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Although, on average, the magnitude of alpha oscillations (8 to 12 Hz) is decreased in task-relevant cortices during externally oriented attention, its fluctuations have significant consequences, with increased level of alpha associated with decreased level of visual processing and poorer behavioral performance. Functional MRI signals exhibit similar(More)
Studies using event-related potentials (ERPs) have shown that affectively arousing stimuli enhance attention and perception. In addition, simple neutral stimuli, when paired with emotionally engaging unconditioned stimuli (i.e., the CS+) in classical conditioning paradigms, were found to evoke increased sensory responses as learning progresses, compared to(More)
The late positive potential (LPP) is a reliable electrophysiological index of emotional perception in humans. Despite years of research, the brain structures that contribute to the generation and modulation of LPP are not well understood. Recording EEG and fMRI simultaneously, and applying a recently proposed single-trial ERP analysis method, we addressed(More)
In covert visual attention, frontoparietal attention control areas are thought to issue signals to selectively bias sensory neurons to facilitate behaviorally relevant information and suppress distraction. We investigated the relationship between activity in attention control areas and attention-related modulation of posterior alpha activity using(More)
Leaf color change of variegated leaves from chimera species is regulated by fine-tuned molecular mechanisms. Hosta "Gold Standard" is a typical chimera Hosta species with golden-green variegated leaves, which is an ideal material to investigate the molecular mechanisms of leaf variegation. In this study, the margin and center regions of young and mature(More)
The mu rhythm is a field oscillation in the ∼10Hz range over the sensorimotor cortex. For decades, the suppression of mu (event-related desynchronization) has been used to index movement planning, execution, and imagery. Recent work reports that non-motor processes, such as spatial attention and movement observation, also desynchronize mu, raising the(More)
Sequential Monte Carlo method has received intense attention among the literature due to its promising applicability to non-linear and non-Gaussian problems. However, while adopting the standard particle filtering method to the area of image restoration, two main drawbacks are found. Firstly, the computational complexity, which mainly comes from a procedure(More)
Although inter-regional phase synchrony of neural oscillations has been proposed as a plausible mechanism for response control, little is known about the possible effects due to normal aging. We recorded multi-channel electroencephalography (EEG) from healthy younger and older adults in a Go/NoGo task, and examined the aging effects on synchronous brain(More)
Speaker verification is among the widely used biometrics which usually offer more secure authentication for user access than regular passwords. In this final project, we study the DTW-based and HMM-based speaker verification algorithms and a comparison between them is made based on their performances on our recorded dataset. The two feature sets commonly(More)
It has been hypothesized that the medial prefrontal cortex (mPFC) is a hub in the network that mediates appetitive responses whereas the amygdala is thought to mediate both aversive and appetitive processing. Both structures may facilitate adaptive responses to emotional challenge by linking perception, attention, memory, and motor circuits. We provide an(More)