Ph.D (Industrial Psychology) / Brain injuries often occur suddenly and without warning, and from that instant, a normal life can be changed. Traumatic Brain Injury (TBI) may result in significant impairment of an individual’s physical, cognitive and psychosocial functioning. Although there is a fair amount of research on the concept of brain damage and the consequent effects on the family and return to work (RTW) prospects, there is far less information available on the actual assessment of workplace capability or workplace potential following the head injury incident. This is important, since the concept of work or job value has been well documented. Employment is far more than just a job; it not only provides for basic sustenance needs and decent living conditions, but also allows someone to fit into the world, create relationships, use talents and skills, learn, grow and build, and develop a sense of identity and belonging. While the value of work is well-documented, the statistics regarding unemployment following a head injury are concerning. It is estimated that approximately 1.5 million Americans sustain head injuries each year, with the majority of these people being under the age of 35 and in their prime years of vocational productivity. A baseline figure of 2% of the American population is currently living with disabilities as a result of head injuries. In South Africa, the rate of occurrence seems to be even more alarming, with published rates of 89,000 cases for 2009. In 2001, this was a baseline figure of 5% of the population living with disabilities resulting from head injuries. Various sources put the occurrence of head injuries in South Africa at 1.5 to 3.5 times higher than the estimated global rate. The negative impact of this on the individual, the family, community and economy is clear.

To date, no research exists examining criterion-related validity of alternate, computerized forms of the Category Test. The intent of this study was to address criterion-related validity of three full forms of the Category Test. In that, the goal was to examine equivalency of each version in their ability to differentiate brain-injured from non-brain-injured individuals. Forty-nine (N = 49) healthy adults and 45 (N = 45) brain-injured adults were tested using three versions of the Category Test, the BDI, and the WAIS-R NI. ANOVA indicated no significant differences between versions of the Category Test or an interaction between Category Test version and group membership on the total error score. MANOVA performed between versions of the Category Test and Subtest error scores indicated significant differences between versions on Subtest 3 and Subtest 6. Group membership (brain-injured v. non-brain-injured) produced a significant main effect on all subtests of the Category Test except Subtest 2. Several exploratory analyses were performed examining the relationship between neuropsychological impairment, group membership based on Category Test error scores, and the WAIS-R NI. Clinical applications, such as the use of serial testing to index neurorehabilitation gains, were discussed.

Individuals undergoing forensic neuropsychological evaluation frequently stand to gain in some manner if neurocognitive dysfunction is diagnosed. As a result, neuropsychologists are customarily asked to test for neurocognitive feigning during the assessment. The current study employed an analogue design with a clinical comparison group to examine the utility of the TOCA (Rogers, 1996) as a measure of feigned neurocognitive impairment. Two groups of simulators (one cautioned about the presence of detection strategies and one not cautioned) were compared to clinical and normal control groups. Fourteen scales were developed based on five detection strategies: symptom validity testing, performance curve, magnitude of error, response time, and floor effect. Each was employed during both verbal and nonverbal tasks. Significant differences were revealed among groups when subjected to ANOVA. Classification rates from subsequent utility estimates and discriminant function analyses on the scales ranged from 58.8% to 100%. Combining strategies yielded a classification rate of 95.7%. The effect of cautioning simulators was modest; however, a trend was noted on some scales for cautioned simulators to appear less obviously impaired than noncautioned. Although the results require crossvalidation, preliminary data suggest that the TOCA is a sensitive and specific measure of feigned neurocognitive performance. Strengths and weaknesses of the study are discussed and directions for future research are proposed.

