No description available.

No description available.

This study investigated the relationship between divergent thinking, assessed by the Product Improvement and Unusual Uses tests of the Torrance Tests of Creative Thinking (1974), and hemisphericity. Hemisphericity, cerebral hemispheric dominance for language function, was assessed by a dichotic listening technique. Sex, age, hand preference, and verbal expression (assessed by a subtest of the Illinois Test of Psycholinguistic Abilities) were controlled. Subjects were selected at three age levels: four years, seven years, and ten years. For the four-year-old group, the findings indicated that a significant positive relationship existed between the fluency and flexibility scores on the Product Improvement task and right dominant subjects; while a significant negative relationship existed between the flexibility scores on the Unusual Uses test and right dominant subjects. In an effort to explain these contradictory findings, the low correlation between the flexibility scores on the Product Improvement and Unusual Uses tasks was noted and discussed in terms of the possibility that these two tests were not measuring the same construct. The effect of hemisphericity on divergent thinking did not reach significance for any other age group. No meaningful interactions were found when the following independent variables were analyzed: sex x hemisphericity, age x hemisphericity, hand preference x hemisphericity, and verbal expression x hemisphericity. When cerebral dominance was examined across the three age groups, there was an increase in mixed dominance with increasing age. This finding was discussed with regard to the physiological maturation of the corpus callosum which may contribute to interhemispheric communication. Further discussion acknowledged that with an increase in age and cognitive growth comes the ability to better use both cerebral hemispheres. Several limitations were considered in the discussion of the results of this study. These included: insensitivity of tests, attentional factors, the role of memory in the dichotic listening task, technical limitations associated with equipment, and the paucity of previous research on which to build in the area of hemisphericity and its relationship to creativity. It was concluded from the findings of this study that for preschool age subjects, there is a positive relationship between right hemispheric dominance for language and the fluency and flexibility scores on the Product Improvement Task. With regard to the development of hemisphericity, the findings of this study indicated a trend toward greater mixed dominance with increasing age. / Ph. D.

OBJETIVO: Investigar e comparar a aprendizagem de uma habilidade motora de alta demanda de planejamento em sujeitos pós-Acidente Vascular Encefálico (AVE) em função do lado da lesão. MÉTODO: Participaram do estudo 22 indivíduos pós-AVE para compor o grupo experimental (GE), sendo 10 LD e 12 LE, e 14 sujeitos saudáveis para o grupo controle (GC). Os critérios de inclusão foram: 40 a 75 anos de idade, lesão em circulação anterior, crônicos, único evento vascular, destros e Mini Exame de Estado Mental (MEEM) com pontuação acima de 23. A tarefa consistiu em realizar a inserção de uma barra em um orifício, o mais rapidamente possível. O estudo foi composto de duas fases, sendo de aquisição (AQ) com 50 tentativas e de testes de retenção em curto (RET1), longo prazo (RET2) e transferência (TR) com 10 tentativas cada. Foram realizadas análises intra (GC, GE, LD e LE) e intergrupos por meio da ANOVA two-way (grupos X blocos) com medidas repetidas no segundo fator, seguida do post hoc de Tukey. O nível de significância adotado foi de 0,05. RESULTADOS: Houve déficit na aprendizagem do GE nas comparações do nível de desempenho entre o último bloco da AQ com os testes de RET2 e TR, que se apresentou dependente do lado da lesão. Quando comparado com o GC e com LD, o LE apresentou deterioração na RET2. CONCLUSÃO: Há diferença entre o GE e GC no que se refere à aprendizagem de uma habilidade motora com alta demanda de planejamento, mensurada por meio do teste de RET em longo prazo, sendo esta diferença dependente do lado da lesão. O grupo com LE apresentou os maiores déficits na aprendizagem / OBJECTIVE: To investigate and compare the motor learning of a motor skill with high planning demand in post-stroke subjects according to the hemisphere side damage. METHOD: The study comprised twenty-two post-stroke individuals in the experimental group (EG), 10 right hemisphere damaged (RHD) and 12 left hemisphere damaged (LHD), and 14 health subjects in the control group (CG). The inclusion criteria were: age between 40 and 75 years old, anterior circulation damage, chronic stage, single stroke, right-handed and Mini Mental State Exam (MMSE) with score over 23 points. The task consisted of inserting a bar into a hole, as fast as possible. The study consisted of two phases, acquisition (ACQ) with 50 trials and retention tests in short-term (RET1), long-term (RET2) and transfer (TR), with 10 trials each. Analyses within group (CG, EG, RHD and LHD) and between groups were performed by ANOVA two-way (groups x blocks) with repeated measures in the second factor followed by post-hoc of Tukey test. The significant level adopted was 0,05. RESULTS: There was a decrease in the EG learning when the level of performance on the last ACQ block was compared with RET 2 and TR tests, dependent on the hemisphere damage side. CONCLUSION: There are differences on motor learning of a motor skill with high planning demand between EG and CG, especially measured at the RET2. LHD subjects showed significant deterioration in motor learning at the RET2

