set of states. We prove that, contrary to quantum correlations, no generalized probabilistic theory satisfying the no-restriction hypothesis is able to reproduce the set of almost-quantum correlations. Therefore, any theory whose correlations are exactly, or very close to, the almost-quantum correlations necessarily requires a rule limiting the possible measurements. Our results suggest that the no-restriction hypothesis may play a fundamental role in singling out the set of quantum correlations among other nonsignaling ones.

The effectiveness of problem-based learning on students’ problem solving ability in vector analysis course

NASA Astrophysics Data System (ADS)

Mushlihuddin, R.; Nurafifah; Irvan

2018-01-01

The student’s low ability in mathematics problem solving proved to the less effective of a learning process in the classroom. Effective learning was a learning that affects student’s math skills, one of which is problem-solving abilities. Problem-solving capability consisted of several stages: understanding the problem, planning the settlement, solving the problem as planned, re-examining the procedure and the outcome. The purpose of this research was to know: (1) was there any influence of PBL model in improving ability Problem solving of student math in a subject of vector analysis?; (2) was the PBL model effective in improving students’ mathematical problem-solving skills in vector analysis courses? This research was a quasi-experiment research. The data analysis techniques performed from the test stages of data description, a prerequisite test is the normality test, and hypothesis test using the ANCOVA test and Gain test. The results showed that: (1) there was an influence of PBL model in improving students’ math problem-solving abilities in vector analysis courses; (2) the PBL model was effective in improving students’ problem-solving skills in vector analysis courses with a medium category.

Assess the Critical Period Hypothesis in Second Language Acquisition

ERIC Educational Resources Information Center

Du, Lihong

2010-01-01

The Critical Period Hypothesis aims to investigate the reason for significant difference between first language acquisition and second language acquisition. Over the past few decades, researchers carried out a series of studies to test the validity of the hypothesis. Although there were certain limitations in these studies, most of their results…

The double-deficit hypothesis: a comprehensive analysis of the evidence.

PubMed

Vukovic, Rose K; Siegel, Linda S

2006-01-01

The double-deficit hypothesis of developmental dyslexia proposes that deficits in phonological processing and naming speed represent independent sources of dysfunction in dyslexia. The present article is a review of the evidence for the double-deficit hypothesis, including a discussion of recent findings related to the hypothesis. Studies in this area have been characterized by variability in methodology--how dyslexia is defined and identified, and how dyslexia subtypes are classified. Such variability sets limitations on the extent to which conclusions may be drawn with respect to the double-deficit hypothesis. Furthermore, the literature is complicated by the persistent finding that measures of phonological processing and naming speed are significantly correlated, resulting in a statistical artifact that makes it difficult to disentangle the influence of naming speed from that of phonological processing. Longitudinal and intervention studies of the double-deficit hypothesis are needed to accumulate evidence that investigates a naming speed deficit that is independent of a phonological deficit for readers with dyslexia. The existing evidence does not support a persistent core deficit in naming speed for readers with dyslexia.

The Implications of the Cancer Stem Cell Hypothesis for Neuro-Oncology and Neurology.

PubMed

Rich, Jeremy N

2008-05-01

The cancer stem cell hypothesis posits that cancers contain a subset of neoplastic cells that propagate and maintain tumors through sustained self-renewal and potent tumorigenecity. Recent excitement has been generated by a number of reports that have demonstrated the existence of cancer stem cells in several types of brain tumors. Brain cancer stem cells - also called tumor initiating cells or tumor propagating cells - share features with normal neural stem cells but do not necessarily originate from stem cells. Although most cancers have only a small fraction of cancer stem cells, these tumor cells have been shown in laboratory studies to contribute to therapeutic resistance, formation of new blood vessels to supply the tumor, and tumor spread. As malignant brain tumors rank among the deadliest of all neurologic diseases, the identification of new cellular targets may have profound implications in neuro-oncology. Novel drugs that target stem cell pathways active in brain tumors have been efficacious against cancer stem cells suggesting that anti-cancer stem cell therapies may advance brain tumor therapy. The cancer stem cell hypothesis may have several implications for other neurologic diseases as caution must be exercised in activating stem cell maintenance pathways in cellular therapies for neurodegenerative diseases. The ability for a small fraction of cells to determine the overall course of a disease may also inform new paradigms of disease that may translate into improved patient outcomes.

Confirmation of the "protein-traffic-hypothesis" and the "protein-localization-hypothesis" using the diabetes-mellitus-type-1-knock-in and transgenic-murine-models and the trepitope sequences.

PubMed

Arneth, Borros

2012-10-01

As possible mechanisms to explain the emergence of autoimmune diseases, the current author has suggested in earlier papers two new pathways: the "protein localization hypothesis" and the "protein traffic hypothesis". The "protein localization hypothesis" states that an autoimmune disease develops if a protein accumulates in a previously unoccupied compartment, that did not previously contain that protein. Similarly, the "protein traffic hypothesis" states that a sudden error within the transport of a certain protein leads to the emergence of an autoimmune disease. The current article discusses the usefulness of the different commercially available transgenic murine models of diabetes mellitus type 1 to confirm the aforementioned hypotheses. This discussion shows that several transgenic murine models of diabetes mellitus type 1 are in-line and confirm the aforementioned hypotheses. Furthermore, these hypotheses are additionally inline with the occurrence of several newly discovered protein sequences, the so-called trepitope sequences. These sequences modulate the immune response to certain proteins. The current study analyzed to what extent the hypotheses are supported by the occurrence of these new sequences. Thereby the occurrence of the trepitope sequences provides additional evidence supporting the aforementioned hypotheses. Both the "protein localization hypothesis" and the "protein traffic hypothesis" have the potential to lead to new causal therapy concepts. The "protein localization hypothesis" and the "protein traffic hypothesis" provide conceptional explanations for the diabetes mouse models as well as for the newly discovered trepitope sequences. Copyright © 2012 Elsevier Ltd. All rights reserved.

Muscle cramps: A comparison of the two-leading hypothesis.

PubMed

Giuriato, Gaia; Pedrinolla, Anna; Federico, Schena; Venturelli, Massimo

2018-05-26

Exercise-Associated Muscle Cramps (EAMC) are a common painful condition of muscle spasms. Despite scientists tried to understand the physiological mechanism that underlies these common phenomena, the etiology is still unclear. From 1900 to nowadays, the scientific world retracted several times the original hypothesis of heat cramps. However, recent literature seems to focus on two potential mechanisms: the dehydration or electrolyte depletion mechanism, and the neuromuscular mechanism. The aim of this review is to examine the recent literature, in terms of physiological mechanisms of EAMC. A comprehensive search was conducted on PubMed and Google Scholar. The following terminology was applied: muscle cramps, neuromuscular hypothesis (or thesis), dehydration hypothesis, Exercise-Associated muscle cramps, nocturnal cramps, muscle spasm, muscle fatigue. From the initial literature of 424 manuscripts, sixty-nine manuscripts were included, analyzed, compared and summarized. Literature analysis indicates that neuromuscular hypothesis may prevails over the initial hypothesis of the dehydration as the trigger event of muscle cramps. New evidence suggests that the action potentials during a muscle cramp are generated in the motoneuron soma, likely accompanied by an imbalance between the rising excitatory drive from the muscle spindles (Ia) and the decreasing inhibitory drive from the Golgi tendon organs. In conclusion, from the latest investigations there seem to be a spinal involvement rather than a peripheral excitation of the motoneurons. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Elaborated Environmental Stress Hypothesis as a Framework for Understanding the Association Between Motor Skills and Internalizing Problems: A Mini-Review

PubMed Central

Mancini, Vincent O.; Rigoli, Daniela; Cairney, John; Roberts, Lynne D.; Piek, Jan P.

2016-01-01

Poor motor skills have been shown to be associated with a range of psychosocial issues, including internalizing problems (anxiety and depression). While well-documented empirically, our understanding of why this relationship occurs remains theoretically underdeveloped. The Elaborated Environmental Stress Hypothesis by Cairney et al. (2013) provides a promising framework that seeks to explain the association between motor skills and internalizing problems, specifically in children with developmental coordination disorder (DCD). The framework posits that poor motor skills predispose the development of internalizing problems via interactions with intermediary environmental stressors. At the time the model was proposed, limited direct evidence was available to support or refute the framework. Several studies and developments related to the framework have since been published. This mini-review seeks to provide an up-to-date overview of recent developments related to the Elaborated Environmental Stress Hypothesis. We briefly discuss the past research that led to its development, before moving to studies that have investigated the framework since it was proposed. While originally developed within the context of DCD in childhood, recent developments have found support for the model in community samples. Through the reviewed literature, this article provides support for the Elaborated Environmental Stress Hypothesis as a promising theoretical framework that explains the psychosocial correlates across the broader spectrum of motor ability. However, given its recent conceptualization, ongoing evaluation of the Elaborated Environmental Stress Hypothesis is recommended. PMID:26941690

In the Beginning-There Is the Introduction-and Your Study Hypothesis.

PubMed

Vetter, Thomas R; Mascha, Edward J

2017-05-01

Writing a manuscript for a medical journal is very akin to writing a newspaper article-albeit a scholarly one. Like any journalist, you have a story to tell. You need to tell your story in a way that is easy to follow and makes a compelling case to the reader. Although recommended since the beginning of the 20th century, the conventional Introduction-Methods-Results-And-Discussion (IMRAD) scientific reporting structure has only been the standard since the 1980s. The Introduction should be focused and succinct in communicating the significance, background, rationale, study aims or objectives, and the primary (and secondary, if appropriate) study hypotheses. Hypothesis testing involves posing both a null and an alternative hypothesis. The null hypothesis proposes that no difference or association exists on the outcome variable of interest between the interventions or groups being compared. The alternative hypothesis is the opposite of the null hypothesis and thus typically proposes that a difference in the population does exist between the groups being compared on the parameter of interest. Most investigators seek to reject the null hypothesis because of their expectation that the studied intervention does result in a difference between the study groups or that the association of interest does exist. Therefore, in most clinical and basic science studies and manuscripts, the alternative hypothesis is stated, not the null hypothesis. Also, in the Introduction, the alternative hypothesis is typically stated in the direction of interest, or the expected direction. However, when assessing the association of interest, researchers typically look in both directions (ie, favoring 1 group or the other) by conducting a 2-tailed statistical test because the true direction of the effect is typically not known, and either direction would be important to report.

Reflections on the "gesture-first" hypothesis of language origins.

PubMed

Kendon, Adam

2017-02-01

The main lines of evidence taken as support for the "gesture-first" hypothesis of language origins are briefly evaluated, and the problem that speech poses for this hypothesis is discussed. I conclude that language must have evolved in the oral-aural and kinesic modalities together, with neither modality taking precedence over the other.

Patterned-string tasks: relation between fine motor skills and visual-spatial abilities in parrots.

PubMed

Krasheninnikova, Anastasia

2013-01-01

String-pulling and patterned-string tasks are often used to analyse perceptual and cognitive abilities in animals. In addition, the paradigm can be used to test the interrelation between visual-spatial and motor performance. Two Australian parrot species, the galah (Eolophus roseicapilla) and the cockatiel (Nymphicus hollandicus), forage on the ground, but only the galah uses its feet to manipulate food. I used a set of string pulling and patterned-string tasks to test whether usage of the feet during foraging is a prerequisite for solving the vertical string pulling problem. Indeed, the two species used techniques that clearly differed in the extent of beak-foot coordination but did not differ in terms of their success in solving the string pulling task. However, when the visual-spatial skills of the subjects were tested, the galahs outperformed the cockatiels. This supports the hypothesis that the fine motor skills needed for advanced beak-foot coordination may be interrelated with certain visual-spatial abilities needed for solving patterned-string tasks. This pattern was also found within each of the two species on the individual level: higher motor abilities positively correlated with performance in patterned-string tasks. This is the first evidence of an interrelation between visual-spatial and motor abilities in non-mammalian animals.

The cardiovascular robustness hypothesis: Unmasking young adults' hidden risk for premature cardiovascular death.

PubMed

Kraushaar, Lutz E; Dressel, Alexander

2018-03-01

An undetected high risk for premature death of cardiovascular disease (CVD) among individuals with low-to-moderate risk factor levels is an acknowledged obstacle to CVD prevention. In this paper, we present the hypothesis that the vasculature's robustness against risk factor load will complement conventional risk factor models as a novel stratifier of risk. Figuratively speaking, mortality risk prediction without robustness scoring is akin to predicting the breaking risk of a lake's ice sheet considering load only while disregarding the sheet's bearing strength. Taking the cue from systems biology, which defines robustness as the ability to maintain function against internal and external challenges, we develop a robustness score from the physical parameters that comprehensively quantitate cardiovascular function. We derive the functional parameters using a recently introduced novel system, VascAssist 2 (iSYMED GmbH, Butzbach, Germany). VascAssist 2 (VA) applies the electronic-hydraulic analogy to a digital model of the arterial tree, replicating non-invasively acquired pule pressure waves by modulating the electronic equivalents of the physical parameters that describe in vivo arterial hemodynamics. As the latter is also subject to aging-associated degeneration which (a) progresses at inter-individually different rates, and which (b) affects the biomarker-mortality association, we express the robustness score as a correction factor to calendar age (CA), the dominant risk factor in all CVD risk factor models. We then propose a method for the validation of the score against known time-to-event data in reference populations. Our conceptualization of robustness implies that risk factor-challenged individuals with low robustness scores will face preferential elimination from the population resulting in a significant robustness-CA correlation in this strata absent in the unchallenged stratum. Hence, we also present an outline of a cross-sectional study design suitable to

Age-related quantitative and qualitative changes in decision making ability.

PubMed

Isella, Valeria; Mapelli, Cristina; Morielli, Nadia; Pelati, Oriana; Franceschi, Massimo; Appollonio, Ildebrando Marco

2008-01-01

The "frontal aging hypothesis" predicts that brain senescence affects predominantly the prefrontal regions. Preliminary evidence has recently been gathered in favour of an age-related change in a typically frontal process, i.e. decision making, using the Iowa Gambling Task (IGT), but overall findings have been conflicting. Following the traditional scoring method, coupled with a qualitative analysis, in the present study we compared IGT performance of 40 young (mean age: 27.9+/-4.7) and 40 old (mean age: 65.4+/-8.6) healthy adults and of 18 patients affected by frontal lobe dementia of mild severity (mean age: 65.1+/-7.4, mean MMSE score: 24.1+/-3.9). Quantitative findings support the notion that decision making ability declines with age; moreover, it approximates the impairment observed in executive dysfunction due to neurodegeneration. Results of the qualitative analysis did not reach statistical significance for the motivational and learning decision making components considered, but approached significance for the attentional component for elderly versus young normals, suggesting a possible decrease in the ability to maintain sustained attention during complex and prolonged tasks as the putative deficit underlying impaired decision making in normal aging.

RPD-based Hypothesis Reasoning for Cyber Situation Awareness

NASA Astrophysics Data System (ADS)

Yen, John; McNeese, Michael; Mullen, Tracy; Hall, David; Fan, Xiaocong; Liu, Peng

Intelligence workers such as analysts, commanders, and soldiers often need a hypothesis reasoning framework to gain improved situation awareness of the highly dynamic cyber space. The development of such a framework requires the integration of interdisciplinary techniques, including supports for distributed cognition (human-in-the-loop hypothesis generation), supports for team collaboration (identification of information for hypothesis evaluation), and supports for resource-constrained information collection (hypotheses competing for information collection resources). We here describe a cognitively-inspired framework that is built upon Klein’s recognition-primed decision model and integrates the three components of Endsley’s situation awareness model. The framework naturally connects the logic world of tools for cyber situation awareness with the mental world of human analysts, enabling the perception, comprehension, and prediction of cyber situations for better prevention, survival, and response to cyber attacks by adapting missions at the operational, tactical, and strategic levels.

Hygiene Hypothesis in Asthma Development: Is Hygiene to Blame?

PubMed

van Tilburg Bernardes, Erik; Arrieta, Marie-Claire

2017-11-01

Industrialized countries have registered epidemic rates on allergic diseases, such as hay fever, asthma, eczema, and food allergies. The Hygiene Hypothesis was born from work made by Dr. David Strachan, who observed that younger siblings were less susceptible to eczema and asthma, and proposed that this was a result of increased transmission of infectious agents via unhygienic practices within a household. This initial hypothesis was then reframed as the old friends/microbiota hypothesis, implicating non-pathogenic commensal microorganisms as the source of immunomodulatory signals necessary to prevent immune-mediated chronic disorders. Although the hygiene hypothesis is supported by epidemiological research of allergic diseases in certain industrialized settings, it often fails to explain the incidence of asthma in less affluent regions of the world. In this review, we summarize up-to-date information on genetic and environmental factors associated with asthma in different human populations, and present evidence that calls for caution when associating hygiene with the pathogenesis of asthma and other allergic conditions. Copyright © 2017 IMSS. Published by Elsevier Inc. All rights reserved.

Neurobiological Evidence for the Primacy of Mania Hypothesis.

PubMed

Kotzalidis, Georgios D; Rapinesi, Chiara; Savoja, Valeria; Cuomo, Ilaria; Simonetti, Alessio; Ambrosi, Elisa; Panaccione, Isabella; Gubbini, Silvia; De Rossi, Pietro; De Chiara, Lavinia; Janiri, Delfina; Sani, Gabriele; Koukopoulos, Alexia E; Manfredi, Giovanni; Napoletano, Flavia; Caloro, Matteo; Pancheri, Lucia; Puzella, Antonella; Callovini, Gemma; Angeletti, Gloria; Del Casale, Antonio

2017-04-01

Athanasios Koukopoulos proposed the primacy of mania hypothesis (PoM) in a 2006 book chapter and later, in two peer-reviewed papers with Nassir Ghaemi and other collaborators. This hypothesis supports that in bipolar disorder, mania leads to depression, while depression does not lead to mania. To identify evidence in literature that supports or falsifies this hypothesis. We searched the medical literature (PubMed, Embase, PsycINFO, and the Cochrane Library) for peer-reviewed papers on the primacy of mania, the default mode function of the brain in normal people and in bipolar disorder patients, and on illusion superiority until 6 June, 2016. Papers resulting from searches were considered for appropriateness to our objective. We adopted the PRISMA method for our review. The search for consistency with PoM was filtered through the neurobiological results of superiority illusion studies. Out of a grand total of 139 records, 59 were included in our analysis. Of these, 36 were of uncertain value as to the primacy of mania hypothesis, 22 favoured it, and 1 was contrary, but the latter pooled patients in their manic and depressive phases, so to invalidate possible conclusions about its consistency with regard to PoM. All considered studies were not focused on PoM or superiority illusion, hence most of their results were, as expected, unrelated to the circuitry involved in superiority illusion. A considerable amount of evidence is consistent with the hypothesis, although indirectly so. Only few studies compared manic with depressive phases, with the majority including patients in euthymia. It is possible that humans have a natural tendency for elation/optimism and positive self-consideration, that are more akin to mania; the depressive state could be a consequence of frustrated or unsustainable mania. This would be consistent with PoM.

On Using Taylor's Hypothesis for Three-Dimensional Mixing Layers

NASA Technical Reports Server (NTRS)

LeBoeuf, Richard L.; Mehta, Rabindra D.

1995-01-01

In the present study, errors in using Taylor's hypothesis to transform measurements obtained in a temporal (or phase) frame onto a spatial one were evaluated. For the first time, phase-averaged ('real') spanwise and streamwise vorticity data measured on a three-dimensional grid were compared directly to those obtained using Taylor's hypothesis. The results show that even the qualitative features of the spanwise and streamwise vorticity distributions given by the two techniques can be very different. This is particularly true in the region of the spanwise roller pairing. The phase-averaged spanwise and streamwise peak vorticity levels given by Taylor's hypothesis are typically lower (by up to 40%) compared to the real measurements.

A test of the reward-contrast hypothesis.

PubMed

Dalecki, Stefan J; Panoz-Brown, Danielle E; Crystal, Jonathon D

2017-12-01

Source memory, a facet of episodic memory, is the memory of the origin of information. Whereas source memory in rats is sustained for at least a week, spatial memory degraded after approximately a day. Different forgetting functions may suggest that two memory systems (source memory and spatial memory) are dissociated. However, in previous work, the two tasks used baiting conditions consisting of chocolate and chow flavors; notably, the source memory task used the relatively better flavor. Thus, according to the reward-contrast hypothesis, when chocolate and chow were presented within the same context (i.e., within a single radial maze trial), the chocolate location was more memorable than the chow location because of contrast. We tested the reward-contrast hypothesis using baiting configurations designed to produce reward-contrast. The reward-contrast hypothesis predicts that under these conditions, spatial memory will survive a 24-h retention interval. We documented elimination of spatial memory performance after a 24-h retention interval using a reward-contrast baiting pattern. These data suggest that reward contrast does not explain our earlier findings that source memory survives unusually long retention intervals. Copyright © 2017 Elsevier B.V. All rights reserved.

The hygiene hypothesis: does it function worldwide?

PubMed

Bresciani, Megon; Parisi, Claudio; Menghi, Ginevra; Manghi, Ginevra; Bonini, Sergio

2005-04-01

This article intends to be a systematic review of papers published during 2003-2004 quoted in a Medline search for 'hygiene hypothesis'. The worldwide perspective of the article does not refer just to a geographical concept, but tries also to address the question of whether the consensus on the hypothesis is global or whether it applies to all types of allergic or immunologic disease, to any age sample or infectious agent. Furthermore, the article outlines those clinical and experimental studies which, in the authors' opinion, may represent significant contributions to a better understanding of the hygiene hypothesis and may guide further investigations on the subject. The association between a reduced exposure to infectious agents (as a part of a changed lifestyle) and a higher prevalence of atopy seems now to be confirmed by consistent evidence. Mechanisms underlying this association, however, are not yet completely clear (immune deviation or immune regulation). Further experimental and clinical studies are needed, with special reference to the time, duration and intensity of exposure to any specific infectious agent which is related to well-defined allergy outcomes. The background information for using microbial products in allergy prevention and treatment is still limited.

Development of Gaze Following Abilities in Wolves (Canis Lupus)

PubMed Central

Range, Friederike; Virányi, Zsófia

2011-01-01

The ability to coordinate with others' head and eye orientation to look in the same direction is considered a key step towards an understanding of others mental states like attention and intention. Here, we investigated the ontogeny and habituation patterns of gaze following into distant space and behind barriers in nine hand-raised wolves. We found that these wolves could use conspecific as well as human gaze cues even in the barrier task, which is thought to be more cognitively advanced than gazing into distant space. Moreover, while gaze following into distant space was already present at the age of 14 weeks and subjects did not habituate to repeated cues, gazing around a barrier developed considerably later and animals quickly habituated, supporting the hypothesis that different cognitive mechanisms may underlie the two gaze following modalities. More importantly, this study demonstrated that following another individuals' gaze around a barrier is not restricted to primates and corvids but is also present in canines, with remarkable between-group similarities in the ontogeny of this behaviour. This sheds new light on the evolutionary origins of and selective pressures on gaze following abilities as well as on the sensitivity of domestic dogs towards human communicative cues. PMID:21373192

An Exercise for Illustrating the Logic of Hypothesis Testing

ERIC Educational Resources Information Center

Lawton, Leigh

2009-01-01

Hypothesis testing is one of the more difficult concepts for students to master in a basic, undergraduate statistics course. Students often are puzzled as to why statisticians simply don't calculate the probability that a hypothesis is true. This article presents an exercise that forces students to lay out on their own a procedure for testing a…

A Molecular–Structure Hypothesis

PubMed Central

Boeyens, Jan C. A.

2010-01-01

The self-similar symmetry that occurs between atomic nuclei, biological growth structures, the solar system, globular clusters and spiral galaxies suggests that a similar pattern should characterize atomic and molecular structures. This possibility is explored in terms of the current molecular structure-hypothesis and its extension into four-dimensional space-time. It is concluded that a quantum molecule only has structure in four dimensions and that classical (Newtonian) structure, which occurs in three dimensions, cannot be simulated by quantum-chemical computation. PMID:21151437

P value and the theory of hypothesis testing: an explanation for new researchers.

PubMed

Biau, David Jean; Jolles, Brigitte M; Porcher, Raphaël

2010-03-01

In the 1920s, Ronald Fisher developed the theory behind the p value and Jerzy Neyman and Egon Pearson developed the theory of hypothesis testing. These distinct theories have provided researchers important quantitative tools to confirm or refute their hypotheses. The p value is the probability to obtain an effect equal to or more extreme than the one observed presuming the null hypothesis of no effect is true; it gives researchers a measure of the strength of evidence against the null hypothesis. As commonly used, investigators will select a threshold p value below which they will reject the null hypothesis. The theory of hypothesis testing allows researchers to reject a null hypothesis in favor of an alternative hypothesis of some effect. As commonly used, investigators choose Type I error (rejecting the null hypothesis when it is true) and Type II error (accepting the null hypothesis when it is false) levels and determine some critical region. If the test statistic falls into that critical region, the null hypothesis is rejected in favor of the alternative hypothesis. Despite similarities between the two, the p value and the theory of hypothesis testing are different theories that often are misunderstood and confused, leading researchers to improper conclusions. Perhaps the most common misconception is to consider the p value as the probability that the null hypothesis is true rather than the probability of obtaining the difference observed, or one that is more extreme, considering the null is true. Another concern is the risk that an important proportion of statistically significant results are falsely significant. Researchers should have a minimum understanding of these two theories so that they are better able to plan, conduct, interpret, and report scientific experiments.

Ability grouping of gifted students: effects on academic self-concept and boredom.

PubMed

Preckel, Franzis; Götz, Thomas; Frenzel, Anne

2010-09-01

Securing appropriate challenge or preventing boredom is one of the reasons frequently used to justify ability grouping of gifted students, which has been shown to have beneficial effects for achievement. On the other hand, critics stress psychosocial costs, such as detrimental effects on academic self-concept (contrast or big-fish-little-pond effect). The effects of full-time ability grouping in special classrooms for the gifted on students' academic self-concept and their experience of boredom in mathematics classes were investigated. The sample comprised 186 ninth-grade students (106 male) from eight classes at one Austrian high school. Four of these classes were part of a gifted track beginning from school year 9 on (N=93). Students were assessed repeatedly within the first half of the school year, three times via self-report questionnaires and once by applying a standardized IQ-test. Students in gifted classes reported a decrease in maths academic self-concept which was most pronounced early in the academic year. Interventions to counterbalance the negative effect of exposure to a high-ability reference group should therefore be implemented when ability grouping begins. No evidence for the boredom hypothesis was found (higher levels of boredom among gifted students in regular classes). However, students clearly differed in the reasons they stated for experiencing boredom. Boredom attributions changed over time and supported the assumption that gifted classes provide more appropriate levels of challenge.

Debates—Hypothesis testing in hydrology: Introduction

NASA Astrophysics Data System (ADS)

Blöschl, Günter

2017-03-01

This paper introduces the papers in the "Debates—Hypothesis testing in hydrology" series. The four articles in the series discuss whether and how the process of testing hypotheses leads to progress in hydrology. Repeated experiments with controlled boundary conditions are rarely feasible in hydrology. Research is therefore not easily aligned with the classical scientific method of testing hypotheses. Hypotheses in hydrology are often enshrined in computer models which are tested against observed data. Testability may be limited due to model complexity and data uncertainty. All four articles suggest that hypothesis testing has contributed to progress in hydrology and is needed in the future. However, the procedure is usually not as systematic as the philosophy of science suggests. A greater emphasis on a creative reasoning process on the basis of clues and explorative analyses is therefore needed.

The RNA world hypothesis: the worst theory of the early evolution of life (except for all the others)a

PubMed Central

2012-01-01

The problems associated with the RNA world hypothesis are well known. In the following I discuss some of these difficulties, some of the alternative hypotheses that have been proposed, and some of the problems with these alternative models. From a biosynthetic – as well as, arguably, evolutionary – perspective, DNA is a modified RNA, and so the chicken-and-egg dilemma of “which came first?” boils down to a choice between RNA and protein. This is not just a question of cause and effect, but also one of statistical likelihood, as the chance of two such different types of macromolecule arising simultaneously would appear unlikely. The RNA world hypothesis is an example of a ‘top down’ (or should it be ‘present back’?) approach to early evolution: how can we simplify modern biological systems to give a plausible evolutionary pathway that preserves continuity of function? The discovery that RNA possesses catalytic ability provides a potential solution: a single macromolecule could have originally carried out both replication and catalysis. RNA – which constitutes the genome of RNA viruses, and catalyzes peptide synthesis on the ribosome – could have been both the chicken and the egg! However, the following objections have been raised to the RNA world hypothesis: (i) RNA is too complex a molecule to have arisen prebiotically; (ii) RNA is inherently unstable; (iii) catalysis is a relatively rare property of long RNA sequences only; and (iv) the catalytic repertoire of RNA is too limited. I will offer some possible responses to these objections in the light of work by our and other labs. Finally, I will critically discuss an alternative theory to the RNA world hypothesis known as ‘proteins first’, which holds that proteins either preceded RNA in evolution, or – at the very least – that proteins and RNA coevolved. I will argue that, while theoretically possible, such a hypothesis is probably unprovable, and that the RNA world hypothesis, although

The "Mevalonate hypothesis": a cholesterol-independent alternative for the etiology of atherosclerosis.

PubMed

Keizer, Hiskias G

2012-11-05

The "cholesterol hypothesis" is the leading theory to explain the cause of atherosclerosis. The "cholesterol hypothesis" assumes that plasma (LDL) cholesterol is an important causal factor for atherosclerosis.However, data of at least seven placebo controlled randomized prospective trials with various cholesterol lowering drugs show that plasma cholesterol lowering does not necessarily lead to protection against cardiovascular disease. Therefore an alternative hypothesis for the etiology of cardiovascular disease is formulated. This alternative hypothesis, the "mevalonate hypothesis", assumes that after stimulation of the mevalonate pathway in endothelial cells by inflammatory factors, these cells start producing cholesterol and free radicals. In this hypothesis, only the latter play a role in the etiology of atherosclerosis by contributing to the formation of oxidized cholesterol which is a widely accepted causal factor for atherosclerosis.Regardless of how the mevalonate pathway is activated (by withdrawal of statin drugs, by inflammatory factors or indirectly by reduced intracellular cholesterol levels) in all these cases free radical production is observed as well as cardiovascular disease. Since in the "mevalonate hypothesis" cholesterol is produced at the same time as the free radicals causing atherosclerosis, this hypothesis provides an explanation for the correlation which exists between cardiovascular disease and plasma cholesterol levels. From an evolutionary perspective, concomitant cholesterol production and free radical production in response to inflammatory factors makes sense if one realizes that both activities potentially protect cells and organisms from infection by gram-negative bacteria.In conclusion, data have been collected which suggest that activation of the mevalonate pathway in endothelial cells is likely to be a causal factor for atherosclerosis. This "mevalonate hypothesis" provides a better explanation for results obtained from recent

A genome-wide association study identifies multiple loci associated with mathematics ability and disability.

