The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform
Erin Carroll - One of the best experts on this subject based on the ideXlab platform.
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lost in semantic space a multi modal non Verbal assessment of feature knowledge in semantic dementia
Brain, 2006Co-Authors: Peter Garrard, Erin CarrollAbstract:A novel, non-Verbal Test of semantic feature knowledge is introduced, enabling subordinate knowledge of four important concept attributes—colour, sound, environmental context and motion—to be individually probed. This methodology provides more specific information than existing non-Verbal semantic Tests about the status of attribute knowledge relating to individual concept representations. Performance on this Test of a group of 12 patients with semantic dementia (10 male, mean age: 64.4 years) correlated strongly with their scores on more conventional Tests of semantic memory, such as naming and word-to-picture matching. The Test's overlapping structure, in which individual concepts were probed in two, three or all four modalities, provided evidence of performance consistency on individual items between feature conditions. Group and individual analyses revealed little evidence for differential performance across the four feature conditions, though sound and colour correlated most strongly, and motion least strongly, with other semantic tasks, and patients were less accurate on the motion features of living than non-living concepts (with no such conceptual domain differences in the other conditions). The results are discussed in the context of their implications for the place of semantic dementia within the classification of progressive aphasic syndromes, and for contemporary models of semantic representation and organization. Original Submission July 19, 2005. Revised December 16, 2005. Accepted March 1, 2006.
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lost in semantic space a multi modal non Verbal assessment of feature knowledge in semantic dementia
Brain, 2006Co-Authors: Peter Garrard, Erin CarrollAbstract:A novel, non-Verbal Test of semantic feature knowledge is introduced, enabling subordinate knowledge of four important concept attributes--colour, sound, environmental context and motion--to be individually probed. This methodology provides more specific information than existing non-Verbal semantic Tests about the status of attribute knowledge relating to individual concept representations. Performance on this Test of a group of 12 patients with semantic dementia (10 male, mean age: 64.4 years) correlated strongly with their scores on more conventional Tests of semantic memory, such as naming and word-to-picture matching. The Test's overlapping structure, in which individual concepts were probed in two, three or all four modalities, provided evidence of performance consistency on individual items between feature conditions. Group and individual analyses revealed little evidence for differential performance across the four feature conditions, though sound and colour correlated most strongly, and motion least strongly, with other semantic tasks, and patients were less accurate on the motion features of living than non-living concepts (with no such conceptual domain differences in the other conditions). The results are discussed in the context of their implications for the place of semantic dementia within the classification of progressive aphasic syndromes, and for contemporary models of semantic representation and organization.
Kenneth C. Land - One of the best experts on this subject based on the ideXlab platform.
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Assessing the Significance of Cohort and Period Effects in Hierarchical Age-Period-Cohort Models: Applications to Verbal Test Scores and Voter Turnout in U.S. Presidential Elections
Social forces; a scientific medium of social study and interpretation, 2013Co-Authors: Steven M. Frenk, Yang Claire Yang, Kenneth C. LandAbstract:In recently developed hierarchical age-period-cohort (HAPC) models, inferential questions arise: How can one assess or judge the significance of estimates of individual cohort and period effects in such models? And how does one assess the overall statistical significance of the cohort and/or the period effects? Beyond statistical significance is the question of substantive significance. This paper addresses these questions. In the context of empirical applications of linear and generalized linear mixed-model specifications of HAPC models using data on Verbal Test scores and voter turnout in U.S. presidential elections, respectively, we describe a two-step approach and a set of guidelines for assessing statistical significance. The guidelines include assessments of patterns of effects and statistical Tests both for the effects of individual cohorts and time periods as well as for entire sets of cohorts and periods. The empirical applications show strong evidence that trends in Verbal Test scores are primarily cohort driven, while voter turnout is primarily a period phenomenon.
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age period cohort analysis of repeated cross section surveys fixed or random effects
Sociological Methods & Research, 2008Co-Authors: Yang Yang, Kenneth C. LandAbstract:Yang and Land (2006) and Yang (forthcoming-b) developed a mixed (fixed and random) effects model for the age–period–cohort (APC) analysis of micro data sets in the form of a series of repeated cross-section sample surveys that are increasingly available to demographers. The authors compare the fixedversus random-effects model specifications for APC analysis. They use data on Verbal Test scores from 15 cross sections of the General Social Survey (GSS), 1974 to 2000, for substantive illustrations. Strengths and weaknesses are identified for both the random- and fixed-effects formulations. However, under each of the two data conditions studied, the random-effects hierarchical APC model is the most appropriate specification. While additional analyses and comparisons of random- and fixed-effects APC models using other data sets are necessary before generalizations can be drawn, this finding is consistent with results from other methodological studies with unbalanced data designs.
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A MIXED MODELS APPROACH TO THE AGE-PERIOD-COHORT ANALYSIS OF REPEATED CROSS-SECTION SURVEYS, WITH AN APPLICATION TO DATA ON TRENDS IN Verbal Test SCORES
Sociological Methodology, 2006Co-Authors: Yang Yang, Kenneth C. LandAbstract:We develop a mixed (fixed and random effects) models approach to the age-period-cohort (AFC) analysis of micro data sets in the form of a series of the repeated cross-section sample surveys that are increasingly available to sociologists. This approach recognizes the multilevel structure of the individual-level responses. As a substantive illustration, we apply our proposed methodology to data on Verbal Test scores from 15 cross-sections of the General Social Survey, 1974–2000. These data have been the subject of recent debates in the sociological literature. We show how our approach can be used to shed new light on these debates by identifying and estimating age, period, and cohort components of change.
