Background: For Diffusion Tensor Imaging (DTI) to become a clinically useful tool in the detection of traumatic brain injury (TBI) and prediction of functional outcome, a reliable method enabling the identification of likely injury in individual patients needs to be developed. Objective: To explore different methods of analysing DTI measures to determine if individual TBI patients can be differentiated from a group of non-brain injured controls and if so, how these differences are associated with cognitive function. Method: 4 participants with TBI and 11 control participants were scanned using DTI and completed a battery of neuropsychological tests. The DTI measures of Fractional Anisotropy (FA) and Mean Diffusivity (MD) in the uncinate fasciculus were compared across individual TBI patients and a control group using 3 different methods of analysis. Results: The comparison of mean FA/MD from individual TBI patients with the overall mean FA/MD of the control group revealed that some TBI patients had lower values of FA whilst others had increased MD. This difference in FA may be associated with deficits in measures of attention. The histogram curves and cumulative frequency plots for individual TBI patients and the controls revealed subtle yet potentially significant differences in the distribution of FA/MD. However at this stage these differences could not be associated with cognitive function. Conclusion: Initial findings indicate that individual TBI patients can be differentiated from a control group using different methods with differing degrees of sensitivity. These differences may be related to cognitive function but further research is warranted before firm conclusions can be drawn.

Among the goals of the neuropsychological assessment are to detect the presence of brain damage, localize which areas of the brain may be dysfunctional and describe subsequent functional impairments. The sensitivity of neuropsychological instruments in carrying out these functions is a question of some debate. The purpose of this study is to determine the utility of lateralizing indicators from the WAIS-III, McCarron Assessment of Neuromuscular Development (MAND) and Haptic Visual Discrimination Test (HVDT), from the McCarron-Dial System Neuropsychological Assessment Battery (MDS), in ascertaining the presence or absence of brain damage as well as location of lesion. The classification accuracies of using performance level indicators from these tests and lateralizing indicators, alone and together, were compared.

Inflammation appears to play a major role in the pathogenesis of Major Depression, and understanding the relationship between the immune system and mood disorders is a growing area of research. Patients undergoing cytokine therapy frequently develop depressive-like signs which cease upon termination of treatment. In addition, depressed patients often present with high levels of circulating pro-inflammatory cytokines. There are also significant behavioural correlates between inflammation-associated sickness behaviours and Major Depression, suggesting there is a bidirectional relationship between the immune system and central systems regulating behaviour. Both sickness behaviours in animals and cytokine-induced depression in humans can be reversed with antidepressants targeting the serotonergic (5-HT) system. Against this background, this thesis sought to investigate the role of inflammation in the development of certain specific characteristics of depressive-like states in animal models. Specifically, a single systemic endotoxin challenge (LPS) was used to model acute sickness behaviour and to study the behaviour and molecular effects of this challenge on the 5-HT system. These studies indicated that a single systemic challenge changed the function of the 5-HT system, as well as increasing expression levels of a number of 5-HT-related genes, and markers of inflammation in the CNS. A rodent chronic stress paradigm was employed to investigate whether these changes also occur in animals displaying depressive-like signs. Chronically stressed mice were shown to display significant features of rodent depression; decreased sucrose preference and increased forced swim immobility. These changes were also accompanied by increased expression of 5-HT-related genes and inflammatory markers within the CNS. Importantly, many of the molecular changes observed in LPS-induced sickness behaviour were conserved in the model of stress-induced Major Depression. In particular, increased TNF expression within the CNS was highlighted as a feature in both models. Novel anti-inflammatory agents were used to study the role of TNF in the development of sickness behaviours. Anti-TNF therapy, specifically the fusion protein etanercept, ameliorated sickness behaviour induced by LPS. Together, these data demonstrate that inflammation is capable of significantly changing the 5-HT system, and that stress per se is capable of inducing an inflammatory state within the CNS, which support the thesis that sickness and Major Depression are closely related at a molecular level.

The fornical tract, a major input-output pathway of the hippocampus, of the primate brain makes crucial contributions to visual memory, as effects after surgical or aetiological lesions of this tract are widely documented in the monkey and human literature. Here, a series of experiments sought to further elucidate the functions of this structure with a battery of novel tasks in macaque monkeys, conducted either on a touchscreen or in an ambulatory chamber, so as to offer a more global view of the mnemonic role accomplished by it. After receiving bilateral transection of the fornix, monkeys are impeded in the 'fast learning' phase of a large number of new visuospatial conditional problems, with major impairments seen in eliminating non-perseverative errors. These fornix transected monkeys are however facilitated in the initial acquisition of a visuovisual conditional task, with facilitation seen in their improved ability in eliminating perseverative errors. It is also demonstrated in an ambulatory apparatus, in comparison to control monkeys, these monkeys are impaired in the new learning of visuospatial context of environments, albeit still displaying intact locomotor and exploratory behaviour patterns. Contrary to the relatively clear role in new learning, the involvement of the fornix in memory retention over the very long-term is unknown. It is shown here that once some visuospatial information is learnt; the fornix is no longer implicated in the retention of the material. The effects of fornix transection are also found to be detrimental on a spatial recognition task, with impairments observed in acquisition of the more demanding stages of the task. The overall results covered in this thesis support previous work suggesting that the fornix mediates the new learning of visual information, and I further propose that this fornical involvement lies primarily in the learning of spatio-temporal contexts, particularly during 'fast learning', as well as in task-sets acquisition. I also argue for dissociation in the contributions of the fornix and hippocampus to some memory processes in the macaque.