PubMed

Docherty, S J; Davis, O S P; Kovas, Y; Meaburn, E L; Dale, P S; Petrill, S A; Schalkwyk, L C; Plomin, R

2010-03-01

Numeracy is as important as literacy and exhibits a similar frequency of disability. Although its etiology is relatively poorly understood, quantitative genetic research has demonstrated mathematical ability to be moderately heritable. In this first genome-wide association study (GWAS) of mathematical ability and disability, 10 out of 43 single nucleotide polymorphism (SNP) associations nominated from two high- vs. low-ability (n = 600 10-year-olds each) scans of pooled DNA were validated (P < 0.05) in an individually genotyped sample of (*)2356 individuals spanning the entire distribution of mathematical ability, as assessed by teacher reports and online tests. Although the effects are of the modest sizes now expected for complex traits and require further replication, interesting candidate genes are implicated such as NRCAM which encodes a neuronal cell adhesion molecule. When combined into a set, the 10 SNPs account for 2.9% (F = 56.85; df = 1 and 1881; P = 7.277e-14) of the phenotypic variance. The association is linear across the distribution consistent with a quantitative trait locus (QTL) hypothesis; the third of children in our sample who harbour 10 or more of the 20 risk alleles identified are nearly twice as likely (OR = 1.96; df = 1; P = 3.696e-07) to be in the lowest performing 15% of the distribution. Our results correspond with those of quantitative genetic research in indicating that mathematical ability and disability are influenced by many genes generating small effects across the entire spectrum of ability, implying that more highly powered studies will be needed to detect and replicate these QTL associations.

Active SAmpling Protocol (ASAP) to Optimize Individual Neurocognitive Hypothesis Testing: A BCI-Inspired Dynamic Experimental Design.

PubMed

Sanchez, Gaëtan; Lecaignard, Françoise; Otman, Anatole; Maby, Emmanuel; Mattout, Jérémie

2016-01-01

The relatively young field of Brain-Computer Interfaces has promoted the use of electrophysiology and neuroimaging in real-time. In the meantime, cognitive neuroscience studies, which make extensive use of functional exploration techniques, have evolved toward model-based experiments and fine hypothesis testing protocols. Although these two developments are mostly unrelated, we argue that, brought together, they may trigger an important shift in the way experimental paradigms are being designed, which should prove fruitful to both endeavors. This change simply consists in using real-time neuroimaging in order to optimize advanced neurocognitive hypothesis testing. We refer to this new approach as the instantiation of an Active SAmpling Protocol (ASAP). As opposed to classical (static) experimental protocols, ASAP implements online model comparison, enabling the optimization of design parameters (e.g., stimuli) during the course of data acquisition. This follows the well-known principle of sequential hypothesis testing. What is radically new, however, is our ability to perform online processing of the huge amount of complex data that brain imaging techniques provide. This is all the more relevant at a time when physiological and psychological processes are beginning to be approached using more realistic, generative models which may be difficult to tease apart empirically. Based upon Bayesian inference, ASAP proposes a generic and principled way to optimize experimental design adaptively. In this perspective paper, we summarize the main steps in ASAP. Using synthetic data we illustrate its superiority in selecting the right perceptual model compared to a classical design. Finally, we briefly discuss its future potential for basic and clinical neuroscience as well as some remaining challenges.

[Visual perceptual abilities of children with low motor abilities--a pilot study].

PubMed

Werpup-Stüwe, Lina; Petermann, Franz

2015-01-01

The results of many studies show visual perceptual deficits in children with low motor abilities. This study aims to indicate the correlation between visual-perceptual and motor abilities. The correlation of visual-perceptual and motor abilities of 41 children is measured by using the German versions of the Developmental Test of Visual Perception--Adolescent and Adult (DTVP-A) and the Movement Assessment Battery for Children--Second Edition (M-ABC-2). The visual-perceptual abilities of children with low motor abilities (n=21) are also compared to the visual-perceptual abilities of children with normal motor abilities (the control group, n=20). High correlations between the visual-perceptual and motor abilities are found. The perceptual abilities of the groups differ significantly. Nearly half of the children with low motor abilities show visual-perceptual deficits. Visual perceptual abilities of children suffering coordination disorders should always be assessed. The DTVP-A is useful, because it provides the possibilities to compare motor-reduced visual-perceptual abilities and visualmotor integration abilities and to estimate the deficit's degree.

Alzheimer's disease: the amyloid hypothesis and the Inverse Warburg effect

PubMed Central

Demetrius, Lloyd A.; Magistretti, Pierre J.; Pellerin, Luc

2014-01-01

Epidemiological and biochemical studies show that the sporadic forms of Alzheimer's disease (AD) are characterized by the following hallmarks: (a) An exponential increase with age; (b) Selective neuronal vulnerability; (c) Inverse cancer comorbidity. The present article appeals to these hallmarks to evaluate and contrast two competing models of AD: the amyloid hypothesis (a neuron-centric mechanism) and the Inverse Warburg hypothesis (a neuron-astrocytic mechanism). We show that these three hallmarks of AD conflict with the amyloid hypothesis, but are consistent with the Inverse Warburg hypothesis, a bioenergetic model which postulates that AD is the result of a cascade of three events—mitochondrial dysregulation, metabolic reprogramming (the Inverse Warburg effect), and natural selection. We also provide an explanation for the failures of the clinical trials based on amyloid immunization, and we propose a new class of therapeutic strategies consistent with the neuroenergetic selection model. PMID:25642192

Three dimensions of the amyloid hypothesis: time, space and 'wingmen'.

PubMed

Musiek, Erik S; Holtzman, David M

2015-06-01

The amyloid hypothesis, which has been the predominant framework for research in Alzheimer's disease (AD), has been the source of considerable controversy. The amyloid hypothesis postulates that amyloid-β peptide (Aβ) is the causative agent in AD. It is strongly supported by data from rare autosomal dominant forms of AD. However, the evidence that Aβ causes or contributes to age-associated sporadic AD is more complex and less clear, prompting criticism of the hypothesis. We provide an overview of the major arguments for and against the amyloid hypothesis. We conclude that Aβ likely is the key initiator of a complex pathogenic cascade that causes AD. However, we argue that Aβ acts primarily as a trigger of other downstream processes, particularly tau aggregation, which mediate neurodegeneration. Aβ appears to be necessary, but not sufficient, to cause AD. Its major pathogenic effects may occur very early in the disease process.

The catecholaminergic-cholinergic balance hypothesis of bipolar disorder revisited

PubMed Central

van Enkhuizen, Jordy; Janowsky, David S; Olivier, Berend; Minassian, Arpi; Perry, William; Young, Jared W; Geyer, Mark A

2014-01-01

Bipolar disorder is a unique illness characterized by fluctuations between mood states of depression and mania. Originally, an adrenergic-cholinergic balance hypothesis was postulated to underlie these different affective states. In this review, we update this hypothesis with recent findings from human and animal studies, suggesting that a catecholaminergic-cholinergic hypothesis may be more relevant. Evidence from neuroimaging studies, neuropharmacological interventions, and genetic associations support the notion that increased cholinergic functioning underlies depression, whereas increased activations of the catecholamines (dopamine and norepinephrine) underlie mania. Elevated functional acetylcholine during depression may affect both muscarinic and nicotinic acetylcholine receptors in a compensatory fashion. Increased functional dopamine and norepinephrine during mania on the other hand may affect receptor expression and functioning of dopamine reuptake transporters. Despite increasing evidence supporting this hypothesis, a relationship between these two neurotransmitter systems that could explain cycling between states of depression and mania is missing. Future studies should focus on the influence of environmental stimuli and genetic susceptibilities that may affect the catecholaminergic-cholinergic balance underlying cycling between the affective states. Overall, observations from recent studies add important data to this revised balance theory of bipolar disorder, renewing interest in this field of research. PMID:25107282

Exploring heterogeneous market hypothesis using realized volatility

NASA Astrophysics Data System (ADS)

Chin, Wen Cheong; Isa, Zaidi; Mohd Nor, Abu Hassan Shaari

2013-04-01

This study investigates the heterogeneous market hypothesis using high frequency data. The cascaded heterogeneous trading activities with different time durations are modelled by the heterogeneous autoregressive framework. The empirical study indicated the presence of long memory behaviour and predictability elements in the financial time series which supported heterogeneous market hypothesis. Besides the common sum-of-square intraday realized volatility, we also advocated two power variation realized volatilities in forecast evaluation and risk measurement in order to overcome the possible abrupt jumps during the credit crisis. Finally, the empirical results are used in determining the market risk using the value-at-risk approach. The findings of this study have implications for informationally market efficiency analysis, portfolio strategies and risk managements.

A hypothesis for delayed dynamic earthquake triggering

USGS Publications Warehouse

Parsons, T.

2005-01-01

It's uncertain whether more near-field earthquakes are triggered by static or dynamic stress changes. This ratio matters because static earthquake interactions are increasingly incorporated into probabilistic forecasts. Recent studies were unable to demonstrate all predictions from the static-stress-change hypothesis, particularly seismicity rate reductions. However, current dynamic stress change hypotheses do not explain delayed earthquake triggering and Omori's law. Here I show numerically that if seismic waves can alter some frictional contacts in neighboring fault zones, then dynamic triggering might cause delayed triggering and an Omori-law response. The hypothesis depends on faults following a rate/state friction law, and on seismic waves changing the mean critical slip distance (Dc) at nucleation zones.

Ophthalmic randomized controlled trials reports: the statement of the hypothesis.

PubMed

Lee, Chun Fan; Cheng, Andy Chi On; Fong, Daniel Yee Tak

2014-01-01

To evaluate whether the ophthalmic randomized controlled trials (RCTs) were designed properly, their hypotheses stated clearly, and their conclusions drawn correctly. A systematic review of 206 ophthalmic RCTs. The objective statement, methods, and results sections and the conclusions of RCTs published in 4 major general clinical ophthalmology journals from 2009 through 2011 were assessed. The clinical objective and specific hypothesis were the main outcome measures. The clinical objective of the trial was presented in 199 (96.6%) studies and the hypothesis was specified explicitly in 56 (27.2%) studies. One hundred ninety (92.2%) studies tested superiority. Among them, 17 (8.3%) studies comparing 2 or more active treatments concluded equal or similar effectiveness between the 2 arms after obtaining insignificant results. There were 5 noninferiority studies and 4 equivalence studies. How the treatments were compared was not mentioned in 1 of the noninferiority studies. Two of the equivalence studies did not specify the equivalence margin and used tests for detecting difference rather than confirming equivalence. The clinical objective commonly was stated, but the prospectively defined hypothesis tended to be understated in ophthalmic RCTs. Superiority was the most common type of comparison. Conclusions made in some of them with negative results were not consistent with the hypothesis, indicating that noninferiority or equivalence may be a more appropriate design. Flaws were common in the noninferiority and equivalence studies. Future ophthalmic researchers should choose the type of comparison carefully, specify the hypothesis clearly, and draw conclusions that are consistent with the hypothesis. Copyright © 2014 Elsevier Inc. All rights reserved.

Hypothesis testing and earthquake prediction.

PubMed

Jackson, D D

1996-04-30

Requirements for testing include advance specification of the conditional rate density (probability per unit time, area, and magnitude) or, alternatively, probabilities for specified intervals of time, space, and magnitude. Here I consider testing fully specified hypotheses, with no parameter adjustments or arbitrary decisions allowed during the test period. Because it may take decades to validate prediction methods, it is worthwhile to formulate testable hypotheses carefully in advance. Earthquake prediction generally implies that the probability will be temporarily higher than normal. Such a statement requires knowledge of "normal behavior"--that is, it requires a null hypothesis. Hypotheses can be tested in three ways: (i) by comparing the number of actual earth-quakes to the number predicted, (ii) by comparing the likelihood score of actual earthquakes to the predicted distribution, and (iii) by comparing the likelihood ratio to that of a null hypothesis. The first two tests are purely self-consistency tests, while the third is a direct comparison of two hypotheses. Predictions made without a statement of probability are very difficult to test, and any test must be based on the ratio of earthquakes in and out of the forecast regions.

Hypothesis testing and earthquake prediction.

PubMed Central

Jackson, D D

1996-01-01

Requirements for testing include advance specification of the conditional rate density (probability per unit time, area, and magnitude) or, alternatively, probabilities for specified intervals of time, space, and magnitude. Here I consider testing fully specified hypotheses, with no parameter adjustments or arbitrary decisions allowed during the test period. Because it may take decades to validate prediction methods, it is worthwhile to formulate testable hypotheses carefully in advance. Earthquake prediction generally implies that the probability will be temporarily higher than normal. Such a statement requires knowledge of "normal behavior"--that is, it requires a null hypothesis. Hypotheses can be tested in three ways: (i) by comparing the number of actual earth-quakes to the number predicted, (ii) by comparing the likelihood score of actual earthquakes to the predicted distribution, and (iii) by comparing the likelihood ratio to that of a null hypothesis. The first two tests are purely self-consistency tests, while the third is a direct comparison of two hypotheses. Predictions made without a statement of probability are very difficult to test, and any test must be based on the ratio of earthquakes in and out of the forecast regions. PMID:11607663

Dopamine and reward: the anhedonia hypothesis 30 years on.

PubMed

Wise, Roy A

2008-10-01

The anhedonia hypothesis--that brain dopamine plays a critical role in the subjective pleasure associated with positive rewards--was intended to draw the attention of psychiatrists to the growing evidence that dopamine plays a critical role in the objective reinforcement and incentive motivation associated with food and water, brain stimulation reward, and psychomotor stimulant and opiate reward. The hypothesis called to attention the apparent paradox that neuroleptics, drugs used to treat a condition involving anhedonia (schizophrenia), attenuated in laboratory animals the positive reinforcement that we normally associate with pleasure. The hypothesis held only brief interest for psychiatrists, who pointed out that the animal studies reflected acute actions of neuroleptics whereas the treatment of schizophrenia appears to result from neuroadaptations to chronic neuroleptic administration, and that it is the positive symptoms of schizophrenia that neuroleptics alleviate, rather than the negative symptoms that include anhedonia. Perhaps for these reasons, the hypothesis has had minimal impact in the psychiatric literature. Despite its limited heuristic value for the understanding of schizophrenia, however, the anhedonia hypothesis has had major impact on biological theories of reinforcement, motivation, and addiction. Brain dopamine plays a very important role in reinforcement of response habits, conditioned preferences, and synaptic plasticity in cellular models of learning and memory. The notion that dopamine plays a dominant role in reinforcement is fundamental to the psychomotor stimulant theory of addiction, to most neuroadaptation theories of addiction, and to current theories of conditioned reinforcement and reward prediction. Properly understood, it is also fundamental to recent theories of incentive motivation.

A test of the orthographic recoding hypothesis

NASA Astrophysics Data System (ADS)

Gaygen, Daniel E.

2003-04-01

The Orthographic Recoding Hypothesis [D. E. Gaygen and P. A. Luce, Percept. Psychophys. 60, 465-483 (1998)] was tested. According to this hypothesis, listeners recognize spoken words heard for the first time by mapping them onto stored representations of the orthographic forms of the words. Listeners have a stable orthographic representation of words, but no phonological representation, when those words have been read frequently but never heard or spoken. Such may be the case for low frequency words such as jargon. Three experiments using visually and auditorily presented nonword stimuli tested this hypothesis. The first two experiments were explicit tests of memory (old-new tests) for words presented visually. In the first experiment, the recognition of auditorily presented nonwords was facilitated when they previously appeared on a visually presented list. The second experiment was similar, but included a concurrent articulation task during a visual word list presentation, thus preventing covert rehearsal of the nonwords. The results were similar to the first experiment. The third experiment was an indirect test of memory (auditory lexical decision task) for visually presented nonwords. Auditorily presented nonwords were identified as nonwords significantly more slowly if they had previously appeared on the visually presented list accompanied by a concurrent articulation task.

Isotopic niches support the resource breadth hypothesis

USGS Publications Warehouse

Rader, Jonathan A.; Newsome, Seth D.; Sabat, Pablo; Chesser, R. Terry; Dillon, Michael E.; Martinez del Rio, Carlos

2017-01-01

Because a broad spectrum of resource use allows species to persist in a wide range of habitat types, and thus permits them to occupy large geographical areas, and because broadly distributed species have access to more diverse resource bases, the resource breadth hypothesis posits that the diversity of resources used by organisms should be positively related with the extent of their geographic ranges.We investigated isotopic niche width in a small radiation of South American birds in the genus Cinclodes. We analysed feathers of 12 species of Cinclodes to test the isotopic version of the resource breadth hypothesis and to examine the correlation between isotopic niche breadth and morphology.We found a positive correlation between the widths of hydrogen and oxygen isotopic niches (which estimate breadth of elevational range) and widths of the carbon and nitrogen isotopic niches (which estimates the diversity of resources consumed, and hence of habitats used). We also found a positive correlation between broad isotopic niches and wing morphology.Our study not only supports the resource breadth hypothesis but it also highlights the usefulness of stable isotope analyses as tools in the exploration of ecological niches. It is an example of a macroecological application of stable isotopes. It also illustrates the importance of scientific collections in ecological studies.

Mismatch or cumulative stress: toward an integrated hypothesis of programming effects.

PubMed

Nederhof, Esther; Schmidt, Mathias V

2012-07-16

This paper integrates the cumulative stress hypothesis with the mismatch hypothesis, taking into account individual differences in sensitivity to programming. According to the cumulative stress hypothesis, individuals are more likely to suffer from disease as adversity accumulates. According to the mismatch hypothesis, individuals are more likely to suffer from disease if a mismatch occurs between the early programming environment and the later adult environment. These seemingly contradicting hypotheses are integrated into a new model proposing that the cumulative stress hypothesis applies to individuals who were not or only to a small extent programmed by their early environment, while the mismatch hypothesis applies to individuals who experienced strong programming effects. Evidence for the main effects of adversity as well as evidence for the interaction between adversity in early and later life is presented from human observational studies and animal models. Next, convincing evidence for individual differences in sensitivity to programming is presented. We extensively discuss how our integrated model can be tested empirically in animal models and human studies, inviting researchers to test this model. Furthermore, this integrated model should tempt clinicians and other intervenors to interpret symptoms as possible adaptations from an evolutionary biology perspective. Copyright © 2011 Elsevier Inc. All rights reserved.

Diagnostic Hypothesis Generation and Human Judgment

ERIC Educational Resources Information Center

Thomas, Rick P.; Dougherty, Michael R.; Sprenger, Amber M.; Harbison, J. Isaiah

2008-01-01

Diagnostic hypothesis-generation processes are ubiquitous in human reasoning. For example, clinicians generate disease hypotheses to explain symptoms and help guide treatment, auditors generate hypotheses for identifying sources of accounting errors, and laypeople generate hypotheses to explain patterns of information (i.e., data) in the…

A sensitive period for musical training: contributions of age of onset and cognitive abilities.

PubMed

Bailey, Jennifer; Penhune, Virginia B

2012-04-01

The experiences we engage in during childhood can stay with us well into our adult years. The idea of a sensitive period--a window during maturation when our brains are most influenced by behavior--has been proposed. Work from our laboratory has shown that early-trained musicians (ET) performed better on visual-motor and auditory-motor synchronization tasks than late-trained musicians (LT), even when matched for total musical experience. Although the groups of musicians showed no cognitive differences, working memory scores correlated with task performance. In this study, we have replicated these findings in a larger sample of musicians and included a group of highly educated nonmusicians (NM). Participants performed six woodblock rhythms of varying levels of metrical complexity and completed cognitive subtests measuring verbal abilities, working memory, and pattern recognition. Working memory scores correlated with task performance across all three groups. Interestingly, verbal abilities were stronger among the NM, while nonverbal abilities were stronger among musicians. These findings are discussed in context of the sensitive period hypothesis as well as the debate surrounding cognitive differences between musicians and NM. © 2012 New York Academy of Sciences.

The association between fear of cancer recurrence and quality of life among Chinese cancer survivors: main effect hypothesis and buffering hypothesis.

PubMed

Cho, Dalnim; Lu, Qian

2017-09-01

The aim of the present study is to examine whether fear of cancer recurrence (FCR) is related to health-related quality of life (HRQOL) among Chinese cancer survivors, an understudied population (i.e., main effect hypothesis). Also, we investigated whether the FCR-HRQOL link is moderated by two coping strategies, avoidance and positive reappraisal (i.e., buffering hypothesis). This is a cross-sectional study conducted among 238 Chinese cancer survivors in Beijing. Participants completed a set of questionnaires including FCR, coping, and HRQOL. FCR was related to lower physical, psychological, social, and spiritual well-beings, even when demographics, cancer-related factors, and coping were taken into account. There was only one moderation effect between FCR and avoidance coping. Surprisingly, the detrimental effect of FCR on spiritual well-being was lessened among those with high avoidance coping such that the negative association between FCR and spiritual well-being was only found in those with low avoidance coping and not among those with high avoidance coping. Findings largely supported the main effect hypothesis. FCR was associated with diverse domains of HRQOL among Chinese cancer survivors. The buffering hypothesis was largely not supported in this population. Rather, in some cases, the effects of FCR and coping strategies on HRQOL were independent. Thus, ways to attenuate the harmful effects of FCR on HRQOL among Chinese cancer survivors remain unresolved. It is urgent and timely that future studies focus on FCR and HRQOL in this population.

Hypothesis Testing Using Spatially Dependent Heavy Tailed Multisensor Data

DTIC Science & Technology

2014-12-01

Office of Research 113 Bowne Hall Syracuse, NY 13244 -1200 ABSTRACT HYPOTHESIS TESTING USING SPATIALLY DEPENDENT HEAVY-TAILED MULTISENSOR DATA Report...consistent with the null hypothesis of linearity and can be used to estimate the distribution of a test statistic that can discrimi- nate between the null... Test for nonlinearity. Histogram is generated using the surrogate data. The statistic of the original time series is represented by the solid line

Absolute Pitch: Effects of Timbre on Note-Naming Ability

PubMed Central

Vanzella, Patrícia; Schellenberg, E. Glenn

2010-01-01

Background Absolute pitch (AP) is the ability to identify or produce isolated musical tones. It is evident primarily among individuals who started music lessons in early childhood. Because AP requires memory for specific pitches as well as learned associations with verbal labels (i.e., note names), it represents a unique opportunity to study interactions in memory between linguistic and nonlinguistic information. One untested hypothesis is that the pitch of voices may be difficult for AP possessors to identify. A musician's first instrument may also affect performance and extend the sensitive period for acquiring accurate AP. Methods/Principal Findings A large sample of AP possessors was recruited on-line. Participants were required to identity test tones presented in four different timbres: piano, pure tone, natural (sung) voice, and synthesized voice. Note-naming accuracy was better for non-vocal (piano and pure tones) than for vocal (natural and synthesized voices) test tones. This difference could not be attributed solely to vibrato (pitch variation), which was more pronounced in the natural voice than in the synthesized voice. Although starting music lessons by age 7 was associated with enhanced note-naming accuracy, equivalent abilities were evident among listeners who started music lessons on piano at a later age. Conclusions/Significance Because the human voice is inextricably linked to language and meaning, it may be processed automatically by voice-specific mechanisms that interfere with note naming among AP possessors. Lessons on piano or other fixed-pitch instruments appear to enhance AP abilities and to extend the sensitive period for exposure to music in order to develop accurate AP. PMID:21085598

Graphic Abilities in Relation to Mathematical and Scientific Ability in Adolescents

ERIC Educational Resources Information Center

Stavridou, Fotini; Kakana, Domna

2008-01-01

Background: The study investigated a small range of cognitive abilities, related to visual-spatial intelligence, in adolescents. This specific range of cognitive abilities was termed "graphic abilities" and defined as a range of abilities to visualise and think in three dimensions, originating in the domain of visual-spatial…

Work ability assessment in a worker population: comparison and determinants of Work Ability Index and Work Ability score.

PubMed

El Fassi, Mehdi; Bocquet, Valery; Majery, Nicole; Lair, Marie Lise; Couffignal, Sophie; Mairiaux, Philippe

2013-04-08

Public authorities in European countries are paying increasing attention to the promotion of work ability throughout working life and the best method to monitor work ability in populations of workers is becoming a significant question. The present study aims to compare the assessment of work ability based on the use of the Work Ability Index (WAI), a 7-item questionnaire, with another one based on the use of WAI's first item, which consists in the worker's self-assessment of his/her current work ability level as opposed to his/her lifetime best, this single question being termed "Work Ability score" (WAS). Using a database created by an occupational health service, the study intends to answer the following questions: could the assessment of work ability be based on a single-item measure and which are the variables significantly associated with self-reported work ability among those systematically recorded by the occupational physician during health examinations? A logistic regression model was used in order to estimate the probability of observing "poor" or "moderate" WAI levels depending on age, gender, body mass index, smoking status, position held, firm size and diseases reported by the worker in a population of workers aged 40 to 65 and examined between January 2006 and June 2010 (n=12389). The convergent validity between WAS and WAI was statistically significant (rs=0.63). In the multivariable model, age (p<0.001), reported diseases (OR=1.13, 95%CI [1.11-1.15]) and holding a position mostly characterized by physical activity (OR=1.67, 95%CI [1.49-1.87]) increased the probability of reporting moderate or poor work ability. A work position characterized by the predominance of mental activity (OR=0.71, 95%CI [0.61-0.84]) had a favourable impact on work ability. These relations were observed regardless of the work ability measurement tool used. The convergent validity and the similarity in results between WAI and WAS observed in a large population of employed

Hypothesis testing of scientific Monte Carlo calculations.

PubMed

Wallerberger, Markus; Gull, Emanuel

2017-11-01

The steadily increasing size of scientific Monte Carlo simulations and the desire for robust, correct, and reproducible results necessitates rigorous testing procedures for scientific simulations in order to detect numerical problems and programming bugs. However, the testing paradigms developed for deterministic algorithms have proven to be ill suited for stochastic algorithms. In this paper we demonstrate explicitly how the technique of statistical hypothesis testing, which is in wide use in other fields of science, can be used to devise automatic and reliable tests for Monte Carlo methods, and we show that these tests are able to detect some of the common problems encountered in stochastic scientific simulations. We argue that hypothesis testing should become part of the standard testing toolkit for scientific simulations.

Hypothesis testing of scientific Monte Carlo calculations

NASA Astrophysics Data System (ADS)

Wallerberger, Markus; Gull, Emanuel

2017-11-01

The steadily increasing size of scientific Monte Carlo simulations and the desire for robust, correct, and reproducible results necessitates rigorous testing procedures for scientific simulations in order to detect numerical problems and programming bugs. However, the testing paradigms developed for deterministic algorithms have proven to be ill suited for stochastic algorithms. In this paper we demonstrate explicitly how the technique of statistical hypothesis testing, which is in wide use in other fields of science, can be used to devise automatic and reliable tests for Monte Carlo methods, and we show that these tests are able to detect some of the common problems encountered in stochastic scientific simulations. We argue that hypothesis testing should become part of the standard testing toolkit for scientific simulations.

The Regression Hypothesis as a Framework for First Language Attrition

ERIC Educational Resources Information Center

Keijzer, Merel

2010-01-01

In an attempt to explain first language attrition in emigrant populations, this paper investigates the explanatory power of a framework that has--until now--received little attention: the regression hypothesis (Jakobson, 1941). This hypothesis predicts that the order of attrition is the reverse of the order of acquisition. The regression…

Making Knowledge Delivery Failsafe: Adding Step Zero in Hypothesis Testing

ERIC Educational Resources Information Center

Pan, Xia; Zhou, Qiang

2010-01-01

Knowledge of statistical analysis is increasingly important for professionals in modern business. For example, hypothesis testing is one of the critical topics for quality managers and team workers in Six Sigma training programs. Delivering the knowledge of hypothesis testing effectively can be an important step for the incapable learners or…

Confirming expectations in asymmetric and symmetric social hypothesis testing.

PubMed

Rusconi, Patrice; Sacchi, Simona; Toscano, Armando; Cherubini, Paolo

2012-01-01

This article examines individuals' expectations in a social hypothesis testing task. Participants selected questions from a list to investigate the presence of personality traits in a target individual. They also identified the responses that they expected to receive and the likelihood of the expected responses. The results of two studies indicated that when people asked questions inquiring about the hypothesized traits that did not entail strong a priori beliefs, they expected to find evidence confirming the hypothesis under investigation. These confirming expectations were more pronounced for symmetric questions, in which the diagnosticity and frequency of the expected evidence did not conflict. When the search for information was asymmetric, confirming expectations were diminished, likely as a consequence of either the rareness or low diagnosticity of the hypothesis-confirming outcome. We also discuss the implications of these findings for confirmation bias.

A biomechanical hypothesis for the pathophysiology of apical lung disease.

PubMed

Casha, Aaron R; Manché, Alexander; Camilleri, Liberato; Gatt, Ruben; Dudek, Krzysztof; Pace-Bardon, Michael; Gauci, Marilyn; Grima, Joseph N

2016-07-01

A hypothesis is presented suggesting that the pathogenesis of apical lung disease is due to progression of subclinical congenital apical bullae in people with low Body Mass Index (BMI), a combination present in 15% of the population, due to high pleural stress levels present in the antero-posteriorly flattened chests of these individuals. The hypothesis was tested for validity in two apical lung pathologies with widespread epidemiological literature, namely tuberculosis (TB) and primary spontaneous pneumothorax (PSP), assessing whether the hypothesis could identify high-risk populations, explain exceptional cases like apical lower lobe disease and confirm predictions. The biomechanical hypothesis can explain the high-risk factors of apical location, age, gender and low-BMI build, as well as the occurrence of disease in the apex of the lower lobe, in both TB and PSP patients. A predicted common pathogenesis for apical lung disease was confirmed by the higher-than-expected incidence of concomitant TB and PSP. Pleural stress levels depend on chest wall shape, but are highest in the apex of young males with low BMI, leading to growth of congenital bullae that can eventually limit clearance inhaled material, superinfect or burst. This hypothesis suggests that low-dose computerized tomography may be used to screen for TB eradication. This paper is the first to propose a biomechanical mechanism for all apical lung disease pathophysiology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Can We Falsify the Consciousness-Causes-Collapse Hypothesis in Quantum Mechanics?

NASA Astrophysics Data System (ADS)

de Barros, J. Acacio; Oas, Gary

2017-10-01

In this paper we examine some proposals to disprove the hypothesis that the interaction between mind and matter causes the collapse of the wave function, showing that such proposals are fundamentally flawed. We then describe a general experimental setup retaining the key features of the ones examined, and show that even a more general case is inadequate to disprove the mind-matter collapse hypothesis. Finally, we use our setup provided to argue that, under some reasonable assumptions about consciousness, such hypothesis is unfalsifiable.

Working ability in relation to disease severity, everyday occupations and well-being in women with limited systemic sclerosis.

