Two Inattentional Blindness type experiments involving 446 participants were performed in order to examine how unexpected objects are noticed. Perception of these unexpected objects was measured using explicit and implicit measurements. Despite initial difficulty in determining implicit perception, results showed a dissociation between implicit measurements and explicit measurements, providing strong evidence for unconscious processing. Research into attention capture often emphasizes the role of either expectations or stimulus properties in attention capture; the current research examines both. Critical objects presented were either of a colour that participants were familiar with, or of a new colour. The different patterns of results for these two categories of objects provide evidence for two separate mechanisms of attention capture: a parallel process driven by the features of objects, and a serial process, driven by the intentions of the observer. Predications of the recent theoretical work produced by Most, Scholl, Clifford & Simons, (2005) are examined, and support is obtained for their theoretical formulation.

The objective of this study was to determine if eye and head based psychophysiological cues can be used to maintain screener vigilance levels during long duration tasks. In two parts, this study first explored which cues are predictive of vigilance levels. The second part of the study developed a vigilance feedback system using the cues established in part one and compared the results of subjects using the feedback system with those subjects having received no feedback or those who received random feedback.In part one, 48 participants reviewed 600 simulated x-rays to determine if any hazardous items (guns or knives) were present. Individual vigilance levels were determined by scoring the number of correct detections during eight 5-minute periods (total study length = 40 minutes). Using an eye-tracking machine, four concurrent eye and head activity measures (blinks, saccades, pupil diameter, and head position) were used to model changes in vigilance level throughout a simulated baggage screening task. At the end of the study, changes in blink and saccade rates proved to be significant predictors of an individual's ability to detect the presence of these hazardous items among other non-significant baggage items.Part two required 126 participants equally distributed across three conditions to repeat the same screening task. For one condition the monitoring system, instead of passively recording the individual's cues, provided near real-time feedback of vigilance levels to a condition. Participants in other conditions received random feedback on their vigilance levels while a third group received no feedback. At the conclusion of the study the subjects who received the real-time feedback performed significantly better than those who received no feedback. However, they did not perform better than the subjects who received random feedback. Perhaps more significantly, the subjects who received random feedback, while performing better than the no feedback group, also experienced a significantly higher number of false detects.The results of this study indicate a vigilance feedback system based upon subject psychophysiological cues may be an effective method to maintain attention levels during long duration vigilance tasks while preventing a corresponding increase in error detection rates.

A better understanding of the neural mechanisms associated with Attention Deficit Hyperactivity Disorder (ADHD) and related cognitive deficits can potentially clarify the neural circuits involved in ADHD symptoms, help define neurobiologically informed subtypes and aid in developing more refined treatments. Two neurotransmitter (NT) systems have been implicated in ADHD: Dopamine (DA), and Norepinephrine (NE), and the primary cognitive deficits associated with ADHD are in working memory, response inhibition, reaction time variability, and reward processing. Frank et al. (2007a) proposes, based on computational models, that DA is associated with deficits in reward-based learning and updating of working memory, while NE is associated with deficits in response inhibition and greater response variability. Therefore, it might be possible to learn more about the NT systems' specific roles in ADHD by studying the associated cognitive deficits. The primary goal of this study was to assess performance in adolescents with and without ADHD on a number of cognitive tasks. We expected that the Attention Deficit Hyperactivity Disorder - Inattentive Subtype (ADHD-I) group would perform the worst on NE tasks and that the Attention Deficit Hyperactivity Disorder - Combined Subtype (ADHD-C) group would perform the worst on DA tasks, and that both groups would perform worse than controls on all tasks. Instead, we found that the ADHD-I group performed the most poorly on updating of working memory, while the ADHD-C group performed the best on this variable. However, the ADHD-C group performed worst on overall working memory. Dimensional analyses revealed that hyperactivity/impulsivity is positively correlated with updating of working memory, while inattention is negatively correlated with updating of working memory. In addition, hyperactivity/impulsivity was positively correlated with reaction time variability. In conclusion, it is likely that the roles of these NT systems are not as mutually exclusive as initially expected. It is also possible that our ADHD group was performing more like control groups in other studies, which might be due to a more 'pure' ADHD sample with less comorbid Oppositional Defiant Disorder (ODD) and Conduct disorder (CD), or could be due to a less symptomatic ADHD group.