A avaliação neuropsicológica de portadores de doença de Parkinson (DP) tem sido de fundamental importância para definição de resultados em procedimentos clínicos, cirúrgicos experimentais ou para diagnóstico de demência nestes doentes. No entanto, ainda não existe consenso quanto aos testes neuropsicológicos necessários e padrões de comprometimento esperados. Este estudo objetivou comparar a produtividade das funções neuropsicológicas entre portadores da Doença de Parkinson, em diferentes estágios da doença, em relação aos indivíduos normais. Foram analisados 60 sujeitos (32 homens e 28 mulheres), emparelhados em relação à idade (média de 65,6 +-9,2) e instrução (média de 5,9 =- 4,0), distribuídos entre normais (n=20) e portadores de DP ambulatoriais, nos estágios leve a moderado (n=20) ou moderado a grave (n=20), de acordo com a escala Hoehn & Yahr. A bateria utilizou 24 testes neuropsicológicos abrangendo as funções de raciocínio, percepção visuoespacial, visuoconstrução, linguagem, memória, atenção e função executiva. Os resultados apontaram diferenças significantes (p < 0,01) entre vários testes e em todas as funções, exceto linguagem. Alguns instrumentos se mostraram mais adequados e outros se mostraram pouco indicados para avaliar estes doentes. Diferenças entre os estágios da doença só se evidenciaram nos testes que exigiam destreza motora. Este trabalho estabelece a adequação dos instrumentos e propõe uma bateria específica para avaliação destes doentes. A investigação de estados situacionais (nível cultural, sintoma afetivo e/ou limitações funcionais), manifestos na avaliação, permitiu estabelecer parâmetros para discriminar o modo como estas variáveis interferem na produção dos doentes de Parkinson. E conclui-se apresentando um método inovador de classificação para subsidiar com objetividade o diagnóstico neuropsicológico diferencial na DP. / The neuropsychological assessment of patients with Parkinson disease (PD) has been very important to define the results in clinical, experimental surgeries procedures or in the diagnostic of dementia of these patients. However, there is no consensus about the necessary neuropsychological tests and about the expected commitment patterns. This study aimed to compare the productivity of the neuropsychological functions among patients with Parkinson Disease, in different stages of the disease, in relation to normal people. Sixty subjects were assessed (32 men and 28 women), pared in relation to the age (average of 65.6 +- 9.2) and age of study (average of 5.9 +- 4.0), distributed among normal (n=20) and outpatients with PD, in the mild to moderate stages (n=20) or moderate to severe (n=20), according to Hoehn & Yahr Scale. The battery used 24 neuropsychological tests comprising the thinking, visuospatial perception, visuoconstruction, language, memory, attention and executive function. The results showed significant differences (p < 0.01) among many tests and in all the functions, except language. Some instruments were more suitable and others proved to be less indicated to assess these patients. Differences in the stages of the disease were highlighted in the tests that required motor ability. This work establishes the adequacy of the instruments and proposes a specific battery to assess these patients. The investigation of the situational state (cultural level, affective symptom and/or functional limitations), that appeared in the assessment, allowed to establish parameters to find out the way that these variables interfered in the Parkinson patients’ production. The work concludes presenting an innovative classification method to objectively subside the neuropsychological differential diagnosis for PD.

