Attentional bias (AB) refers to the tendency to selectively attend to (orientation towards) and/or hold attention on (slowed disengagment from) disorder-relevant stimuli. Females with eating-related concerns are thought to preferentially process threatening stimuli, which in turn is thought to maintain and exacerbate eating concerns. The aim of the present thesis was to explore AB for threatening stimuli in females characterised by restrained, external or emotional eating, and those with high levels of (non-clinical) eating psychopathology. This was carried out with the intention of identifying cognitive processes that contribute to eating behaviours in females, in order to assess the relevance of an attention training (AT) programme for reducing such biases. A pilot study assessed orientation/slowed disengagement, for mood and food words amongst females with high/low levels of restraint. Forty females completed a modified Stroop task with three conditions. Food and mood conditions included sequences of five words ( target food/mood followed by four neutral). The neutral condition consisted of all neutral words. Performance did not significantly differ according to high/low restraint groups. All participants took longest to colour-name word position 2 (demonstrating slowed disengagement lasting one consecutive trial). However, this pattern was also found in the neutral condition. Methodological limitations were then addressed in study one. High/low restrained eaters (n=48) completed a modified Stroop where targets (food, interpersonal threat, animal) were presented prior to four neutral words. Participants were slow to disengage from targets (slowest for word position 2) in all conditions. Patterns of responding indicated that restrained eaters might take longer to disengage (i.e. the carry-over effect from the food word seemed to last longer than one trial). However, more neutral words in the sequence were needed to assess this. As slowed disengagement from animals also arose, a categorical effect may have occurred. Study two explored attention processing of food using modified Stroop and dot probe tasks. In the Stroop task targets (food, interpersonal threat, household objects) were presented prior to six matched neutral words. This task revealed no evidence of AB. No significant pattern of differences between restrained (n=29)/unrestrained eaters (n=31) emerged; however, binge eating scores were significantly negatively correlated with response times. A dot probe task with food/neutral picture pairs also revealed no evidence of AB. Both restrained/unrestrained eaters had negative mean interference scores indicating avoidance of food. None of the following eating behaviours significantly correlated with AB: restraint, disinhibition, external eating, emotional eating and non-clinical eating psychopathology. Study three employed a further modified dot probe task based on image ratings. There was no evidence of AB, and no significant relation between task performance and restrained, emotional or external eating. 2000ms bias scores (assessing disengagement) were significantly negatively correlated with eating psychopathology and age, suggesting that those with high levels of non-clinical eating psychopathology attentionally avoid food stimuli and that younger females are slower to disengage attention from food (although found within a limited age range). Study four employed further modified Stroop and dot probe tasks, and assessed whether AB mediates the negative mood-eating relationship. Participants were allocated to negative or neutral mood conditions. No evidence of AB was found with the dot probe, but greater levels of emotional eating were associated with slower responding. In the Stroop task, all participants displayed an orientation bias towards food. Emotional eating and drive for thinness (DFT) scores were significantly positively correlated with food word colour-naming times but only amongst participants in a negative mood. However, those with high levels of external eating showed greater AB towards food when in a neutral mood. Highly emotional eaters in a negative mood showed a greater desire to eat than those in a neutral mood but did not increase in food intake. Furthermore, those with a high DFT (in a negative mood) showed no evidence of increased desire to eat or food intake. AB was not significantly related to subjective appetite or food intake. Therefore, AB does not seem to mediate the negative-mood eating relationship. The present thesis provides important suggestions for modifications of Stroop and dot probe tasks targeting orientation and disengagement. A modified Stroop has been more sensitive at detecting food AB than the dot probe. Implications of biased attention processing are discussed in relation to the development of harmful eating behaviours, and the present findings have important implications for developing programmes to prevent eating disorders amongst at-risk females (e.g. through AT or training at-risk females how to effectively cope with negative mood).

In a series of two experiments, the first involving 121 participants and the second 114, I investigated whether level of racial prejudice is related to performance on a cognitive task and helping behavior in participants who had just interacted with the target of their prejudice. The moderating effect of control was tested and, unlike previous research, the responses of African-American participants were studied too. It was proposed that when people interact with the target of their prejudice, they will experience stress and the aftereffects of stress will lead to a decrement in Stroop task performance and a lower likelihood of helping someone in need. Control was believed to moderate this effect such that those given control would suffer less of a performance decrement and would help more often. Data were analyzed using ANCOVA and logistic regression. Racial prejudice was found to affect European-American but not African-American Stroop performance following the interracial interaction. Control moderated this effect and also influenced whether someone helped a person in need.