PubMed

Sandqvist, G; Scheja, A; Eklund, M

2008-11-01

To investigate how women with SSc and varying degrees of working ability differed regarding disease severity, everyday occupations and well-being. Working ability was operationalized according to the degree of sick leave. Forty-four women of working age with lcSSc were assessed regarding sociodemographic characteristics, disease severity including organ manifestation, perceived physical symptoms, hand function, and satisfaction with everyday occupations, self-rated health and well-being. The subjects formed three groups with regard to reduction in working capacity. Twenty-one women (48%) had no sick leave, 15 women (34%) were on partial sick leave and eight women (18%) were temporarily on full-time sick leave or had a full disability pension. There were no statistically significant differences concerning sociodemographics between the groups. Women without sick leave had less physically demanding jobs (P = 0.026), and the hypothesis that working ability reflects lower disease severity was confirmed regarding dexterity grip force and perceived fatigue and breathlessness (P < 0.05). Greater working ability was associated with better capacity to perform activities of daily life (P < 0.01), greater satisfaction with occupations (P < 0.01), better well-being (P < 0.001) and better health (P < 0.001). Fifty per cent of the women were restricted in their working ability; the lower the working ability, the lower their perceived well-being. This emphasizes the need for further research into the factors that promote working ability and the development of suitable methods to improve working ability.

Evolution of Motor Control: From Reflexes and Motor Programs to the Equilibrium-Point Hypothesis

PubMed Central

Latash, Mark L.

2009-01-01

This brief review analyzes the evolution of motor control theories along two lines that emphasize active (motor programs) and reactive (reflexes) features of voluntary movements. It suggests that the only contemporary hypothesis that integrates both approaches in a fruitful way is the equilibrium-point hypothesis. Physical, physiological, and behavioral foundations of the EP-hypothesis are considered as well as relations between the EP-hypothesis and the recent developments of the notion of motor synergies. The paper ends with a brief review of the criticisms of the EP-hypothesis and challenges that the hypothesis faces at this time. PMID:19823595

Evolution of Motor Control: From Reflexes and Motor Programs to the Equilibrium-Point Hypothesis.

PubMed

Latash, Mark L

2008-01-01

This brief review analyzes the evolution of motor control theories along two lines that emphasize active (motor programs) and reactive (reflexes) features of voluntary movements. It suggests that the only contemporary hypothesis that integrates both approaches in a fruitful way is the equilibrium-point hypothesis. Physical, physiological, and behavioral foundations of the EP-hypothesis are considered as well as relations between the EP-hypothesis and the recent developments of the notion of motor synergies. The paper ends with a brief review of the criticisms of the EP-hypothesis and challenges that the hypothesis faces at this time.

Hygiene hypothesis and prevalence of glomerulonephritis.

PubMed

Hurtado, Abdias; Johnson, Richard J

2005-08-01

The hygiene hypothesis was proposed to explain the marked increase in allergies that has been observed in industrialized (Westernized) societies. This hypothesis proposes that early and frequent exposure to bacterial and other antigens, such as is common in developing nations, leads to a normal Th1 response, but that better public hygiene and less infections observed in industrialized nations may lead to persistence of the Th2 phenotype and thereby increase our risk for developing allergies. Infection early in life with measles or hepatitis A virus, immunization with bacille Calmette-Guérin, certain gastrointestinal bacteria (lactobacillus), and environmental endotoxin exposure may protect individuals from developing allergy in adulthood. Paradoxically, infestation by parasites stimulates a Th2-cell response; however, the incidence of allergic disease is very low, perhaps due to the stimulation of T-regulatory lymphocytes that can downregulate Th1 and Th2 responses. Some types of human glomerulonephritis (GN) have Th1-predominant immune responses, including crescentic and membranoproliferative GN, whereas other types of GN have a predominant Th2 immune response, including membranous nephropathy, minimal change disease, and immunoglobulin A nephropathy. A review of the prevalence of specific GN shows that the higher prevalence of membranoproliferative GN in developing countries and the higher frequency of immunoglobulin A nephropathy and minimal change disease in industrialized countries could be explained by the hygiene hypothesis. We suggest that studies examining Th1/Th2 balance, particularly as it develops in childhood, should be performed to determine if early polarization of the immune response is responsible for the later development of specific forms of GN.

A Hypothesis: Life Initiated from Two Genes, as Deduced from the RNA World Hypothesis and the Characteristics of Life-Like Systems

PubMed Central

Kawamura, Kunio

2016-01-01

RNA played a central role in the emergence of the first life-like system on primitive Earth since RNA molecules contain both genetic information and catalytic activity. However, there are several drawbacks regarding the RNA world hypothesis. Here, I briefly discuss the feasibility of the RNA world hypothesis to deduce the RNA functions that are essential for forming a life-like system. At the same time, I have conducted a conceptual analysis of the characteristics of biosystems as a useful approach to deduce a realistic life-like system in relation to the definition of life. For instance, an RNA-based life-like system should possess enough stability to resist environmental perturbations, by developing a cell-like compartment, for instance. Here, a conceptual viewpoint is summarized to provide a realistic life-like system that is compatible with the primitive Earth environment and the capabilities of RNA molecules. According to the empirical and conceptual analysis, I propose the hypothesis that the first life-like system could have initiated from only two genes. PMID:27490571

A genome-wide association study identifies multiple loci associated with mathematics ability and disability

PubMed Central

Docherty, S J; Davis, O S P; Kovas, Y; Meaburn, E L; Dale, P S; Petrill, S A; Schalkwyk, L C; Plomin, R

2010-01-01

Numeracy is as important as literacy and exhibits a similar frequency of disability. Although its etiology is relatively poorly understood, quantitative genetic research has demonstrated mathematical ability to be moderately heritable. In this first genome-wide association study (GWAS) of mathematical ability and disability, 10 out of 43 single nucleotide polymorphism (SNP) associations nominated from two high- vs. low-ability (n = 600 10-year-olds each) scans of pooled DNA were validated (P < 0.05) in an individually genotyped sample of *2356 individuals spanning the entire distribution of mathematical ability, as assessed by teacher reports and online tests. Although the effects are of the modest sizes now expected for complex traits and require further replication, interesting candidate genes are implicated such as NRCAM which encodes a neuronal cell adhesion molecule. When combined into a set, the 10 SNPs account for 2.9% (F = 56.85; df = 1 and 1881; P = 7.277e–14) of the phenotypic variance. The association is linear across the distribution consistent with a quantitative trait locus (QTL) hypothesis; the third of children in our sample who harbour 10 or more of the 20 risk alleles identified are nearly twice as likely (OR = 1.96; df = 1; P = 3.696e–07) to be in the lowest performing 15% of the distribution. Our results correspond with those of quantitative genetic research in indicating that mathematical ability and disability are influenced by many genes generating small effects across the entire spectrum of ability, implying that more highly powered studies will be needed to detect and replicate these QTL associations. PMID:20039944

Review series on helminths, immune modulation and the hygiene hypothesis: the broader implications of the hygiene hypothesis.

PubMed

Rook, Graham A W

2009-01-01

Man has moved rapidly from the hunter-gatherer environment to the living conditions of the rich industrialized countries. The hygiene hypothesis suggests that the resulting changed and reduced pattern of exposure to microorganisms has led to disordered regulation of the immune system, and hence to increases in certain inflammatory disorders. The concept began with the allergic disorders, but there are now good reasons for extending it to autoimmunity, inflammatory bowel disease, neuroinflammatory disorders, atherosclerosis, depression associated with raised inflammatory cytokines, and some cancers. This review discusses these possibilities in the context of Darwinian medicine, which uses knowledge of evolution to cast light on human diseases. The Darwinian approach enables one to correctly identify some of the organisms that are important for the 'Hygiene' or 'Old Friends' hypothesis, and to point to the potential exploitation of these organisms or their components in novel types of prophylaxis with applications in several branches of medicine.

Examination of the embargo hypothesis as an explanation for the Great Silence

NASA Astrophysics Data System (ADS)

Deardorff, J. W.

1987-08-01

The embargo or quarantine hypothesis for explaining the 'Great Silence' is reviewed and found to be more plausible than the view that, at most, earth might expect to receive radio messages from some distant star. The latter hypothesis is shown to be compatible with extraterrestrial technologies only a few hundred years in advance of those on earth, whereas the embargo hypothesis more reasonably infers that they should be tens of thousands of years in advance and in control of any contact with humanity. Reasons why the embargo hypothesis has received insufficient attention are presented; they involve failure to allow for the application of both greatly advanced technology and high ethical values by maturing societies of extraterrestrial intelligence. The implication of the embargo hypothesis for space development is that planets already harboring diverse biota are ethically off-limits for exploitive colonization.

A Clinical Evaluation of the Competing Sources of Input Hypothesis

ERIC Educational Resources Information Center

Fey, Marc E.; Leonard, Laurence B.; Bredin-Oja, Shelley L.; Deevy, Patricia

2017-01-01

Purpose: Our purpose was to test the competing sources of input (CSI) hypothesis by evaluating an intervention based on its principles. This hypothesis proposes that children's use of main verbs without tense is the result of their treating certain sentence types in the input (e.g., "Was 'she laughing'?") as models for declaratives…

White matter microstructural properties correlate with sensorimotor synchronization abilities.

PubMed

Blecher, Tal; Tal, Idan; Ben-Shachar, Michal

2016-09-01

Sensorimotor synchronization (SMS) to an external auditory rhythm is a developed ability in humans, particularly evident in dancing and singing. This ability is typically measured in the lab via a simple task of finger tapping to an auditory beat. While simplistic, there is some evidence that poor performance on this task could be related to impaired phonological and reading abilities in children. Auditory-motor synchronization is hypothesized to rely on a tight coupling between auditory and motor neural systems, but the specific pathways that mediate this coupling have not been identified yet. In this study, we test this hypothesis and examine the contribution of fronto-temporal and callosal connections to specific measures of rhythmic synchronization. Twenty participants went through SMS and diffusion magnetic resonance imaging (dMRI) measurements. We quantified the mean asynchrony between an auditory beat and participants' finger taps, as well as the time to resynchronize (TTR) with an altered meter, and examined the correlations between these behavioral measures and diffusivity in a small set of predefined pathways. We found significant correlations between asynchrony and fractional anisotropy (FA) in the left (but not right) arcuate fasciculus and in the temporal segment of the corpus callosum. On the other hand, TTR correlated with FA in the precentral segment of the callosum. To our knowledge, this is the first demonstration that relates these particular white matter tracts with performance on an auditory-motor rhythmic synchronization task. We propose that left fronto-temporal and temporal-callosal fibers are involved in prediction and constant comparison between auditory inputs and motor commands, while inter-hemispheric connections between the motor/premotor cortices contribute to successful resynchronization of motor responses with a new external rhythm, perhaps via inhibition of tapping to the previous rhythm. Our results indicate that auditory

Recent sediment studies refute Glen Canyon Dam hypothesis

USGS Publications Warehouse

Rubin, David M.; Topping, David J.; Schmidt, John C.; Hazel, Joe; Kaplinski, Matt; Melis, Theodore S.

2002-01-01

Recent studies of sedimentology hydrology, and geomorphology indicate that releases from Glen Canyon Dam are continuing to erode sandbars and beaches in the Colorado River in Grand Canyon National Park, despite attempts to restore these resources. The current strategy for dam operations is based on the hypothesis that sand supplied by tributaries of the Colorado River downstream from the dam will accumulate in the channel during normal dam operations and remain available for restoration floods. Recent work has shown that this hypothesis is false, and that tributary sand inputs are exported downstream rapidly typically within weeks or months under the current flow regime.

The equilibrium-point hypothesis--past, present and future.

PubMed

Feldman, Anatol G; Levin, Mindy F

2009-01-01

This chapter is a brief account of fundamentals of the equilibrium-point hypothesis or more adequately called the threshold control theory (TCT). It also compares the TCT with other approaches to motor control. The basic notions of the TCT are reviewed with a major focus on solutions to the problems of multi-muscle and multi-degrees of freedom redundancy. The TCT incorporates cognitive aspects by explaining how neurons recognize that internal (neural) and external (environmental) events match each other. These aspects as well as how motor learning occurs are subjects of further development of the TCT hypothesis.

Isotopic niches support the resource breadth hypothesis.

PubMed

Rader, Jonathan A; Newsome, Seth D; Sabat, Pablo; Chesser, R Terry; Dillon, Michael E; Martínez Del Rio, Carlos

2017-03-01

Because a broad spectrum of resource use allows species to persist in a wide range of habitat types, and thus permits them to occupy large geographical areas, and because broadly distributed species have access to more diverse resource bases, the resource breadth hypothesis posits that the diversity of resources used by organisms should be positively related with the extent of their geographic ranges. We investigated isotopic niche width in a small radiation of South American birds in the genus Cinclodes. We analysed feathers of 12 species of Cinclodes to test the isotopic version of the resource breadth hypothesis and to examine the correlation between isotopic niche breadth and morphology. We found a positive correlation between the widths of hydrogen and oxygen isotopic niches (which estimate breadth of elevational range) and widths of the carbon and nitrogen isotopic niches (which estimates the diversity of resources consumed, and hence of habitats used). We also found a positive correlation between broad isotopic niches and wing morphology. Our study not only supports the resource breadth hypothesis but it also highlights the usefulness of stable isotope analyses as tools in the exploration of ecological niches. It is an example of a macroecological application of stable isotopes. It also illustrates the importance of scientific collections in ecological studies. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

Paleoindian demography and the extraterrestrial impact hypothesis

NASA Astrophysics Data System (ADS)

Buchanan, Briggs; Collard, Mark; Edinborough, Kevan

2008-08-01

Recently it has been suggested that one or more large extraterrestrial (ET) objects struck northern North America 12,900 ± 100 calendar years before present (calBP) [Firestone RB, et al. (2007) Proc Natl Acad Sci USA 104: 16016-16021]. This impact is claimed to have triggered the Younger Dryas major cooling event and resulted in the extinction of the North American megafauna. The impact is also claimed to have caused major cultural changes and population decline among the Paleoindians. Here, we report a study in which ≈1,500 radiocarbon dates from archaeological sites in Canada and the United States were used to test the hypothesis that the ET resulted in population decline among the Paleoindians. Following recent studies [e.g., Gamble C, Davies W, Pettitt P, Hazelwood L, Richards M (2005) Camb Archaeol J 15:193-223), the summed probability distribution of the calibrated dates was used to identify probable changes in human population size between 15,000 and 9,000 calBP. Subsequently, potential biases were evaluated by modeling and spatial analysis of the dated occupations. The results of the analyses were not consistent with the predictions of extraterrestrial impact hypothesis. No evidence of a population decline among the Paleoindians at 12,900 ± 100 calBP was found. Thus, minimally, the study suggests the extraterrestrial impact hypothesis should be amended.

Paleoindian demography and the extraterrestrial impact hypothesis.

PubMed

Buchanan, Briggs; Collard, Mark; Edinborough, Kevan

2008-08-19

Recently it has been suggested that one or more large extraterrestrial (ET) objects struck northern North America 12,900 +/- 100 calendar years before present (calBP) [Firestone RB, et al. (2007) Proc Natl Acad Sci USA 104: 16016-16021]. This impact is claimed to have triggered the Younger Dryas major cooling event and resulted in the extinction of the North American megafauna. The impact is also claimed to have caused major cultural changes and population decline among the Paleoindians. Here, we report a study in which approximately 1,500 radiocarbon dates from archaeological sites in Canada and the United States were used to test the hypothesis that the ET resulted in population decline among the Paleoindians. Following recent studies [e.g., Gamble C, Davies W, Pettitt P, Hazelwood L, Richards M (2005) Camb Archaeol J 15:193-223), the summed probability distribution of the calibrated dates was used to identify probable changes in human population size between 15,000 and 9,000 calBP. Subsequently, potential biases were evaluated by modeling and spatial analysis of the dated occupations. The results of the analyses were not consistent with the predictions of extraterrestrial impact hypothesis. No evidence of a population decline among the Paleoindians at 12,900 +/- 100 calBP was found. Thus, minimally, the study suggests the extraterrestrial impact hypothesis should be amended.

Paleoindian demography and the extraterrestrial impact hypothesis

PubMed Central

Buchanan, Briggs; Collard, Mark; Edinborough, Kevan

2008-01-01

Recently it has been suggested that one or more large extraterrestrial (ET) objects struck northern North America 12,900 ± 100 calendar years before present (calBP) [Firestone RB, et al. (2007) Proc Natl Acad Sci USA 104: 16016–16021]. This impact is claimed to have triggered the Younger Dryas major cooling event and resulted in the extinction of the North American megafauna. The impact is also claimed to have caused major cultural changes and population decline among the Paleoindians. Here, we report a study in which ≈1,500 radiocarbon dates from archaeological sites in Canada and the United States were used to test the hypothesis that the ET resulted in population decline among the Paleoindians. Following recent studies [e.g., Gamble C, Davies W, Pettitt P, Hazelwood L, Richards M (2005) Camb Archaeol J 15:193–223), the summed probability distribution of the calibrated dates was used to identify probable changes in human population size between 15,000 and 9,000 calBP. Subsequently, potential biases were evaluated by modeling and spatial analysis of the dated occupations. The results of the analyses were not consistent with the predictions of extraterrestrial impact hypothesis. No evidence of a population decline among the Paleoindians at 12,900 ± 100 calBP was found. Thus, minimally, the study suggests the extraterrestrial impact hypothesis should be amended. PMID:18697936

Basic Timing Abilities Stay Intact in Patients with Musician's Dystonia

PubMed Central

van der Steen, M. C.; van Vugt, Floris T.; Keller, Peter E.; Altenmüller, Eckart

2014-01-01

Task-specific focal dystonia is a movement disorder that is characterized by the loss of voluntary motor control in extensively trained movements. Musician's dystonia is a type of task-specific dystonia that is elicited in professional musicians during instrumental playing. The disorder has been associated with deficits in timing. In order to test the hypothesis that basic timing abilities are affected by musician's dystonia, we investigated a group of patients (N = 15) and a matched control group (N = 15) on a battery of sensory and sensorimotor synchronization tasks. Results did not show any deficits in auditory-motor processing for patients relative to controls. Both groups benefited from a pacing sequence that adapted to their timing (in a sensorimotor synchronization task at a stable tempo). In a purely perceptual task, both groups were able to detect a misaligned metronome when it was late rather than early relative to a musical beat. Overall, the results suggest that basic timing abilities stay intact in patients with musician's dystonia. This supports the idea that musician's dystonia is a highly task-specific movement disorder in which patients are mostly impaired in tasks closely related to the demands of actually playing their instrument. PMID:24667273

Alzheimer’s Disease as the Product of a Progressive Energy Deficiency Syndrome in the Central Nervous System: The Neuroenergetic Hypothesis

PubMed Central

Blonz, Edward R.

2017-01-01

The decreased availability of metabolizable energy resources in the central nervous system is hypothesized to be a key factor in the pathogenesis of Alzheimer’s disease. More specifically, the age-related decline in the ability of glucose to cross the blood-brain barrier creates a metabolic stress that shifts the normal, benign processing of amyloid-β protein precursor toward pathways associated with the production of amyloid-β plaques and tau-containing neurofibrillary tangles that are characteristic of the disease. The neuroenergetic hypothesis provides insight into the etiology of Alzheimer’s disease and illuminates new approaches for diagnosis, monitoring, and treatment. PMID:28946565

Developmental changes in children's abilities to share and allocate attention in a dual task.

PubMed

Irwin-Chase, H; Burns, B

2000-09-01

Characterizing developmental changes in children's dual-task performance has been problematic because differences in divided attention abilities are easily confounded with differences in overall capacity. Two experiments showed that after individual differences in children's capacity for single-task performance were controlled for, age differences between second- (M = 8.1 years) and fifth-grade (M = 11.1 years) children did not exist in dual-task performance when tasks were of equal priority. However, when tasks had different priorities, only fifth-grade children could differentially allocate attention in the dual task. Results are discussed within the coordination hypothesis framework (see A. F. Kramer & J. L. Larish, 1996), which suggests that changes in dual-task performance with aging are due to changes in the ability to coordinate and control the allocation of attention. It is argued that linking the investigations of children's attention with research on attention and aging provides both methodological and theoretical benefits. Copyright 2000 Academic Press.

About-face on face recognition ability and holistic processing.

PubMed

Richler, Jennifer J; Floyd, R Jackie; Gauthier, Isabel

2015-01-01

Previous work found a small but significant relationship between holistic processing measured with the composite task and face recognition ability measured by the Cambridge Face Memory Test (CFMT; Duchaine & Nakayama, 2006). Surprisingly, recent work using a different measure of holistic processing (Vanderbilt Holistic Face Processing Test [VHPT-F]; Richler, Floyd, & Gauthier, 2014) and a larger sample found no evidence for such a relationship. In Experiment 1 we replicate this unexpected result, finding no relationship between holistic processing (VHPT-F) and face recognition ability (CFMT). A key difference between the VHPT-F and other holistic processing measures is that unique face parts are used on each trial in the VHPT-F, unlike in other tasks where a small set of face parts repeat across the experiment. In Experiment 2, we test the hypothesis that correlations between the CFMT and holistic processing tasks are driven by stimulus repetition that allows for learning during the composite task. Consistent with our predictions, CFMT performance was correlated with holistic processing in the composite task when a small set of face parts repeated over trials, but not when face parts did not repeat. A meta-analysis confirms that relationships between the CFMT and holistic processing depend on stimulus repetition. These results raise important questions about what is being measured by the CFMT, and challenge current assumptions about why faces are processed holistically.

About-face on face recognition ability and holistic processing

PubMed Central

Richler, Jennifer J.; Floyd, R. Jackie; Gauthier, Isabel

2015-01-01

Previous work found a small but significant relationship between holistic processing measured with the composite task and face recognition ability measured by the Cambridge Face Memory Test (CFMT; Duchaine & Nakayama, 2006). Surprisingly, recent work using a different measure of holistic processing (Vanderbilt Holistic Face Processing Test [VHPT-F]; Richler, Floyd, & Gauthier, 2014) and a larger sample found no evidence for such a relationship. In Experiment 1 we replicate this unexpected result, finding no relationship between holistic processing (VHPT-F) and face recognition ability (CFMT). A key difference between the VHPT-F and other holistic processing measures is that unique face parts are used on each trial in the VHPT-F, unlike in other tasks where a small set of face parts repeat across the experiment. In Experiment 2, we test the hypothesis that correlations between the CFMT and holistic processing tasks are driven by stimulus repetition that allows for learning during the composite task. Consistent with our predictions, CFMT performance was correlated with holistic processing in the composite task when a small set of face parts repeated over trials, but not when face parts did not repeat. A meta-analysis confirms that relationships between the CFMT and holistic processing depend on stimulus repetition. These results raise important questions about what is being measured by the CFMT, and challenge current assumptions about why faces are processed holistically. PMID:26223027

Selfing ability and dispersal are positively related, but not affected by range position: a multispecies study on southern African Asteraceae.

PubMed

de Waal, C; Rodger, J G; Anderson, B; Ellis, A G

2014-05-01

Dispersal and breeding system traits are thought to affect colonization success. As species have attained their present distribution ranges through colonization, these traits may vary geographically. Although several theories predict associations between dispersal ability, selfing ability and the relative position of a population within its geographic range, there is little theoretical or empirical consensus on exactly how these three variables are related. We investigated relationships between dispersal ability, selfing ability and range position across 28 populations of 13 annual, wind-dispersed Asteraceae species from the Namaqualand region of South Africa. Controlling for phylogeny, relative dispersal ability--assessed from vertical fall time of fruits--was positively related to an index of autofertility--determined from hand-pollination experiments. These findings support the existence of two discrete syndromes: high selfing ability associated with good dispersal and obligate outcrossing associated with lower dispersal ability. This is consistent with the hypothesis that selection for colonization success drives the evolution of an association between these traits. However, no general effect of range position on dispersal or breeding system traits was evident. This suggests selection on both breeding system and dispersal traits acts consistently across distribution ranges. © 2014 The Authors. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

A Critique of One-Tailed Hypothesis Test Procedures in Business and Economics Statistics Textbooks.

ERIC Educational Resources Information Center

Liu, Tung; Stone, Courtenay C.

1999-01-01

Surveys introductory business and economics statistics textbooks and finds that they differ over the best way to explain one-tailed hypothesis tests: the simple null-hypothesis approach or the composite null-hypothesis approach. Argues that the composite null-hypothesis approach contains methodological shortcomings that make it more difficult for…

The frequentist implications of optional stopping on Bayesian hypothesis tests.

PubMed

Sanborn, Adam N; Hills, Thomas T

2014-04-01

Null hypothesis significance testing (NHST) is the most commonly used statistical methodology in psychology. The probability of achieving a value as extreme or more extreme than the statistic obtained from the data is evaluated, and if it is low enough, the null hypothesis is rejected. However, because common experimental practice often clashes with the assumptions underlying NHST, these calculated probabilities are often incorrect. Most commonly, experimenters use tests that assume that sample sizes are fixed in advance of data collection but then use the data to determine when to stop; in the limit, experimenters can use data monitoring to guarantee that the null hypothesis will be rejected. Bayesian hypothesis testing (BHT) provides a solution to these ills because the stopping rule used is irrelevant to the calculation of a Bayes factor. In addition, there are strong mathematical guarantees on the frequentist properties of BHT that are comforting for researchers concerned that stopping rules could influence the Bayes factors produced. Here, we show that these guaranteed bounds have limited scope and often do not apply in psychological research. Specifically, we quantitatively demonstrate the impact of optional stopping on the resulting Bayes factors in two common situations: (1) when the truth is a combination of the hypotheses, such as in a heterogeneous population, and (2) when a hypothesis is composite-taking multiple parameter values-such as the alternative hypothesis in a t-test. We found that, for these situations, while the Bayesian interpretation remains correct regardless of the stopping rule used, the choice of stopping rule can, in some situations, greatly increase the chance of experimenters finding evidence in the direction they desire. We suggest ways to control these frequentist implications of stopping rules on BHT.

Distinguishing between the Partial-Mapping Preparation Hypothesis and the Failure-to-Engage Hypothesis of Residual Switch Costs

ERIC Educational Resources Information Center

Lindsen, Job P.; de Jong, Ritske

2010-01-01

Lien, Ruthruff, Remington, & Johnston (2005) reported residual switch cost differences between stimulus-response (S-R) pairs and proposed the partial-mapping preparation (PMP) hypothesis, which states that advance preparation will typically be limited to a subset of S-R pairs because of structural capacity limitations, to account for these…

Dopamine treatment and cognitive functioning in individuals with Parkinson's disease: the "cognitive flexibility" hypothesis seems to work.

PubMed

Costa, Alberto; Peppe, Antonella; Mazzù, Ilenia; Longarzo, Mariachiara; Caltagirone, Carlo; Carlesimo, Giovanni A

2014-01-01

Previous data suggest that (i) dopamine modulates the ability to implement nonroutine schemata and update operations (flexibility processes) and that (ii) dopamine-related improvement may be related to baseline dopamine levels in target pathways (inverted U-shaped hypothesis). To investigate above hypotheses in individuals with Parkinson's disease (PD). Twenty PD patients were administered tasks varying as to flexibility load in two treatment conditions: (i) "off" condition, about 18 hours after dopamine dose and (ii) "on" condition, after dopamine administration. PD patients were separated into two groups: low performers (i.e., performance on Digit Span Backward below the sample mean) and high performers (i.e., performance above the mean). Twenty healthy individuals performed the tasks in two sessions without taking drugs. Passing from the "off" to the "on" state, only low performer PD patients significantly improved their performance on high-flexibility measures (interference condition of the Stroop test; P < 0.05); no significant effect was found on low-flexibility tasks. These findings document that high-flexibility processes are sensitive to dopamine neuromodulation in the early phases of PD. This is in line with the hypothesis that striatal dopamine pathways, affected early by PD, are precociously implicated in the expression of cognitive disorders in these individuals.

A critique of statistical hypothesis testing in clinical research

PubMed Central

Raha, Somik

2011-01-01

Many have documented the difficulty of using the current paradigm of Randomized Controlled Trials (RCTs) to test and validate the effectiveness of alternative medical systems such as Ayurveda. This paper critiques the applicability of RCTs for all clinical knowledge-seeking endeavors, of which Ayurveda research is a part. This is done by examining statistical hypothesis testing, the underlying foundation of RCTs, from a practical and philosophical perspective. In the philosophical critique, the two main worldviews of probability are that of the Bayesian and the frequentist. The frequentist worldview is a special case of the Bayesian worldview requiring the unrealistic assumptions of knowing nothing about the universe and believing that all observations are unrelated to each other. Many have claimed that the first belief is necessary for science, and this claim is debunked by comparing variations in learning with different prior beliefs. Moving beyond the Bayesian and frequentist worldviews, the notion of hypothesis testing itself is challenged on the grounds that a hypothesis is an unclear distinction, and assigning a probability on an unclear distinction is an exercise that does not lead to clarity of action. This critique is of the theory itself and not any particular application of statistical hypothesis testing. A decision-making frame is proposed as a way of both addressing this critique and transcending ideological debates on probability. An example of a Bayesian decision-making approach is shown as an alternative to statistical hypothesis testing, utilizing data from a past clinical trial that studied the effect of Aspirin on heart attacks in a sample population of doctors. As a big reason for the prevalence of RCTs in academia is legislation requiring it, the ethics of legislating the use of statistical methods for clinical research is also examined. PMID:22022152

On the widespread use of the Corrsin hypothesis in diffusion theories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tautz, R. C.; Shalchi, A.

2010-12-15

In the past four decades, several nonlinear theories have been developed to describe (i) the motion of charged test particles through a turbulent magnetized plasma and (ii) the random walk of magnetic field lines. In many such theories, the so-called Corrsin independence hypothesis has been applied to enforce analytical tractability. In this note, it is shown that the Corrsin hypothesis is part of most nonlinear diffusion theories. In some cases, the Corrsin approximation is somewhat hidden, while in other cases a different name is used for the same approach. It is shown that even the researchers who criticized the applicationmore » of this hypothesis have used it in their nonlinear diffusion theories. It is hoped that the present article will eliminate the recently caused confusion about the applicability and validity of the Corrsin hypothesis.« less

Does the Slow-Growth, High-Mortality Hypothesis Apply Below Ground?

PubMed

Hourston, James E; Bennett, Alison E; Johnson, Scott N; Gange, Alan C

2016-01-01

Belowground tri-trophic study systems present a challenging environment in which to study plant-herbivore-natural enemy interactions. For this reason, belowground examples are rarely available for testing general ecological theories. To redress this imbalance, we present, for the first time, data on a belowground tri-trophic system to test the slow growth, high mortality hypothesis. We investigated whether the differing performance of entomopathogenic nematodes (EPNs) in controlling the common pest black vine weevil Otiorhynchus sulcatus could be linked to differently resistant cultivars of the red raspberry Rubus idaeus. The O. sulcatus larvae recovered from R. idaeus plants showed significantly slower growth and higher mortality on the Glen Rosa cultivar, relative to the more commercially favored Glen Ample cultivar creating a convenient system for testing this hypothesis. Heterorhabditis megidis was found to be less effective at controlling O. sulcatus than Steinernema kraussei, but conformed to the hypothesis. However, S. kraussei maintained high levels of O. sulcatus mortality regardless of how larval growth was influenced by R. idaeus cultivar. We link this to direct effects that S. kraussei had on reducing O. sulcatus larval mass, indicating potential sub-lethal effects of S. kraussei, which the slow-growth, high-mortality hypothesis does not account for. Possible origins of these sub-lethal effects of EPN infection and how they may impact on a hypothesis designed and tested with aboveground predator and parasitoid systems are discussed.

