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Categorical Representations (categorical + representation)
Selected AbstractsDo Novel Words Facilitate 18-Month-Olds' Spatial Categorization?CHILD DEVELOPMENT, Issue 6 2007Marianella Casasola Eighteen-month-olds' spatial categorization was tested when hearing a novel spatial word. Infants formed an abstract categorical representation of support (i.e., placing 1 object on another) when hearing a novel spatial particle during habituation but not when viewing the events in silence. Infants with a productive spatial vocabulary did not discriminate the support relation when hearing the same novel word as a count noun. However, infants who were not yet producing spatial words did attend to the support relation when presented with the novel count noun. The results indicate that 18-month-olds can use a novel particle (possibly assisted by a familiar verb) to facilitate their spatial categorization but that the specificity of this effect varies with infants' acquisition of spatial language. [source] Six-Month-Old Infants' Categorization of Containment Spatial RelationsCHILD DEVELOPMENT, Issue 3 2003Marianella Casasola Six-month-old infants' ability to form an abstract category of containment was examined using a standard infant categorization task. Infants were habituated to 4 pairs of objects in a containment relation. Following habituation, infants were tested with a novel example of the familiar containment relation and an example of an unfamiliar relation. Results indicate that infants look reliably longer at the unfamiliar versus familiar relation, indicating that they can form a categorical representation of containment. A second experiment demonstrated that infants do not rely on object occlusion to discriminate containment from a support or a behind spatial relation. Together, the results indicate that by 6 months, infants can recognize a containment relation from different angles and across different pairs of objects. [source] A taxometric study of alcohol abuse and dependence in a general population sample: evidence of dimensional latent structure and implications for DSM-VADDICTION, Issue 5 2009Tim Slade ABSTRACT Aims To explore, with the aid of taxometric analysis, whether alcohol abuse and alcohol dependence are each conceptualized most effectively as single latent dimensions or distinct latent categories. Design Data were taken from a nationally representative cross-sectional epidemiological survey of psychiatric and substance use disorders. Setting General population of Australia. Participants A subsample of all respondents who had consumed at least 12 drinks in the year prior to the survey and who had consumed at least three drinks on at least one single day (n = 4920 of a possible 10 641). Measurements DSM-IV criteria for alcohol abuse and dependence were assessed with the Composite International Diagnostic Interview, version 2.1. Two independent taxometric procedures, MAXimum EIGenvalue (MAXEIG) and mean above minus below a cut (MAMBAC), together with analysis of simulated dimensional and categorical data sets, were carried out. Findings Consistent evidence was found for a single latent dimension underlying the symptoms of alcohol dependence. Less consistent evidence of dimensionality was found for the symptoms of alcohol abuse. Conclusions These findings support the growing consensus regarding the need for continuous measures of alcohol use disorders to complement the traditional categorical representations in upcoming versions of the major psychiatric classification systems. [source] Young Infants' Performance in the Object-Variation Version of the Above-Below Categorization Task: A Result of Perceptual Distraction or Conceptual Limitation?INFANCY, Issue 3 2002Paul C. Quinn Five experiments were conducted to examine the performance of young infants on above versus below categorization tasks. Experiments 1 and 2 showed that infants did not form abstract categorical representations for above and below when familiarized with different objects depicted in a constant spatial relation relative to a horizontal bar and tested on a novel object depicted in the familiar and novel spatial relation. Experiments 3 through 5 examined perceptual-attentional distraction versus conceptually based generalization explanations for young infant performance in the object-variation version of the above-below categorization task. Experiments 3 and 4 demonstrated that infants still did not form abstract categorical representations for above and below when object variation was removed from the familiarization trials or when object novelty was reduced during the preference test trials. However, Experiment 5 showed that 3- and 4-month-olds succeeded on the above versus below categorization task when familiarized with object variation and preference tested with a familiar versus novel object-bar relation. These results indicate that young infants can form categorical representations for above and below in the object-variation version of the above-below categorization task, but that such representations are specific to the particular objects presented. Young infant performance in the object-variation version of the above-below categorization task thus reflects a conceptually based generalization limit rather than a problem of perceptual-attentional distraction. [source] | ||||||||||