It is still unresolved whether individuals with dyslexia suffer non-verbal auditory processing deficits that may explain their phonological problems. Many studies have shown that dyslexic individuals are poor at discriminating pure tones, and this deficit has been attributed to impaired rapid auditory processing. In order to investigate the temporal properties of auditory processing in dyslexia, I have therefore studied the pure tone discrimination abilities of dyslexics, and then analysed the effects of varying interstimulus interval, the amount of frequency difference, and the effect of adding distractor tones during the interstimulus interval. In an investigation of dyslexic individuals’ ability to remember sequences of tones or digits (tonal and digit recognition memory), Rose and Rosner (2005) found that their results were affected by the education their subjects had received. The university educated dyslexics showed little tone discrimination deficit, whereas the dyslexic participants who never attended university showed greater deficits. Therefore, another aim of this thesis was to further study these findings and to identify any auditory processing compensatory mechanisms used by dyslexics who have received higher education. In eight different auditory tasks, the majority of which I programmed, I found strong evidence of non-verbal auditory processing deficits in dyslexic individuals. The comparison of university and non-university groups showed that educational differences had clear effects on many of their abilities, and should not be underestimated. The results showed that: • In general, dyslexics had poorer auditory frequency discrimination than controls. • Dyslexics who did not attend university had lower performance on almost all the auditory tests than the university dyslexic or control groups. • Unexpectedly, university educated dyslexics were less distracted by interrupting tones during frequency discrimination than university educated controls. • In a tone sequence memory task, the university educated dyslexics compensated in their performance to a level not much below that of the university educated controls, and above the controls who did not go to university. • The frequency recognition tasks positively correlated with literacy abilities, and were independent of general intelligence. The strongest correlations were in the non-university dyslexic group. The implications of these results are that not only do dyslexic individuals suffer from a low level, non-linguistic, auditory processing deficit, but those who do not get to university are less able to compensate for these difficulties. It is impossible to say if the higher performance in university educated dyslexics was due to compensation, or if their presence at university was due to a lack of these deficits in the first place. Nevertheless, since university educated dyslexics were better at resisting distractions this may underlie their ability to compensate. These findings could facilitate the creation of new teaching methods to support the development of dyslexics’ compensatory skills and new non-linguistic diagnostic aids. These would help with identifying dyslexia in second languages and enable earlier testing and identification, before reading failure exerts its inevitable negative effects on children’s self-confidence, happiness and future academic potential.

To study potential hyperactivity and hyperconnectivity based on the latent resource hypothesis, this study assessed functional connectivity in survivors of childhood brain tumors compared to their healthy peers during an attention task using psychophysiological interaction (PPI) analyses and evaluated for a relationship with performance. Twenty-three survivors and 23 healthy controls completed a letter n-back task in the scanner. An empirically-based seed was placed in the parietal lobe, a theoretical seed was placed in the hippocampus, and a control seed was placed in the occipital lobe. Differences in both performance and functional connectivity networks from each seed emerged between groups, with some findings supporting the latent resource hypothesis and other networks showing compensatory function in survivors. Attention networks, phonological networks, and executive function networks were all found to differ between controls and survivors.

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.

This study analyzed the relationship between the OF functioning of 100 incarcerated male offenders and their psychopathy symptoms. The study's rejected hypothesis had predicted a significant relationship between measures of OF functioning and the Defective Affective Experience (DAE) and Impulsive and Irresponsible Behavioral Style (IIB) factors of the Cooke and Michie (2001) three-factor model of psychopathy. Regression analysis failed to demonstrate a relationship between OF functioning and the DAE and IIB factors. Group differences on OF functioning were not demonstrated between participants in the upper and lower quartiles of a summed DAE and IIB factor score. A general role for OF functioning in criminal behavior was suggested as two OF measures accounted for 14.9% of the variance of criminal convictions.

The present study examined developmental changes in the establishment of mother-infant tactile and visual communication within depressed and non-depressed breast- and bottlefeeding dyads. 113 (30 depressed, 83 non-depressed mothers) mother-infant dyads participated at the 1-month visit and 87 dyads returned at the 3-month lab visit. Maternal mood status was assessed. EEG recordings were taken from the infants at mid-frontal, central, parietal and occipital sites. Mothers and their infants were videotaped during a 5- minute feeding. The feeding session was coded for touch and gaze, utilizing coding scales similar to those of Polan and Ward (1994) and Moszkowski and Stack (2007). Infant self-touch significantly predicted infant EEG asymmetry scores. Non-depressed and depressed breast-feeding mothers displayed more affectionate touch while depressed bottle-feeding mothers displayed an absence of touch. / by Jillian Sader. / Thesis (M.A.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.