Does active psychosis cause neurobiological pathology? A critical review of the neurotoxicity hypothesis.

PubMed

Rund, B R

2014-06-01

Since the neurotoxicity hypothesis was launched in 1991, it has generated a great deal of interest and given rise to several studies investigating the validity of the hypothesis that being psychotic has a toxic effect on the brain. The toxicity argument is used to justify early treatment. This review attempts to assess the studies that have addressed the question: Does an active psychosis, indexed by the duration of untreated psychosis (DUP), cause neurobiological pathology? The validity of the hypothesis has been studied primarily by correlation analyses that assess whether there are significant correlations between DUP and changes in neurocognitive functioning or brain structure. In this review, relevant reports were identified by a literature survey. Of the 35 studies (33 papers) evaluated, six neurocognitive studies supported the hypothesis and 16 did not. Eight morphology studies supported the hypothesis and five did not. In general, the studies that did not support the neurotoxicity hypothesis were larger in size and had more adequate designs (longitudinal) than those that supported the hypothesis. Overall, there is limited empirical evidence for the neurotoxicity hypothesis in the studies reviewed. However, it is possible that there is a threshold value for a toxic effect of psychosis, rather than a linear relationship between DUP and a neurotoxic effect, and that several of the studies evaluated did not have a long enough DUP to detect a toxic effect of active psychosis.

Testing the arousal hypothesis of neonatal imitation in infant rhesus macaques

PubMed Central

Pedersen, Eric J.; Simpson, Elizabeth A.

2017-01-01

Neonatal imitation is the matching of (often facial) gestures by newborn infants. Some studies suggest that performance of facial gestures is due to general arousal, which may produce false positives on neonatal imitation assessments. Here we examine whether arousal is linked to facial gesturing in newborn infant rhesus macaques (Macaca mulatta). We tested 163 infants in a neonatal imitation paradigm in their first postnatal week and analyzed their lipsmacking gestures (a rapid opening and closing of the mouth), tongue protrusion gestures, and yawn responses (a measure of arousal). Arousal increased during dynamic stimulus presentation compared to the static baseline across all conditions, and arousal was higher in the facial gestures conditions than the nonsocial control condition. However, even after controlling for arousal, we found a condition-specific increase in facial gestures in infants who matched lipsmacking and tongue protrusion gestures. Thus, we found no support for the arousal hypothesis. Consistent with reports in human newborns, imitators’ propensity to match facial gestures is based on abilities that go beyond mere arousal. We discuss optimal testing conditions to minimize potentially confounding effects of arousal on measurements of neonatal imitation. PMID:28617816

Human consciousness and its relationship to social neuroscience: A novel hypothesis

PubMed Central

Graziano, Michael S. A.; Kastner, Sabine

2011-01-01

A common modern view of consciousness is that it is an emergent property of the brain, perhaps caused by neuronal complexity, and perhaps with no adaptive value. Exactly what emerges, how it emerges, and from what specific neuronal process, is in debate. One possible explanation of consciousness, proposed here, is that it is a construct of the social perceptual machinery. Humans have specialized neuronal machinery that allows us to be socially intelligent. The primary role for this machinery is to construct models of other people’s minds thereby gaining some ability to predict the behavior of other individuals. In the present hypothesis, awareness is a perceptual reconstruction of attentional state; and the machinery that computes information about other people’s awareness is the same machinery that computes information about our own awareness. The present article brings together a variety of lines of evidence including experiments on the neural basis of social perception, on hemispatial neglect, on the out-of-body experience, on mirror neurons, and on the mechanisms of decision-making, to explore the possibility that awareness is a construct of the social machinery in the brain. PMID:22121395

The sound symbolism bootstrapping hypothesis for language acquisition and language evolution

PubMed Central

Imai, Mutsumi; Kita, Sotaro

2014-01-01

Sound symbolism is a non-arbitrary relationship between speech sounds and meaning. We review evidence that, contrary to the traditional view in linguistics, sound symbolism is an important design feature of language, which affects online processing of language, and most importantly, language acquisition. We propose the sound symbolism bootstrapping hypothesis, claiming that (i) pre-verbal infants are sensitive to sound symbolism, due to a biologically endowed ability to map and integrate multi-modal input, (ii) sound symbolism helps infants gain referential insight for speech sounds, (iii) sound symbolism helps infants and toddlers associate speech sounds with their referents to establish a lexical representation and (iv) sound symbolism helps toddlers learn words by allowing them to focus on referents embedded in a complex scene, alleviating Quine's problem. We further explore the possibility that sound symbolism is deeply related to language evolution, drawing the parallel between historical development of language across generations and ontogenetic development within individuals. Finally, we suggest that sound symbolism bootstrapping is a part of a more general phenomenon of bootstrapping by means of iconic representations, drawing on similarities and close behavioural links between sound symbolism and speech-accompanying iconic gesture. PMID:25092666

Sex differences in spatial ability: a lateralization of function approach.

PubMed

Rilea, Stacy L; Roskos-Ewoldsen, Beverly; Boles, David

2004-12-01

The current study was designed to examine whether the extent of the male advantage in performance on a spatial task was determined by the extent to which the task was right-hemisphere dependent. Participants included 108 right-handed men and women who completed the mental rotation, waterlevel, and paperfolding tasks, all of which were presented bilaterally. The results partially supported the hypothesis. On the mental rotation task, men showed a right-hemisphere advantage, whereas women showed no hemispheric differences; however, no overall sex differences were observed. On the waterlevel task, men outperformed women, and both men and women showed a right-hemisphere advantage. On the paperfolding task, no sex or hemispheric differences were observed. Although the findings of the current study were mixed, the study provides a framework for examining sex differences across different types of spatial ability.

Colloquium: Physics of the Riemann hypothesis

NASA Astrophysics Data System (ADS)

Schumayer, Dániel; Hutchinson, David A. W.

2011-04-01

Physicists become acquainted with special functions early in their studies. Consider our perennial model, the harmonic oscillator, for which we need Hermite functions, or the Laguerre functions in quantum mechanics. Here a particular number-theoretical function is chosen, the Riemann zeta function, and its influence on the realm of physics is examined and also how physics may be suggestive for the resolution of one of mathematics’ most famous unconfirmed conjectures, the Riemann hypothesis. Does physics hold an essential key to the solution for this more than 100-year-old problem? In this work numerous models from different branches of physics are examined, from classical mechanics to statistical physics, where this function plays an integral role. This function is also shown to be related to quantum chaos and how its pole structure encodes when particles can undergo Bose-Einstein condensation at low temperature. Throughout these examinations light is shed on how the Riemann hypothesis can highlight physics. Naturally, the aim is not to be comprehensive, but rather focusing on the major models and aim to give an informed starting point for the interested reader.

A lateralization of function approach to sex differences in spatial ability: a reexamination.

PubMed

Rilea, Stacy L

2008-07-01

The current study assessed the lateralization of function hypothesis (Rilea, S. L., Roskos-Ewoldsen, B., & Boles, D. (2004). Sex differences in spatial ability: A lateralization of function approach. Brain and Cognition, 56, 332-343) which suggested that it was the interaction of brain organization and the type of spatial task that led to sex differences in spatial ability. A second purpose was to evaluate explanations for their unexpected findings on the mental rotation task. In Experiment 1, participants completed the Water Level, Paper Folding, and mental rotation tasks (using an object-based or self-based perspective), presented bilaterally. Sex differences were only observed on the Water Level Task; a right hemisphere advantage was observed on Water Level and mental rotation tasks. In Experiment 2, a human stick figure or a polygon was mentally rotated. Men outperformed women when rotating polygons, but not when rotating stick figures. Men demonstrated a right hemisphere advantage when rotating polygons; women showed no hemisphere differences for either stimulus. Thus, hemisphere processing, task complexity, and stimulus type may influence performance for men and women across different spatial measures.

Parallelism Effects and Verb Activation: The Sustained Reactivation Hypothesis

PubMed Central

Shapiro, Lewis P.; Love, Tracy

2010-01-01

This study investigated the processes underlying parallelism by evaluating the activation of a parallel element (i.e., a verb) throughout and-coordinated sentences. Four points were tested: (1) approximately 1,600ms after the verb in the first conjunct (PP1), (2) immediately following the conjunction (PP2), (3) approximately 1,100ms after the conjunction (PP3), (4) at the end of the second conjunct (PP4). The results revealed no activation at PP1, suggesting activation related to the initial presentation had decayed by this point; however, activation was observed at PP2, PP3, and PP4, suggesting the conjunction elicits reactivation that is sustained throughout the second conjunct. These findings support a specific hypothesis about parallelism, the sustained reactivation hypothesis. This hypothesis claims that, in conjoined structures, a cue that is associated with parallelism elicits the reactivation of material from the first conjunct and that this activation is sustained until integration with the second conjunct can be completed. PMID:19774464

Parallelism effects and verb activation: the sustained reactivation hypothesis.

PubMed

Callahan, Sarah M; Shapiro, Lewis P; Love, Tracy

2010-04-01

This study investigated the processes underlying parallelism by evaluating the activation of a parallel element (i.e., a verb) throughout and-coordinated sentences. Four points were tested: (1) approximately 1,600 ms after the verb in the first conjunct (PP1), (2) immediately following the conjunction (PP2), (3) approximately 1,100 ms after the conjunction (PP3), (4) at the end of the second conjunct (PP4). The results revealed no activation at PP1, suggesting activation related to the initial presentation had decayed by this point; however, activation was observed at PP2, PP3, and PP4, suggesting the conjunction elicits reactivation that is sustained throughout the second conjunct. These findings support a specific hypothesis about parallelism, the sustained reactivation hypothesis. This hypothesis claims that, in conjoined structures, a cue that is associated with parallelism elicits the reactivation of material from the first conjunct and that this activation is sustained until integration with the second conjunct can be completed.

Sensorimotor adaptation to inertial forces in a multi-force environment does not depend on the number of targets: indirect validation of the altered-proprioception hypothesis.

PubMed

Bourdin, C; Bock, O

2006-11-20

The ability of our sensorimotor system to adapt to changing and complex environmental demands has been under experimental scrutiny for more than a century. Previous works have shown that aimed arm movements adapt quickly and completely to Coriolis force, but incompletely to the combination of Coriolis and centrifugal forces without visual cues. Two hypotheses may be advanced to explain this discrepancy: the workspace-exploration hypothesis, and the degraded-proprioception hypothesis. The aim of this study was to distinguish between the above two alternatives by comparing adaptive improvement during off-axis rotation in subjects pointing at one, three or seven different targets in complete darkness. Two main results emerge: (a) off-axis rotation led initially to errors in the direction of Coriolis force and in the opposite direction of the centrifugal force; (b) the size of the visited workspace has no effect on the way the subjects adapt to a multi-force environment. The lack of a target-number effect and the persistence of lateral errors in the pointing movements performed during rotation of the platform, support the degraded-proprioception rather than the workspace-exploration hypothesis of adaptation to a multi-force environment.

The role of responsibility and fear of guilt in hypothesis-testing.

PubMed

Mancini, Francesco; Gangemi, Amelia

2006-12-01

Recent theories argue that both perceived responsibility and fear of guilt increase obsessive-like behaviours. We propose that hypothesis-testing might account for this effect. Both perceived responsibility and fear of guilt would influence subjects' hypothesis-testing, by inducing a prudential style. This style implies focusing on and confirming the worst hypothesis, and reiterating the testing process. In our experiment, we manipulated the responsibility and fear of guilt of 236 normal volunteers who executed a deductive task. The results show that perceived responsibility is the main factor that influenced individuals' hypothesis-testing. Fear of guilt has however a significant additive effect. Guilt-fearing participants preferred to carry on with the diagnostic process, even when faced with initial favourable evidence, whereas participants in the responsibility condition only did so when confronted with an unfavourable evidence. Implications for the understanding of obsessive-compulsive disorder (OCD) are discussed.

Mechanisms of eyewitness suggestibility: tests of the explanatory role hypothesis.

PubMed

Rindal, Eric J; Chrobak, Quin M; Zaragoza, Maria S; Weihing, Caitlin A

2017-10-01

In a recent paper, Chrobak and Zaragoza (Journal of Experimental Psychology: General, 142(3), 827-844, 2013) proposed the explanatory role hypothesis, which posits that the likelihood of developing false memories for post-event suggestions is a function of the explanatory function the suggestion serves. In support of this hypothesis, they provided evidence that participant-witnesses were especially likely to develop false memories for their forced fabrications when their fabrications helped to explain outcomes they had witnessed. In three experiments, we test the generality of the explanatory role hypothesis as a mechanism of eyewitness suggestibility by assessing whether this hypothesis can predict suggestibility errors in (a) situations where the post-event suggestions are provided by the experimenter (as opposed to fabricated by the participant), and (b) across a variety of memory measures and measures of recollective experience. In support of the explanatory role hypothesis, participants were more likely to subsequently freely report (E1) and recollect the suggestions as part of the witnessed event (E2, source test) when the post-event suggestion helped to provide a causal explanation for a witnessed outcome than when it did not serve this explanatory role. Participants were also less likely to recollect the suggestions as part of the witnessed event (on measures of subjective experience) when their explanatory strength had been reduced by the presence of an alternative explanation that could explain the same outcome (E3, source test + warning). Collectively, the results provide strong evidence that the search for explanatory coherence influences people's tendency to misremember witnessing events that were only suggested to them.

Visual perception and imagery: a new molecular hypothesis.

PubMed

Bókkon, I

2009-05-01

Here, we put forward a redox molecular hypothesis about the natural biophysical substrate of visual perception and visual imagery. This hypothesis is based on the redox and bioluminescent processes of neuronal cells in retinotopically organized cytochrome oxidase-rich visual areas. Our hypothesis is in line with the functional roles of reactive oxygen and nitrogen species in living cells that are not part of haphazard process, but rather a very strict mechanism used in signaling pathways. We point out that there is a direct relationship between neuronal activity and the biophoton emission process in the brain. Electrical and biochemical processes in the brain represent sensory information from the external world. During encoding or retrieval of information, electrical signals of neurons can be converted into synchronized biophoton signals by bioluminescent radical and non-radical processes. Therefore, information in the brain appears not only as an electrical (chemical) signal but also as a regulated biophoton (weak optical) signal inside neurons. During visual perception, the topological distribution of photon stimuli on the retina is represented by electrical neuronal activity in retinotopically organized visual areas. These retinotopic electrical signals in visual neurons can be converted into synchronized biophoton signals by radical and non-radical processes in retinotopically organized mitochondria-rich areas. As a result, regulated bioluminescent biophotons can create intrinsic pictures (depictive representation) in retinotopically organized cytochrome oxidase-rich visual areas during visual imagery and visual perception. The long-term visual memory is interpreted as epigenetic information regulated by free radicals and redox processes. This hypothesis does not claim to solve the secret of consciousness, but proposes that the evolution of higher levels of complexity made the intrinsic picture representation of the external visual world possible by regulated

Some consequences of using the Horsfall-Barratt scale for hypothesis testing

USDA-ARS?s Scientific Manuscript database

Comparing treatment effects by hypothesis testing is a common practice in plant pathology. Nearest percent estimates (NPEs) of disease severity were compared to Horsfall-Barratt (H-B) scale data to explore whether there was an effect of assessment method on hypothesis testing. A simulation model ba...

Classroom-Based Strategies to Incorporate Hypothesis Testing in Functional Behavior Assessments

ERIC Educational Resources Information Center

Lloyd, Blair P.; Weaver, Emily S.; Staubitz, Johanna L.

2017-01-01

When results of descriptive functional behavior assessments are unclear, hypothesis testing can help school teams understand how the classroom environment affects a student's challenging behavior. This article describes two hypothesis testing strategies that can be used in classroom settings: structural analysis and functional analysis. For each…

Psychomotor Ability and Short-term Memory, and Reading and Mathematics Achievement in Children.

PubMed

Murrihy, Cherée; Bailey, Maria; Roodenburg, John

2017-08-01

The aim of our study was to examine whether the findings from previous research, indicating the role of short-term memory as a mediator of the relationship between motor coordination and academic achievement in adolescents, is also evident in a younger child population. The study utilized a quantative cross-sectional design involving 133 children aged 8-12. The McCarron Assessment of Neuromuscular Development (MAND) provided four indicators of psychomotor ability (Finger Nose, Walking, Balancing, and Jumping). The Woodcock-Johnson Cognitive battery and the Automated Working Memory Assessment (AWMA) provided two measures of short-term memory (Numbers Reversed and Digit Recall) and the WJIII Achievement battery provided two measures of reading achievement (Letter-word Identification and Passage Comprehension) and two measures of mathematics achievement (Applied Problems and Calculation). Structural equation modeling was used, controlling for age, processing speed, crystallized, and fluid intelligence where appropriate. The results found support for the hypothesis that short-term memory fully mediates the relationship between psychomotor ability and reading and mathematics achievement. These findings indicate the significant affect of psychomotor ability on learning outcomes and consequently the need to assess these in considering learning difficulties, and as such these findings also advance understanding of developmental neural mechanisms underpinning the relationships. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Specific Abilities May Increment Psychometric g for High Ability Populations

DTIC Science & Technology

2016-04-14

tend to sort themselves into jobs that are commensurate with their ability level ( McCormick , DeNisi, & Staw, 1979; McCormick , Jeanneret, & Mecham...of Genetic Psychology, 153, 229-230. Specific abilities, g, & high ability populations 14 McCormick , E. J., DeNisi, A. S., & Shaw, J. B... McCormick , E. J., Jeanneret, P. R., & Mecham, R. C. (1972). A study of job characteristics and job dimensions as based on the Position Analysis Questionnaire

Considerations for multiple hypothesis correlation on tactical platforms

NASA Astrophysics Data System (ADS)

Thomas, Alan M.; Turpen, James E.

2013-05-01

Tactical platforms benefit greatly from the fusion of tracks from multiple sources in terms of increased situation awareness. As a necessary precursor to this track fusion, track-to-track association, or correlation, must first be performed. The related measurement-to-track fusion problem has been well studied with multiple hypothesis tracking and multiple frame assignment methods showing the most success. The track-to-track problem differs from this one in that measurements themselves are not available but rather track state update reports from the measuring sensors. Multiple hypothesis, multiple frame correlation systems have previously been considered; however, their practical implementation under the constraints imposed by tactical platforms is daunting. The situation is further exacerbated by the inconvenient nature of reports from legacy sensor systems on bandwidth- limited communications networks. In this paper, consideration is given to the special difficulties encountered when attempting the correlation of tracks from legacy sensors on tactical aircraft. Those difficulties include the following: covariance information from reporting sensors is frequently absent or incomplete; system latencies can create temporal uncertainty in data; and computational processing is severely limited by hardware and architecture. Moreover, consideration is given to practical solutions for dealing with these problems in a multiple hypothesis correlator.

Semantically enabled and statistically supported biological hypothesis testing with tissue microarray databases

PubMed Central

2011-01-01

Background Although many biological databases are applying semantic web technologies, meaningful biological hypothesis testing cannot be easily achieved. Database-driven high throughput genomic hypothesis testing requires both of the capabilities of obtaining semantically relevant experimental data and of performing relevant statistical testing for the retrieved data. Tissue Microarray (TMA) data are semantically rich and contains many biologically important hypotheses waiting for high throughput conclusions. Methods An application-specific ontology was developed for managing TMA and DNA microarray databases by semantic web technologies. Data were represented as Resource Description Framework (RDF) according to the framework of the ontology. Applications for hypothesis testing (Xperanto-RDF) for TMA data were designed and implemented by (1) formulating the syntactic and semantic structures of the hypotheses derived from TMA experiments, (2) formulating SPARQLs to reflect the semantic structures of the hypotheses, and (3) performing statistical test with the result sets returned by the SPARQLs. Results When a user designs a hypothesis in Xperanto-RDF and submits it, the hypothesis can be tested against TMA experimental data stored in Xperanto-RDF. When we evaluated four previously validated hypotheses as an illustration, all the hypotheses were supported by Xperanto-RDF. Conclusions We demonstrated the utility of high throughput biological hypothesis testing. We believe that preliminary investigation before performing highly controlled experiment can be benefited. PMID:21342584

The Effectiveness of the Comprehension Hypothesis: A Review on the Current Research on Incidental Vocabulary Acquisition

ERIC Educational Resources Information Center

Ponniah, Joseph

2011-01-01

The Comprehension Hypothesis (CH) is the most powerful hypothesis in the field of Second Language Acquisition despite the presence of the rivals the skill-building hypothesis, the output hypothesis, and the interaction hypothesis. The competing hypotheses state that consciously learned linguistic knowledge is a necessary step for the development…

The limits to pride: A test of the pro-anorexia hypothesis.

PubMed

Cornelius, Talea; Blanton, Hart

2016-01-01

Many social psychological models propose that positive self-conceptions promote self-esteem. An extreme version of this hypothesis is advanced in "pro-anorexia" communities: identifying with anorexia, in conjunction with disordered eating, can lead to higher self-esteem. The current study empirically tested this hypothesis. Results challenge the pro-anorexia hypothesis. Although those with higher levels of pro-anorexia identification trended towards higher self-esteem with increased disordered eating, this did not overcome the strong negative main effect of pro-anorexia identification. These data suggest a more effective strategy for promoting self-esteem is to encourage rejection of disordered eating and an anorexic identity.

The Empathizing-Systemizing Theory, Social Abilities, and Mathematical Achievement in Children

PubMed Central

Escovar, Emily; Rosenberg-Lee, Miriam; Uddin, Lucina Q.; Menon, Vinod

2016-01-01

The Empathizing-Systemizing (E-S) theory describes a profile of traits that have been linked to autism spectrum disorders, and are thought to encompass a continuum that includes typically developing (TD) individuals. Although systemizing is hypothesized to be related to mathematical abilities, empirical support for this relationship is lacking. We examine the link between empathizing and systemizing tendencies and mathematical achievement in 112 TD children (57 girls) to elucidate how socio-cognitive constructs influence early development of mathematical skills. Assessment of mathematical achievement included standardized tests designed to examine calculation skills and conceptual mathematical reasoning. Empathizing and systemizing were assessed using the Combined Empathy Quotient-Child (EQ-C) and Systemizing Quotient-Child (SQ-C). Contrary to our hypothesis, we found that mathematical achievement was not related to systemizing or the discrepancy between systemizing and empathizing. Surprisingly, children with higher empathy demonstrated lower calculation skills. Further analysis using the Social Responsiveness Scale (SRS) revealed that the relationship between EQ-C and mathematical achievement was mediated by social ability rather than autistic behaviors. Finally, social awareness was found to play a differential role in mediating the relationship between EQ-C and mathematical achievement in girls. These results identify empathy, and social skills more generally, as previously unknown predictors of mathematical achievement. PMID:26972835

The Empathizing-Systemizing Theory, Social Abilities, and Mathematical Achievement in Children.

PubMed

Escovar, Emily; Rosenberg-Lee, Miriam; Uddin, Lucina Q; Menon, Vinod

2016-03-14

The Empathizing-Systemizing (E-S) theory describes a profile of traits that have been linked to autism spectrum disorders, and are thought to encompass a continuum that includes typically developing (TD) individuals. Although systemizing is hypothesized to be related to mathematical abilities, empirical support for this relationship is lacking. We examine the link between empathizing and systemizing tendencies and mathematical achievement in 112 TD children (57 girls) to elucidate how socio-cognitive constructs influence early development of mathematical skills. Assessment of mathematical achievement included standardized tests designed to examine calculation skills and conceptual mathematical reasoning. Empathizing and systemizing were assessed using the Combined Empathy Quotient-Child (EQ-C) and Systemizing Quotient-Child (SQ-C). Contrary to our hypothesis, we found that mathematical achievement was not related to systemizing or the discrepancy between systemizing and empathizing. Surprisingly, children with higher empathy demonstrated lower calculation skills. Further analysis using the Social Responsiveness Scale (SRS) revealed that the relationship between EQ-C and mathematical achievement was mediated by social ability rather than autistic behaviors. Finally, social awareness was found to play a differential role in mediating the relationship between EQ-C and mathematical achievement in girls. These results identify empathy, and social skills more generally, as previously unknown predictors of mathematical achievement.

Testing hypotheses and the advancement of science: recent attempts to falsify the equilibrium point hypothesis.

PubMed

Feldman, Anatol G; Latash, Mark L

2005-02-01

Criticisms of the equilibrium point (EP) hypothesis have recently appeared that are based on misunderstandings of some of its central notions. Starting from such interpretations of the hypothesis, incorrect predictions are made and tested. When the incorrect predictions prove false, the hypothesis is claimed to be falsified. In particular, the hypothesis has been rejected based on the wrong assumptions that it conflicts with empirically defined joint stiffness values or that it is incompatible with violations of equifinality under certain velocity-dependent perturbations. Typically, such attempts use notions describing the control of movements of artificial systems in place of physiologically relevant ones. While appreciating constructive criticisms of the EP hypothesis, we feel that incorrect interpretations have to be clarified by reiterating what the EP hypothesis does and does not predict. We conclude that the recent claims of falsifying the EP hypothesis and the calls for its replacement by EMG-force control hypothesis are unsubstantiated. The EP hypothesis goes far beyond the EMG-force control view. In particular, the former offers a resolution for the famous posture-movement paradox while the latter fails to resolve it.

Testing the neurovascular hypothesis of Alzheimer's disease: LRP-1 antisense reduces blood-brain barrier clearance, increases brain levels of amyloid-beta protein, and impairs cognition.

PubMed

Jaeger, Laura B; Dohgu, Shinya; Hwang, Mark C; Farr, Susan A; Murphy, M Paul; Fleegal-DeMotta, Melissa A; Lynch, Jessica L; Robinson, Sandra M; Niehoff, Michael L; Johnson, Steven N; Kumar, Vijaya B; Banks, William A

2009-01-01

Decreased clearance is the main reason amyloid-beta protein (Abeta) is increased in the brains of patients with Alzheimer's disease (AD). The neurovascular hypothesis states that this decreased clearance is caused by impairment of low density lipoprotein receptor related protein-1 (LRP-1), the major brain-to-blood transporter of Abeta at the blood-brain barrier (BBB). As deletion of the LRP-1 gene is a lethal mutation, we tested the neurovascular hypothesis by developing a cocktail of phosphorothioate antisenses directed against LRP-1 mRNA. We found these antisenses in comparison to random antisense selectively decreased LRP-1 expression, reduced BBB clearance of Abeta42, increased brain levels of Abeta42, and impaired learning ability and recognition memory in mice. These results support dysfunction of LRP-1 at the BBB as a mechanism by which brain levels of Abeta could increase and AD would be promoted.

The role of female search behaviour in determining host plant range in plant feeding insects: a test of the information processing hypothesis

PubMed Central

Janz, N.; Nylin, S.

1997-01-01

Recent theoretical studies have suggested that host range in herbivorous insects may be more restricted by constraints on information processing on the ovipositing females than by trade-offs in larval feeding efficiency. We have investigated if females from polyphagous species have to pay for their ability to localize and evaluate plants from different species with a lower ability to discriminate between conspecific host plants with differences in quality. Females of the monophagous butterflies Polygonia satyrus, Vanessa indica and Inachis io and the polyphagous P. c-album and Cynthia cardui (all in Lepidoptera, Nymphalidae) were given a simultaneous choice of stinging nettles (Urtica dioica) of different quality. In addition, the same choice trial was given to females from two populations of P. c-album with different degrees of specificity. As predicted from the information processing hypothesis, all specialists discriminated significantly against the bad quality nettle, whereas the generalists laid an equal amount of eggs on both types of nettle. There were no corresponding differences between specialist and generalist larvae in their ability to utilize poor quality leaves. Our study therefore suggests that female host-searching behaviour plays an important role in determining host plant range.

The Role of Female Search Behaviour in Determining Host Plant Range in Plant Feeding Insects: A Test of the Information Processing Hypothesis

NASA Astrophysics Data System (ADS)

Janz, Niklas; Nylin, Soren

1997-05-01

Recent theoretical studies have suggested that host range in herbivorous insects may be more restricted by constraints on information processing on the ovipositing females than by trade-offs in larval feeding efficiency. We have investigated if females from polyphagous species have to pay for their ability to localize and evaluate plants from different species with a lower ability to discriminate between conspecific host plants with differences in quality. Females of the monophagous butterflies Polygonia satyrus, Vanessa indica and Inachis io and the polyphagous P. c-album and Cynthia cardui (all in Lepidoptera, Nymphalidae) were given a simultaneous choice of stinging nettles (Urtica dioica) of different quality. In addition, the same choice trial was given to females from two populations of P. c-album with different degrees of specificity. As predicted from the information processing hypothesis, all specialists discriminated significantly against the bad quality nettle, whereas the generalists laid an equal amount of eggs on both types of nettle. There were no corresponding differences between specialist and generalist larvae in their ability to utilize poor quality leaves. Our study therefore suggests that female host-searching behaviour plays an important role in determining host plant range.

Human adaptations for the visual assessment of strength and fighting ability from the body and face

PubMed Central

Sell, Aaron; Cosmides, Leda; Tooby, John; Sznycer, Daniel; von Rueden, Christopher; Gurven, Michael

2008-01-01

Selection in species with aggressive social interactions favours the evolution of cognitive mechanisms for assessing physical formidability (fighting ability or resource-holding potential). The ability to accurately assess formidability in conspecifics has been documented in a number of non-human species, but has not been demonstrated in humans. Here, we report tests supporting the hypothesis that the human cognitive architecture includes mechanisms that assess fighting ability—mechanisms that focus on correlates of upper-body strength. Across diverse samples of targets that included US college students, Bolivian horticulturalists and Andean pastoralists, subjects in the US were able to accurately estimate the physical strength of male targets from photos of their bodies and faces. Hierarchical linear modelling shows that subjects were extracting cues of strength that were largely independent of height, weight and age, and that corresponded most strongly to objective measures of upper-body strength—even when the face was all that was available for inspection. Estimates of women's strength were less accurate, but still significant. These studies are the first empirical demonstration that, for humans, judgements of strength and judgements of fighting ability not only track each other, but accurately track actual upper-body strength. PMID:18945661

Unicorns do exist: a tutorial on "proving" the null hypothesis.

PubMed

Streiner, David L

2003-12-01

Introductory statistics classes teach us that we can never prove the null hypothesis; all we can do is reject or fail to reject it. However, there are times when it is necessary to try to prove the nonexistence of a difference between groups. This most often happens within the context of comparing a new treatment against an established one and showing that the new intervention is not inferior to the standard. This article first outlines the logic of "noninferiority" testing by differentiating between the null hypothesis (that which we are trying to nullify) and the "nill" hypothesis (there is no difference), reversing the role of the null and alternate hypotheses, and defining an interval within which groups are said to be equivalent. We then work through an example and show how to calculate sample sizes for noninferiority studies.

The Target Income Hypothesis and Related Issues in Health Manpower Policy.

ERIC Educational Resources Information Center

Health Resources Administration (DHEW/PHS), Bethesda, MD. Bureau of Health Manpower.