Induktion präfrontaler Dysfunktion bei gesunden Probanden durch inhibitorische TMS: Eine NIRS-Messung / Induction of a prefrontal dysfunction on healthy subjects with inhibitory TMS: a near-infrared spectroscopy (NIRS) study

Increased attention towards threatening stimuli in both the external and internal environments is thought to be a factor in the causation and maintenance of pathological anxiety. Attentional biases for threatening information have been demonstrated in anxiety disorders, however the cortical mechanisms involved remain unclear. In this investigation, an Emotional Stroop task consisting of neutral, positive, depression-related and anxietyrelated words, was used to investigate attentional biases in 14 Panic Disorder patients and 32 psychiatrically healthy controls. The standard colour-word Stroop was also performed to determine whether any general cognitive deficits exist in Panic Disorder. Steady-state probe topography (SSPT), a brain electrical activity imaging methodology, was used to investigate participants' brain activity during performance of the tasks. It was hypothesised that Panic Disorder is associated with specific biases for disorder-specific information and thus patients would exhibit increased interference for anxiety-related words only, compared to neutral words. Mean reaction times for the Standard Stroop was similar for the two groups. For the Emotional Stroop task, neither group showed an interference effect for any emotional category. However, Panic Disorder patients performed the Emotional Stroop significantly more slowly than the Controls. The SSPT data suggest that the Standard and Emotional Stroop tasks are associated with different patterns of brain activity in the Control and Panic Disorder groups despite the similarities in the reaction time data. Specifically, the Standard Stroop was marked by strong temporo-parietal excitation in the Panic Disorder group only. In addition, anterior SSVEP patterns further differentiated between the Control and Panic Disorder groups. The most striking finding for the Emotional Stroop was strong sustained bilateral temporo-parieto-occipital excitation in the Panic Disorder group. In addition, a subgroup of the Controls exhibited increased interference for anxiety-related words and therefore the brain activity for this group and the remainder of Controls who did not show interference was analysed separately. It was found that the presence of interference for anxiety-related words was associated with right prefrontal inhibition prior to response. Other time-varying changes in the SSVEP further distinguished between the subgroup of Controls who showed an interference effect and those who did not.

對於精神分裂症患者注意力歷程缺失現象的探討，過去大多集中在 對注意力歷程本身機制的探究；但在結果上一直找不到令人滿意的解釋． 然而在心理學的研究中發現， 個體在進入注意力歷程對刺激做進一步處 理之前，有一個前注意力歷程會先對視野中所現刺激做整體性的處理；之 後才能使個體經由選擇將注意力集中在所欲處理的訊息上，此即注意力歷 程二階段論． 本研究即以注意力歷程二階段論為起點，利用兩個以擬 似叫色作業進行的實驗去區辨精神分裂症患者在注意力表現的異常，究竟 導因於那一階段的運作失常．本研究的兩個實驗均是以伴隨分心項同時呈 現的 Stroop 色字為實驗刺激，藉由操弄目標項（ 即Stroop色字）刺激 類型及分心項與目標項間關係，觀察精神分裂症患者與正常在前注意力歷 程運作上有何差異，並期能據此瞭解精神分裂症患者注意力歷程缺失的可 能原因． 綜合兩實驗所得結果，精神分裂症患者在前注意力歷程的運 作上與正常人並無差別；但在進入注意力歷程對刺激做進一步處理時，抑 制機制的運作失常（運作不足或運作過度）為其注意力失常的可能原因之 一，但仍無法對本研究的結果作一完整的說明．此外，由研究結果中，也 可推測精神分裂症患者在對目標項進行細部分析時，其持續性的注意力也 有異於正常人；這部份仍有待進一步的研究． / There is a wealth of literature associating schizophrenia withdisorders of attention. This study bases on the two-stage approach of visual selective attention. The pre- attentiveparallel processcomputes how different each object is from each of the other objectswithin a particular stimulus dimension. Attention automatically drawto the location having the highest activation, implying that the subjects select location automatically and are irrespective of their intention. Two Stroop tasks used to differentiate schizophrenics and nornalic'sattentional processes, and try to figure out which stageis the caution of schizophrenic's dysfunctional attention. As the result, schizophrenic is not different with normalics on pre-attentiveprocess, but do have something problem onattentional process when theywhen they have to inhibit some information. It'sstill not a conclution,because the deficit of inhibition can not explain the results perfectly.

The purpose of this study is to investigate the usefulness of a 20-minute brief mindfulness meditation in positively affecting mood and attention. Its effects were compared with the effects from a period of distraction and a control condition. The sample consisted of 63 veterans with Posttraumatic Stress Disorder. Pre-post test of the State-Trait Anxiety Inventory and the Positive and Negative Affect Schedule were used to assess levels of state anxiety and mood. The Stroop Task was employed as a measure of selective attention. A one-way analysis of variance and split-plot analysis of variance were conducted. To control high comorbidity within this sample, sub-analyses were conducted excluding participants with other psychological or physical conditions. The results revealed that meditators without sleep problems indicated greater selective attention levels. A negative mood decrease was found in all participants regardless of the intervention group assignment. Implications for research and practice were discussed.