O autismo infantil vem sendo amplamente estudado desde sua primeira definição por Leo Kanner em 1943, sendo um dos mais graves distúrbios do desenvolvimento infantil. Diversas hipóteses etiológicas e propostas terapêuticas foram criadas, partindo-se de concepções psicodinâmicas bem como cognitivas e comportamentais. Atualmente observa-se a possibilidade de uma abordagem do autismo apoiada na compreensão de que os padrões de desenvolvimento atípicos destas crianças seriam essencialmente determinados por alterações primárias no funcionamento neuropsicológico, que afetariam os processos cognitivos e afetivos de modo abrangente. Estudos atuais acerca do processo de maturação cerebral indicam um tratamento particular das informações sensoriais no autismo e igualmente das mensagens sociais, como os gestos, as mímicas faciais, a palavra. Os estudos de Piaget nos permitem discutir esta abordagem contemporânea do autismo a partir de uma teoria clássica do desenvolvimento infantil considerando-se: os fatores necessários ao desenvolvimento, a base biológica das estruturas cognitivas, os níveis evolutivos do período sensório-motor e da construção do real, a noção de inter-ação, construção e coordenação dos esquemas. Tais conceitos nos permitem criar hipóteses sobre os processos interativos implicados no desenvolvimento atípico da criança com autismo, bem como compreender a influência das possíveis abordagens terapêuticas sobre estes processos, tais como a Terapia de Troca e de Desenvolvimento (Thérapie dÉchange et de Développement - TED, no original francês). A TED é uma proposta terapêutica criada progressivamente nos últimos trinta anos no serviço de psiquiatria infantil da Universidade de Tours, na França, a partir de uma compreensão neurofisiológica e desenvolvimentista do autismo. Ela conjuga um enquadre e intervenções particulares, buscando enriquecer as possibilidades de interação da criança autista, e reorganizar o funcionamento neurológico e cognitivo, base dos processos de troca com o ambiente e com o outro. O objetivo deste estudo foi o de articular a teoria de desenvolvimento de Piaget à proposta metodológica da TED, refletindo sobre as construções cognitivas e os processos evolutivos alterados no autismo. Para tanto, apresenta (a) uma breve introdução dos estudos anteriores ligados ao presente trabalho, (b) os principais constructos piagetianos sobre o desenvolvimento que permitem uma articulação com a TED, (c) uma apresentação preliminar da TED, incluindo-se seus princípios organizadores e sua técnica própria, para finalmente passar à (d) uma articulação teórica entre os conceitos piagetianos apresentados e a TED, baseada na apresentação de vinhetas clínicas. Os resultados apontaram para uma relação possível entre alguns dos conceitos mais centrais à teoria piagetiana e a proposta da TED, confirmando a hipótese de uma articulação possível entre a compreensão de desenvolvimento proposta por Piaget e os processos implicados no trabalho com crianças autistas, compreendidos a partir da Terapia de Troca e Desenvolvimento (TED) / Childhood autism has been widely studied since its first definition by Leo Kanner in 1943, being one of the most serious childhood development disorders. Several etiological hypothesis and therapeutic proposals were created, based on psychodynamic, cognitive or behavioral approaches. Presently, a new approach to autism is possible, in which the atypical developmental patterns observed in these children can be understood as essentially determined by primary neuropsychological impairments, which have an effect on cognitive and affective processes. Recent studies concerning the brain maturation process in autism indicate atypical sensory information treatment, as well as regarding social messages, such as gestures, facial expression and language. Piagets research allows the discussion of this contemporary approach to autism from the standpoint of a classical childhood development theory, considering: the necessary development factors; the biological basis of cognitive structures; the sensory-motor period evolutionary levels and the construction of the real; the inter-action, construction and coordination between schemes. Such concepts allow the creation of hypothesis about the interactive processes involved in the autistic childs atypical development, as well as enhance the understanding of the influence of possible therapeutic approaches on these processes, such as the Exchange and Development Therapy (EDT). The EDT is a therapeutic proposal progressively created over the past 30 years at the childhood psychiatric service at Tours University, in France, from a neurophysiological and developmental standpoint of autism. It combines a specific setting and interventions, seeking to enrich the child\'s interaction, and rearrange the neurological and cognitive functioning, which is the basis for the exchange with the environment and with the other. This research intended to associate Piagets development theory to EDTs methodological proposal, reflecting on cognitive construction and the developmental impairments in autism. In doing so, it presents (a) a brief introduction to previous studies related to this work, (b) piagetians main constructs on the development, that allow the parallel with the EDT, (c) a preliminary presentation of the EDT, including its organizing principles and its own technique, to finally move to (d) a theoretical association between the presented Piagetian constructs and EDT, based on the presentation of clinical extracts. It was concluded that the parallel between some of Piagetian central concepts and EDTs proposal is coherent, confirming the hypothesis of a possible relationship between Piagets development understanding and the processes involved in working with autistic children, considering the Exchange and Development Therapy (EDT)