[Truncated abstract] Central to the study of general intelligence is Spearman?s g, one definition of which is general fluid reasoning ability. At a cognitive level of explanation, it has recently been hypothesized that individual differences in g is based in the executive functions of the frontal lobes. This theory can be contrasted with the theory that the fount of g is speed of information processing. The aim of this thesis was to test the idea that the two contrasting theories of g could be reconciled by invoking an alternative theory which suggests that there may be two g?s one related to individual differences in intelligence and attributable to differences in speed of information processing and one related to the development of intelligence and based in executive functions of the frontal lobes. This was done with a series of neuropsychological studies that tested groups of adults and children with and without putative central nervous system damage on tests of fluid intelligence, executive function, goal-neglect, and speed of information processing. In study 1, three adults with focal frontal lobe lesions and ten adults with frontotemporal dementia (FTD) were administered three common intelligence tests. In comparison to premorbid and crystallized measures on intelligence, the majority of frontal patients exhibited impaired fluid g. In study 2, 10 patients with FTD, 8 patients with Alzheimer?s disease (AD), 10 adult controls, and 15 adults with low fluid g, were tested on a fast and slow version of a goal-neglect task (thought to measure executive functioning) and a measure of speed of processing. A classical double dissociation was found. Frontal patients with impaired fluid g displayed goal-neglect but intact speed of information processing whereas the adults with low fluid g exhibited slowed speed of information 2 processing but not goal-neglect. It was concluded that the link between fluid g and goal-neglect in adults (demonstrated by previous research) was based on a speed of information processing confound in the goal-neglect task. In study 3, a series of hierarchical regressions were conducted to analyse the performances of 116 children aged 6- to 11-years on all tests. The statistical attempt to dissociate executive function and speed of information processing only provided tentative support for the hypothesis that executive functions are the basis of developmental changes in g

Current theorising in the area of cognitive arithmetic suggests that simple arithmetic knowledge is stored in memory and accessed in the same way as word knowledge i.e., it is stored in a network of associations, with simple facts retrieved automatically from memory. However, to date, the main methodologies that have been employed to investigate automaticity in simple arithmetic processing (e.g., production and verification) have produced a wide variety of difficulties in interpretation. In an attempt to address this, the present series of investigations utilised a numerical variant of the well established single word semantic priming paradigm that involved the presentation of problems as primes (e.g., 2 + 3) and solutions as targets (e.g., 5), as they would occur in a natural setting. Adult university students were exposed to both addition and multiplication problems in each of three main prime target relationship conditions, including congruent (e.g., 2 + 3 and 5), incongruent (e.g., 2 + 3 and 13), and neutral conditions (X + Y and 5). When combined with a naming task and the use of short stimulus onset asynchronies (SOAs), this procedure enabled a more valid and reliable investigation into automaticity and the cognitive mechanisms underlying simple arithmetic processing. The first investigation in the present series addressed the question of automaticity in arithmetic fact retrieval, whilst the remaining investigations examined the main factors thought to influence simple arithmetic processing i.e., skill level, surface form, problem type and split. All factors, except for problem type, were found to influence processing in the arithmetic priming paradigm. For example, the results of all five investigations were consistent in revealing significant facilitation in naming congruent targets for skilled participants, following exposure to Arabic digit primes at the short SOA. Accordingly, the facilitation was explained in terms of the operation of an automatic spreading activation mechanism. Additionally, significant inhibitory effects in incongruent target naming were identified in skilled performance in all of the studies in the present series of investigations. Throughout the course of these investigations, these effects were found to vary with operation, surface form and SOA, and in the final investigation, the level of inhibition was found to vary with the split between the correct solution and the incongruent target. Consequently, a number of explanations were put forward to account for these effects. In the first two investigations, it was suggested that the inhibitory effects resulted from the use of a response validity checking mechanism, whilst in the final investigation, the results were more consistent with the activation of magnitude representations in memory (this can be likened to Dehaene’s, 1997, ‘number sense’). In contrast, the results of the third investigation led to the proposal that for number word primes, inhibition in processing results from the activation of phonological representations in memory, via a reading based mechanism. The present series of investigations demonstrated the utility of the numerical variant of the single word semantic priming paradigm for the investigation of simple arithmetic processing. Given its capacity to uncover the fundamental cognitive mechanisms at work in simple arithmetic operations, this methodology has many applications in future research.

