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Attention Processes (attention + process)
Selected AbstractsERD as an index of anticipatory attention?PSYCHOPHYSIOLOGY, Issue 1 2002Effects of stimulus degradation Previous research has suggested that the stimulus-preceding negativity (SPN) is largely independent of stimulus modality. In contrast, the scalp topography of the event-related desynchronization (ERD) related to the anticipation of stimuli providing knowledge of results (KR) is modality dependent. These findings, combined with functional SPN research, lead to the hypothesis that anticipatory ERD reflects anticipatory attention, whereas the SPN mainly depends on the affective-motivational properties of the anticipated stimulus. To further investigate the prestimulus ERD, and compare this measure with the SPN, 12 participants performed a time-estimation task, and were informed about the quality of their time estimation by an auditory or a visual stimulus providing KR. The KR stimuli could be either intact or degraded. Auditory degraded KR stimuli were less effective than other KR stimuli in guiding subsequent behavior, and were preceded by a larger SPN. There were no effects of degradation on the SPN in the visual modality. Preceding auditory KR stimuli no ERD was present, whereas preceding visual stimuli an occipital ERD was found. However, contrary to expectation, the latter was larger preceding intact than preceding degraded stimuli. It is concluded that the data largely agree with an interpretation of the pre-KR SPN as a reflection of the anticipation of the affective-motivational value of KR stimuli, and of the prestimulus ERD as a perceptual anticipatory attention process. [source] Immediate effects of methylphenidate on cognitive attention skills of children with attention-deficit-hyperactivity disorderDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 6 2005Jane Hood MSc This study investigated the immediate effects of stimulant medication (methylphenidate) on cognitive attention processes in children with attention-deficit-hyperactivity disorder (ADHD). Thirteen males and two females (mean age 9y 5mo, SD 18.3mo) with a diagnosis of ADHD and who were to be prescribed methylphenidate were assessed twice on one day with the Test of Everyday Attention for Children, a neuropsychological battery designed to tap different aspects of cognitive attention. Between assessments, the children were administered methylphenidate (10mg). Each child had at least average intelligence (IQ 80 or over, as measured by the Wechsler Intelligence Scale for Children - III UK) and was on no other medication. A group of 16 children, who were matched for age, sex, and intelligence, also performed the cognitive tests twice on the same day to control for practice effects of testing. At the first assessment, children with ADHD demonstrated significant impairments in several aspects of cognitive attention in comparison with the control group, particularly sustained attention. After administration of methylphenidate for the children with ADHD, they showed significant improvements in their performance on measures of cognitive attention compared to controls. The immediate effects of methylphenidate and the significance of measuring cognitive aspects of attention as well as behavioural measures are discussed. [source] Seven-year-olds allocate attention like adults unless working memory is overloadedDEVELOPMENTAL SCIENCE, Issue 1 2010Nelson Cowan Previous studies have indicated that visual working memory performance increases with age in childhood, but it is not clear why. One main hypothesis has been that younger children are less efficient in their attention; specifically, they are less able to exclude irrelevant items from working memory to make room for relevant items. We examined this hypothesis by measuring visual working memory capacity under a continuum of five attention conditions. A recognition advantage was found for items to be attended as opposed to ignored. The size of this attention-related effect was adult-like in young children with small arrays, suggesting that their attention processes are efficient even though their working memory capacity is smaller than that of older children and adults. With a larger working memory load, this efficiency in young children was compromised. The efficiency of attention cannot be the sole explanation for the capacity difference. [source] Global,Local Interference is Related to Callosal Compromise in Alcoholism: A Behavior-DTI Association StudyALCOHOLISM, Issue 3 2009Eva M. Müller-Oehring Background:, Visuospatial ability is a multifactorial process commonly impaired in chronic alcoholism. Identification of which features of visuospatial processing are affected and which are spared in alcoholism, however, has not been clearly determined. We used a global,local paradigm to assess component processes of visuospatial ability and MR diffusion tensor imaging (DTI) to examine whether alcoholism-related microstructural degradation of the corpus callosum contributes to disruption of selective lateralized visuospatial and attention processes. Methods:, A hierarchical letter paradigm was devised, where large global letters were composed of small local letters. The task required identification of target letters among distractors presented at global, local, both, or neither level. Attention was either selectively directed to global or local levels or divided between levels. Participants were 18 detoxified chronic alcoholics and 22 age-matched healthy controls. DTI provided quantitative assessment of the integrity of corpus callosal white matter microstructure. Results:, Alcoholics generally had longer reaction times than controls but obtained similar accuracy scores. Both groups processed local targets faster than global targets and showed interference from targets at the unattended level. Alcoholics exhibited moderate compromise in selectively attending to the global level when the global stimuli were composed of local targets. Such local interference was less with longer abstinence. Callosal microstructural integrity compromise predicted degree of interference from stimulus incongruency in the alcoholic group. This relationship was not observed for lateral or third ventricular volumes, which are measures of nonspecific cortical volume deficits. Conclusion:, Global,local feature perception was generally spared in abstinent chronic alcoholics, but impairments were observed when directing attention to global features and when global and local information interfered at stimulus or response levels. Furthermore, the interference-callosal integrity relationship in alcoholics indicates that compromised visuospatial functions include those requiring bilateral integration of information. [source] Probing attentional dysfunctions in schizophrenia: Startle modification during a continuous performance testPSYCHOPHYSIOLOGY, Issue 4 2008Erin A. Hazlett Abstract Startle eyeblink modification was measured in 20 relatively asymptomatic medicated schizophrenia outpatients and 18 matched controls in order to test for deficits in early and later stages of attentional processing during a memory-load version of the Continuous Performance Test. Participants viewed a series of digits and pressed a button after the digit 7 of each 3,7 sequence. On some trials, a startling noise burst was presented either 120 or 1200 ms following cues that a response might be needed soon (the digit 3) and also following noncues. Controls showed greater startle inhibition at 120 ms following cue than noncue prepulses, whereas patients showed equal inhibition to both, suggesting a deficiency in allocation of controlled attentional resources in early stages of processing. The patients, however, did show large startle inhibition at 120 ms when a distracting stimulus accompanied the task-relevant cue, unlike the controls, who ignored the distracting stimulus. In contrast, both groups showed equal startle inhibition 1200 ms following cue and noncue prepulses, indicating that later modality-specific attention processes are not impaired in patients during this paradigm. Both groups also showed equal inhibition at 120 ms during passively attended prepulses, suggesting that automatic attentional processes were not impaired in these patients. 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