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You searched for +publisher:"Brown University" +contributor:("Sasaki, Yuka"). Showing records 1 – 3 of 3 total matches.

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1. Berard, Aaron V. Enhancing Visual Perceptual Learning Through Reward and Sleep.

Degree: PhD, Cognitive Sciences, 2016, Brown University

Abstract of “Enhancing Visual Perceptual Learning Through Reward and Sleep” by Aaron V. Berard, Ph.D., Brown University, May 2016 Visual perceptual learning (VPL) is defined as a long-term performance improvement on a perceptual task as a result of perceptual experience. Although VPL is regarded as a manifestation of plasticity in the visual cortex, research has shown that factors beyond the visual cortex facilitate VPL, such as playing video games, reward processing, and sleep related enhancements. In the first experiment of this dissertation, we tested whether frequent video game players have more robust consolidation of VPL compared to non-gamers by employing an interference experiment. As a result, we found the gamers resisted the interference effect while the non-gamers did not, suggesting more robust consolidative mechanisms compared to non-gamers. Since reward is a significant portion of playing video games, this finding was further investigated in the second experiment by examining the effects of reward on VPL sleep consolidation. Four groups were trained over a 12-hour period where two sleep groups and two wake groups received reward and two did not. This experiment yielded a significant interaction between sleep and reward over VPL. We then examined the neural mechanisms of this interaction of reward and sleep on VPL in the third experiment, where two groups were trained (one with and one without reward during training) and then tested after a 2-hour nap. We replicated the behavioral performance results from the second experiment and found that sleep and reward specifically interacted over VPL during post-training REM sleep. This finding was illustrated by extended REM durations found in the post-training nap in the reward group compared to the control group that did not receive reward. Additionally, during REM sleep, the reward group showed significantly different alpha and theta brain wave oscillation patterns compared to the control group that suggested reactivation of reward processing during REM sleep, which modulated visual processing contributing to the enhancement of VPL. Advisors/Committee Members: Watanabe, Takeo (Director), Sasaki, Yuka (Reader), Welch, Leslie (Reader).

Subjects/Keywords: visual perceptual learning

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Berard, A. V. (2016). Enhancing Visual Perceptual Learning Through Reward and Sleep. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:674380/

Chicago Manual of Style (16th Edition):

Berard, Aaron V. “Enhancing Visual Perceptual Learning Through Reward and Sleep.” 2016. Doctoral Dissertation, Brown University. Accessed October 22, 2019. https://repository.library.brown.edu/studio/item/bdr:674380/.

MLA Handbook (7th Edition):

Berard, Aaron V. “Enhancing Visual Perceptual Learning Through Reward and Sleep.” 2016. Web. 22 Oct 2019.

Vancouver:

Berard AV. Enhancing Visual Perceptual Learning Through Reward and Sleep. [Internet] [Doctoral dissertation]. Brown University; 2016. [cited 2019 Oct 22]. Available from: https://repository.library.brown.edu/studio/item/bdr:674380/.

Council of Science Editors:

Berard AV. Enhancing Visual Perceptual Learning Through Reward and Sleep. [Doctoral Dissertation]. Brown University; 2016. Available from: https://repository.library.brown.edu/studio/item/bdr:674380/

2. Bang, Ji Won. Plasticity in visual perceptual learning.

Degree: PhD, Psychology, 2016, Brown University

Visual perceptual learning (VPL) goes through temporal dynamics of consolidation after the offset of visual training. This temporal dynamics of consolidation consists of at least two phases, that is wake-dependent stabilization and sleep-dependent enhancement. After the visual task, VPL becomes stabilized and enhanced during following wakefulness and sleep periods, respectively. This finding is well established based on behavioral results. However, its underlying neural mechanisms have not been clearly identified yet, despite of its importance in understanding the temporal dynamics of VPL. Furthermore, previous findings from the other memory domains including declarative, motor and fear memory suggest that even the previously consolidated memory becomes fragile once again when the memory is reactivated via brief recall. This reactivated memory then becomes reconsolidated with a passage of time. However, it has not been studied yet whether the reactivation and reconsolidation processes also exist in VPL. Studying the reactivation and reconsolidation processes in VPL is important because the finding can reveal how the adult’s visual system changes after training in the long-term periods. In this dissertation study, I investigated three aspects of VPL: (1) underlying mechanism of wake-dependent stabilization, (2) underlying mechanism of sleep-dependent enhancement, and (3) reactivation and reconsolidation processes in VPL. To study these three aspects, I used anatomical and functional magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), magnetoencephalography (MEG), and psychophysics. The results indicate three important things. First, the ratio between excitatory and inhibitory signals (E/I ratio) in the early visual cortex is associated with the wake-dependent stabilization process in VPL. Second, the slow sigma activity corresponding to slow spindles in the early visual cortex is involved in the sleep-dependent enhancement in VPL. Third, reactivation and reconsolidation processes exist in VPL and are associated with the E/I ratio in the early visual cortex. Taken together, the findings reveal how the adult’s visual system balances between stability and instability and changes in the long-term periods after the offset of training. Advisors/Committee Members: Watanabe, Takeo (Director), Sasaki, Yuka (Reader), Song, Joo-Hyun (Reader).