The target income hypothesis as applied to health personnel is discussed in seven papers and three commentaries. The hypothesis pertains to the economic behavior of physicians, and it has recently been applied to dentists as well. The issues concern the production/supply of practitioners and the resulting cost for their services. Whether…

The Focusing of Responsibility: An Alternative Hypothesis in Help-Demanding Situations.

ERIC Educational Resources Information Center

Misavage, Robert; Richardson, James T.

The "diffusion of responsibility" hypothesis as an explanation of helping behavior (or lack of same) is qualified by suggesting that the hypothesis applies only in non-interacting situations. It is hypothesized that interacting groups who are aware of a help-demanding situation actually focus the responsibility and, therefore, take action as a…

Effect of Mixing Ability Groups on Ability Levels Attained.

ERIC Educational Resources Information Center

de Jong, John H. A. L.

In 1983, in the Netherlands' highly differentiated school system, two types of curriculum representing different ability levels were combined as a first step towards a more heterogeneous grouping of student abilities. A study of one aspect of the results of this change compared over 1000 samples of English and German second language listening…

Electromagnetic structure of the proton within the CP-violation hypothesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krutov, A. F., E-mail: krutov@ssu.samara.ru; Kudinov, M. Yu., E-mail: kudinov@ssu.samara.ru

2013-11-15

The so-called non-Rosenbluth behavior of the proton electromagnetic form factors can be explained within the hypothesis of CP violation in electromagnetic processes involving composite systems of strongly interacting particles. It is shown that this hypothesis leads to the appearance of an additional, anapole, form factor of the proton. The proton electromagnetic form factors, including the anapole form factor, are estimated on the basis of experimental data on elastic electron-proton scattering.

Applicability of Taylor's hypothesis in thermally driven turbulence

PubMed Central

Verma, Mahendra K.

2018-01-01

In this paper, we show that, in the presence of large-scale circulation (LSC), Taylor’s hypothesis can be invoked to deduce the energy spectrum in thermal convection using real-space probes, a popular experimental tool. We perform numerical simulation of turbulent convection in a cube and observe that the velocity field follows Kolmogorov’s spectrum (k−5/3). We also record the velocity time series using real-space probes near the lateral walls. The corresponding frequency spectrum exhibits Kolmogorov’s spectrum (f−5/3), thus validating Taylor’s hypothesis with the steady LSC playing the role of a mean velocity field. The aforementioned findings based on real-space probes provide valuable inputs for experimental measurements used for studying the spectrum of convective turbulence. PMID:29765668

Applicability of Taylor's hypothesis in thermally driven turbulence

NASA Astrophysics Data System (ADS)

Kumar, Abhishek; Verma, Mahendra K.

2018-04-01

In this paper, we show that, in the presence of large-scale circulation (LSC), Taylor's hypothesis can be invoked to deduce the energy spectrum in thermal convection using real-space probes, a popular experimental tool. We perform numerical simulation of turbulent convection in a cube and observe that the velocity field follows Kolmogorov's spectrum (k-5/3). We also record the velocity time series using real-space probes near the lateral walls. The corresponding frequency spectrum exhibits Kolmogorov's spectrum (f-5/3), thus validating Taylor's hypothesis with the steady LSC playing the role of a mean velocity field. The aforementioned findings based on real-space probes provide valuable inputs for experimental measurements used for studying the spectrum of convective turbulence.

Art as an indicator of male fitness: does prenatal testosterone influence artistic ability?

PubMed

Crocchiola, Danae

2014-05-28

In his groundbreaking research, Geoffrey Miller (1999) suggests that artistic and creative displays are male-predominant behaviors and can be considered to be the result of an evolutionary advantage. The outcomes of several surveys conducted on jazz and rock musicians, contemporary painters, English writers (Miller, 1999), and scientists (Kanazawa, 2000) seem to be consistent with the Millerian hypothesis, showing a predominance of men carrying out these activities, with an output peak corresponding to the most fertile male period and a progressive decline in late maturity. One way to evaluate the sex-related hypothesis of artistic and cultural displays, considered as sexual indicators of male fitness, is to focus on sexually dimorphic traits. One of them, within our species, is the 2nd to 4th digit length (2D:4D), which is a marker for prenatal testosterone levels. This study combines the Millerian theories on sexual dimorphism in cultural displays with the digit ratio, using it as an indicator of androgen exposure in utero. If androgenic levels are positively correlated with artistic exhibition, both female and male artists should show low 2D:4D ratios. In this experiment we tested the association between 2D:4D and artistic ability by comparing the digit ratios of 50 artists (25 men and 25 women) to the digit ratios of 50 non-artists (25 men and 25 women). Both male and female artists had significantly lower 2D:4D ratios (indicating high testosterone) than male and female controls. These results support the hypothesis that art may represent a sexually selected, typically masculine behavior that advertises the carrier's good genes within a courtship context.

Role of parietal regions in episodic memory retrieval: the dual attentional processes hypothesis.

PubMed

Cabeza, Roberto

2008-01-01

Although parietal cortex is frequently activated during episodic memory retrieval, damage to this region does not markedly impair episodic memory. To account for these and other findings, a new dual attentional processes (DAP) hypothesis is proposed. According to this hypothesis, dorsal parietal cortex (DPC) contributes top-down attentional processes guided by retrieval goals, whereas ventral parietal cortex (VPC) contributes bottom-up attentional processes captured by the retrieval output. Consistent with this hypothesis, DPC activity increases with retrieval effort whereas VPC activity increases with confidence in old and new responses. The DAP hypothesis can also account for the overlap of parietal activations across different cognitive domains and for opposing effects of parietal activity on encoding vs. retrieval. Finally, the DAP hypothesis explains why VPC lesions yield a memory neglect syndrome: a deficit in spontaneously reporting relevant memory details but not in accessing the same details when guided by specific questions.

Hypothesis-driven physical examination curriculum.

PubMed

Allen, Sharon; Olson, Andrew; Menk, Jeremiah; Nixon, James

2017-12-01

Medical students traditionally learn physical examination skills as a rote list of manoeuvres. Alternatives like hypothesis-driven physical examination (HDPE) may promote students' understanding of the contribution of physical examination to diagnostic reasoning. We sought to determine whether first-year medical students can effectively learn to perform a physical examination using an HDPE approach, and then tailor the examination to specific clinical scenarios. Medical students traditionally learn physical examination skills as a rote list of manoeuvres CONTEXT: First-year medical students at the University of Minnesota were taught both traditional and HDPE approaches during a required 17-week clinical skills course in their first semester. The end-of-course evaluation assessed HDPE skills: students were assigned one of two cardiopulmonary cases. Each case included two diagnostic hypotheses. During an interaction with a standardised patient, students were asked to select physical examination manoeuvres in order to make a final diagnosis. Items were weighted and selection order was recorded. First-year students with minimal pathophysiology performed well. All students selected the correct diagnosis. Importantly, students varied the order when selecting examination manoeuvres depending on the diagnoses under consideration, demonstrating early clinical decision-making skills. An early introduction to HDPE may reinforce physical examination skills for hypothesis generation and testing, and can foster early clinical decision-making skills. This has important implications for further research in physical examination instruction. © 2016 John Wiley & Sons Ltd and The Association for the Study of Medical Education.

The hydraulic limitation hypothesis revisited.

PubMed

Ryan, Michael G; Phillips, Nathan; Bond, Barbara J

2006-03-01

We proposed the hydraulic limitation hypothesis (HLH) as a mechanism to explain universal patterns in tree height, and tree and stand biomass growth: height growth slows down as trees grow taller, maximum height is lower for trees of the same species on resource-poor sites and annual wood production declines after canopy closure for even-aged forests. Our review of 51 studies that measured one or more of the components necessary for testing the hypothesis showed that taller trees differ physiologically from shorter, younger trees. Stomatal conductance to water vapour (g(s)), photosynthesis (A) and leaf-specific hydraulic conductance (K L) are often, but not always, lower in taller trees. Additionally, leaf mass per area is often greater in taller trees, and leaf area:sapwood area ratio changes with tree height. We conclude that hydraulic limitation of gas exchange with increasing tree size is common, but not universal. Where hydraulic limitations to A do occur, no evidence supports the original expectation that hydraulic limitation of carbon assimilation is sufficient to explain observed declines in wood production. Any limit to height or height growth does not appear to be related to the so-called age-related decline in wood production of forests after canopy closure. Future work on this problem should explicitly link leaf or canopy gas exchange with tree and stand growth, and consider a more fundamental assumption: whether tree biomass growth is limited by carbon availability.

Covert Auditory Spatial Orienting: An Evaluation of the Spatial Relevance Hypothesis

ERIC Educational Resources Information Center

Roberts, Katherine L.; Summerfield, A. Quentin; Hall, Deborah A.

2009-01-01

The spatial relevance hypothesis (J. J. McDonald & L. M. Ward, 1999) proposes that covert auditory spatial orienting can only be beneficial to auditory processing when task stimuli are encoded spatially. We present a series of experiments that evaluate 2 key aspects of the hypothesis: (a) that "reflexive activation of location-sensitive neurons is…

The mitonuclear compatibility hypothesis of sexual selection

PubMed Central

Hill, Geoffrey E.; Johnson, James D.

2013-01-01

Why females assess ornaments when choosing mates remains a central question in evolutionary biology. We hypothesize that the imperative for a choosing female to find a mate with nuclear oxidative phosphorylation (OXPHOS) genes that are compatible with her mitochondrial OXPHOS genes drives the evolution of ornaments. Indicator traits are proposed to signal the efficiency of OXPHOS function thus enabling females to select mates with nuclear genes that are compatible with maternal mitochondrial genes in the formation of OXPHOS complexes. Species-typical pattern of ornamentation is proposed to serve as a marker of mitochondrial type ensuring that females assess prospective mates with a shared mitochondrial background. The mitonuclear compatibility hypothesis predicts that the production of ornaments will be closely linked to OXPHOS pathways, and that sexual selection for compatible mates will be strongest when genes for nuclear components of OXPHOS complexes are Z-linked. The implications of this hypothesis are that sexual selection may serve as a driver for the evolution of more efficient cellular respiration. PMID:23945683

A default Bayesian hypothesis test for mediation.

PubMed

Nuijten, Michèle B; Wetzels, Ruud; Matzke, Dora; Dolan, Conor V; Wagenmakers, Eric-Jan

2015-03-01

In order to quantify the relationship between multiple variables, researchers often carry out a mediation analysis. In such an analysis, a mediator (e.g., knowledge of a healthy diet) transmits the effect from an independent variable (e.g., classroom instruction on a healthy diet) to a dependent variable (e.g., consumption of fruits and vegetables). Almost all mediation analyses in psychology use frequentist estimation and hypothesis-testing techniques. A recent exception is Yuan and MacKinnon (Psychological Methods, 14, 301-322, 2009), who outlined a Bayesian parameter estimation procedure for mediation analysis. Here we complete the Bayesian alternative to frequentist mediation analysis by specifying a default Bayesian hypothesis test based on the Jeffreys-Zellner-Siow approach. We further extend this default Bayesian test by allowing a comparison to directional or one-sided alternatives, using Markov chain Monte Carlo techniques implemented in JAGS. All Bayesian tests are implemented in the R package BayesMed (Nuijten, Wetzels, Matzke, Dolan, & Wagenmakers, 2014).

Eat dirt and avoid atopy: the hygiene hypothesis revisited.

PubMed

Patki, Anil

2007-01-01

The explosive rise in the incidence of atopic diseases in the Western developed countries can be explained on the basis of the so-called "hygiene hypothesis". In short, it attributes the rising incidence of atopic dermatitis to reduced exposure to various childhood infections and bacterial endotoxins. Reduced exposure to dirt in the clean environment results in a skewed development of the immune system which results in an abnormal allergic response to various environmental allergens which are otherwise innocuous. This article reviews the historical aspects, epidemiological and immunological basis of the hygiene hypothesis and implications for Indian conditions.

Thermalization without eigenstate thermalization hypothesis after a quantum quench.

PubMed

Mori, Takashi; Shiraishi, Naoto

2017-08-01

Nonequilibrium dynamics of a nonintegrable system without the eigenstate thermalization hypothesis is studied. It is shown that, in the thermodynamic limit, this model thermalizes after an arbitrary quantum quench at finite temperature, although it does not satisfy the eigenstate thermalization hypothesis. In contrast, when the system size is finite and the temperature is low enough, the system may not thermalize. In this case, the steady state is well described by the generalized Gibbs ensemble constructed by using highly nonlocal conserved quantities. We also show that this model exhibits prethermalization, in which the prethermalized state is characterized by nonthermal energy eigenstates.

Exploring students’ perceived and actual ability in solving statistical problems based on Rasch measurement tools

NASA Astrophysics Data System (ADS)

Azila Che Musa, Nor; Mahmud, Zamalia; Baharun, Norhayati

2017-09-01

One of the important skills that is required from any student who are learning statistics is knowing how to solve statistical problems correctly using appropriate statistical methods. This will enable them to arrive at a conclusion and make a significant contribution and decision for the society. In this study, a group of 22 students majoring in statistics at UiTM Shah Alam were given problems relating to topics on testing of hypothesis which require them to solve the problems using confidence interval, traditional and p-value approach. Hypothesis testing is one of the techniques used in solving real problems and it is listed as one of the difficult concepts for students to grasp. The objectives of this study is to explore students’ perceived and actual ability in solving statistical problems and to determine which item in statistical problem solving that students find difficult to grasp. Students’ perceived and actual ability were measured based on the instruments developed from the respective topics. Rasch measurement tools such as Wright map and item measures for fit statistics were used to accomplish the objectives. Data were collected and analysed using Winsteps 3.90 software which is developed based on the Rasch measurement model. The results showed that students’ perceived themselves as moderately competent in solving the statistical problems using confidence interval and p-value approach even though their actual performance showed otherwise. Item measures for fit statistics also showed that the maximum estimated measures were found on two problems. These measures indicate that none of the students have attempted these problems correctly due to reasons which include their lack of understanding in confidence interval and probability values.

Humans have evolved specialized skills of social cognition: the cultural intelligence hypothesis.

PubMed

Herrmann, Esther; Call, Josep; Hernàndez-Lloreda, Maráa Victoria; Hare, Brian; Tomasello, Michael

2007-09-07

Humans have many cognitive skills not possessed by their nearest primate relatives. The cultural intelligence hypothesis argues that this is mainly due to a species-specific set of social-cognitive skills, emerging early in ontogeny, for participating and exchanging knowledge in cultural groups. We tested this hypothesis by giving a comprehensive battery of cognitive tests to large numbers of two of humans' closest primate relatives, chimpanzees and orangutans, as well as to 2.5-year-old human children before literacy and schooling. Supporting the cultural intelligence hypothesis and contradicting the hypothesis that humans simply have more "general intelligence," we found that the children and chimpanzees had very similar cognitive skills for dealing with the physical world but that the children had more sophisticated cognitive skills than either of the ape species for dealing with the social world.

Higher Language Ability is Related to Angular Gyrus Activation Increase During Semantic Processing, Independent of Sentence Incongruency.

PubMed

Van Ettinger-Veenstra, Helene; McAllister, Anita; Lundberg, Peter; Karlsson, Thomas; Engström, Maria

2016-01-01

This study investigates the relation between individual language ability and neural semantic processing abilities. Our aim was to explore whether high-level language ability would correlate to decreased activation in language-specific regions or rather increased activation in supporting language regions during processing of sentences. Moreover, we were interested if observed neural activation patterns are modulated by semantic incongruency similarly to previously observed changes upon syntactic congruency modulation. We investigated 27 healthy adults with a sentence reading task-which tapped language comprehension and inference, and modulated sentence congruency-employing functional magnetic resonance imaging (fMRI). We assessed the relation between neural activation, congruency modulation, and test performance on a high-level language ability assessment with multiple regression analysis. Our results showed increased activation in the left-hemispheric angular gyrus extending to the temporal lobe related to high language ability. This effect was independent of semantic congruency, and no significant relation between language ability and incongruency modulation was observed. Furthermore, there was a significant increase of activation in the inferior frontal gyrus (IFG) bilaterally when the sentences were incongruent, indicating that processing incongruent sentences was more demanding than processing congruent sentences and required increased activation in language regions. The correlation of high-level language ability with increased rather than decreased activation in the left angular gyrus, a region specific for language processing, is opposed to what the neural efficiency hypothesis would predict. We can conclude that no evidence is found for an interaction between semantic congruency related brain activation and high-level language performance, even though the semantic incongruent condition shows to be more demanding and evoking more neural activation.

Higher Language Ability is Related to Angular Gyrus Activation Increase During Semantic Processing, Independent of Sentence Incongruency

PubMed Central

Van Ettinger-Veenstra, Helene; McAllister, Anita; Lundberg, Peter; Karlsson, Thomas; Engström, Maria

2016-01-01

This study investigates the relation between individual language ability and neural semantic processing abilities. Our aim was to explore whether high-level language ability would correlate to decreased activation in language-specific regions or rather increased activation in supporting language regions during processing of sentences. Moreover, we were interested if observed neural activation patterns are modulated by semantic incongruency similarly to previously observed changes upon syntactic congruency modulation. We investigated 27 healthy adults with a sentence reading task—which tapped language comprehension and inference, and modulated sentence congruency—employing functional magnetic resonance imaging (fMRI). We assessed the relation between neural activation, congruency modulation, and test performance on a high-level language ability assessment with multiple regression analysis. Our results showed increased activation in the left-hemispheric angular gyrus extending to the temporal lobe related to high language ability. This effect was independent of semantic congruency, and no significant relation between language ability and incongruency modulation was observed. Furthermore, there was a significant increase of activation in the inferior frontal gyrus (IFG) bilaterally when the sentences were incongruent, indicating that processing incongruent sentences was more demanding than processing congruent sentences and required increased activation in language regions. The correlation of high-level language ability with increased rather than decreased activation in the left angular gyrus, a region specific for language processing, is opposed to what the neural efficiency hypothesis would predict. We can conclude that no evidence is found for an interaction between semantic congruency related brain activation and high-level language performance, even though the semantic incongruent condition shows to be more demanding and evoking more neural activation. PMID

Testing the cultural group selection hypothesis in Northern Ghana and Oaxaca.

PubMed

Acedo-Carmona, Cristina; Gomila, Antoni

2016-01-01

We examine the cultural group selection (CGS) hypothesis in light of our fieldwork in Northern Ghana and Oaxaca, highly multi-ethnic regions. Our evidence fails to corroborate two central predictions of the hypothesis: that the cultural group is the unit of evolution, and that cultural homogenization is to be expected as the outcome of a selective process.

The public goods hypothesis for the evolution of life on Earth

PubMed Central

2011-01-01

It is becoming increasingly difficult to reconcile the observed extent of horizontal gene transfers with the central metaphor of a great tree uniting all evolving entities on the planet. In this manuscript we describe the Public Goods Hypothesis and show that it is appropriate in order to describe biological evolution on the planet. According to this hypothesis, nucleotide sequences (genes, promoters, exons, etc.) are simply seen as goods, passed from organism to organism through both vertical and horizontal transfer. Public goods sequences are defined by having the properties of being largely non-excludable (no organism can be effectively prevented from accessing these sequences) and non-rival (while such a sequence is being used by one organism it is also available for use by another organism). The universal nature of genetic systems ensures that such non-excludable sequences exist and non-excludability explains why we see a myriad of genes in different combinations in sequenced genomes. There are three features of the public goods hypothesis. Firstly, segments of DNA are seen as public goods, available for all organisms to integrate into their genomes. Secondly, we expect the evolution of mechanisms for DNA sharing and of defense mechanisms against DNA intrusion in genomes. Thirdly, we expect that we do not see a global tree-like pattern. Instead, we expect local tree-like patterns to emerge from the combination of a commonage of genes and vertical inheritance of genomes by cell division. Indeed, while genes are theoretically public goods, in reality, some genes are excludable, particularly, though not only, when they have variant genetic codes or behave as coalition or club goods, available for all organisms of a coalition to integrate into their genomes, and non-rival within the club. We view the Tree of Life hypothesis as a regionalized instance of the Public Goods hypothesis, just like classical mechanics and euclidean geometry are seen as regionalized

The Public Goods Hypothesis for the evolution of life on Earth.

PubMed

McInerney, James O; Pisani, Davide; Bapteste, Eric; O'Connell, Mary J

2011-08-23

It is becoming increasingly difficult to reconcile the observed extent of horizontal gene transfers with the central metaphor of a great tree uniting all evolving entities on the planet. In this manuscript we describe the Public Goods Hypothesis and show that it is appropriate in order to describe biological evolution on the planet. According to this hypothesis, nucleotide sequences (genes, promoters, exons, etc.) are simply seen as goods, passed from organism to organism through both vertical and horizontal transfer. Public goods sequences are defined by having the properties of being largely non-excludable (no organism can be effectively prevented from accessing these sequences) and non-rival (while such a sequence is being used by one organism it is also available for use by another organism). The universal nature of genetic systems ensures that such non-excludable sequences exist and non-excludability explains why we see a myriad of genes in different combinations in sequenced genomes. There are three features of the public goods hypothesis. Firstly, segments of DNA are seen as public goods, available for all organisms to integrate into their genomes. Secondly, we expect the evolution of mechanisms for DNA sharing and of defense mechanisms against DNA intrusion in genomes. Thirdly, we expect that we do not see a global tree-like pattern. Instead, we expect local tree-like patterns to emerge from the combination of a commonage of genes and vertical inheritance of genomes by cell division. Indeed, while genes are theoretically public goods, in reality, some genes are excludable, particularly, though not only, when they have variant genetic codes or behave as coalition or club goods, available for all organisms of a coalition to integrate into their genomes, and non-rival within the club. We view the Tree of Life hypothesis as a regionalized instance of the Public Goods hypothesis, just like classical mechanics and euclidean geometry are seen as regionalized

A Developmental Study of the Infrahumanization Hypothesis

ERIC Educational Resources Information Center

Martin, John; Bennett, Mark; Murray, Wayne S.

2008-01-01

Intergroup attitudes in children were examined based on Leyen's "infrahumanization hypothesis". This suggests that some uniquely human emotions, such as shame and guilt (secondary emotions), are reserved for the in-group, whilst other emotions that are not uniquely human and shared with animals, such as anger and pleasure (primary…

Category transfer in sequential causal learning: the unbroken mechanism hypothesis.

PubMed

Hagmayer, York; Meder, Björn; von Sydow, Momme; Waldmann, Michael R

2011-07-01

The goal of the present set of studies is to explore the boundary conditions of category transfer in causal learning. Previous research has shown that people are capable of inducing categories based on causal learning input, and they often transfer these categories to new causal learning tasks. However, occasionally learners abandon the learned categories and induce new ones. Whereas previously it has been argued that transfer is only observed with essentialist categories in which the hidden properties are causally relevant for the target effect in the transfer relation, we here propose an alternative explanation, the unbroken mechanism hypothesis. This hypothesis claims that categories are transferred from a previously learned causal relation to a new causal relation when learners assume a causal mechanism linking the two relations that is continuous and unbroken. The findings of two causal learning experiments support the unbroken mechanism hypothesis. Copyright © 2011 Cognitive Science Society, Inc.

Empathy and universal values explicated by the empathy-altruism hypothesis.

PubMed

Persson, Björn N; Kajonius, Petri J

2016-01-01

Research reports that empathy is on the decline in present-day society, together with an increasing trend in self-enhancing values. Based on the empathy-altruism hypothesis, we investigated whether these constructs are interlinked by analyzing the relationships between emotional and cognitive empathy and 10 universal values. In the first study, using a middle-aged U.S. sample, the results showed that empathy was strongly and positively related to altruistic values and negatively to self-enhancing values in a pattern that aligned with the empathy-altruism hypothesis. In a second confirmation study, these findings were replicated and extended, while also controlling for the Big Five personality traits, to discount that empathy is only captured by basic personality. Only emotional empathy, not cognitive empathy, accounted for up to 18% additional variance in altruistic values, which further confirmed the emphasis on feelings, as postulated by the empathy-altruism hypothesis.

The Double-Deficit Hypothesis in Spanish Developmental Dyslexia

ERIC Educational Resources Information Center

Jimenez, Juan E.; Hernandez-Valle, Isabel; Rodriguez, Cristina; Guzman, Remedios; Diaz, Alicia; Ortiz, Rosario

2008-01-01

The double-deficit hypothesis (DDH) of developmental dyslexia was investigated in seven to twelve year old Spanish children. It was observed that the double deficit (DD) group had the greatest difficulty with reading.

Hypothesis Testing as an Act of Rationality

NASA Astrophysics Data System (ADS)

Nearing, Grey

2017-04-01

Statistical hypothesis testing is ad hoc in two ways. First, setting probabilistic rejection criteria is, as Neyman (1957) put it, an act of will rather than an act of rationality. Second, physical theories like conservation laws do not inherently admit probabilistic predictions, and so we must use what are called epistemic bridge principles to connect model predictions with the actual methods of hypothesis testing. In practice, these bridge principles are likelihood functions, error functions, or performance metrics. I propose that the reason we are faced with these problems is because we have historically failed to account for a fundamental component of basic logic - namely the portion of logic that explains how epistemic states evolve in the presence of empirical data. This component of Cox' (1946) calculitic logic is called information theory (Knuth, 2005), and adding information theory our hypothetico-deductive account of science yields straightforward solutions to both of the above problems. This also yields a straightforward method for dealing with Popper's (1963) problem of verisimilitude by facilitating a quantitative approach to measuring process isomorphism. In practice, this involves data assimilation. Finally, information theory allows us to reliably bound measures of epistemic uncertainty, thereby avoiding the problem of Bayesian incoherency under misspecified priors (Grünwald, 2006). I therefore propose solutions to four of the fundamental problems inherent in both hypothetico-deductive and/or Bayesian hypothesis testing. - Neyman (1957) Inductive Behavior as a Basic Concept of Philosophy of Science. - Cox (1946) Probability, Frequency and Reasonable Expectation. - Knuth (2005) Lattice Duality: The Origin of Probability and Entropy. - Grünwald (2006). Bayesian Inconsistency under Misspecification. - Popper (1963) Conjectures and Refutations: The Growth of Scientific Knowledge.

The Variability Hypothesis: The History of a Biological Model of Sex Differences in Intelligence.

ERIC Educational Resources Information Center

Shields, Stephanie A.

1982-01-01

Describes the origin and development of the variability hypothesis as applied to the study of social and psychological sex differences. Explores changes in the hypothesis over time, social and scientific factors that fostered its acceptance, and possible parallels between the variability hypothesis and contemporary theories of sex differences.…

Does Ability to Defend Moderate the Association between Exposure to Bullying and Symptoms of Anxiety?

PubMed Central

Nielsen, Morten Birkeland; Gjerstad, Johannes; Jacobsen, Daniel Pitz; Einarsen, Ståle Valvatne

2017-01-01

In the context of workplace bullying, the ability to defend refers to whether or not a target feels able to deal with those negative behaviors that typically constitute bullying. The aim of this study was to determine whether the perceived ability to defend oneself moderates the association between exposure to bullying behaviors at work and symptoms of anxiety as predicted by the definition of workplace bullying. It was hypothesized that exposure to bullying behaviors would be more strongly related to symptoms of anxiety among targets feeling unable to defend oneself than among targets who do feel that they are able to defend themselves in the actual situation. This survey study was based on a probability sample of 1,608 Norwegian employees (response rate 32%). Only respondents exposed to at least one bullying behavior were included (N = 739). In contrast to hypothesis, the findings showed that ability to defend only had a protective effect on the relationship between exposure to bullying behaviors and anxiety in cases of low exposure. In cases of high exposure, there was a stronger increase in anxiety among employees able to defend themselves than among those who generally felt unable to defend. Hence, the ability to defend against exposure to bullying behaviors does not seem to protect high-exposed targets against symptoms of anxiety. Organization should therefore intervene against bullying in early stages rather than relying on the individual resilience of those exposed. PMID:29163321

Does Ability to Defend Moderate the Association between Exposure to Bullying and Symptoms of Anxiety?

PubMed

Nielsen, Morten Birkeland; Gjerstad, Johannes; Jacobsen, Daniel Pitz; Einarsen, Ståle Valvatne

2017-01-01

In the context of workplace bullying, the ability to defend refers to whether or not a target feels able to deal with those negative behaviors that typically constitute bullying. The aim of this study was to determine whether the perceived ability to defend oneself moderates the association between exposure to bullying behaviors at work and symptoms of anxiety as predicted by the definition of workplace bullying. It was hypothesized that exposure to bullying behaviors would be more strongly related to symptoms of anxiety among targets feeling unable to defend oneself than among targets who do feel that they are able to defend themselves in the actual situation. This survey study was based on a probability sample of 1,608 Norwegian employees (response rate 32%). Only respondents exposed to at least one bullying behavior were included ( N = 739). In contrast to hypothesis, the findings showed that ability to defend only had a protective effect on the relationship between exposure to bullying behaviors and anxiety in cases of low exposure. In cases of high exposure, there was a stronger increase in anxiety among employees able to defend themselves than among those who generally felt unable to defend. Hence, the ability to defend against exposure to bullying behaviors does not seem to protect high-exposed targets against symptoms of anxiety. Organization should therefore intervene against bullying in early stages rather than relying on the individual resilience of those exposed.

The sound symbolism bootstrapping hypothesis for language acquisition and language evolution.

PubMed

Imai, Mutsumi; Kita, Sotaro

2014-09-19

Sound symbolism is a non-arbitrary relationship between speech sounds and meaning. We review evidence that, contrary to the traditional view in linguistics, sound symbolism is an important design feature of language, which affects online processing of language, and most importantly, language acquisition. We propose the sound symbolism bootstrapping hypothesis, claiming that (i) pre-verbal infants are sensitive to sound symbolism, due to a biologically endowed ability to map and integrate multi-modal input, (ii) sound symbolism helps infants gain referential insight for speech sounds, (iii) sound symbolism helps infants and toddlers associate speech sounds with their referents to establish a lexical representation and (iv) sound symbolism helps toddlers learn words by allowing them to focus on referents embedded in a complex scene, alleviating Quine's problem. We further explore the possibility that sound symbolism is deeply related to language evolution, drawing the parallel between historical development of language across generations and ontogenetic development within individuals. Finally, we suggest that sound symbolism bootstrapping is a part of a more general phenomenon of bootstrapping by means of iconic representations, drawing on similarities and close behavioural links between sound symbolism and speech-accompanying iconic gesture. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Haploid, diploid, and triploid--discrimination ability against polyploid mating partner in the parasitic wasp, Bracon brevicornis (Hymenoptera: Braconidae).

