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Individuals with Alcohol Related Neurodevelopmental Disorder (ARND) and Attention-Deficit/Hyperactivity Disorder (ADHD) display similar deficits in behavioural, cognitive, and executive dysfunction symptoms; however, the underlying impairment in brain function and attention pathways is thought to be different. This study compared these two clinical groups, and healthy controls, using psychological assessments and functional magnetic resonance imaging (fMRI). The two clinical groups had significantly different scores on measures of overall intellectual functioning, working memory, and the conjunction trials on the fMRI assessment but could not be differentiated on other measures from rating scales, standardized psychological assessments, and performance data from fMRI tasks. The fMRI task accuracy variables were strongly correlated with related standardized psychological measures. All groups demonstrated difficulties with response inhibition compared to attention, and the clinical groups demonstrated more difficulties with attention and variability compared to the control group on a computer-paced Go/No-Go task. The comparison of a self-paced and a computer-paced Go/No-Go task indicated that the computer-paced task would be more appropriate to use with fMRI to assess cortical activation in response inhibition. It was found that the ADHD group had higher levels of cortical activation (indicating that more cognitive effort was require to reach the same level of behavioural performance) compared to the ARND group during the visual-spatial attention tasks, whereas the ARND group had higher levels of activation during the response inhibition and working memory tasks. Despite no significant differences in behavioural performance, the fMRI tasks helped to demonstrate different activation patterns that could help distinguish and differentially diagnose these two similar groups. / October 2016

Blood oxygen level dependent (BOLD) functional magnetic resonance imaging is a non-invasive technique used to trace changes in neural dynamics in reaction to mental activity caused by perceptual, motor or cognitive tasks. The BOLD response is a complex signal, a consequence of a series of physiological events regulated by increased neural activity. A method to infer from the BOLD signal onto underlying neuronal activity (hemodynamic inverse problem) is proposed in Chapter 2 under the assumption of a previously proposed mathematical model on the transduction of neural activity to the BOLD signal. Also, in this chapter we clarify the meaning of the neural activity function used as the input for an intrinsic dynamic system which can be viewed as an advanced substitute for the impulse response function. Chapter 3 describes an approach for recovering neural timing information (mental chronometry) in an object interaction decision task via solving the hemodynamic inverse problem. In contrast to the hemodynamic level, at the neural level, we were able to determine statistically significant latencies in activation between functional units in the model used. In Chapter 4, two approaches for regularization parameter tuning in a regularized-regression analysis are compared in an attempt to find the optimal amount of smoothing to be imposed on fMRI data in determining an empirical hemodynamic response function. We found that the noise autocorrelation structure can be improved by tuning the regularization parameter but the whitening-based criterion provides too much smoothing when compared to cross-validation. Chapter~5 illustrates that the smoothing techniques proposed in Chapter 4 can be useful in the issue of correlating behavioral and hemodynamic characteristics. Specifically, Chapter 5, based on the smoothing techniques from Chapter 4, seeks to correlate several parameters characterizing the hemodynamic response in Broca's area to behavioral measures in a naming task. In particular, a condition for independence between two routes of converting print to speech in a dual route cognitive model was verified in terms of hemodynamic parameters.

Blood oxygen level dependent (BOLD) functional magnetic resonance imaging is a non-invasive technique used to trace changes in neural dynamics in reaction to mental activity caused by perceptual, motor or cognitive tasks. The BOLD response is a complex signal, a consequence of a series of physiological events regulated by increased neural activity. A method to infer from the BOLD signal onto underlying neuronal activity (hemodynamic inverse problem) is proposed in Chapter 2 under the assumption of a previously proposed mathematical model on the transduction of neural activity to the BOLD signal. Also, in this chapter we clarify the meaning of the neural activity function used as the input for an intrinsic dynamic system which can be viewed as an advanced substitute for the impulse response function. Chapter 3 describes an approach for recovering neural timing information (mental chronometry) in an object interaction decision task via solving the hemodynamic inverse problem. In contrast to the hemodynamic level, at the neural level, we were able to determine statistically significant latencies in activation between functional units in the model used. In Chapter 4, two approaches for regularization parameter tuning in a regularized-regression analysis are compared in an attempt to find the optimal amount of smoothing to be imposed on fMRI data in determining an empirical hemodynamic response function. We found that the noise autocorrelation structure can be improved by tuning the regularization parameter but the whitening-based criterion provides too much smoothing when compared to cross-validation. Chapter~5 illustrates that the smoothing techniques proposed in Chapter 4 can be useful in the issue of correlating behavioral and hemodynamic characteristics. Specifically, Chapter 5, based on the smoothing techniques from Chapter 4, seeks to correlate several parameters characterizing the hemodynamic response in Broca's area to behavioral measures in a naming task. In particular, a condition for independence between two routes of converting print to speech in a dual route cognitive model was verified in terms of hemodynamic parameters.

