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dc.contributor.authorCovey, Thomas Jared
dc.date.accessioned2017-08-23T20:27:06Z
dc.date.available2017-08-23T20:27:06Z
dc.date.issued2016
dc.identifier.isbn9781369184976
dc.identifier.other1844988572
dc.identifier.urihttp://hdl.handle.net/10477/76573
dc.description.abstractDesign and Methods of the Present Study: During an n-back task, participants have to compare a currently displayed stimulus to a stimulus that was presented n trials back. This allows for the adjustment of the demand placed on working memory by increasing or decreasing the n (e.g., a 3-back places greater demands on working memory than a 2-back). In many studies the level of the n-back task during a training session is adaptively altered based on performance during each block of trials. Thus, participants are consistently challenged across blocks, and can train on progressively more difficult levels of the n-back if they are able to. Including “lure” trial stimuli during the n-back provides a means for increasing the requirement for interference control mechanisms, which may be particularly important for eliciting transfer effects. In the present study, an adaptive n-back protocol was utilized to examine the effects of working memory training. This training protocol also included lure trials in order to place additional demand on interference control mechanisms during working memory. The n-back training protocol was compared to a control training task that was of equal difficulty to the n-back training task, but did not require working memory: an adaptive perceptual search task that had analogous trial types and frequencies to the n-back. This provided a strong control group as a point of comparison, in contrast to many previous studies. There were several major aims of this work, as follows: (1) examine the effects of adaptive n-back and perceptual search task training (with high demand on interference control) on a broad variety of cognitive performance and fluid reasoning measures (near and far transfer performance measures), (2) examine the effects of adaptive n-back and search training (with high interference control demands) on neural processes underlying cognitive performance, and (3) examine the effects of adaptive n-back training (with high interference control demands) on patients with Multiple Sclerosis, a neurodegenerative disorder where cognitive impairments are prevalent. This study used a pretest-training-posttest design. At pre- and posttest, young adult participants were (a) tested on a battery of computerized cognitive tests during which electroencephalographic (EEG) data were obtained, and (b) tested outside of the EEG environment on a battery of psychometric tests of working memory/processing speed, and fluid intelligence. Following the pretest in the laboratory, participants completed 20 sessions of training at home (n-back group n = 20, search group n = 20), after which they returned to the laboratory for posttest. Aim (1) from above was fulfilled by examining changes in behavioral performance on the training tasks (a Verbal 3-Back task, and a Search task), on near transfer tasks of working memory, and on far transfer tasks of cognitive control and fluid reasoning ability. Aim (2) from above was fulfilled by examining alterations from pre- to posttest in event-related potential (ERP) measures of brain function on the training tasks (Verbal 3-Back task, Search task), a near transfer task of working memory (Spatial 3-Back task), and a task of cognitive control (Go/Nogo Flanker task). Alterations in early occurring, exogenously driven ERP components following training provides evidence for changes in early sensory processing and selective attention; alterations in later occurring, endogenously driven ERP components following training provides evidence for changes in higher order cognitive processes and stimulus categorization. Thus, ERPs provide a method for evaluating which specific neurocognitive mechanisms are affected following training. Aim (3) from above was fulfilled by examining these effects (behavioral performance and ERP measures) in MS patients compared to healthy individuals that completed the n-back training protocol. Conclusions: The findings suggest that both adaptive n-back training and adaptive search task training resulted in improved overall cognitive performance and changes in brain function. However, n-back training resulted in more pronounced transfer effects to tasks involving working memory compared to search training. Changes in brain function also occurred differentially for each training group. The search training group exhibited a significant reduction in all ERP latencies (early occurring and later occurring components) on the Search task (training outcome measure for the search group) as a result of training. The n-back group exhibited significant enhancement of multiple ERP components during the Verbal 3-back task (training outcome measure for the n-back group), including a pronounced enhancement of N2 amplitude and reduced latency in this component, following training. Interestingly, significant improvements were found on measures of fluid reasoning regardless of the training protocol. Examination of patients with MS also revealed that patients showed, overall, similar improvements (although sometimes more subtle) in cognitive performance compared to controls following n-back training. Importantly, MS patients also exhibited a pronounced enhancement of N2 amplitude and reduced N2 latency during the Verbal 3-back task. (Abstract shortened by ProQuest.)
dc.languageEnglish
dc.sourceDissertations & Theses @ SUNY Buffalo,ProQuest Dissertations & Theses Global
dc.subjectBiological sciences
dc.subjectPsychology
dc.subjectCognitive training
dc.subjectEvent-related potentials
dc.subjectInterference control
dc.subjectMultiple sclerosis
dc.subjectPerceptual training
dc.subjectWorking memory training
dc.titleAdaptive working memory and visual search training have differential effects on brain function and cognitive performance: Evidence from event-related brain potentials and transfer of gains
dc.typeDissertation/Thesis


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