PubMed

Thiel, Andra; Weeda, Anne C

2014-01-01

Because the quality of mating partners varies, females of several taxa have evolved the ability to discriminate against low-quality mates. Although males in the Hymenoptera are usually haploid, diploid males may occur in species with complementary sex determination. Diploid males are almost always sterile in most of the species studied so far. They are thus of very low quality as mating partners, especially when females mate only once in life. We hypothesize that hymenopteran females might have evolved the ability to discriminate against infertile diploid males and avoid mating with them. To test this hypothesis, we studied diploid male fitness in the parasitoid wasp Bracon brevicornis Wesmael (Hymenoptera: Braconidae) by measuring survival rate and fertility and then estimated their chances of actually mating with a female. Flow cytometry was used to determine the ploidy level of wasps. The fitness costs of mating a diploid male are indeed high in this species: only 15% were able to sire daughters, of which 97% were triploid and hardly able to produce viable offspring. In contrast to the hypothesis of unsuitable mate discrimination though, no evidence was found for increased rejection of diploid males by females. Male discrimination against an unsuitable partner did also not occur: triploid females elicited the same intensity of courtship behavior in males than did diploid ones. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

Testing the single-state dominance hypothesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Álvarez-Rodríguez, R.; Moreno, O.; Moya de Guerra, E.

2013-12-30

We present a theoretical analysis of the single-state dominance hypothesis for the two-neutrino double-beta decay process. The theoretical framework is a proton-neutron QRPA based on a deformed Hartree-Fock mean field with BCS pairing correlations. We focus on the decays of {sup 100}Mo, {sup 116}Cd and {sup 128}Te. We do not find clear evidences for single-state dominance within the present approach.

You have the right to understand: the deleterious effect of stress on suspects' ability to comprehend Miranda.

PubMed

Scherr, Kyle C; Madon, Stephanie

2012-08-01

Miranda v. Arizona (384 U.S. 436, 1966) required that suspects be explicitly warned of the right to avoid self-incrimination and the right to legal representation. This research was designed to examine whether stress, induced via an accusation of wrong-doing, undermined or enhanced suspects' ability to comprehend their Miranda rights. Participants were randomly assigned to either be accused (n = 15) or not accused (n = 15) of having cheated on an experimental task in a two-cell between-subjects experimental design. Results supported the hypothesis that stress undermines suspects' ability to comprehend their Miranda rights. Participants who were accused of cheating exhibited significantly lower levels of Miranda comprehension than participants who were not accused of cheating. The theoretical processes responsible for these effects and the implications of the findings for police interrogation are discussed. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

The 'aerobic/resistance/inspiratory muscle training hypothesis in heart failure'.

PubMed

Laoutaris, Ioannis D

2018-01-01

Evidence from large multicentre exercise intervention trials in heart failure patients, investigating both moderate continuous aerobic training and high intensity interval training, indicates that the 'crème de la crème' exercise programme for this population remains to be found. The 'aerobic/resistance/inspiratory (ARIS) muscle training hypothesis in heart failure' is introduced, suggesting that combined ARIS muscle training may result in maximal exercise pathophysiological and functional benefits in heart failure patients. The hypothesis is based on the decoding of the 'skeletal muscle hypothesis in heart failure' and on revision of experimental evidence to date showing that exercise and functional intolerance in heart failure patients are associated not only with reduced muscle endurance, indication for aerobic training (AT), but also with reduced muscle strength and decreased inspiratory muscle function contributing to weakness, dyspnoea, fatigue and low aerobic capacity, forming the grounds for the addition of both resistance training (RT) and inspiratory muscle training (IMT) to AT. The hypothesis will be tested by comparing all potential exercise combinations, ARIS, AT/RT, AT/IMT, AT, evaluating both functional and cardiac indices in a large sample of heart failure patients of New York Heart Association class II-III and left ventricular ejection fraction ≤35% ad hoc by the multicentre randomized clinical trial, Aerobic Resistance, InSpiratory Training OutcomeS in Heart Failure (ARISTOS-HF trial).

The qualitative similarity hypothesis.

PubMed

Paul, Peter V; Lee, Chongmin

2010-01-01

Evidence is presented for the qualitative similarity hypothesis (QSH) with respect to children and adolescents who are d/Deaf or hard of hearing. The primary focus is on the development of English language and literacy skills, and some information is provided on the acquisition of English as a second language. The QSH is briefly discussed within the purview of two groups of cognitive models: those that emphasize the cognitive development of individuals and those that pertain to disciplinary or knowledge structures. It is argued that the QSH has scientific merit with implications for classroom instruction. Future research should examine the validity of the QSH in other disciplines such as mathematics and science and should include perspectives from social as well as cognitive models.

Subsystem eigenstate thermalization hypothesis

NASA Astrophysics Data System (ADS)

Dymarsky, Anatoly; Lashkari, Nima; Liu, Hong

2018-01-01

Motivated by the qualitative picture of canonical typicality, we propose a refined formulation of the eigenstate thermalization hypothesis (ETH) for chaotic quantum systems. This formulation, which we refer to as subsystem ETH, is in terms of the reduced density matrix of subsystems. This strong form of ETH outlines the set of observables defined within the subsystem for which it guarantees eigenstate thermalization. We discuss the limits when the size of the subsystem is small or comparable to its complement. In the latter case we outline the way to calculate the leading volume-proportional contribution to the von Neumann and Renyi entanglment entropies. Finally, we provide numerical evidence for the proposal in the case of a one-dimensional Ising spin chain.

The Feminization of School Hypothesis Called into Question among Junior and High School Students

ERIC Educational Resources Information Center

Verniers, Catherine; Martinot, Delphine; Dompnier, Benoît

2016-01-01

Background: The feminization of school hypothesis suggests that boys underachieve in school compared to girls because school rewards feminine characteristics that are at odds with boys' masculine features. Aims: The feminization of school hypothesis lacks empirical evidence. The aim of this study was to test this hypothesis by examining the extent…

Forty Years Later: Updating the Fossilization Hypothesis

ERIC Educational Resources Information Center

Han, ZhaoHong

2013-01-01

A founding concept in second language acquisition (SLA) research, fossilization has been fundamental to understanding second language (L2) development. The Fossilization Hypothesis, introduced in Selinker's seminal text (1972), has thus been one of the most influential theories, guiding a significant bulk of SLA research for four decades; 2012…

The Antieconomy Hypothesis (Part 2): Theoretical Roots

ERIC Educational Resources Information Center

Vanderburg, Willem H.

2009-01-01

The hypothesis of an antieconomy developed in part 1 is incommensurate with mainstream economics. This article explores three reasons for this situation: the limits of discipline-based scholarship in general and of mainstream economics in particular, the status of economists in contemporary societies, and the failure of economists to accept any…

The Marathon Group Hypothesis: An Unanswered Question

ERIC Educational Resources Information Center

Marks, Stephen E.; And Others

1973-01-01

The authors of this article contend that the Guinan and Foulds study was inadequately designed and executed, and the results indicate little of the "usefulness" of the test, much less illuminate the important hypothesis central to the investigation. Specific suggestions for further research in marathon group evaluation are made. (Author)

Relationships between rabbit semen characteristics and fertilising ability after insemination.

PubMed

Theau-Clément, M; Ailloud, E; Sanchez, A; Saleil, G; Brun, J M

2016-03-01

This study aimed to analyse the relationship between rabbit semen characteristics and semen fertilising ability after insemination, which is generally found to be weak. Our hypothesis was that using high semen dilutions (1 : 19), non-oestrus-stimulated does, and homospermic inseminations would make it easier to predict semen fertilising ability. Semen characteristics were evaluated on 275 ejaculates of 128 INRA1001 bucks, distributed into five successive batches. A total of 1970 inseminations were performed. The continuous semen variables were subdivided into three classes of similar size to account for any non-linear relationship between semen characteristics and fertilising ability. Mass motility was divided into two classes according to the presence or absence of waves under microscope observation. Libido, the presence or absence of gel, volume, percentage of progressive sperms, curvilinear velocity, beat frequency of the flagellum, and straightness and linearity of sperm movement did not affect fertility, prolificacy or productivity. It was confirmed that mass motility, estimated by visual observation under the microscope, significantly influenced fertility as well as the percentage of motile and of rapid sperms, and the amplitude of lateral head displacement, estimated by a computer-assisted semen analysis system. To a lesser extent, the percentage of motile cells and of rapid cells significantly influenced prolificacy. Consequently, mass motility and the percentage of motile cells significantly influenced rabbit doe productivity (+1 live births/AI when the semen showed at least a beginning of wave movement, or when the percentage of motile cells was >84%). Interestingly, a gain of 1.5 rabbits was observed when the percentage of rapid cells changed from 64% to 79%, whereas productivity significantly dropped beyond 83% of rapid cells, reflecting a non-linear relationship.

A checklist to facilitate objective hypothesis testing in social psychology research.

PubMed

Washburn, Anthony N; Morgan, G Scott; Skitka, Linda J

2015-01-01

Social psychology is not a very politically diverse area of inquiry, something that could negatively affect the objectivity of social psychological theory and research, as Duarte et al. argue in the target article. This commentary offers a number of checks to help researchers uncover possible biases and identify when they are engaging in hypothesis confirmation and advocacy instead of hypothesis testing.

Autosomal STRs provide genetic evidence for the hypothesis that Tai people originate from southern China.

PubMed

Sun, Hao; Zhou, Chi; Huang, Xiaoqin; Lin, Keqin; Shi, Lei; Yu, Liang; Liu, Shuyuan; Chu, Jiayou; Yang, Zhaoqing

2013-01-01

Tai people are widely distributed in Thailand, Laos and southwestern China and are a large population of Southeast Asia. Although most anthropologists and historians agree that modern Tai people are from southwestern China and northern Thailand, the place from which they historically migrated remains controversial. Three popular hypotheses have been proposed: northern origin hypothesis, southern origin hypothesis or an indigenous origin. We compared the genetic relationships between the Tai in China and their "siblings" to test different hypotheses by analyzing 10 autosomal microsatellites. The genetic data of 916 samples from 19 populations were analyzed in this survey. The autosomal STR data from 15 of the 19 populations came from our previous study (Lin et al., 2010). 194 samples from four additional populations were genotyped in this study: Han (Yunnan), Dai (Dehong), Dai (Yuxi) and Mongolian. The results of genetic distance comparisons, genetic structure analyses and admixture analyses all indicate that populations from northern origin hypothesis have large genetic distances and are clearly differentiated from the Tai. The simulation-based ABC analysis also indicates this. The posterior probability of the northern origin hypothesis is just 0.04 [95%CI: (0.01-0.06)]. Conversely, genetic relationships were very close between the Tai and populations from southern origin or an indigenous origin hypothesis. Simulation-based ABC analyses were also used to distinguish the southern origin hypothesis from the indigenous origin hypothesis. The results indicate that the posterior probability of the southern origin hypothesis [0.640, 95%CI: (0.524-0.757)] is greater than that of the indigenous origin hypothesis [0.324, 95%CI: (0.211-0.438)]. Therefore, we propose that the genetic evidence does not support the hypothesis of northern origin. Our genetic data indicate that the southern origin hypothesis has higher probability than the other two hypotheses statistically

Test of the Brink-Axel Hypothesis for the Pygmy Dipole Resonance

NASA Astrophysics Data System (ADS)

Martin, D.; von Neumann-Cosel, P.; Tamii, A.; Aoi, N.; Bassauer, S.; Bertulani, C. A.; Carter, J.; Donaldson, L.; Fujita, H.; Fujita, Y.; Hashimoto, T.; Hatanaka, K.; Ito, T.; Krugmann, A.; Liu, B.; Maeda, Y.; Miki, K.; Neveling, R.; Pietralla, N.; Poltoratska, I.; Ponomarev, V. Yu.; Richter, A.; Shima, T.; Yamamoto, T.; Zweidinger, M.

2017-11-01

The gamma strength function and level density of 1- states in 96Mo have been extracted from a high-resolution study of the (p → , p→ ' ) reaction at 295 MeV and extreme forward angles. By comparison with compound nucleus γ decay experiments, this allows a test of the generalized Brink-Axel hypothesis in the energy region of the pygmy dipole resonance. The Brink-Axel hypothesis is commonly assumed in astrophysical reaction network calculations and states that the gamma strength function in nuclei is independent of the structure of the initial and final state. The present results validate the Brink-Axel hypothesis for 96Mo and provide independent confirmation of the methods used to separate gamma strength function and level density in γ decay experiments.

An experimental re-examination of the inferential confusion hypothesis of obsessive-compulsive doubt.

PubMed

Gangemi, Amelia; Mancini, Francesco; Dar, Reuven

2015-09-01

The inferential confusion hypothesis postulates that obsessive doubt is perpetuated by a subjective form of reasoning characterized primarily by a distrust of reality and an overreliance on imagined possibilities. However, experimental evidence for this hypothesis may be compromised by a potential confound between type of information (reality vs. possibility) and its valence (danger vs. safety). In the present study we aimed to untangle this potential confound. Forty OCD and 40 non-clinical participants underwent two versions of the Inferential Processes Task (Aardema, F., et al. (2009). The quantification of doubt in obsessive-compulsive disorder. International Journal of Cognitive Therapy, 2, 188-205). In the original version, the reality-based information is congruent with the safety hypothesis, whereas the possibility-based information is congruent with the danger hypothesis. In the modified version incorporated in the present study, the reality-based information is congruent with the danger hypothesis, whereas the possibility-based information is congruent with the safety hypothesis. Our findings did not support the inferential confusion hypothesis: both OCD and control participants changed their estimations of the probability of unwanted events based on the type of information they received (whether it conveyed danger or safety) regardless of whether it was framed as reality or possibility. The design of the present study does not lend itself to examining alternative explanations for the persistence of doubt in OCD. The hypothesized inferential confusion in OCD requires further validation. It is particularly important to demonstrate that findings do not reflect a prudential reasoning strategy. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Alliance Hypothesis for Human Friendship

PubMed Central

DeScioli, Peter; Kurzban, Robert

2009-01-01

Background Exploration of the cognitive systems underlying human friendship will be advanced by identifying the evolved functions these systems perform. Here we propose that human friendship is caused, in part, by cognitive mechanisms designed to assemble support groups for potential conflicts. We use game theory to identify computations about friends that can increase performance in multi-agent conflicts. This analysis suggests that people would benefit from: 1) ranking friends, 2) hiding friend-ranking, and 3) ranking friends according to their own position in partners' rankings. These possible tactics motivate the hypotheses that people possess egocentric and allocentric representations of the social world, that people are motivated to conceal this information, and that egocentric friend-ranking is determined by allocentric representations of partners' friend-rankings (more than others' traits). Methodology/Principal Findings We report results from three studies that confirm predictions derived from the alliance hypothesis. Our main empirical finding, replicated in three studies, was that people's rankings of their ten closest friends were predicted by their own perceived rank among their partners' other friends. This relationship remained strong after controlling for a variety of factors such as perceived similarity, familiarity, and benefits. Conclusions/Significance Our results suggest that the alliance hypothesis merits further attention as a candidate explanation for human friendship. PMID:19492066

Inoculation Stress Hypothesis of Environmental Enrichment

PubMed Central

Crofton, Elizabeth J.; Zhang, Yafang; Green, Thomas A.

2014-01-01

One hallmark of psychiatric conditions is the vast continuum of individual differences in susceptibility vs. resilience resulting from the interaction of genetic and environmental factors. The environmental enrichment paradigm is an animal model that is useful for studying a range of psychiatric conditions, including protective phenotypes in addiction and depression models. The major question is how environmental enrichment, a non-drug and non-surgical manipulation, can produce such robust individual differences in such a wide range of behaviors. This paper draws from a variety of published sources to outline a coherent hypothesis of inoculation stress as a factor producing the protective enrichment phenotypes. The basic tenet suggests that chronic mild stress from living in a complex environment and interacting non-aggressively with conspecifics can inoculate enriched rats against subsequent stressors and/or drugs of abuse. This paper reviews the enrichment phenotypes, mulls the fundamental nature of environmental enrichment vs. isolation, discusses the most appropriate control for environmental enrichment, and challenges the idea that cortisol/corticosterone equals stress. The intent of the inoculation stress hypothesis of environmental enrichment is to provide a scaffold with which to build testable hypotheses for the elucidation of the molecular mechanisms underlying these protective phenotypes and thus provide new therapeutic targets to treat psychiatric/neurological conditions. PMID:25449533

Advent of Continents: A New Hypothesis

PubMed Central

Tamura, Yoshihiko; Sato, Takeshi; Fujiwara, Toshiya; Kodaira, Shuichi; Nichols, Alexander

2016-01-01

The straightforward but unexpected relationship presented here relates crustal thickness to magma type in the Izu-Ogasawara (Bonin) and Aleutian oceanic arcs. Volcanoes along the southern segment of the Izu-Ogasawara arc and the western Aleutian arc (west of Adak) are underlain by thin crust (10–20 km). In contrast those along the northern segment of the Izu-Ogasawara arc and eastern Aleutian arc are underlain by crust ~35 km thick. Interestingly, andesite magmas dominate eruptive products from the former volcanoes and mostly basaltic lavas erupt from the latter. According to the hypothesis presented here, rising mantle diapirs stall near the base of the oceanic crust at depths controlled by the thickness of the overlying crust. Where the crust is thin, melting occurs at relatively low pressures in the mantle wedge producing andesitic magmas. Where the crust is thick, melting pressures are higher and only basaltic magmas tend to be produced. The implications of this hypothesis are: (1) the rate of continental crust accumulation, which is andesitic in composition, would have been greatest soon after subduction initiated on Earth, when most crust was thin; and (2) most andesite magmas erupted on continental crust could be recycled from “primary” andesite originally produced in oceanic arcs. PMID:27669662

Tunguska, 1908: the gas pouch and soil fluidization hypothesis

NASA Astrophysics Data System (ADS)

Nistor, I.

2012-01-01

The Siberian taiga explosion of 30 June 1908 remains one of the great mysteries of the 20th century: millions of trees put down over an area of 2200 km2 without trace of a crater or meteorite fragments. Hundred years of failed searches have followed, resulting in as many flawed hypothesis which could not offer satisfactory explanations: meteorite, comet, UFO, etc. In the author's opinion, the cause is that the energy the explorers looked for was simply not there! The author's hypothesis is that a meteoroid encountered a gas pouch in the atmosphere, producing a devastating explosion, its effects being amplified by soil fluidization.

Undergraduate Students’ Initial Ability in Understanding Phylogenetic Tree

NASA Astrophysics Data System (ADS)

Sa'adah, S.; Hidayat, T.; Sudargo, Fransisca

2017-04-01

The Phylogenetic tree is a visual representation depicts a hypothesis about the evolutionary relationship among taxa. Evolutionary experts use this representation to evaluate the evidence for evolution. The phylogenetic tree is currently growing for many disciplines in biology. Consequently, learning about the phylogenetic tree has become an important part of biological education and an interesting area of biology education research. Skill to understanding and reasoning of the phylogenetic tree, (called tree thinking) is an important skill for biology students. However, research showed many students have difficulty in interpreting, constructing, and comparing among the phylogenetic tree, as well as experiencing a misconception in the understanding of the phylogenetic tree. Students are often not taught how to reason about evolutionary relationship depicted in the diagram. Students are also not provided with information about the underlying theory and process of phylogenetic. This study aims to investigate the initial ability of undergraduate students in understanding and reasoning of the phylogenetic tree. The research method is the descriptive method. Students are given multiple choice questions and an essay that representative by tree thinking elements. Each correct answer made percentages. Each student is also given questionnaires. The results showed that the undergraduate students’ initial ability in understanding and reasoning phylogenetic tree is low. Many students are not able to answer questions about the phylogenetic tree. Only 19 % undergraduate student who answered correctly on indicator evaluate the evolutionary relationship among taxa, 25% undergraduate student who answered correctly on indicator applying concepts of the clade, 17% undergraduate student who answered correctly on indicator determines the character evolution, and only a few undergraduate student who can construct the phylogenetic tree.

Assessing the geographic dichotomy hypothesis with cacti in South America.

PubMed

Arzabe, A A; Aguirre, L F; Baldelomar, M P; Molina-Montenegro, M A

2018-03-01

The Cactaceae is one of the most conspicuous and ecologically important plant families in the world. Its species may have specialist or generalist pollination systems that show geographic patterns, which are synthesised in the Geographic Dichotomy Hypothesis. Here, we assess this hypothesis in five countries in both tropical and extratropical regions, evaluating the pollinator visitation rate and pollinator identity and abundance. We calculate the Shannon diversity index (H') and evenness (J) and evaluate differences between latitude parameters with a Student t-test. Overall, we found more specialised pollination systems in all tropical sites; the richness, diversity and evenness of pollinators was reduced in comparison to extratropical regions, where the pollination system was generalised. Our results support the geographic dichotomy hypothesis in the cacti of South America, suggesting that environmental factors underlying the latitudinal patterns can help to explain differences in the pollination syndrome between tropical and extratropical regions. © 2017 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

A test of the submentalizing hypothesis: Apes' performance in a false belief task inanimate control

PubMed Central

Hirata, Satoshi; Call, Josep; Tomasello, Michael

2017-01-01

ABSTRACT Much debate concerns whether any nonhuman animals share with humans the ability to infer others' mental states, such as desires and beliefs. In a recent eye-tracking false-belief task, we showed that great apes correctly anticipated that a human actor would search for a goal object where he had last seen it, even though the apes themselves knew that it was no longer there. In response, Heyes proposed that apes' looking behavior was guided not by social cognitive mechanisms but rather domain-general cueing effects, and suggested the use of inanimate controls to test this alternative submentalizing hypothesis. In the present study, we implemented the suggested inanimate control of our previous false-belief task. Apes attended well to key events but showed markedly fewer anticipatory looks and no significant tendency to look to the correct location. We thus found no evidence that submentalizing was responsible for apes' anticipatory looks in our false-belief task. PMID:28919941

A test of the submentalizing hypothesis: Apes' performance in a false belief task inanimate control.

PubMed

Krupenye, Christopher; Kano, Fumihiro; Hirata, Satoshi; Call, Josep; Tomasello, Michael

2017-01-01

Much debate concerns whether any nonhuman animals share with humans the ability to infer others' mental states, such as desires and beliefs. In a recent eye-tracking false-belief task, we showed that great apes correctly anticipated that a human actor would search for a goal object where he had last seen it, even though the apes themselves knew that it was no longer there. In response, Heyes proposed that apes' looking behavior was guided not by social cognitive mechanisms but rather domain-general cueing effects, and suggested the use of inanimate controls to test this alternative submentalizing hypothesis. In the present study, we implemented the suggested inanimate control of our previous false-belief task. Apes attended well to key events but showed markedly fewer anticipatory looks and no significant tendency to look to the correct location. We thus found no evidence that submentalizing was responsible for apes' anticipatory looks in our false-belief task.

The "Discouraged-Business-Major" Hypothesis: Policy Implications

ERIC Educational Resources Information Center

Marangos, John

2012-01-01

This paper uses a relatively large dataset of the stated academic major preferences of economics majors at a relatively large, not highly selective, public university in the USA to identify the "discouraged-business-majors" (DBMs). The DBM hypothesis addresses the phenomenon where students who are screened out of the business curriculum often…

Giant Panda Maternal Care: A Test of the Experience Constraint Hypothesis

PubMed Central

Snyder, Rebecca J.; Perdue, Bonnie M.; Zhang, Zhihe; Maple, Terry L.; Charlton, Benjamin D.

2016-01-01

The body condition constraint and the experience condition constraint hypotheses have both been proposed to account for differences in reproductive success between multiparous (experienced) and primiparous (first-time) mothers. However, because primiparous mothers are typically characterized by both inferior body condition and lack of experience when compared to multiparous mothers, interpreting experience related differences in maternal care as support for either the body condition constraint hypothesis or the experience constraint hypothesis is extremely difficult. Here, we examined maternal behaviour in captive giant pandas, allowing us to simultaneously control for body condition and provide a rigorous test of the experience constraint hypothesis in this endangered animal. We found that multiparous mothers spent more time engaged in key maternal behaviours (nursing, grooming, and holding cubs) and had significantly less vocal cubs than primiparous mothers. This study provides the first evidence supporting the experience constraint hypothesis in the order Carnivora, and may have utility for captive breeding programs in which it is important to monitor the welfare of this species’ highly altricial cubs, whose survival is almost entirely dependent on receiving adequate maternal care during the first few weeks of life. PMID:27272352

Giant Panda Maternal Care: A Test of the Experience Constraint Hypothesis.

PubMed

Snyder, Rebecca J; Perdue, Bonnie M; Zhang, Zhihe; Maple, Terry L; Charlton, Benjamin D

2016-06-07

The body condition constraint and the experience condition constraint hypotheses have both been proposed to account for differences in reproductive success between multiparous (experienced) and primiparous (first-time) mothers. However, because primiparous mothers are typically characterized by both inferior body condition and lack of experience when compared to multiparous mothers, interpreting experience related differences in maternal care as support for either the body condition constraint hypothesis or the experience constraint hypothesis is extremely difficult. Here, we examined maternal behaviour in captive giant pandas, allowing us to simultaneously control for body condition and provide a rigorous test of the experience constraint hypothesis in this endangered animal. We found that multiparous mothers spent more time engaged in key maternal behaviours (nursing, grooming, and holding cubs) and had significantly less vocal cubs than primiparous mothers. This study provides the first evidence supporting the experience constraint hypothesis in the order Carnivora, and may have utility for captive breeding programs in which it is important to monitor the welfare of this species' highly altricial cubs, whose survival is almost entirely dependent on receiving adequate maternal care during the first few weeks of life.

The membrane pacemaker hypothesis: novel tests during the ontogeny of endothermy.

PubMed

Price, Edwin R; Sirsat, Tushar S; Sirsat, Sarah K G; Curran, Thomas; Venables, Barney J; Dzialowski, Edward M

2018-03-29

The 'membrane pacemaker' hypothesis proposes a biochemical explanation for among-species variation in resting metabolism, based on the positive correlation between membrane docosahexaenoic acid (DHA) and metabolic rate. We tested this hypothesis using a novel model, altricial red-winged blackbird nestlings, predicting that the proportion of DHA in muscle and liver membranes should increase with the increasing metabolic rate of the nestling as it develops endothermy. We also used a dietary manipulation, supplementing the natural diet with fish oil (high DHA) or sunflower oil (high linoleic acid) to alter membrane composition and then assessed metabolic rate. In support of the membrane pacemaker hypothesis, DHA proportions increased in membranes from pectoralis muscle, muscle mitochondria and liver during post-hatch development. By contrast, elevated dietary DHA had no effect on resting metabolic rate, despite causing significant changes to membrane lipid composition. During cold challenges, higher metabolic rates were achieved by birds that had lower DHA and higher linoleic acid in membrane phospholipids. Given the mixed support for this hypothesis, we conclude that correlations between membrane DHA and metabolic rate are likely spurious, and should be attributed to a still-unidentified confounding variable. © 2018. Published by The Company of Biologists Ltd.

The Reference Ability Neural Network Study: Life-time stability of reference-ability neural networks derived from task maps of young adults.

PubMed

Habeck, C; Gazes, Y; Razlighi, Q; Steffener, J; Brickman, A; Barulli, D; Salthouse, T; Stern, Y

2016-01-15

derivation of these networks, we also observed some brain-behavioral correlations, notably for the fluid-reasoning network whose network score correlated with performance on the memory and fluid-reasoning tasks. While age did not influence the expression of this RANN, the slope of the association between network score and fluid-reasoning performance was negatively associated with higher ages. These results provide support for the hypothesis that a set of specific, age-invariant neural networks underlies these four RAs, and that these networks maintain their cognitive specificity and level of intensity across age. Activation common to all 12 tasks was identified as another activation pattern resulting from a mean-contrast Partial-Least-Squares technique. This common pattern did show associations with age and some subject demographics for some of the reference domains, lending support to the overall conclusion that aspects of neural processing that are specific to any cognitive reference ability stay constant across age, while aspects that are common to all reference abilities differ across age. Copyright © 2015 Elsevier Inc. All rights reserved.

Malnutrition at Age 3 Years and Lower Cognitive Ability at Age 11 Years

PubMed Central

Liu, Jianghong; Raine, Adrian; Venables, Peter H.; Dalais, Cyril; Mednick, Sarnoff A.

2014-01-01

Background Early malnutrition is linked to poor cognition, but long-term effects have not been extensively examined and psychosocial confounds have not always been controlled. Objective To test the hypothesis that malnutrition at age 3 years will be associated with poorer cognitive ability at age 11 years independent of psychosocial confounds. Design A prospective, longitudinal study of a birth cohort of 1559 children originally assessed at age 3 years for malnutrition (low hemoglobin level, angular stomatitis, kwashiorkor, and sparse, thin hair) and followed up to age 11 years. Setting and Participants A community sample of 1559 children (51.4% boys and 48.6% girls) born between September 1, 1969, and August 31, 1970, in 2 towns in the island of Mauritius, with 68.7% Indians and 25.7% Creoles (African origin). Main Outcome Measures Verbal and spatial ability measured at ages 3 and 11 years and reading, scholastic ability, and neuropsychologic performance measured at age 11 years. Results Malnourished children had poorer cognition at both ages. Deficits were stable across time, applied to all sex and ethnic groups, and remained after controlling for multiple measures of psychosocial adversity. Children with 3 indicators of malnutrition had a 15.3-point deficit in IQ at age 11 years. Conclusions Malnutrition at age 3 years is associated with poor cognition at age 11 years independent of psychosocial adversity. Promoting early childhood nutrition could enhance long-term cognitive development and school performance, especially in children with multiple nutritional deficits. PMID:12796242

The relationship between intelligence and creativity: New support for the threshold hypothesis by means of empirical breakpoint detection

PubMed Central

Jauk, Emanuel; Benedek, Mathias; Dunst, Beate; Neubauer, Aljoscha C.

2013-01-01

The relationship between intelligence and creativity has been subject to empirical research for decades. Nevertheless, there is yet no consensus on how these constructs are related. One of the most prominent notions concerning the interplay between intelligence and creativity is the threshold hypothesis, which assumes that above-average intelligence represents a necessary condition for high-level creativity. While earlier research mostly supported the threshold hypothesis, it has come under fire in recent investigations. The threshold hypothesis is commonly investigated by splitting a sample at a given threshold (e.g., at 120 IQ points) and estimating separate correlations for lower and upper IQ ranges. However, there is no compelling reason why the threshold should be fixed at an IQ of 120, and to date, no attempts have been made to detect the threshold empirically. Therefore, this study examined the relationship between intelligence and different indicators of creative potential and of creative achievement by means of segmented regression analysis in a sample of 297 participants. Segmented regression allows for the detection of a threshold in continuous data by means of iterative computational algorithms. We found thresholds only for measures of creative potential but not for creative achievement. For the former the thresholds varied as a function of criteria: When investigating a liberal criterion of ideational originality (i.e., two original ideas), a threshold was detected at around 100 IQ points. In contrast, a threshold of 120 IQ points emerged when the criterion was more demanding (i.e., many original ideas). Moreover, an IQ of around 85 IQ points was found to form the threshold for a purely quantitative measure of creative potential (i.e., ideational fluency). These results confirm the threshold hypothesis for qualitative indicators of creative potential and may explain some of the observed discrepancies in previous research. In addition, we obtained

Moon origin - The impact-trigger hypothesis

NASA Technical Reports Server (NTRS)

Hartmann, William K.