Human handedness is likely related to brain lateralization and major cognitive innovations in human evolution. Identifying handedness in the archaeological record is, therefore, an important step in understanding our cognitive evolution. This thesis reports on experiments in identifying knapper handedness in lithic debitage. I conducted a blind study on flakes (n=631) from Acheulean handaxes replicated by right- and left-handed flintknappers. Several flake characteristics significantly indicated handedness, with a binary logistic regression correctly predicting handedness for 71.7% of the flakes. However, other characteristics were not associated with handedness. This is a result of personal knapping styles, as additional analyses show that individual knappers associate with some attributes better than handedness does. Continued work on these methodologies will enable analysis of Paleolithic assemblages in the future, with the ultimate goal of tracking population-level hominid handedness rates through time and using them as a proxy for cognitive evolution and language acquisition. / Includes bibliography. / Thesis (M.A.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

Humans display a 90% population level bias towards right-handedness, implying the vast majority of people have a left-hemisphere dominant for motor control. Although handedness presents a weak, but very consistent heritability across the literature (estimated to be approximately 25%), to date few genetic loci associated with this complex trait have been identified and replicated in subsequent studies. One such gene which has been found to be associated with handedness and subsequently replicated is PCSK6, most recently through a quantitative GWAS (P < 0.5*10−8, Brandler et al. (2013)). Interestingly, PCSK6 is known to activate Nodal, a morphogen involved in a highly conserved bilaterian pathway known to regulate left-right body axis determination. Here I present the first molecular characterisation of a handedness-associated region by conducting a detailed functional analysis of the PCSK6 locus, combining genetic analysis, in silico prediction and molecular assays to investigate how common genetic variants influence handedness-related phenotypes. Specifically, I defined the associated locus to be 12.7 kb in size, spanning a predicted 1.8 kb bidirectional promoter which controls the expression of both an antisense long non-coding RNA (lncRNA), and a novel short PCSK6 isoform. A series of luciferase-expressing constructs were generated to characterise the promoter, identifying a minimal sequence capable of driving transcription in a sense strand direction. I have demonstrated experimentally that one of the top associated markers in previous GWA studies, rs11855145, directly creates/disrupts a suspected transcription factor bind site in the vicinity of this bidirectional promoter. Further functional studies of the genetic variation within PCSK6 may help explain the molecular regulatory mechanisms affecting gene expression. This project provides a model for assays to study other GWAS-nominated candidate genes, and in particular for establishing the role of noncoding variants. The findings from this study support the role of common variants in influencing complex phenotypes, such as handedness.

Bibliography: leaves 350-389 / xii, 389 leaves : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (M.D.)--University of Adelaide, Dept. of Psychiatry, 1987

Thesis (M.Communication pathology)-Universiteit van Pretoria, 2001.

No description available.

The purpose of this thesis was to investigate manual asymmetries in the reach-to-grasp movement based on two hypotheses: 1) manual asymmetries are resultant from asymmetries in the dorsal vision-for-action system; and 2) manual asymmetries are contingent on task difficulty. Participants grasped glasses of water under different visual-feedback conditions. Demand was manipulated by varying the level of the water contained in the glass. Hand asymmetries of the reach-to-grasp movement were studied through kinematic analyses. Visual feedback availability and task demand affected all kinematic measures. Manual asymmetries were found in peak velocity, movement time, and variability of maximum grip aperture. Consistent with reach-to-point literature, reach-to-grasp actions were faster and more accurate when performed with the right hand and when guided by the dorsal vision-for-action system. The results of the thesis provide support for a theory of left-hemisphere specialization for the visual control of actions. / xiv, 121 leaves : ill. ; 29 cm