Subjects/Keywords: visual perceptual learning

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Bang, J. W. (2016). Plasticity in visual perceptual learning. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:674117/

Chicago Manual of Style (16th Edition):

Bang, Ji Won. “Plasticity in visual perceptual learning.” 2016. Doctoral Dissertation, Brown University. Accessed October 22, 2019. https://repository.library.brown.edu/studio/item/bdr:674117/.

MLA Handbook (7th Edition):

Bang, Ji Won. “Plasticity in visual perceptual learning.” 2016. Web. 22 Oct 2019.

Vancouver:

Bang JW. Plasticity in visual perceptual learning. [Internet] [Doctoral dissertation]. Brown University; 2016. [cited 2019 Oct 22]. Available from: https://repository.library.brown.edu/studio/item/bdr:674117/.

Council of Science Editors:

Bang JW. Plasticity in visual perceptual learning. [Doctoral Dissertation]. Brown University; 2016. Available from: https://repository.library.brown.edu/studio/item/bdr:674117/

3. Chang, Li-Hung. The Effects of Aging on Visual Perceptual Learning and Plasticity.

Degree: PhD, Cognitive Sciences, 2014, Brown University

Human brain processing declines with aging and reveals cognitive and perceptual impairments. Previous researches on cognitive neuroscience in aging have provided evidence on the relationship in cognitive declinations with distinctive brain activation patterns compared with younger adults. However, it remains unclear how the course of aging affects brain plasticity. Is an aging brain still plastic? If so, can older people recover age-associated impaired functions through plasticity? In order to answer such questions, I applied visual perceptual learning (VPL) in my dissertation research. VPL refers to long-term improvement on a visual task and is regarded as a manifestation of brain plasticity. Several studies have demonstrated that repetitive and intensive practice leads to enhance impaired visual functions in younger adults, and the learning is associated with the functional activation changes in the early visual area V1. My research focuses on whether VPL can be acquired by older adults in order to enhance impaired visual ability. If it can, what is the underlying neuronal mechanism of VPL in aging? Although some studies suggest that an older brain tends to have a degraded capability of learning and plasticity, my dissertation demonstrated that older people are able to improve their task performance through intensive practice, thereby providing evidence of visual plasticity. More importantly, unlike younger adults, VPL is associated with structural changes in the early visual area in older adults. The advanced morphological analysis indicated that the cortical areal size of the early visual area V3 is associated with the magnitude of VPL improvement. Finally, my research demonstrated that the aging brain could be more plastic than the younger brain due to less inhibition from higher cortical areas, thereby enhancing visual perception especially when exposed to salient task-irrelevant signals. These results provide evidence of plasticity in the visual system in older adults and further suggest that visual plasticity has different underlying neural mechanisms between older and younger adults. Advisors/Committee Members: Watanabe, Takeo (Director), Song, Joo-Hyun (Reader), Sasaki, Yuka (Reader).

Subjects/Keywords: FA

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Chang, L. (2014). The Effects of Aging on Visual Perceptual Learning and Plasticity. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:386181/

Chicago Manual of Style (16th Edition):

Chang, Li-Hung. “The Effects of Aging on Visual Perceptual Learning and Plasticity.” 2014. Doctoral Dissertation, Brown University. Accessed October 22, 2019. https://repository.library.brown.edu/studio/item/bdr:386181/.

MLA Handbook (7th Edition):

Chang, Li-Hung. “The Effects of Aging on Visual Perceptual Learning and Plasticity.” 2014. Web. 22 Oct 2019.

Vancouver:

Chang L. The Effects of Aging on Visual Perceptual Learning and Plasticity. [Internet] [Doctoral dissertation]. Brown University; 2014. [cited 2019 Oct 22]. Available from: https://repository.library.brown.edu/studio/item/bdr:386181/.

Council of Science Editors:

Chang L. The Effects of Aging on Visual Perceptual Learning and Plasticity. [Doctoral Dissertation]. Brown University; 2014. Available from: https://repository.library.brown.edu/studio/item/bdr:386181/

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