Emerging evidence supports the use of methylphenidate (MPH) for the treatment of apathy in Alzheimer’s disease (AD). This study aimed to investigate the additional effects of MPH on attention in an AD sample and the relationship between apathy and attention. AD patients enrolled in a randomized, double-blind placebo-controlled study to examine the safety and efficacy of MPH (10mg PO twice daily) for the treatment of apathetic symptoms were tested on attention and apathy every 2 weeks for 6 weeks. A mixed effects linear regression revealed attention change scores (endpoint - baseline) over time favouring MPH (δ=1.01, p=0.03), though there were no significant associations between apathy and attention change scores (r=-0.08, p=0.54). These results suggest that while MPH can improve both apathy and attention, the effects appear independent in this patient population. This study provides insight into the different effects MPH can produce in a heterogeneous disease such as AD.

Emerging evidence supports the use of methylphenidate (MPH) for the treatment of apathy in Alzheimer’s disease (AD). This study aimed to investigate the additional effects of MPH on attention in an AD sample and the relationship between apathy and attention. AD patients enrolled in a randomized, double-blind placebo-controlled study to examine the safety and efficacy of MPH (10mg PO twice daily) for the treatment of apathetic symptoms were tested on attention and apathy every 2 weeks for 6 weeks. A mixed effects linear regression revealed attention change scores (endpoint - baseline) over time favouring MPH (δ=1.01, p=0.03), though there were no significant associations between apathy and attention change scores (r=-0.08, p=0.54). These results suggest that while MPH can improve both apathy and attention, the effects appear independent in this patient population. This study provides insight into the different effects MPH can produce in a heterogeneous disease such as AD.

Attention is a cognitive process essential to daily function. As attention encompasses an extremely broad array of cognitive subprocesses, there remains much to be discovered about the brain regions related to attention with neuroimaging. This thesis presents two studies that used functional magnetic resonance imaging to examine neural activity associated with different forms of attentional control. In the first study, we scanned healthy young adults while they performed the Stroop task, which measures selective attention, to investigate neural responses underlying unanticipated conflict detection. We found several regions across the frontal, parietal, and occipital lobes that became more active during states of unanticipated conflicts, relative to states of anticipated conflicts. These regions included the anterior cingulate, dorsolateral prefrontal cortex, angular gyrus, inferior parietal lobule, precuneus, lingual gyrus, and fusiform gyrus. Activity in these regions has previously been associated with attentional processes such as conflict detection, attention, orientation, and oddball detection. Our results therefore suggest that widespread areas of the cortex serve several cognitive processes involved in successfully monitoring and responding to unanticipated conflicts. In the second study, we tested young and cognitively healthy older adults with the Stroop task to determine whether aging affects the neural mechanisms underlying attentional lapses, defined as relatively longer response times. Like previous studies in young adults, we found regions in the default mode network exhibited greater activity as reaction time to stimuli increased. Attentional lapses were also preceded by decreased activity in regions related to attention, including the anterior cingulate and prefrontal cortices. Most importantly, young adults showed greater positive reaction time-modulated activity in default mode areas, while older adults exhibited greater positive reaction time-modulated activity in more prefrontal areas. Our results suggest that the neural correlates of attentional lapses change with healthy aging, reinforcing the idea of functional plasticity to maintain high cognitive function throughout the lifespan. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2013-08-22 11:33:32.418

