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EEG

2019

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Articles 1 - 11 of 11

Full-Text Articles in Neuroscience and Neurobiology

Visual Modulation Of Resting State Α Oscillations, Kelly Webster, Tony Ro Dec 2019

Visual Modulation Of Resting State Α Oscillations, Kelly Webster, Tony Ro

Publications and Research

Once thought to simply reflect passive cortical idling, recent studies have demonstrated that α oscillations play a causal role in cognition and perception. However, whether and how cognitive or sensory processes modulate various components of the α rhythm is poorly understood. Sensory input and resting states were manipulated in human subjects while electroencephalography (EEG) activity was recorded in three conditions: eyes-open fixating on a visual stimulus, eyes-open without visual input (darkness), and eyes-closed without visual input (darkness). We show that α power and peak frequency increase when visual input is reduced compared to the eyes open, fixating condition. These results …

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The Role Of Gamma Oscillations And Cortical Inhibition In The Development Of Working Memory In Adolescence, Christopher P. Walker Dec 2019

The Role Of Gamma Oscillations And Cortical Inhibition In The Development Of Working Memory In Adolescence, Christopher P. Walker

Dissertations & Theses (Open Access)

Adolescence is a dynamic period of social, cognitive, and biological changes. In particular, working memory, the ability to actively encode and maintain information over a short period of time, develops early in childhood and gradually increases in capacity and stability during adolescence. The precise neurophysiological mechanism by which working memory capacity increases during adolescence is unclear. The objective of this investigation was to evaluate the role of cortical gamma-band (> 30 Hz) oscillations—which are associated with working memory in adults—for the development of working memory capacity in adolescents, and to identify the extent to which the temporal profile of gamma-aminobutyric …

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The Influence Of Neural Reward Processing On Memory In Depression, Nathan M. Hager Dec 2019

The Influence Of Neural Reward Processing On Memory In Depression, Nathan M. Hager

Psychology Theses & Dissertations

Theories and research suggest that depression involves impaired reward sensitivity and a deficit in memory for rewarding stimuli. Some researchers propose that this memory deficit may result from reduced neural reward sensitivity, which impairs the encoding of reward-related memories, but few studies have directly probed this connection. Such research may benefit from examining the reward positivity (RewP), an event-related potential (ERP) previously linked to reduced reward sensitivity in depression. Undergraduates with high or low self-reported depression completed a task in which they chose one of three doors, revealing a neutral word written in a color which indicated an outcome of …

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Visual Entrainment Of Perception-Related Neural Oscillations As A Mechanism For Maintaining Rhythmic Temporal Expectations Across A Wide Range Of Frequencies, Michael James Gray Sep 2019

Visual Entrainment Of Perception-Related Neural Oscillations As A Mechanism For Maintaining Rhythmic Temporal Expectations Across A Wide Range Of Frequencies, Michael James Gray

Dissertations, Theses, and Capstone Projects

Visual sensitivity fluctuates rhythmically, in-synch with ongoing, EEG-recorded neural oscillations across a wide range of frequencies (~1-25hz). Some recent work has suggested that these perception-related neural oscillations can be entrained by rhythmic visual stimulation. Evidence is also emerging that the entrainment of ongoing oscillations in visual and auditory cortices is involved in rhythmic temporal expectations. In the introduction chapter, I attempt to bridge these bodies of literature and hypothesize that rhythmic visual stimuli automatically entrain ongoing, perception-related neural oscillations and that this mechanism supports the maintenance of rhythmic temporal expectations. Chapters 2 and 3 address this hypothesis from different angles. …

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Neural Correlates Of Automatic Emotional Processing And Emotion Regulation In Empathy And Psychopathy-Related Coldheartedness, Danielle Difilipo Sep 2019

Neural Correlates Of Automatic Emotional Processing And Emotion Regulation In Empathy And Psychopathy-Related Coldheartedness, Danielle Difilipo