Neurons are connected to form functional networks in the brain. When neurons are combined in sequence, nontrivial effects arise. One example is disinhibition; that is, inhibition to another inhibitory factor. Disinhibition may be serving an important purpose because a large number of local circuits in the brain contain disinhibitory connections. However, their exact functional role is not well understood. The objective of this dissertation is to analyze the computational role of disinhibition in brain function, especially in visual perception and attentional control. My approach is to propose computational models of disinhibition and then map the model to the local circuits in the brain to explain psychological phenomena. Several computational models are proposed in this dissertation to account for disinhibition. (1) A static inverse difference of Gaussian filter (IDoG) is derived to account explicitly for the spatial effects of disinhibition. IDoG can explain a number of complex brightness-contrast illusions, such as the periphery problem in the Hermann grid and the White's effect. The IDoG model can also be used to explain orientation perception of multiple lines as in the modified version of Poggendorff illusion. (2) A spatio-temporal model (IDoGS) in early vision is derived and it successfully explains the scintillating grid illusion, which is a stationary display giving rise to a striking, dynamic, scintillating effect. (3) An interconnected Cohen-Grossberg neural network model (iCGNN) is proposed to address the dynamics of disinhibitory neural networks with a layered structure. I derive a set of sufficient conditions for such an interconnected system to reach asymptotic stability. (4) A computational model combining recurrent and feed-forward disinhibition is designed to account for input-modulation in temporal selective attention. The main contribution of this research is that it developed a unified framework of disinhibition to model several different kinds of neural circuits to account for various perceptual and attentional phenomena. Investigating the role of disinhibition in the brain can provide us with a deeper understanding of how the brain can give rise to intelligent and complex functions.

Childhood emotional maltreatment is associated with damaging consequences, although relatively little is known about the mechanisms underlying its effects. This dissertation investigated the concurrent influences of adult attachment and mindfulness on internalizing symptoms and emotional processing in young adults with and without a history of emotional maltreatment. Study 1 revealed that a sequential mediation model, with adult attachment orientations as first-step mediators and mindfulness as a second-step mediator, fit the data better than a simultaneous mediation model. In addition, moderation analyses revealed that high self-reported levels of mindfulness protected against the development of internalizing symptoms, even in at-risk individuals. Study 2 replicated these findings in a new sample, while also extending the results beyond a self-report outcome, using behavioural measures of emotional processing. Emotional maltreatment, adult attachment, and mindfulness predicted the amount of perceptual information required to correctly identify fearful faces and the amount of interference demonstrated in response to positive and negative emotional words. Cumulatively, these findings suggest that childhood emotional maltreatment can disrupt attachment relationships and encumber the development of mindfulness, contributing to internalizing symptoms and the biased processing of emotional information. However, alternative outcomes are possible, given the presence of high levels of mindfulness and secure attachment representations. This has implications for clarifying developmental theories and evaluating clinical interventions that may mitigate the negative effects of childhood emotional maltreatment.

Living environments are seldom, if ever, devoid of all background auditory stimuli. However, the relationship between particular structural components of acoustic backgrounds and cognitive task performance remains unclear. Two experiments were completed to examine the influence of sound on a visual selective attention task. Participants performed the Stroop task (Stroop, 1935) while silence or background acoustic patterns of various complexities were presented over headphones. No effect of background sound on performance was found. A post-hoc analysis indicated that in comparison with participants who do not regularly listen to music while studying, participants who regularly listen to music while studying performed better on the Stroop task when a structured auditory pattern that included variation in both frequency and time interval was presented in the background. These results indicate that distinct structural components of background auditory sequences may interact with individual characteristics to influence cognitive performance on a task involving selective attention.

Living environments are seldom, if ever, devoid of all background auditory stimuli. However, the relationship between particular structural components of acoustic backgrounds and cognitive task performance remains unclear. Two experiments were completed to examine the influence of sound on a visual selective attention task. Participants performed the Stroop task (Stroop, 1935) while silence or background acoustic patterns of various complexities were presented over headphones. No effect of background sound on performance was found. A post-hoc analysis indicated that in comparison with participants who do not regularly listen to music while studying, participants who regularly listen to music while studying performed better on the Stroop task when a structured auditory pattern that included variation in both frequency and time interval was presented in the background. These results indicate that distinct structural components of background auditory sequences may interact with individual characteristics to influence cognitive performance on a task involving selective attention.