Neuropsykiatriska funktionsnedsättningar är idag lättare att diagnostisera och det är vanligare att barn och ungdomar i skolan vet om att de lever med en diagnos som till exempel Attention deficit hyperactivity disorder (mer känt som ADHD), eller Aspergers syndrom. Trots att dessa diagnoser blir allt vanligare, finns det ett ökat behov för kunskapen om dem. Syftet med denna uppsats var att studera barn och ungdomar med neuropsykiatriska funktionsnedsättningar, och framförallt studera deras liv i skolmiljö. Att få mer förståelse för hur barn och ungdomar har upplevt skolan och relationen till sina lärare, men även hur de upplevt de hinder och möjligheter deras neuropsykiatriska funktionsnedsättning medfört var i fokus. Metoden i denna studie var semistrukturerade intervjuer med 6 ungdomar, deras föräldrar och lärare. Frågorna har handlat om hur ungdomarna sett på diagnosen, livet med den och även hur de klarat av skolgången med sin funktionsnedsättning. Resultatet visar att lärare behöver mer utbildning när det kommer till neuropsykiatriska funktionsnedsättningar Studien visar att barn och ungdomar med neuropsykiatriska funktionsnedsättningar har lättare att lära sig om de får göra praktiska saker. Att ta in mer praktiska moment i undervisningen skulle kunna förenkla för många av dessa barn och ungdomar. Informanterna har varit eniga om att kunskapen om neuropsykiatriska funktionsnedsättningar överlag är för låg. Familjen är en viktig del i ett barns säkerhet, men det betyder att föräldrar och syskon måste få veta hur de ska bemöta ett barn som lever med en neuropsykiatrisk funktionsnedsättning. Det är inte enbart i skolan kunskapen bör vara hög.

This portfolio thesis comprises three parts: a systematic literature review, an empirical study and a set of appendixes. Part one is a systematic literature review, in which the empirical literature relating to interventions for siblings of children with chronic illness and developmental disorder is reviewed. Siblings of children with such conditions have not been extensively studied within research and the review aimed to identify what interventions exist to support siblings in this area, to provide an overview of how rigorously these have been evaluated and to synthesise what findings have been documented with regards to the effectiveness of such interventions. An introduction to family and sibling research in this area is presented, followed by a rationale for why a review of intervention based literature in this area is considered to be a useful addition to the field. The paper goes on to specify the methods and search strategies used to identify suitable articles to meet the research aims and which satisfied set criteria for inclusion. Main findings are presented, conclusions made, and areas for further research identified. Part two is an empirical study of siblings of children with ADHD. Part one highlighted the paucity of research in the domain of siblings and developmental disorder. The cross-sectional study examines the level of empathy, self-esteem, and the sibling relationship quality factors of warmth/closeness and conflict reported by a sample of siblings of children with ADHD, and compares these variables to a sample of children who have siblings with no diagnosed disorders. The paper reports the between groups outcomes for these variables, along with an examination of whether children�s individual characteristics such as empathy and self-esteem predict reports of warmth/closeness and conflict, based on Furman and Buhrmester�s (1985) model of the determinants of sibling relationship quality. This is followed by an explanation of the clinical implications, the limitations of the study and consideration of further areas of research. Finally, part three is a set of appendixes to support the work in the previous parts of the portfolio thesis. It contains a reflective account of the research process and documents the experiences and lessons learned in planning, implementing and writing this document.

This study proposed that new insights about attention, including its phenomenon and pathology, would be provided by combining perspectives of the neurobiological discourse about attention with analyses of artworks that exploit the constraints of the attentional system. To advance the central argument that art offers a training ground for the attentional system, a wide range of contemporary art was analysed in light of specific tasks invoked. The kinds of cognitive tasks these works initiate with respect to the attentional system have been particularly critical to this research. Attention was explored within the context of transdisciplinary art practices, varied circumstances of viewing, new neuroscientific findings, and new approaches towards learning. Research for this dissertation required practical investigations in a gallery setting, and this original work was contextualised and correlated with pertinent neuroscientific approaches. It was also concluded that art can enhance public awareness of attention disorders and assist the public in discriminating between medical and social factors through questioning how norms of behaviour are defined and measured. This territory was examined through the comparative analysis of several diagnostic tests for attention deficit hyperactivity disorder (ADHD), through the adaptation of a methodology from economics involving patent citation in order to show market incentives, and through examples of data visualisation. The construction of an installation and collaborative animation allowed participants to experience first-hand the constraints on the attentional system, provoking awareness of our own “normal” physiological limitations. The embodied knowledge of images, emotion, and social context that are deeply embedded in art practices appeared to be capable of supplementing neuroscience’s understanding of attention and its disorders.

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