1986-01-01

Arguments in favor of the impact-trigger model of lunar origin are presented. Lunar properties favoring this hypothesis include: (1) lunar iron and volatile deficiency; (2) angular momentum of the earth-moon system; and (3) similar O isotopes, bulk iron contents, and densities of earth's mantle and the moon. It is shown that the intense early bombardment averaged during earth's formation was several billion times the present meteoritic mass flux, consistent with a giant impact.

Otolith shape lends support to the sensory drive hypothesis in rockfishes.

PubMed

Tuset, V M; Otero-Ferrer, J L; Gómez-Zurita, J; Venerus, L A; Stransky, C; Imondi, R; Orlov, A M; Ye, Z; Santschi, L; Afanasiev, P K; Zhuang, L; Farré, M; Love, M S; Lombarte, A

2016-10-01

The sensory drive hypothesis proposes that environmental factors affect both signalling dynamics and the evolution of signals and receivers. Sound detection and equilibrium in marine fishes are senses dependent on the sagittae otoliths, whose morphological variability appears intrinsically linked to the environment. The aim of this study was to understand if and which environmental factors could be conditioning the evolution of this sensory structure, therefore lending support to the sensory drive hypothesis. Thus, we analysed the otolith shape of 42 rockfish species (Sebastes spp.) to test the potential associations with the phylogeny, biological (age), ecological (feeding habit and depth distribution) and biogeographical factors. The results showed strong differences in the otolith shapes of some species, noticeably influenced by ecological and biogeographical factors. Moreover, otolith shape was clearly conditioned by phylogeny, but with a strong environmental effect, cautioning about the use of this structure for the systematics of rockfishes or other marine fishes. However, our most relevant finding is that the data supported the sensory drive hypothesis as a force promoting the radiation of the genus Sebastes. This hypothesis holds that adaptive divergence in communication has significant influence relative to other life history traits. It has already been established in Sebastes for visual characters and organs; our results showed that it applies to otolith transformations as well (despite the clear influence of feeding and depth), expanding the scope of the hypothesis to other sensory structures. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

The glial growth factors deficiency and synaptic destabilization hypothesis of schizophrenia

PubMed Central

Moises, Hans W; Zoega, Tomas; Gottesman, Irving I

2002-01-01

Background A systems approach to understanding the etiology of schizophrenia requires a theory which is able to integrate genetic as well as neurodevelopmental factors. Presentation of the hypothesis Based on a co-localization of loci approach and a large amount of circumstantial evidence, we here propose that a functional deficiency of glial growth factors and of growth factors produced by glial cells are among the distal causes in the genotype-to-phenotype chain leading to the development of schizophrenia. These factors include neuregulin, insulin-like growth factor I, insulin, epidermal growth factor, neurotrophic growth factors, erbB receptors, phosphatidylinositol-3 kinase, growth arrest specific genes, neuritin, tumor necrosis factor alpha, glutamate, NMDA and cholinergic receptors. A genetically and epigenetically determined low baseline of glial growth factor signaling and synaptic strength is expected to increase the vulnerability for additional reductions (e.g., by viruses such as HHV-6 and JC virus infecting glial cells). This should lead to a weakening of the positive feedback loop between the presynaptic neuron and its targets, and below a certain threshold to synaptic destabilization and schizophrenia. Testing the hypothesis Supported by informed conjectures and empirical facts, the hypothesis makes an attractive case for a large number of further investigations. Implications of the hypothesis The hypothesis suggests glial cells as the locus of the genes-environment interactions in schizophrenia, with glial asthenia as an important factor for the genetic liability to the disorder, and an increase of prolactin and/or insulin as possible working mechanisms of traditional and atypical neuroleptic treatments. PMID:12095426

Loss of ability to work and ability to live independently in Parkinson's disease.

PubMed

Jasinska-Myga, Barbara; Heckman, Michael G; Wider, Christian; Putzke, John D; Wszolek, Zbigniew K; Uitti, Ryan J

2012-02-01

Ability to work and live independently is of particular concern for patients with Parkinson's disease (PD). We studied a series of PD patients able to work or live independently at baseline, and evaluated potential risk factors for two separate outcomes: loss of ability to work and loss of ability to live independently. The series comprised 495 PD patients followed prospectively. Ability to work and ability to live independently were based on clinical interview and examination. Cox regression models adjusted for age and disease duration were used to evaluate associations of baseline characteristics with loss of ability to work and loss of ability to live independently. Higher UPDRS dyskinesia score, UPDRS instability score, UPDRS total score, Hoehn and Yahr stage, and presence of intellectual impairment at baseline were all associated with increased risk of future loss of ability to work and loss of ability to live independently (P ≤ 0.0033). Five years after initial visit, for patients ≤70 years of age with a disease duration ≤4 years at initial visit, 88% were still able to work and 90% to live independently. These estimates worsened as age and disease duration at initial visit increased; for patients >70 years of age with a disease duration >4 years, estimates at 5 years were 43% able to work and 57% able to live independently. The information provided in this study can offer useful information for PD patients in preparing for future ability to perform activities of daily living. Copyright © 2011 Elsevier Ltd. All rights reserved.

The nephridial hypothesis of the gill slit origin.

PubMed

Ezhova, Olga V; Malakhov, Vladimir V

2015-12-01

Metameric gill slits are mysterious structures, unique for Chordata and Hemichordata, and also, perhaps, for the extinct Cambrian Calcichordata. There is a discussed hypothesis of the gill slits origin from the metameric nephridia. According to the hypothesis, the hypothetical metameric deuterostome ancestor had in each segment a pair of coelomoducts and a pair of intestinal pockets. In the anterior segments, the coelomoducts have fused with the intestinal pockets. As a result, each nephridium opened both into the gut and into the environment. Then the dissepiments and funnels reduced in all segments except the collar one. Thus, in recent enteropneusts, only the first pair of gill slits keeps the ancestral arrangement communicating at the same time with the gut, with the environment, and with the coelom of the preceding (collar) segment. In the anterior part of the branchio-genital trunk region of enteropneusts, the metameric intestinal pockets remained, as well as the metameric coelomoducts functioning as the ducts of the metameric gonads, i.e., as the gonoducts. The consequence of the hypothesis is that the metameric gill pores originate from the metameric excreting pores, and the metameric branchial sacs originate from the metameric endodermal pockets of the gut fused with the coelomoducts. The metameric gill slits by themselves correspond with metameric openings connecting the gut with metameric intestinal pockets. J. Exp. Zool. (Mol. Dev. Evol.) 324B: 647-652, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

[Steady car engine noise does not affect the cognitive abilities of sleep apnea syndrome patients].

PubMed

Mayoralas, L R; Barbé, F; Muñoz, A; Agustí, A G N

2003-09-01

Traffic accidents are more frequent for sleep apnea syndrome (SAS) patients than in the population at large. The mechanisms that underlie this observation are poorly defined. Our working hypothesis was that in SAS patients the steady noise of a car engine might alter cognitive capacities that may be involved in driving, thus increasing the risk of traffic accidents. To test this hypothesis we designed a prospective randomized controlled trial. Eighteen SAS patients (apnea-hypopnea index [SEM] 62 [6] h1) and 18 healthy controls were studied. All the participants were evaluated in random order both in basal conditions and after exposure to the steady noise of a car engine recorded on a compact disc. Their level of vigilance was evaluated (Steer-Clear) as well as their reaction time (PVT 192). Attention, coordination, and memory were measured using the following tests: Wechsler Memory Scale (digit span), the Wechsler Intelligence Scale (digit symbol), and Lezack's Trail Making tests A and B. The SAS patients were slightly younger than the control group (mean 50 [7] vs 57 [11] years, respectively; P=.05). The patients showed a lower level of vigilance than the controls both in basal and engine noise conditions (P<.05). No differences between groups were found for the other variables studied. Exposure to steady car engine noise had no effect on the tests of either group. In conclusion, the results of our study do not support the hypothesis that steady car engine noise significantly alters the cognitive ability of SAS patients.

An 'outrageous hypothesis' for Mars - Episodic oceans

NASA Astrophysics Data System (ADS)

Kerr, R. A.

1993-02-01

The conventional view of Mars is that, during the past 3 billion years, the atmosphere has been so thin and cold that the planet's water has remained locked up underground as ice. However, Baker et al. (1991) proposed a radically different and far-reaching alternative: a Mars that is periodically shrouded in an earthlike atmosphere, with a temporary ocean and massive ice sheets. This hypothesis was proposed in order to explain the assortment of surface features sent back by the Viking spacecraft in 1970, such as huge channels, apparent ocean shorelines, and possible glacial landforms. To support this hypothesis, Baker and his coworkers invoked a spate of catastrophic floods, all cutting their channels at the same geological moment due a great outburst of Mars's volcanic activity which could have melted some subsurface ice and belched out CO2. This gas, together with some additional CO2 released as the water interacted with the surface, caused a strong greenhouse warming, causing melting of underground ice and the formation of an ocean.

Examinations of the reward comparison hypothesis: The modulation of gender and footshock.

PubMed

Huang, Andrew Chih Wei; Wang, Cheng Chung; Wang, Shiun

2015-11-01

The reward comparison hypothesis suggests that drugs of abuse-induced conditioned saccharin suppression intake is due to the reward value of drugs of abuse that outweighs that of a saccharin solution dissociating from the aversive LiCl-induced conditioned taste aversion (CTA). Huang and Hsiao (2008) provided some conflict data to challenge the reward comparison hypothesis. Whether the rewarding drugs of abuse-induced conditioned suppression and the aversive LiCl-induced CTA resulted from aversion or reward should be addressed. The present study investigated how gender and footshock affect aversive LiCl- and rewarding morphine- and methamphetamine (MAMPH)-induced conditioned suppression to re-examine the reward comparison hypothesis. The results indicated that gender and footshock did not directly influence the aversive LiCl-induced CTA or rewarding morphine- and MAMPH-induced conditioned suppression. The gender effect interacted with the drug effect in the aversive LiCl- and rewarding MAMPH-induced conditioned suppression but did not interact with the drug effect in the rewarding morphine-induced conditioned suppression. Footshock interacted with the drug effect in rewarding morphine- and MAMPH-induced conditioned suppression, but footshock did not interact with the drug effect in the aversive LiCl-induced CTA. Therefore, the gender and footshock effects might play a modulatory (but not a mediating) role with the drug effect. The present data indicated that footshock modulates drugs of abuse-induced conditioned suppression, which is consistent with the reward comparison hypothesis, but our findings with regard to the modulatory role of the gender effect and the drug effect do not support this hypothesis. The reward comparison hypothesis should be discussed and possibly reconsidered. Copyright © 2015. Published by Elsevier Inc.

Concerns regarding a call for pluralism of information theory and hypothesis testing

USGS Publications Warehouse

Lukacs, P.M.; Thompson, W.L.; Kendall, W.L.; Gould, W.R.; Doherty, P.F.; Burnham, K.P.; Anderson, D.R.

2007-01-01

1. Stephens et al . (2005) argue for `pluralism? in statistical analysis, combining null hypothesis testing and information-theoretic (I-T) methods. We show that I-T methods are more informative even in single variable problems and we provide an ecological example. 2. I-T methods allow inferences to be made from multiple models simultaneously. We believe multimodel inference is the future of data analysis, which cannot be achieved with null hypothesis-testing approaches. 3. We argue for a stronger emphasis on critical thinking in science in general and less reliance on exploratory data analysis and data dredging. Deriving alternative hypotheses is central to science; deriving a single interesting science hypothesis and then comparing it to a default null hypothesis (e.g. `no difference?) is not an efficient strategy for gaining knowledge. We think this single-hypothesis strategy has been relied upon too often in the past. 4. We clarify misconceptions presented by Stephens et al . (2005). 5. We think inference should be made about models, directly linked to scientific hypotheses, and their parameters conditioned on data, Prob(Hj| data). I-T methods provide a basis for this inference. Null hypothesis testing merely provides a probability statement about the data conditioned on a null model, Prob(data |H0). 6. Synthesis and applications. I-T methods provide a more informative approach to inference. I-T methods provide a direct measure of evidence for or against hypotheses and a means to consider simultaneously multiple hypotheses as a basis for rigorous inference. Progress in our science can be accelerated if modern methods can be used intelligently; this includes various I-T and Bayesian methods.

Nicotine and food deprivation decrease the ability to resist smoking.

PubMed

Leeman, Robert F; O'Malley, Stephanie S; White, Marney A; McKee, Sherry A

2010-09-01

Attempts to simultaneously control food intake and smoking may lead to smoking cessation failure. We sought to model this relationship using a human laboratory paradigm of smoking lapse behavior. We examined the combined effect of food and nicotine deprivation, compared to nicotine deprivation alone, on the ability to resist smoking and on subsequent ad libitum smoking. In a between-subjects design, daily smokers (N = 30) were all deprived of nicotine for 18 h and were either food-deprived (12 h) or not during a laboratory session. Following exposure to individualized food cues, participants had the option of initiating tobacco self-administration or delaying up to 50 min in exchange for monetary reinforcement. Subsequently, the tobacco self-administration period consisted of 1 h in which participants could choose to smoke or receive monetary reinforcement for cigarettes not smoked. Smokers who had been deprived of food and nicotine smoked their first cigarette sooner and were more likely to smoke at some point during the laboratory session, compared to those who were only nicotine-deprived. Those who were food- and nicotine-deprived smoked slightly more cigarettes than those who were nicotine-deprived only, although this difference was not statistically significant. There were no sex differences in outcomes. Hunger and food craving ratings while trying to resist smoking were greater in the food + nicotine-deprived group. Tobacco craving was predictive of outcome in both conditions. These findings support the hypothesis that food deprivation can undermine a smoker's ability to resist smoking.

Competitive ability, stress tolerance and plant interactions along stress gradients.

PubMed

Qi, Man; Sun, Tao; Xue, SuFeng; Yang, Wei; Shao, DongDong; Martínez-López, Javier

2018-04-01

Exceptions to the generality of the stress-gradient hypothesis (SGH) may be reconciled by considering species-specific traits and stress tolerance strategies. Studies have tested stress tolerance and competitive ability in mediating interaction outcomes, but few have incorporated this to predict how species interactions shift between competition and facilitation along stress gradients. We used field surveys, salt tolerance and competition experiments to develop a predictive model interspecific interaction shifts across salinity stress gradients. Field survey and greenhouse tolerance tests revealed tradeoffs between stress tolerance and competitive ability. Modeling showed that along salinity gradients, (1) plant interactions shifted from competition to facilitation at high salinities within the physiological limits of salt-intolerant plants, (2) facilitation collapsed when salinity stress exceeded the physiological tolerance of salt-intolerant plants, and (3) neighbor removal experiments overestimate interspecific facilitation by including intraspecific effects. A community-level field experiment, suggested that (1) species interactions are competitive in benign and, facilitative in harsh condition, but fuzzy under medium environmental stress due to niche differences of species and weak stress amelioration, and (2) the SGH works on strong but not weak stress gradients, so SGH confusion arises when it is applied across questionable stress gradients. Our study clarifies how species interactions vary along stress gradients. Moving forward, focusing on SGH applications rather than exceptions on weak or nonexistent gradients would be most productive. © 2018 by the Ecological Society of America.

Measuring Work Ability with Its Antecedents: Evaluation of the Work Ability Survey.

PubMed

Voltmer, Jan-Bennet; Deller, Jürgen

2017-07-24

Purpose The revised version of the Work Ability Survey (WAS-R) assesses work ability on several sub-scales at the intersection of personal and organizational capacity, thus adding to the measurement of work ability by integrating the holistic model. It, therefore, improves on two features of the current standard measurement tool of work ability, the Work Ability Index (WAI): (1) a ceiling effect and (2) limited detail due to a focus on physical health and personal capacity. Method In two samples (n 1  = 1093, n 2  = 359), psychometric properties and the structure of the WAS-R were analyzed. To evaluate construct validity, inter-correlations of the WAS-R and WAI, sickness absence, expected and desired retirement age, and post-retirement work intention were calculated. Results The WAS-R was found to be distributed closer to normality than the WAI. The structural analyses yielded acceptable results for the hypothesized model. The WAS-R was adequately correlated with the WAI, negatively with sickness absence, and positively with desired retirement age. Conclusions The WAS-R extends the measurement of work ability, reflecting organizations' work demands. Its broad sub-scales lead to high acceptance of the results within the participating companies. In particular, the organizational capacity scales can be used to guide interventions aiming at organizational characteristics to improve work ability.

Female employment and fertility in Peninsular Malaysia: the maternal role incompatibility hypothesis reconsidered.

PubMed

Mason, K O; Palan, V T

1981-11-01

Multivariate analysis of the 1974 Malaysian Fertility and Family Survey tests the hypothesis that an inverse relationship between women's work and fertility occurs only when there are serious conflicts between working and caring for children. The results are only partly consistent with the hypothesis and suggest that normative conflicts between working and mothering affect the employment-fertility relationship in Malaysia more than spacio-temporal conflicts do. The lack of consistent evidence for the hypothesis, as well as some conceptual problems, lead us to propose an alternative framework for understanding variation in the employment-fertility relationship, both in Malaysia and elsewhere. This framework incorporates ideas from the role incompatibility hypothesis but views the employment-fertility relationship as dependent not just on role conflicts but more generally on the structure of the household's socioeconomic opportunities.

In Defense of Chi's Ontological Incompatibility Hypothesis

ERIC Educational Resources Information Center

Slotta, James D.

2011-01-01

This article responds to an article by A. Gupta, D. Hammer, and E. F. Redish (2010) that asserts that M. T. H. Chi's (1992, 2005) hypothesis of an "ontological commitment" in conceptual development is fundamentally flawed. In this article, I argue that Chi's theoretical perspective is still very much intact and that the critique offered by Gupta…

The "One-Shot" Hypothesis for Context Storage

ERIC Educational Resources Information Center

Malmberg, Kenneth J.; Shiffrin, Richard M.

2005-01-01

In 3 experiments motivated by the implicit memory literature, the authors investigated the effects of different strengthening operations on the list strength effect (LSE) for explicit free recall, an effect posited by R. M. Shiffrin, R. Ratcliff, and S. E. Clark (1990) to be due to context cuing. According to the one-shot hypothesis, a fixed…

Hypothesis on the nature of atmospheric UFOs

NASA Astrophysics Data System (ADS)

Mukharev, L. A.

1991-08-01

A hypothesis is developed according to which the atmospheric UFO phenomenon has an electromagnetic nature. It is suggested that an atmospheric UFO is an agglomeration of charged atmospheric dust within which there exists a slowly damped electromagnetic field. This field is considered to be the source of the observed optical effects and the motive force of the UFO.

The Nebular Hypothesis - A False Paradigm Misleading Scientists

NASA Astrophysics Data System (ADS)

Myers, L. S.

2005-05-01

Science has reached a turning point in history after being misled for 250 years by Immanuel Kant's nebular hypothesis, the most fundamental assumption in science. The nebular hypothesis assumes all nine planets were created 4.5 billion years ago (Ga) as molten bodies that cooled with the same size and chemical composition they have today. Reevaluation of the nebular hypothesis proves it has been wrong since its inception. The proof has lain in plain sight for centuries-coal beds that could not have existed at the assumed time of creation because they formed on Earth's surface after creation of the planet when forests and swamps were exposed to solar energy. The coal beds were subsequently buried under overburden accreted in later millennia, steadily increasing Earth's mass and diameter. The coal beds and layers of overburden are proof Earth was not created 4.5 Ga but is growing and expanding by accretion of extraterrestrial mass and core expansion-a process termed "Accreation" (creation by accretion). Each process accelerates over time, but internal expansion exceeds the rate of external accretion. Because the nebular hypothesis is erroneous researchers assumed Earth's diameter never changes, and, faced with the possibility the Earth might be expanding after the Atlantic basin was discovered to be widening, this assumption led to the unworkable concept of subduction to maintain a constant diameter Earth. Subduction will prove to be one of the greatest errors in the history of science. Nullification of the nebular hypothesis also nullifies subduction and rejuvenates Carey's earth expansion theory. Accreation provides Carey's missing energy source and mechanism of expansion. Expansion is proved by morphologic evidence today's continents were once a single planetary landmass on a smaller Earth when today's oceans, covering 70% of the planet, did not exist 200-250 Ma. Despite hundreds of tons of meteorites and dust known to accrete daily, its cumulative effect has been

Theoretical results which strengthen the hypothesis of electroweak bioenantioselection

NASA Astrophysics Data System (ADS)

Zanasi, R.; Lazzeretti, P.; Ligabue, A.; Soncini, A.

1999-03-01

It is shown via a large series of numerical tests on two fundamental organic molecules, the L-α-amino acid L-valine and the sugar precursor hydrated D-glyceraldheyde, that the ab initio calculation of the parity-violating energy shift, at the random-phase approximation level of accuracy, provides results that are about one order of magnitude larger than those obtained by means of less accurate methods employed previously. These findings would make more plausible the hypothesis of electroweak selection of natural enantiomers via the Kondepudi-Nelson scenario, or could imply that Salam phase-transition temperature is higher than previously inferred: accordingly, the hypothesis of terrestrial origin of life would become more realistic.

Quantitative implementation of the endogenous molecular-cellular network hypothesis in hepatocellular carcinoma.

PubMed

Wang, Gaowei; Zhu, Xiaomei; Gu, Jianren; Ao, Ping

2014-06-06

A quantitative hypothesis for cancer genesis and progression-the endogenous molecular-cellular network hypothesis, intended to include both genetic and epigenetic causes of cancer-has been proposed recently. Using this hypothesis, here we address the molecular basis for maintaining normal liver and hepatocellular carcinoma (HCC), and the potential strategy to cure or relieve HCC. First, we elaborate the basic assumptions of the hypothesis and establish a core working network of HCC according to the hypothesis. Second, we quantify the working network by a nonlinear dynamical system. We show that the working network reproduces the main known features of normal liver and HCC at both the modular and molecular levels. Lastly, the validated working network reveals that (i) specific positive feedback loops are responsible for the maintenance of normal liver and HCC; (ii) inhibiting proliferation and inflammation-related positive feedback loops and simultaneously inducing a liver-specific positive feedback loop is predicated as a potential strategy to cure or relieve HCC; and (iii) the genesis and regression of HCC are asymmetric. In light of the characteristic properties of the nonlinear dynamical system, we demonstrate that positive feedback loops must exist as a simple and general molecular basis for the maintenance of heritable phenotypes, such as normal liver and HCC, and regulating the positive feedback loops directly or indirectly provides potential strategies to cure or relieve HCC.

Measuring creative imagery abilities

PubMed Central

Jankowska, Dorota M.; Karwowski, Maciej

2015-01-01

Over the decades, creativity and imagination research developed in parallel, but they surprisingly rarely intersected. This paper introduces a new theoretical model of creative visual imagination, which bridges creativity and imagination research, as well as presents a new psychometric instrument, called the Test of Creative Imagery Abilities (TCIA), developed to measure creative imagery abilities understood in accordance with this model. Creative imagination is understood as constituted by three interrelated components: vividness (the ability to create images characterized by a high level of complexity and detail), originality (the ability to produce unique imagery), and transformativeness (the ability to control imagery). TCIA enables valid and reliable measurement of these three groups of abilities, yielding the general score of imagery abilities and at the same time making profile analysis possible. We present the results of nine studies on a total sample of more than 1700 participants, showing the factor structure of TCIA using confirmatory factor analysis, as well as provide data confirming this instrument's validity and reliability. The availability of TCIA for interested researchers may result in new insights and possibilities of integrating the fields of creativity and imagination science. PMID:26539140

Interpreting “statistical hypothesis testing” results in clinical research

PubMed Central

Sarmukaddam, Sanjeev B.

2012-01-01

Difference between “Clinical Significance and Statistical Significance” should be kept in mind while interpreting “statistical hypothesis testing” results in clinical research. This fact is already known to many but again pointed out here as philosophy of “statistical hypothesis testing” is sometimes unnecessarily criticized mainly due to failure in considering such distinction. Randomized controlled trials are also wrongly criticized similarly. Some scientific method may not be applicable in some peculiar/particular situation does not mean that the method is useless. Also remember that “statistical hypothesis testing” is not for decision making and the field of “decision analysis” is very much an integral part of science of statistics. It is not correct to say that “confidence intervals have nothing to do with confidence” unless one understands meaning of the word “confidence” as used in context of confidence interval. Interpretation of the results of every study should always consider all possible alternative explanations like chance, bias, and confounding. Statistical tests in inferential statistics are, in general, designed to answer the question “How likely is the difference found in random sample(s) is due to chance” and therefore limitation of relying only on statistical significance in making clinical decisions should be avoided. PMID:22707861

A test of the substitution-habitat hypothesis in amphibians.

PubMed

Martínez-Abraín, Alejandro; Galán, Pedro

2018-06-01

Most examples that support the substitution-habitat hypothesis (human-made habitats act as substitutes of original habitat) deal with birds and mammals. We tested this hypothesis in 14 amphibians by using percentage occupancy as a proxy of habitat quality (i.e., higher occupancy percentages indicate higher quality). We classified water body types as original habitat (no or little human influence) depending on anatomical, behavioral, or physiological adaptations of each amphibian species. Ten species had relatively high probabilities (0.16-0.28) of occurrence in original habitat, moderate probability of occurrence in substitution habitats (0.11-0.14), and low probability of occurrence in refuge habitats (0.05-0.08). Thus, the substitution-habitat hypothesis only partially applies to amphibians because the low occupancy of refuges could be due to the negligible human persecution of this group (indicating good conservation status). However, low occupancy of refuges could also be due to low tolerance of refuge conditions, which could have led to selective extinction or colonization problems due to poor dispersal capabilities. That original habitats had the highest probabilities of occupancy suggests amphibians have a good conservation status in the region. They also appeared highly adaptable to anthropogenic substitution habitats. © 2017 Society for Conservation Biology.

Alertness and cognitive control: Testing the early onset hypothesis.

PubMed

Schneider, Darryl W

2018-05-01

Previous research has revealed a peculiar interaction between alertness and cognitive control in selective-attention tasks: Congruency effects are larger on alert trials (on which an alerting cue is presented briefly in advance of the imperative stimulus) than on no-alert trials, despite shorter response times (RTs) on alert trials. One explanation for this finding is the early onset hypothesis, which is based on the assumptions that increased alertness shortens stimulus-encoding time and that cognitive control involves gradually focusing attention during a trial. The author tested the hypothesis in 3 experiments by manipulating alertness and stimulus quality (which were intended to shorten and lengthen stimulus-encoding time, respectively) in an arrow-based flanker task involving congruent and incongruent stimuli. Replicating past findings, the alerting manipulation led to shorter RTs but larger congruency effects on alert trials than on no-alert trials. The stimulus-quality manipulation led to longer RTs and larger congruency effects for degraded stimuli than for intact stimuli. These results provide mixed support for the early onset hypothesis, but the author discusses how data and theory might be reconciled if stimulus quality affects stimulus-encoding time and the rate of evidence accumulation in the decision process. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Should the Equilibrium Point Hypothesis (EPH) be Considered a Scientific Theory?

PubMed Central

Sainburg, Robert L.

2017-01-01

The purpose of this commentary is to discuss factors that limit consideration of the equilibrium point hypothesis as a scientific theory. The EPH describes control of motor neuron threshold through the variable lambda, which corresponds to a unique referent configuration for a muscle, joint, or combination of joints. One of the most compelling features of the equilibrium point hypothesis is the integration of posture and movement control into a single mechanism. While the essential core of the hypothesis is based upon spinal circuitry interacting with peripheral mechanics, the proponents have extended the theory to include the higher-level processes that generate lambda, and in doing so, imposed an injunction against the supraspinal nervous system modeling, computing, or predicting dynamics. This limitation contradicts evidence that humans take account of body and environmental dynamics in motor selection, motor control, and motor adaptation processes. A number of unresolved limitations to the EPH have been debated in the literature for many years, including whether muscle resistance to displacement, measured during movement, is adequate to support this form of control, violations in equifinality predictions, spinal circuits that alter the proposed invariant characteristic for muscles, and limitations in the description of how the complexity of spinal circuitry might be integrated to yield a unique and stable equilibrium position for a given motor neuron threshold. In addition, an important empirical limitation of EPH is the measurement of the invariant characteristic, which needs to be done under a constant central state. While there is no question that the EPH is an elegant and generative hypothesis for motor control research, the claim that this hypothesis has reached the status of a scientific theory is premature. PMID:25386681

Should the Equilibrium Point Hypothesis (EPH) be Considered a Scientific Theory?

PubMed

Sainburg, Robert L

2015-04-01

The purpose of this commentary is to discuss factors that limit consideration of the equilibrium point hypothesis as a scientific theory. The EPH describes control of motor neuron threshold through the variable lambda, which corresponds to a unique referent configuration for a muscle, joint, or combination of joints. One of the most compelling features of the equilibrium point hypothesis is the integration of posture and movement control into a single mechanism. While the essential core of the hypothesis is based upon spinal circuitry interacting with peripheral mechanics, the proponents have extended the theory to include the higher-level processes that generate lambda, and in doing so, imposed an injunction against the supraspinal nervous system modeling, computing, or predicting dynamics. This limitation contradicts evidence that humans take account of body and environmental dynamics in motor selection, motor control, and motor adaptation processes. A number of unresolved limitations to the EPH have been debated in the literature for many years, including whether muscle resistance to displacement, measured during movement, is adequate to support this form of control, violations in equifinality predictions, spinal circuits that alter the proposed invariant characteristic for muscles, and limitations in the description of how the complexity of spinal circuitry might be integrated to yield a unique and stable equilibrium position for a given motor neuron threshold. In addition, an important empirical limitation of EPH is the measurement of the invariant characteristic, which needs to be done under a constant central state. While there is no question that the EPH is an elegant and generative hypothesis for motor control research, the claim that this hypothesis has reached the status of a scientific theory is premature.

The equilibrium point hypothesis and its application to speech motor control.

PubMed

Perrier, P; Ostry, D J; Laboissière, R

1996-04-01

In this paper, we address a number of issues in speech research in the context of the equilibrium point hypothesis of motor control. The hypothesis suggests that movements arise from shifts in the equilibrium position of the limb or the speech articulator. The equilibrium is a consequence of the interaction of central neural commands, reflex mechanisms, muscle properties, and external loads, but it is under the control of central neural commands. These commands act to shift the equilibrium via centrally specified signals acting at the level of the motoneurone (MN) pool. In the context of a model of sagittal plane jaw and hyoid motion based on the lambda version of the equilibrium point hypothesis, we consider the implications of this hypothesis for the notion of articulatory targets. We suggest that simple linear control signals may underlie smooth articulatory trajectories. We explore as well the phenomenon of intraarticulator coarticulation in jaw movement. We suggest that even when no account is taken of upcoming context, that apparent anticipatory changes in movement amplitude and duration may arise due to dynamics. We also present a number of simulations that show in different ways how variability in measured kinematics can arise in spite of constant magnitude speech control signals.

The evolution of bacterial cell size: the internal diffusion-constraint hypothesis.