Thesis (M.A.)--Miami University, Dept. of Psychology, 2007. / Title from first page of PDF document. Includes bibliographical references (p. 17-18).

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 149-157).

Thesis (M.A.) - Carleton University, 2002. / Includes bibliographical references (p. 59-66). Also available in electronic format on the Internet.

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 178-200).

Thesis (D.B.A.)--Harvard University, Graduate School of Business Administration, 1997. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 2005. / Available online via OhioLINK's ETD Center; full text release delayed at author's request until 2006 Jun 17.

Thesis (M.Psych.Org) - University of Queensland, 2006. / Includes bibliography.

A presença de diferenças individuais no desempenho motor de crianças e jovens da mesma faixa etária é um aspecto relatado por grande parte da literatura. O presente estudo escolheu o modelo de capacidades perceptivo-motoras para explorar estas diferenças e focou na questão de níveis diferenciados de maturação do sistema nervoso central (SNC). Uma vez que a maioria dos estudos sobre capacidades perceptivo-motoras investiga adultos e não se conhece como o nível do SNC influencia a associação entre as capacidades e desempenho motor. Com isso, o presente estudo teve como objetivo investigar a associação entre as capacidades perceptivo-motoras e o desempenho de tarefas motoras em sujeitos de 7 e 13 anos de idade. A amostra refere-se aos sujeitos que fizeram parte do estudo de Crescimento e Desenvolvimento Motor Longitudinal Misto de Muzambinho-MG. Foram selecionados 110 sujeitos, contrabalanceados em termos de sexo e idade. As capacidades perceptivo-motoras analisadas foram a de coordenação multimembros (CM), timing coincidente (TC), tempo de reação (TR) e tempo de movimento (TM), por sua vez as tarefas motoras analisadas foram correr, rebater e receber. Para a análise da correlação foi utilizado o teste de Spearman, uma vez que não houve distribuição normal. Os resultados indicaram que o desempenho do correr se associou a CM tanto para os 7 anos (ρ=-0,33) quanto para 13 anos (ρ=-0,34). Por sua vez, o desempenho do receber se associou com a CM (ρ=0,41) e TR (ρ=-0,41) para os 7 anos, mas apenas com a CM (ρ=0,29) para os 13 anos. E o desempenho do rebater não se associou com nenhuma das capacidades perceptivo-motoras analisadas. Com base nestes resultados, pode-se inferir que o desempenho em tarefas motoras típicas da infância é associado as capacidades perceptivo-motoras, mas o nível maturacional do sistema nervoso central pode ser um aspecto que interfere nesta associação. Estes resultados permitem identificar um campo de investigação promissor para entender as diferenças individuais que ocorrem no desempenho de crianças e jovens / The presence of individual differences in motor performance of children and teenagers of the same age group is a reported aspect for much of the literature. This study chose the model of perceptual-motor abilities to explore these differences and focused on issue of different central nervous system development levels (CNS). Since most of the studies investigate perceptual-motor abilities in adults and it is not known how the CNS level affects the association between ability and motor performance. This study aimed to investigate the association between perceptual-motor abilities and performance of motor tasks in individuals of 7 and 13 years old. The sample refers to subjects who participated in the study of mixed longitudinal motor growth and development in the city of Muzambinho - Minas Gerais/Brazil. It was selected 110 individuals, balanced in terms of gender and age. The perceptual-motor abilities analysed were the multilimb coordination (MC), coincident timing (CT), reaction time (RT) and movement time (TM) in turn analysed motor tasks were running, batting and receiving. For the correlation analysis it was used the Spearman\'s test, since there were no normal distribution. The results related to the running performances were associated with MC for both 7 years old (p = -0.33) and for 13 years old (p = -0.34). In turn, the receiving performances were associated with the MC (p = 0.41) and RT (p = -0.41) for 7 years old, but only with the MC (p = 0.29) for the 13 year old. Moreover, the batting performances were not associated with any of the perceptual-motor abilities analysed. Based on these results, we can infer that the performance in typical motor tasks of childhood is associated with the perceptual-motor abilities, but the maturity level of the central nervous system can be an aspect that interferes in this association. These results identify a promising field of research to understand individual differences occurring in the performance of children and teenagers