A dislexia é um transtorno específico de leitura que consiste em um rendimento na leitura e na escrita inferior ao esperado para a idade cronológica, para nível de escolaridade e para o nível de inteligência, sendo a eficiência intelectual adequada (QI 80). Os principais comprometimentos envolvem habilidades de competências linguísticas como dificuldade de consciência fonológica, memória fonológica, discriminação e nomeação. Estudos apontam relação entre as dificuldades na leitura e na escrita e fatores neurobiológicos. O objetivo deste projeto foi investigar se existem diferenças entre morfometria cerebral através de segmentação automática para análise de espessura e volume e diferenças entre o desempenho cognitivo em testes neuropsicológicos do grupo de indivíduos com dislexia comparados com um grupo controle pareado. Foi realizado um estudo prospectivo no qual participaram 30 crianças, sendo 15 indivíduos com dislexia e 15 controles pareados por idade e por sexo. Foram avaliadas habilidades cognitivas tais como: eficiência intelectual, funções de atenção, habilidade visuoconstrutivas e habilidades de linguagem oral e escrita. A morfometria cerebral foi baseada em sequência T1 volumétrica de ressonância magnética e segmentação automática com medida da espessura e volume utilizando o pacote de software FreeSurfer. Na avaliação neuropsicológica, as habilidades que se mostraram mais prejudicadas foram aspectos da memória e da linguagem oral e escrita, tais como rebaixamento de span de memória operacional fonológica e dificuldade de fluência verbal, de associação e integração de ideias, de definição/conceitos, de nomeação e principalmente de consciência fonológica, de leitura e de escrita. As análises de neuroimagem sugerem alterações estruturais no cérebro do grupo clínico com redução no volume de substância cinzenta em regiões corticais, tais como lobo temporal inferior esquerdo e lobo temporal médio direito, e redução no volume de substância branca de ambos os hemisférios. Não foram identificadas alterações significativas na espessura. As alterações estruturais observadas através das técnicas de imagem podem estar relacionadas às funções cognitivas que se mostraram afetadas. / Dyslexia is a specific reading disorder that consists of a performance in reading and writing lower than expected for chronological age, educational level and for the level of intelligence, with an adequate intellectual efficiency (IQ 80 ). The main commitments involve abilities of language skills as difficulty in phonological awareness, phonological memory, discrimination and naming. Studies show link between difficulties in reading and writing and neurobiological factors. The objective of this project was to investigate whether differences in brain morphometry using automatic segmentation for the analysis of thickness and volume differences between cognitive performance on neuropsychological tests of the group of individuals with dyslexia compared with a control group. This is a prospective study in which 30 children participated, with 15 individuals with dyslexia and 15 controls matched by age and sex. Cognitive skills were evaluated as such: Intellectual efficiency, attention skill, visuo- constructive abilities and skills of oral and written language. Brain morphometry was based on sequence T1 volumetric MRI automatic segmentation and measurement of the thickness and volume using FreeSurfer software package. Neuropsychological skills that were more impaired were aspects of memory and oral and written language, such as flattening of phonological working memory span and difficulty in verbal fluency, association and integration of ideas, definitions / concepts, appointment and especially phonological awareness, reading and writing. Neuroimaging studies suggest structural changes in the brain with clinical group reduction in gray matter volume in cortical regions such as the left inferior temporal lobe and right middle temporal lobe, and a reduction in the volume of white matter of both hemispheres. No significant changes were identified in thickness. Structural changes observed through imaging techniques may be related to cognitive functions that have proven affected.

Refer to document

Graduation date: 2006

Thesis (Ph. D.)--Ball State University, 2009. / Title from PDF t.p. (viewed on Nov. 12, 2009). Includes bibliographical references (p. 73-82).

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 79-100). Available also in a digital version from Dissertation Abstracts.

Virtual-reality neuropsychological tests offer a novel way to assess real-life executive functioning within the context of standardized test conditions whilst maximizing ecological validity. Given the limited empirical evidence base for many of these virtual-reality tests, the current study aimed to further examine the relative ecological validity, sensitivity to brain-injury and diagnostic accuracy of the virtual-reality based Jansari assessment of Executive Functions (JEF). To do this, the test was compared to seven standard tests of executive function, in a New Zealand sample of 27 brain-injured and 28 non brain-injured participants matched for age, gender and education. The JEF’s ecological validity was supported, with JEF total percent scores exhibiting large correlations with participants’ independently reported levels of everyday functioning, as measured by the Dysexecutive Questionnaire: Independent-Rater (DEX-IR) and Patient Competency Rating Scale-Relative (PCRS-R) (both rs = 0.606, p < 0.001). Compared to the standard executive function test variables included in the current study, the JEF’s associations with the everyday functioning measures were the largest, but only significantly larger than the respective correlations of some standard executive function test variables. These results indicated that the JEF is trending towards being relatively more ecologically valid than most of the standard executive function tests included in the study. The JEF also exhibited good sensitivity to brain-injury and diagnostic accuracy for discriminating brain-injured from non brain-injured participants, which was generally consistent with most of the standard tests, but only significantly better than some. These results provide empirical support for the JEF’s clinical utility, particularly in the assessment of brain-injured persons’ functional abilities. It also suggests that both virtual-reality and standard executive function tests have a place in the routine neuropsychological test batteries used to assess brain-injured persons.