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Lag: A Look at Circadian Desynchronization
Bill Ragan, M.S. said that circadian desynchronization was one of the causes of several aircraft accidents over the years. While the exact cause of these accidents was hard to pinpoint, many of them were linked to human error. Lag: A Look at Circadian Desynchronization (ISBN 978-1-4357-0221-9) was focused on stress that resulted from jet lag, shift work, and fatigue in aviation. Many of the principles included here transfer over to other industries like commercial overland transportation, law enforcement, and health care. How much does fatigue cost you? Only the reader will know, but factors that can influence the costs were discussed in this book. Not intended to be a substitute for a consultation by a provider, some interventions intended to help lower the cost of fatigue were included, as well..
Price: $11.82
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Intelligence and working memory systems: evidence of neural efficiency in alpha band ERD [An article from: Cognitive Brain Research]
This digital document is a journal article from Cognitive Brain Research, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: Starting from the well-established finding that brighter individuals display a more efficient brain function when performing cognitive tasks (i.e., neural efficiency), we investigated the relationship between intelligence and cortical activation in the context of working memory (WM) tasks. Fifty-five male (n=28) and female (n=27) participants worked on (1) a classical forward digit span task demanding only short-term memory (STM), (2) an attention-switching task drawing on the central executive (CE) of WM and (3) a WM task involving both STM storage and CE processes. During performance of these three types of tasks, cortical activation was quantified by the extent of Event-Related Desynchronization (ERD) in the alpha band of the human EEG. Correlational analyses revealed associations between the amount of ERD in the upper alpha band and intelligence in several brain regions. In all tasks, the males were more likely to display the negative intelligence-cortical activation relationship. Furthermore, stronger associations between ERD and intelligence were found for fluid rather than crystallized intelligence. Analyses also point to topographical differences in neural efficiency depending on sex, task type and the associated cognitive subsystems engaged during task performance. .
Price: $5.95
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Behavioural and physiological impairments of sustained attention after traumatic brain injury [An article from: Cognitive Brain Research]
This digital document is a journal article from Cognitive Brain Research, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: Sustaining attention under conditions of low external demand taxes our ability to stay on task and to avoid more appealing trains of thought or environmental distractions. By contrast, a stimulating, novel environment engages attention far more freely without the subjective feeling of having to override monotony. Our ability to maintain a goal-directed focus without support from the environment requires the endogenous control of behaviour. This control can be modulated by fronto-parietal circuits and this ability is compromised following traumatic brain injury (TBI) leading to increased lapses of attention. In this paper, we further explore a laboratory paradigm that we argue is particularly sensitive to sustained attention as opposed to other aspects of attentional control involving the selection and management of goals in working memory. The paradigm (fixed sequence Sustained Attention to Response Task-SART"f"i"x"e"d) involves withholding a key press to an infrequent no-go target embedded within a predictable sequence of numbers. We demonstrate that TBI patients in this study make disproportionately more errors than controls on this task. An analysis of response times (RTs) and EEG alpha power across the task demonstrates group differences preceding the critical no-go trial. Controls demonstrate a lengthening of RTs accompanied by desynchronization of power within the alpha band (~10 Hz) preceding the no-go trial. Conversely, the TBI group showed a shortening of RTs during this period with no evidence of alpha desynchronization. These findings suggest that TBI patients may have dysfunctional alpha generators as a consequence of their injury that impairs endogenous control during the task. .
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Alpha power dependent light stimulation: dynamics of event-related (de)synchronization in human electroencephalogram [An article from: Cognitive Brain Research]
This digital document is a journal article from Cognitive Brain Research, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: The desynchronization and resynchronization of alpha oscillations was studied in 10 normal subjects after visual stimulation of both eyes under two experimental conditions, ''eyes opened'' and ''eyes closed''. The electroencephalogram (EEG) was recorded bipolarly over the occipital area and sampled at 200 Hz. The data was processed in real time and evaluated online. In accordance with the alpha power in the 7 to 13 Hz band, short red light flashes of 10 ms duration were presented at intervals of at least 2 s. This stimulation resulted in an event-related desynchronization (ERD) followed by resynchronization. Trials were controlled for artifacts, averaged offline, and the amount of event-related (de)synchronization was calculated. The event-related desynchronization was significantly larger in the eyes open paradigm. In addition, the latencies of event-related desynchronization and resynchronization maxima were larger in the eyes open paradigm compared to the eyes closed one. .
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Sub-second ''temporal attention'' modulates alpha rhythms. A high-resolution EEG study [An article from: Cognitive Brain Research]
This digital document is a journal article from Cognitive Brain Research, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: In the present high-resolution electroencephalographic (EEG) study, event-related desynchronization/synchronization (ERD/ERS) of alpha rhythms was computed during an S1-S2 paradigm, in which a visual cue (S1) predicted a SHORT (600 ms) or LONG (1400 ms) foreperiod, preceding a visual go stimulus (S2) triggering right or left finger movement. Could orienting attention to a selective point in time influence the alpha rhythms as a function of the SHORT vs. LONG foreperiod? Stronger selective attentional modulations were predicted for the SHORT than LONG condition. EEG data from 54 channels were ''depurated'' from phase-locked visual evoked potentials and spatially enhanced by surface Laplacian estimation (i.e., final data analysis was conducted on 16 subjects having a sufficient number of artifact-free EEG single trials). Low-band alpha rhythms (about 6-10 Hz) were supposed to be related to anticipatory attentional processes, whereas high-band alpha rhythms (10-12 Hz) would indicate task-specific visuo-motor processes. Compared to the LONG condition (foreperiod), the SHORT condition induced a quicker and stronger ERS at low-band alpha rhythm (about 6-8 Hz) over midline and bilateral prefrontal, sensorimotor, and posterior parietal areas. In contrast, the concomitant high-band alpha (about 10-12 Hz) ERD/ERS showed no significant difference between the two conditions. In conclusion, temporal attention for a sub-second delay (800 ms) did modulate low-band alpha rhythm over large regions of both cortical hemispheres. .
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Event-related desynchronization in the EEG during emotional and cognitive information processing: Differential effects of extraversion [An article from: Biological Psychology]
This digital document is a journal article from Biological Psychology, published by Elsevier in . The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: The aim of the present study was to analyze the influence of the personality dimension extraversion/introversion (E) on the level and topographical distribution of event-related desynchronization (ERD) in the EEG whilst participants were engaged in emotional face and cognitive information processing. In this context we build up on former studies dealing with the role of E as a possible moderator variable in cortical activation patterns during performance of mental speed, reasoning and working memory tasks (i.e., cognitive information processing). In a sample of 33 introverts and 33 extraverts (31 were male, 35 female) we found extraverted individuals displaying a lower (left-hemispheric) cortical activation than introverts when their task was to judge the identity of two simultaneously presented facial emotions. This effect was only observed in the upper alpha frequency band (~9.6-11.6Hz). In analyzing E differences during cognitive information processing (i.e., performance of a verbal and a figural-spatial task) E effects - which were moderated by participants' sex - were restricted to lower EEG (alpha) frequency ranges (~5.6-9.6Hz). The results generally suggest that E is differently involved when different kinds of information are processed. .
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