Peter Garrard - One of the best experts on this subject based on the ideXlab platform.
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lost in semantic space a multi modal non Verbal assessment of feature knowledge in semantic dementia
Brain, 2006Co-Authors: Peter Garrard, Erin CarrollAbstract:A novel, non-Verbal Test of semantic feature knowledge is introduced, enabling subordinate knowledge of four important concept attributes—colour, sound, environmental context and motion—to be individually probed. This methodology provides more specific information than existing non-Verbal semantic Tests about the status of attribute knowledge relating to individual concept representations. Performance on this Test of a group of 12 patients with semantic dementia (10 male, mean age: 64.4 years) correlated strongly with their scores on more conventional Tests of semantic memory, such as naming and word-to-picture matching. The Test's overlapping structure, in which individual concepts were probed in two, three or all four modalities, provided evidence of performance consistency on individual items between feature conditions. Group and individual analyses revealed little evidence for differential performance across the four feature conditions, though sound and colour correlated most strongly, and motion least strongly, with other semantic tasks, and patients were less accurate on the motion features of living than non-living concepts (with no such conceptual domain differences in the other conditions). The results are discussed in the context of their implications for the place of semantic dementia within the classification of progressive aphasic syndromes, and for contemporary models of semantic representation and organization. Original Submission July 19, 2005. Revised December 16, 2005. Accepted March 1, 2006.
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lost in semantic space a multi modal non Verbal assessment of feature knowledge in semantic dementia
Brain, 2006Co-Authors: Peter Garrard, Erin CarrollAbstract:A novel, non-Verbal Test of semantic feature knowledge is introduced, enabling subordinate knowledge of four important concept attributes--colour, sound, environmental context and motion--to be individually probed. This methodology provides more specific information than existing non-Verbal semantic Tests about the status of attribute knowledge relating to individual concept representations. Performance on this Test of a group of 12 patients with semantic dementia (10 male, mean age: 64.4 years) correlated strongly with their scores on more conventional Tests of semantic memory, such as naming and word-to-picture matching. The Test's overlapping structure, in which individual concepts were probed in two, three or all four modalities, provided evidence of performance consistency on individual items between feature conditions. Group and individual analyses revealed little evidence for differential performance across the four feature conditions, though sound and colour correlated most strongly, and motion least strongly, with other semantic tasks, and patients were less accurate on the motion features of living than non-living concepts (with no such conceptual domain differences in the other conditions). The results are discussed in the context of their implications for the place of semantic dementia within the classification of progressive aphasic syndromes, and for contemporary models of semantic representation and organization.
Yang Yang - One of the best experts on this subject based on the ideXlab platform.
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age period cohort analysis of repeated cross section surveys fixed or random effects
Sociological Methods & Research, 2008Co-Authors: Yang Yang, Kenneth C. LandAbstract:Yang and Land (2006) and Yang (forthcoming-b) developed a mixed (fixed and random) effects model for the age–period–cohort (APC) analysis of micro data sets in the form of a series of repeated cross-section sample surveys that are increasingly available to demographers. The authors compare the fixedversus random-effects model specifications for APC analysis. They use data on Verbal Test scores from 15 cross sections of the General Social Survey (GSS), 1974 to 2000, for substantive illustrations. Strengths and weaknesses are identified for both the random- and fixed-effects formulations. However, under each of the two data conditions studied, the random-effects hierarchical APC model is the most appropriate specification. While additional analyses and comparisons of random- and fixed-effects APC models using other data sets are necessary before generalizations can be drawn, this finding is consistent with results from other methodological studies with unbalanced data designs.
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A MIXED MODELS APPROACH TO THE AGE-PERIOD-COHORT ANALYSIS OF REPEATED CROSS-SECTION SURVEYS, WITH AN APPLICATION TO DATA ON TRENDS IN Verbal Test SCORES
Sociological Methodology, 2006Co-Authors: Yang Yang, Kenneth C. LandAbstract:We develop a mixed (fixed and random effects) models approach to the age-period-cohort (AFC) analysis of micro data sets in the form of a series of the repeated cross-section sample surveys that are increasingly available to sociologists. This approach recognizes the multilevel structure of the individual-level responses. As a substantive illustration, we apply our proposed methodology to data on Verbal Test scores from 15 cross-sections of the General Social Survey, 1974–2000. These data have been the subject of recent debates in the sociological literature. We show how our approach can be used to shed new light on these debates by identifying and estimating age, period, and cohort components of change.
Jacqueline J Hill - One of the best experts on this subject based on the ideXlab platform.
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do children with autism have a theory of mind a non Verbal Test of autism vs specific language impairment
Journal of Autism and Developmental Disorders, 2007Co-Authors: Livia Colle, Simon Baroncohen, Jacqueline J HillAbstract:Children with autism have delays in the development of theory of mind. However, the sub-group of children with autism who have little or no language have gone unTested since false belief Tests (FB) typically involve language. FB understanding has been reported to be intact in children with specific language impairment (SLI). This raises the possibility that a non-Verbal FB Test would distinguish children with autism vs. children with SLI. The present study Tested two predictions: (1) FB understanding is to some extent independent of language ability; and (2) Children with autism with low language levels show specific impairment in theory of mind. Results confirmed both predictions. Results are discussed in terms of the role of language in the development of mindreading.