PubMed

Gallet, Romain; Violle, Cyrille; Fromin, Nathalie; Jabbour-Zahab, Roula; Enquist, Brian J; Lenormand, Thomas

2017-07-01

Size is one of the most important biological traits influencing organismal ecology and evolution. However, we know little about the drivers of body size evolution in unicellulars. A long-term evolution experiment (Lenski's LTEE) in which Escherichia coli adapts to a simple glucose medium has shown that not only the growth rate and the fitness of the bacterium increase over time but also its cell size. This increase in size contradicts prominent 'external diffusion' theory (EDC) predicting that cell size should have evolved toward smaller cells. Among several scenarios, we propose and test an alternative 'internal diffusion-constraint' (IDC) hypothesis for cell size evolution. A change in cell volume affects metabolite concentrations in the cytoplasm. The IDC states that a higher metabolism can be achieved by a reduction in the molecular traffic time inside of the cell, by increasing its volume. To test this hypothesis, we studied a population from the LTEE. We show that bigger cells with greater growth and CO 2 production rates and lower mass-to-volume ratio were selected over time in the LTEE. These results are consistent with the IDC hypothesis. This novel hypothesis offers a promising approach for understanding the evolutionary constraints on cell size.

When Null Hypothesis Significance Testing Is Unsuitable for Research: A Reassessment.

PubMed

Szucs, Denes; Ioannidis, John P A

2017-01-01

Null hypothesis significance testing (NHST) has several shortcomings that are likely contributing factors behind the widely debated replication crisis of (cognitive) neuroscience, psychology, and biomedical science in general. We review these shortcomings and suggest that, after sustained negative experience, NHST should no longer be the default, dominant statistical practice of all biomedical and psychological research. If theoretical predictions are weak we should not rely on all or nothing hypothesis tests. Different inferential methods may be most suitable for different types of research questions. Whenever researchers use NHST they should justify its use, and publish pre-study power calculations and effect sizes, including negative findings. Hypothesis-testing studies should be pre-registered and optimally raw data published. The current statistics lite educational approach for students that has sustained the widespread, spurious use of NHST should be phased out.

When Null Hypothesis Significance Testing Is Unsuitable for Research: A Reassessment

PubMed Central

Szucs, Denes; Ioannidis, John P. A.

2017-01-01

Null hypothesis significance testing (NHST) has several shortcomings that are likely contributing factors behind the widely debated replication crisis of (cognitive) neuroscience, psychology, and biomedical science in general. We review these shortcomings and suggest that, after sustained negative experience, NHST should no longer be the default, dominant statistical practice of all biomedical and psychological research. If theoretical predictions are weak we should not rely on all or nothing hypothesis tests. Different inferential methods may be most suitable for different types of research questions. Whenever researchers use NHST they should justify its use, and publish pre-study power calculations and effect sizes, including negative findings. Hypothesis-testing studies should be pre-registered and optimally raw data published. The current statistics lite educational approach for students that has sustained the widespread, spurious use of NHST should be phased out. PMID:28824397

On the Role of the Ventromedial Prefrontal Cortex in Self-Processing: The Valuation Hypothesis

PubMed Central

D’Argembeau, Arnaud

2013-01-01

With the development of functional neuroimaging, important progress has been made in identifying the brain regions involved in self-related processing. One of the most consistent findings has been that the ventromedial prefrontal cortex (vMPFC) is activated when people contemplate various aspects of themselves and their life, such their traits, experiences, preferences, abilities, and goals. Recent evidence suggests that this region may not support the act of self-reflection per se, but its precise function in self-processing remains unclear. In this article, I examine the hypothesis that the vMPFC may contribute to assign personal value or significance to self-related contents: stimuli and mental representations that refer or relate to the self tend to be assigned unique value or significance, and the function of the vMPFC may precisely be to evaluate or represent such significance. Although relatively few studies to date have directly tested this hypothesis, several lines of evidence converge to suggest that vMPFC activity during self-processing depends on the personal significance of self-related contents. First, increasing psychological distance from self-representations leads to decreased activation in the vMPFC. Second, the magnitude of vMPFC activation increases linearly with the personal importance attributed to self-representations. Third, the activity of the vMPFC is modulated by individual differences in the interest placed on self-reflection. Finally, the evidence shows that the vMPFC responds to outer aspects of self that have high personal value, such as possessions and close others. By assigning personal value to self-related contents, the vMPFC may play an important role in the construction, stabilization, and modification of self-representations, and ultimately in guiding our choices and decisions. PMID:23847521

The pathologic physiology of chronic Bright's disease. An exposition of the "intact nephron hypothesis".

PubMed

Bricker, N S; Morrin, P A; Kime, S W

1997-09-01

Clinical and experimental data relating to the functional capacity of the surviving nephrons of the chronically diseased kidney for the most part support the thesis that these nephrons retain their essential functional integrity regardless of the nature of the underlying form of chronic Bright's disease. There are instances in which specific alterations of function correlate with pathologic involvement of a particular site of the nephron but these appear to represent the exceptions, and in general the more advanced the disease becomes, the less evident are the differentiating features. Studies on dogs with unilateral renal disease indicate that the functional capacity of the nephrons of the diseased kidney parallels that of the nephrons of the contralateral normal kidney. These data tend to exclude widespread intrinsic damage to the functioning nephrons by the underlying pathologic processes. From these observations, as well as from certain supporting clinical and experimental observations, it is suggested that the majority of surviving nephrons in the patient with bilateral renal disease similarly are functionally intact. Concepts of the pathologic physiology of the kidney, based on the "intact nephron hypothesis", are presented. Within the framework of this hypothesis it is concluded that (1) the diseased kidney consists of a diminished number of nephrons, most of which retain essentially normal functional abilities; (2) certain of the apparent abnormalities in function in bilateral renal disease may relate to adaptive changes imposed by the decreased nephron population and the attendant derangements in body fluids rather than to structural distortion of nephrons; (3) the over-all flexibility of the diseased kidney decreases as the number of constituent nephrons decreases; but (4) there is an orderly and predictable pattern of excretion for all substances.

Inoculation stress hypothesis of environmental enrichment.

PubMed

Crofton, Elizabeth J; Zhang, Yafang; Green, Thomas A

2015-02-01

One hallmark of psychiatric conditions is the vast continuum of individual differences in susceptibility vs. resilience resulting from the interaction of genetic and environmental factors. The environmental enrichment paradigm is an animal model that is useful for studying a range of psychiatric conditions, including protective phenotypes in addiction and depression models. The major question is how environmental enrichment, a non-drug and non-surgical manipulation, can produce such robust individual differences in such a wide range of behaviors. This paper draws from a variety of published sources to outline a coherent hypothesis of inoculation stress as a factor producing the protective enrichment phenotypes. The basic tenet suggests that chronic mild stress from living in a complex environment and interacting non-aggressively with conspecifics can inoculate enriched rats against subsequent stressors and/or drugs of abuse. This paper reviews the enrichment phenotypes, mulls the fundamental nature of environmental enrichment vs. isolation, discusses the most appropriate control for environmental enrichment, and challenges the idea that cortisol/corticosterone equals stress. The intent of the inoculation stress hypothesis of environmental enrichment is to provide a scaffold with which to build testable hypotheses for the elucidation of the molecular mechanisms underlying these protective phenotypes and thus provide new therapeutic targets to treat psychiatric/neurological conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Gaussian Hypothesis Testing and Quantum Illumination.

PubMed

Wilde, Mark M; Tomamichel, Marco; Lloyd, Seth; Berta, Mario

2017-09-22

Quantum hypothesis testing is one of the most basic tasks in quantum information theory and has fundamental links with quantum communication and estimation theory. In this paper, we establish a formula that characterizes the decay rate of the minimal type-II error probability in a quantum hypothesis test of two Gaussian states given a fixed constraint on the type-I error probability. This formula is a direct function of the mean vectors and covariance matrices of the quantum Gaussian states in question. We give an application to quantum illumination, which is the task of determining whether there is a low-reflectivity object embedded in a target region with a bright thermal-noise bath. For the asymmetric-error setting, we find that a quantum illumination transmitter can achieve an error probability exponent stronger than a coherent-state transmitter of the same mean photon number, and furthermore, that it requires far fewer trials to do so. This occurs when the background thermal noise is either low or bright, which means that a quantum advantage is even easier to witness than in the symmetric-error setting because it occurs for a larger range of parameters. Going forward from here, we expect our formula to have applications in settings well beyond those considered in this paper, especially to quantum communication tasks involving quantum Gaussian channels.

Urbanization and the more-individuals hypothesis.

PubMed

Chiari, Claudia; Dinetti, Marco; Licciardello, Cinzia; Licitra, Gaetano; Pautasso, Marco

2010-03-01

1. Urbanization is a landscape process affecting biodiversity world-wide. Despite many urban-rural studies of bird assemblages, it is still unclear whether more species-rich communities have more individuals, regardless of the level of urbanization. The more-individuals hypothesis assumes that species-rich communities have larger populations, thus reducing the chance of local extinctions. 2. Using newly collated avian distribution data for 1 km(2) grid cells across Florence, Italy, we show a significantly positive relationship between species richness and assemblage abundance for the whole urban area. This richness-abundance relationship persists for the 1 km(2) grid cells with less than 50% of urbanized territory, as well as for the remaining grid cells, with no significant difference in the slope of the relationship. These results support the more-individuals hypothesis as an explanation of patterns in species richness, also in human modified and fragmented habitats. 3. However, the intercept of the species richness-abundance relationship is significantly lower for highly urbanized grid cells. Our study confirms that urban communities have lower species richness but counters the common notion that assemblages in densely urbanized ecosystems have more individuals. In Florence, highly inhabited areas show fewer species and lower assemblage abundance. 4. Urbanized ecosystems are an ongoing large-scale natural experiment which can be used to test ecological theories empirically.

Sex-Biased Parental Investment among Contemporary Chinese Peasants: Testing the Trivers-Willard Hypothesis.

PubMed

Luo, Liqun; Zhao, Wei; Weng, Tangmei

2016-01-01

The Trivers-Willard hypothesis predicts that high-status parents will bias their investment to sons, whereas low-status parents will bias their investment to daughters. Among humans, tests of this hypothesis have yielded mixed results. This study tests the hypothesis using data collected among contemporary peasants in Central South China. We use current family status (rated by our informants) and father's former class identity (assigned by the Chinese Communist Party in the early 1950s) as measures of parental status, and proportion of sons in offspring and offspring's years of education as measures of parental investment. Results show that (i) those families with a higher former class identity such as landlord and rich peasant tend to have a higher socioeconomic status currently, (ii) high-status parents are more likely to have sons than daughters among their biological offspring, and (iii) in higher-status families, the years of education obtained by sons exceed that obtained by daughters to a larger extent than in lower-status families. Thus, the first assumption and the two predictions of the hypothesis are supported by this study. This article contributes a contemporary Chinese case to the testing of the Trivers-Willard hypothesis.

Using modern human cortical bone distribution to test the systemic robusticity hypothesis.

PubMed

Baab, Karen L; Copes, Lynn E; Ward, Devin L; Wells, Nora; Grine, Frederick E

2018-06-01

The systemic robusticity hypothesis links the thickness of cortical bone in both the cranium and limb bones. This hypothesis posits that thick cortical bone is in part a systemic response to circulating hormones, such as growth hormone and thyroid hormone, possibly related to physical activity or cold climates. Although this hypothesis has gained popular traction, only rarely has robusticity of the cranium and postcranial skeleton been considered jointly. We acquired computed tomographic scans from associated crania, femora and humeri from single individuals representing 11 populations in Africa and North America (n = 228). Cortical thickness in the parietal, frontal and occipital bones and cortical bone area in limb bone diaphyses were analyzed using correlation, multiple regression and general linear models to test the hypothesis. Absolute thickness values from the crania were not correlated with cortical bone area of the femur or humerus, which is at odds with the systemic robusticity hypothesis. However, measures of cortical bone scaled by total vault thickness and limb cross-sectional area were positively correlated between the cranium and postcranium. When accounting for a range of potential confounding variables, including sex, age and body mass, variation in relative postcranial cortical bone area explained ∼20% of variation in the proportion of cortical cranial bone thickness. While these findings provide limited support for the systemic robusticity hypothesis, cranial cortical thickness did not track climate or physical activity across populations. Thus, some of the variation in cranial cortical bone thickness in modern humans is attributable to systemic effects, but the driving force behind this effect remains obscure. Moreover, neither absolute nor proportional measures of cranial cortical bone thickness are positively correlated with total cranial bone thickness, complicating the extrapolation of these findings to extinct species where only cranial

[How are the hypothesis and the objectives established in a Radiology research project?].

PubMed

Alústiza Echeverría, J M; Salvador Pardo, E; Castiella Eguzkiza, A

2012-01-01

Research is a systematic process designed to answer a question. This is the starting point of the whole project and specifically formulates a problem observed in the analysis of the reality. The answer to this attempts to clarify an uncertainty in our knowledge. The conceptual hypothesis is the theoretical answer to the question set out. The operational hypothesis is the particular form that which sets out to demonstrate the conceptual hypothesis. The objectives are the justification for conducting the research. They help to define what it attempts to obtain, and what answers it will give to the formulated questions. It must show a clear and consistent relationship with the description of the problem and, specifically, with the questions and/or hypothesis that are to be resolved. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

The ability of lens alpha crystallin to protect against heat-induced aggregation is age-dependent

NASA Technical Reports Server (NTRS)

Horwitz, J.; Emmons, T.; Takemoto, L.; Spooner, B. S. (Principal Investigator)

1992-01-01

Alpha crystallin was prepared from newborn and aged bovine lenses. SDS-PAGE and tryptic peptide mapping demonstrated that both preparations contained only the alpha-A and alpha-B chains, with no significant contamination of other crystallins. Compared with alpha crystallin from the aged lens, alpha crystallin from the newborn lens was much more effective in the inhibition of beta L crystallin denaturation and precipitation induced in vitro by heat. Together, these results demonstrate that during the aging process, the alpha crystallins lose their ability to protect against protein denaturation, consistent with the hypothesis that the alpha crystallins play an important role in the maintenance of protein native structure in the intact lens.

Advancing Young Adolescents' Hypothesis-Development Performance in a Computer-Supported and Problem-Based Learning Environment

ERIC Educational Resources Information Center

Kim, Hye Jeong; Pedersen, Susan

2011-01-01

Hypothesis development is a complex cognitive activity, but one that is critical as a means of reducing uncertainty during ill-structured problem solving. In this study, we examined the effect of metacognitive scaffolds in strengthening hypothesis development. We also examined the influence of hypothesis development on young adolescents'…

Testing the Münch hypothesis of long distance phloem transport in plants.

PubMed

Knoblauch, Michael; Knoblauch, Jan; Mullendore, Daniel L; Savage, Jessica A; Babst, Benjamin A; Beecher, Sierra D; Dodgen, Adam C; Jensen, Kaare H; Holbrook, N Michele

2016-06-02

Long distance transport in plants occurs in sieve tubes of the phloem. The pressure flow hypothesis introduced by Ernst Münch in 1930 describes a mechanism of osmotically generated pressure differentials that are supposed to drive the movement of sugars and other solutes in the phloem, but this hypothesis has long faced major challenges. The key issue is whether the conductance of sieve tubes, including sieve plate pores, is sufficient to allow pressure flow. We show that with increasing distance between source and sink, sieve tube conductivity and turgor increases dramatically in Ipomoea nil. Our results provide strong support for the Münch hypothesis, while providing new tools for the investigation of one of the least understood plant tissues.

[Dr James Lovelock and story about GAIA hypothesis].

PubMed

Gajić, Vladimir

2011-01-01

Gaia is the Anglo-Saxon term for the Hellenic term Gea or Ge, which means Earth. The GAIA hypothesis was launched almost 40 years ago by the famous chemist James Lovelock, who was engaged by the National Aeronautics and Space Administration (NASA) to create a sensitive instrument for searching forms of extraterrestrial life on other planets. Then he published the book The ages of GAIA, which perturbed the world's scientific public of those days. Lovelock struck upon this idea in the late sixties of the past century, during the space race with Russians, when he was hired hy the National Aeronautics and Space Administration to conduct a series of experiments to find and explore life forms on the planet Mars. Experiments executed by the American module Viking failed to trace any life form, as Lovelock had predicted. He called it a dead equilibrium. Then he turned to Earth, whose perspective is totally different from its first neighbors. Venus and Mars, and is far from a dead equilibrium. DAISYWORLD: In this hypothesis. Lovelock represents Earth as one living, giant super organism, composed of all living creatures and its material environnent. In that super organisnm, the level of oxygen, weather conditions, ocean salinity and so on are under constant influence of physical, chemical and biological processes, which provide the existence for such life forms on Earth. Dr James Lovelock represents a pioneer of climatology, and his hypothesis gives a unique insight into the correlation of dynamic processes on our planet, no matter whether they are of physical or biological nature.

Etiology of inflammatory bowel disease: A unified hypothesis

PubMed Central

Qin, Xiaofa

2012-01-01

Inflammatory bowel disease (IBD), including both ulcerative colitis (UC) and Crohn’s disease (CD), emerged and dramatically increased for about a century. Despite extensive research, its cause remains regarded as unknown. About a decade ago, a series of findings made me suspect that saccharin may be a key causative factor for IBD, through its inhibition on gut bacteria and the resultant impaired inactivation of digestive proteases and over digestion of the mucus layer and gut barrier (the Bacteria-Protease-Mucus-Barrier hypothesis). It explained many puzzles in IBD such as its emergence and temporal changes in last century. Recently I further found evidence suggesting sucralose may be also linked to IBD through a similar mechanism as saccharin and have contributed to the recent worldwide increase of IBD. This new hypothesis suggests that UC and CD are just two symptoms of the same morbidity, rather than two different diseases. They are both caused by a weakening in gut barrier and only differ in that UC is mainly due to increased infiltration of gut bacteria and the resultant recruitment of neutrophils and formation of crypt abscess, while CD is mainly due to increased infiltration of antigens and particles from gut lumen and the resultant recruitment of macrophages and formation of granulomas. It explained the delayed appearance but accelerated increase of CD over UC and many other phenomena. This paper aims to provide a detailed description of a unified hypothesis regarding the etiology of IBD, including the cause and mechanism of IBD, as well as the relationship between UC and CD. PMID:22553395

Adolescents' Body Image Trajectories: A Further Test of the Self-Equilibrium Hypothesis

ERIC Educational Resources Information Center

Morin, Alexandre J. S.; Maïano, Christophe; Scalas, L. Francesca; Janosz, Michel; Litalien, David

2017-01-01

The self-equilibrium hypothesis underlines the importance of having a strong core self, which is defined as a high and developmentally stable self-concept. This study tested this hypothesis in relation to body image (BI) trajectories in a sample of 1,006 adolescents (M[subscript age] = 12.6, including 541 males and 465 females) across a 4-year…

The Aspect Hypothesis, Defective Tense, and Obligatory Contexts: Comments on Haznedar, 2007

ERIC Educational Resources Information Center

Costello, Willie; Shirai, Yasuhiro

2011-01-01

Haznedar (2007) argues that longitudinal data from a child learner of English who has Turkish as a first language (L1) constitute a counterexample to the Aspect Hypothesis. In this commentary, we show that her argument is not warranted because the Aspect Hypothesis does not presuppose that tense is defective, contra her claim. However, Haznedar's…

FLO11 gene length and transcriptional level affect biofilm-forming ability of wild flor strains of Saccharomyces cerevisiae.

PubMed

Zara, Giacomo; Zara, Severino; Pinna, Claudia; Marceddu, Salvatore; Budroni, Marilena

2009-12-01

In Saccharomyces cerevisiae, FLO11 encodes an adhesin that is associated with different phenotypes, such as adherence to solid surfaces, hydrophobicity, mat and air-liquid biofilm formation. In the present study, we analysed FLO11 allelic polymorphisms and FLO11-associated phenotypes of 20 flor strains. We identified 13 alleles of different lengths, varying from 3.0 to 6.1 kb, thus demonstrating that FLO11 is highly polymorphic. Two alleles of 3.1 and 5.0 kb were cloned into strain BY4742 to compare the FLO11-associated phenotypes in the same genetic background. We show that there is a significant correlation between biofilm-forming ability and FLO11 length both in different and in the same genetic backgrounds. Moreover, we propose a multiple regression model that allows prediction of air-liquid biofilm-forming ability on the basis of transcription levels and lengths of FLO11 alleles in a population of S. cerevisiae flor strains. Considering that transcriptional differences are only partially explained by the differences in the promoter sequences, our results are consistent with the hypothesis that FLO11 transcription levels are strongly influenced by genetic background and affect biofilm-forming ability.

A hypothesis to explain accuracy of wasp resemblances.

PubMed

Boppré, Michael; Vane-Wright, Richard I; Wickler, Wolfgang

2017-01-01

Mimicry is one of the oldest concepts in biology, but it still presents many puzzles and continues to be widely debated. Simulation of wasps with a yellow-black abdominal pattern by other insects (commonly called "wasp mimicry") is traditionally considered a case of resemblance of unprofitable by profitable prey causing educated predators to avoid models and mimics to the advantage of both (Figure 1a). However, as wasps themselves are predators of insects, wasp mimicry can also be seen as a case of resemblance to one's own potential antagonist. We here propose an additional hypothesis to Batesian and Müllerian mimicry (both typically involving selection by learning vertebrate predators; cf. Table 1) that reflects another possible scenario for the evolution of multifold and in particular very accurate resemblances to wasps: an innate, visual inhibition of aggression among look-alike wasps, based on their social organization and high abundance. We argue that wasp species resembling each other need not only be Müllerian mutualists and that other insects resembling wasps need not only be Batesian mimics, but an innate ability of wasps to recognize each other during hunting is the driver in the evolution of a distinct kind of masquerade, in which model, mimic, and selecting agent belong to one or several species (Figure  1b). Wasp mimics resemble wasps not (only) to be mistaken by educated predators but rather, or in addition, to escape attack from their wasp models. Within a given ecosystem, there will be selection pressures leading to masquerade driven by wasps and/or to mimicry driven by other predators that have to learn to avoid them. Different pressures by guilds of these two types of selective agents could explain the widely differing fidelity with respect to the models in assemblages of yellow jackets and yellow jacket look-alikes.

Neuromuscular deficits after peripheral joint injury: a neurophysiological hypothesis.

PubMed

Ward, Sarah; Pearce, Alan J; Pietrosimone, Brian; Bennell, Kim; Clark, Ross; Bryant, Adam L

2015-03-01

In addition to biomechanical disturbances, peripheral joint injuries (PJIs) can also result in chronic neuromuscular alterations due in part to loss of mechanoreceptor-mediated afferent feedback. An emerging perspective is that PJI should be viewed as a neurophysiological dysfunction, not simply a local injury. Neurophysiological and neuroimaging studies have provided some evidence for central nervous system (CNS) reorganization at both the cortical and spinal levels after PJI. The novel hypothesis proposed is that CNS reorganization is the underlying mechanism for persisting neuromuscular deficits after injury, particularly muscle weakness. There is a lack of direct evidence to support this hypothesis, but future studies utilizing force-matching tasks with superimposed transcranial magnetic stimulation may be help clarify this notion. © 2014 Wiley Periodicals, Inc.

Mechanism of drug-induced gingival overgrowth revisited: a unifying hypothesis

PubMed Central

Brown, RS; Arany, PR

2015-01-01

Drug-induced gingival overgrowth (DIGO) is a disfiguring side effect of anti-convulsants, calcineurin inhibitors, and calcium channel blocking agents. A unifying hypothesis has been constructed which begins with cation flux inhibition induced by all three of these drug categories. Decreased cation influx of folic acid active transport within gingival fibroblasts leads to decreased cellular folate uptake, which in turn leads to changes in matrix metalloproteinases metabolism and the failure to activate collagenase. Decreased availability of activated collagenase results in decreased degradation of accumulated connective tissue which presents as DIGO. Studies supporting this hypothesis are discussed. PMID:24893951

Method for a quantitative investigation of the frozen flow hypothesis

PubMed

Schock; Spillar

2000-09-01

We present a technique to test the frozen flow hypothesis quantitatively, using data from wave-front sensors such as those found in adaptive optics systems. Detailed treatments of the theoretical background of the method and of the error analysis are presented. Analyzing data from the 1.5-m and 3.5-m telescopes at the Starfire Optical Range, we find that the frozen flow hypothesis is an accurate description of the temporal development of atmospheric turbulence on time scales of the order of 1-10 ms but that significant deviations from the frozen flow behavior are present for longer time scales.

Proform-Antecedent Linking in Individuals with Agrammatic Aphasia: A Test of the Intervener Hypothesis.

PubMed

Engel, Samantha; Shapiro, Lewis P; Love, Tracy

2018-02-01

To evaluate processing and comprehension of pronouns and reflexives in individuals with agrammatic (Broca's) aphasia and age-matched control participants. Specifically, we evaluate processing and comprehension patterns in terms of a specific hypothesis -- the Intervener Hypothesis - that posits that the difficulty of individuals with agrammatic (Broca's) aphasia results from similarity-based interference caused by the presence of an intervening NP between two elements of a dependency chain. We used an eye tracking-while-listening paradigm to investigate real-time processing (Experiment 1) and a sentence-picture matching task to investigate final interpretive comprehension (Experiment 2) of sentences containing proforms in complement phrase and subject relative constructions. Individuals with agrammatic aphasia demonstrated a greater proportion of gazes to the correct referent of reflexives relative to pronouns and significantly greater comprehension accuracy of reflexives relative to pronouns. These results provide support for the Intervener Hypothesis, previous support for which comes from studies of Wh- questions and unaccusative verbs, and we argue that this account provides an explanation for the deficits of individuals with agrammatic aphasia across a growing set of sentence constructions. The current study extends this hypothesis beyond filler-gap dependencies to referential dependencies and allows us to refine the hypothesis in terms of the structural constraints that meet the description of the Intervener Hypothesis.

EyeTribe Tracker Data Accuracy Evaluation and Its Interconnection with Hypothesis Software for Cartographic Purposes.

PubMed

Popelka, Stanislav; Stachoň, Zdeněk; Šašinka, Čeněk; Doležalová, Jitka

2016-01-01

The mixed research design is a progressive methodological discourse that combines the advantages of quantitative and qualitative methods. Its possibilities of application are, however, dependent on the efficiency with which the particular research techniques are used and combined. The aim of the paper is to introduce the possible combination of Hypothesis with EyeTribe tracker. The Hypothesis is intended for quantitative data acquisition and the EyeTribe is intended for qualitative (eye-tracking) data recording. In the first part of the paper, Hypothesis software is described. The Hypothesis platform provides an environment for web-based computerized experiment design and mass data collection. Then, evaluation of the accuracy of data recorded by EyeTribe tracker was performed with the use of concurrent recording together with the SMI RED 250 eye-tracker. Both qualitative and quantitative results showed that data accuracy is sufficient for cartographic research. In the third part of the paper, a system for connecting EyeTribe tracker and Hypothesis software is presented. The interconnection was performed with the help of developed web application HypOgama. The created system uses open-source software OGAMA for recording the eye-movements of participants together with quantitative data from Hypothesis. The final part of the paper describes the integrated research system combining Hypothesis and EyeTribe.

EyeTribe Tracker Data Accuracy Evaluation and Its Interconnection with Hypothesis Software for Cartographic Purposes

PubMed Central

Stachoň, Zdeněk; Šašinka, Čeněk; Doležalová, Jitka

2016-01-01

The mixed research design is a progressive methodological discourse that combines the advantages of quantitative and qualitative methods. Its possibilities of application are, however, dependent on the efficiency with which the particular research techniques are used and combined. The aim of the paper is to introduce the possible combination of Hypothesis with EyeTribe tracker. The Hypothesis is intended for quantitative data acquisition and the EyeTribe is intended for qualitative (eye-tracking) data recording. In the first part of the paper, Hypothesis software is described. The Hypothesis platform provides an environment for web-based computerized experiment design and mass data collection. Then, evaluation of the accuracy of data recorded by EyeTribe tracker was performed with the use of concurrent recording together with the SMI RED 250 eye-tracker. Both qualitative and quantitative results showed that data accuracy is sufficient for cartographic research. In the third part of the paper, a system for connecting EyeTribe tracker and Hypothesis software is presented. The interconnection was performed with the help of developed web application HypOgama. The created system uses open-source software OGAMA for recording the eye-movements of participants together with quantitative data from Hypothesis. The final part of the paper describes the integrated research system combining Hypothesis and EyeTribe. PMID:27087805

Colour vision in ADHD: part 1--testing the retinal dopaminergic hypothesis.

PubMed

Kim, Soyeon; Al-Haj, Mohamed; Chen, Samantha; Fuller, Stuart; Jain, Umesh; Carrasco, Marisa; Tannock, Rosemary

2014-10-24

To test the retinal dopaminergic hypothesis, which posits deficient blue color perception in ADHD, resulting from hypofunctioning CNS and retinal dopamine, to which blue cones are exquisitely sensitive. Also, purported sex differences in red color perception were explored. 30 young adults diagnosed with ADHD and 30 healthy young adults, matched on age and gender, performed a psychophysical task to measure blue and red color saturation and contrast discrimination ability. Visual function measures, such as the Visual Activities Questionnaire (VAQ) and Farnsworth-Munsell 100 hue test (FMT), were also administered. Females with ADHD were less accurate in discriminating blue and red color saturation relative to controls but did not differ in contrast sensitivity. Female control participants were better at discriminating red saturation than males, but no sex difference was present within the ADHD group. Poorer discrimination of red as well as blue color saturation in the female ADHD group may be partly attributable to a hypo-dopaminergic state in the retina, given that color perception (blue-yellow and red-green) is based on input from S-cones (short wavelength cone system) early in the visual pathway. The origin of female superiority in red perception may be rooted in sex-specific functional specialization in hunter-gather societies. The absence of this sexual dimorphism for red colour perception in ADHD females warrants further investigation.

[Importance of the tumor stem cell hypothesis for understanding ovarian cancer].

PubMed

Vochem, R; Einenkel, J; Horn, L-C; Ruschpler, P

2014-07-01

Despite complex surgical and systemic therapies epithelial ovarian cancer has a poor prognosis. A small quantity of tumorigenic cells termed cancer stem cells (CSC) are responsible for the development of chemoresistance and high rates of recurrence. This review presents the CSC hypothesis and describes methods of identification and enrichment of CSCs as well as approaches for the therapeutic use of these findings. A systematic literature review based on PubMed and Web of Science was carried out. The CSC model is based on a hierarchical structure of tumors with few CSCs and variably differentiated tumor cells constituting the tumor bulk. Only the CSCs possess tumorigenic potential. Other essential functional characteristics of CSCs are their potential for self-renewal and their ability to differentiate into further cell types. The CSCs are structurally characterized by different surface markers and changes in certain signaling pathways. Currently there are phase I and II studies in progress investigating specific influences on CSCs. Various clinical characteristics of the course of disease in ovarian cancer are aptly represented by the tumor stem cell model. In spite of precisely defined functional characteristics of CSCs, surface markers and signaling pathways show individual differences and vary between tumor entities. This complicates identification and enrichment. Current experimental findings in various approaches and even first clinical studies raise hopes for a personalized cancer therapy targeting CSCs.

Readability and Reading Ability.

ERIC Educational Resources Information Center