With an estimated prevalence of ~1%, Autism Spectrum Disorder (ASD) is relatively common. Whilst accepted as a neurodevelopmental disorder, currently the diagnosis of autism is based on the observation of characteristic behaviour: deficits in language, communication and social skills in addition to unusual or restricted interests. Research in the condition has been approached with psychological and physiological methodology however a full understanding of the underlying neuropathology of autism is still unclear. Functional Magnetic Resonance Imaging (fMRI) has been employed to study face processing in ASD with varied results. The processing of other types of social cues has been far less extensively explored and similarly, whilst there have been some reports of aberrant neural responsiveness to emotion in ASD, this component of social cognition requires further study. In particular, it is unclear whether there is a specific deficit in processing faces in ASD or rather a global deficit in emotion processing which is present across stimulus types, sensory domains and emotions. In this study basic emotion labelling using a range of stimulus types has been investigated within the same ASD cohort. In comparison to a control group, deficits were apparent in the ASD group when processing emotion in face, whole body and voice stimuli. This indicates a global emotion processing deficit in ASD that cannot be fully accounted for by deficits in basic face processing alone. Processing neutral and emotional faces and static whole body images was subsequently investigated using fMRI. When neutral faces, neutral bodies, fearful faces and fearful bodies were contrasted with fixation baseline, both groups broadly recruited the expected network of brain regions. When the emotional condition was contrasted with the neutral condition for each stimulus type significant between groups differences were apparent. The bilateral inferior parietal lobe responded significantly differently in response to facial emotion and the right supplementary motor area and superior temporal sulcus region was differentially activated in response to emotion in body stimuli. Findings reported here suggest that there are wide ranging social deficits in ASD which relate to the processing of a variety of social cues. fMRI evidence suggests that these deficits have a neural basis, in which elements of the social brain, including regions associated with mirror neuron function, activate in an atypical manner in ASD.

Recently functional magnetic resonance imaging has become popular in the studies of human brain functions. As the area of auditory cortex has been proven and defined, we consider music cognition as the next step. In this study, we focus on the response of rhythm. Professional musicians and amateurs were involved in our experiments. Our preliminary result revealed that three of professional musicians have distinguished activation on left cerebrum Inferior Frontal Gyrus BA45/BA47 (language areas). However, since the subjects¡¦ background is difficult to be strictly controlled, further discussion is necessary to define meaning and brain functions of our experiments.

Alcohol-induced blackouts, or periods of anterograde amnesia without loss of consciousness, were a diagnostic indicator in Jellinek’s (1952) theory of alcoholism and have been correlated with alcohol use problems (Campbell & Hodgins, 1993; Goodwin, Crane, & Guze, 1969; Ryback, 1970; Tarter & Schneider, 1976). Other findings suggest that blackouts are a warning sign of problem drinking, but not a predictor of alcohol use disorders (Anthenelli, Klein, Tsuang, Smith, & Schuckit, 1994). Most published research on blackouts focuses on cognitive deficits among older alcohol-dependent adults, yet recent research indicates prevalence rates for blackouts as high as 50% among college students (White, Jamieson-Drake, & Swartzwelder, 2002). In addition, young adults who reported experiencing a blackout were later told that they had vandalized property, driven a car, or engaged in other risky behaviors without remembering (Buelow & Koeppel, 1995). Despite their high prevalence and associated negative consequences, relatively little is known about alcohol-induced blackouts or their neural, social, and behavioral correlates among non-dependent populations. The current research explored individual variation in memory functioning under sober and intoxicated conditions and alcohol’s effects on neural activation during memory processes. / text

Metamemory is defined as the knowledge about one's memory capabilities and about strategies that can aid memory (Shimamura, 1994). One particularly intriguing type of metamemory judgment is a tip-of-the-tongue experience, which refers to a strong feeling that a target word, though presently not recalled, is known and on the verge of being produced. Older adults report more TOT experiences than young adults. However, there is great variability among older adults in performance on memory and executive function tasks, and it is unknown whether subsets of older adults experience more TOT states. Additionally, the neural correlates of successful retrieval, TOTs, and unsuccessful retrieval in aging have not been studied. In the studies reported here, the relationship between frontal and medial temporal neuropsychological factor scores (see Glisky et al., 1995) and performance on metamemory tasks was examined. Importantly, this was the first study to examine the neural correlates of tip-of-the-tongue experiences in older adults. In an event-related fMRI design, participants viewed famous and novel faces and were asked to respond regarding successful retrieval, unsuccessful retrieval, or tip-of-the-tongue experiences. Results show that, as a group, older adults had activation in the medial prefrontal cortex and anterior cingulate during tip-of-the-tongue states, consistent with similar studies in young adults (Maril et al., 2001; Pannu et al., 2004, Schnyer et al., 2005). Additionally, activations in lateral prefrontal cortex and medial temporal areas during the task varied systematically with frontal and temporal lobe factor scores. These results provide evidence for differences in neural activation between groups of healthy older adults characterized on the basis of neuropsychological performance, and shed light on the neural underpinnings of the tip-of-the-tongue states in aging.