Dissertations, Theses, and Capstone Projects

Psychopathy is a personality disorder that is defined, in part, by a lack of empathy. Psychopathy-related empathic deficits have been associated with atypical behavioral and neural responses to emotional facial expressions. Although the mirror neuron system (MNS) has been implicated in empathy, very few studies have examined the role of MNS functioning as it pertains to empathy impairments in psychopathy. Moreover, there is very little empirical research regarding emotion regulation in psychopathy, and specifically whether emotional responses can be intentionally upregulated. The present study sought to clarify whether the MNS is functionally intact in adults with subclinical psychopathic traits, particularly …

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Using Meditation To Improve Measures Of Attention In Older Adults, Sabrina Ford Aug 2019

Using Meditation To Improve Measures Of Attention In Older Adults, Sabrina Ford

Electronic Thesis and Dissertation Repository

Age-related cognitive decline greatly impacts quality of life for older adults. Previous research has indicated that meditation may act as a neuroprotective factor to prevent age-related cognitive decline. This thesis sought to replicate previous findings and investigate if a four-week meditation intervention would improve sustained attention. Participants 60 years and older (n=27, 17 female) were recruited and assigned to a focused-attention (FA) meditation or relaxation group which met for four weeks, three times a week. Resting-state EEG was used to collect individual alpha peak frequency (iAPF) and frontal alpha asymmetry (FAA). The Sustained Attention to Response Task (SART) was also …

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An Event-Related Potential Study Of Inhibition To Sugar-Sweetened Beverages, Hanel Watkins Aug 2019

An Event-Related Potential Study Of Inhibition To Sugar-Sweetened Beverages, Hanel Watkins

Undergraduate Honors Theses

In the United States, the intake of sugar-sweetened beverages per capita from 1977 to 2002 doubled across all age groups. One factor that may contribute to the consumption of sugar-sweetened beverages is inhibitory control, or the ability to withhold a dominant response in order to correctly respond to one’s environment. Studies suggest that increased recruitment of inhibitory control resources plays a role in decreasing the consumption of high-calorie foods and that strengthening an individual’s inhibitory control may help them manage their food intake. However, the neural response to sugar-sweetened beverages versus non-sweetened beverages is unknown. Thus, we tested event-related potential …

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Reduced Gabaergic Signaling At The Axon Initial Segment Decreases Vigilance State Transitioning, Austin John Boren Aug 2019

Reduced Gabaergic Signaling At The Axon Initial Segment Decreases Vigilance State Transitioning, Austin John Boren

UNLV Theses, Dissertations, Professional Papers, and Capstones

Sleep is a highly regulated homeostatic process that is disrupted in an estimated 50-70 million Americans. Regulation of sleep depends upon coordinated signaling of multiple neurotransmitter systems. In particular, inhibitory gamma-aminobutyric acid (GABA) signaling is required to suppress wake-active brain regions in order to initiate and maintain sleep states. GABA type A receptors (GABAARs) are ionotropic receptors with subunit compositions uniquely enriched on subcellular domains of target cells. α2 subunit-containing GABAARs are the primary target of GABA released onto the axon initial segment (AIS), a site critical for phasing the oscillatory activity of cortical cells. α2-containing GABAARs have previously been …

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Electrophysiological Correlates Of Natural Language Processing In Children And Adults, Margaret Ugolini Jul 2019

Electrophysiological Correlates Of Natural Language Processing In Children And Adults, Margaret Ugolini

Doctoral Dissertations

To understand the causes of differences in language ability we must measure the specific and separable processes that contribute to natural language comprehension. Specifically, we need measures of the three language subsystems – semantics, syntax, and phonology – as they are used during the comprehension of real speech. Event-Related Potentials (ERPs) are a promising approach to reaching this level of specificity. Previous research has identified distinct ERP effects for each of the subsystems – the N400 to semantic anomalies, the Anterior Negativity and P600 to syntactic anomalies, and the Phonological Mapping Negativity to unexpected speech sounds. However, these studies typically …

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A Hidden Markov Factor Analysis Framework For Seizure Detection In Epilepsy Patients, Mahboubeh Madadi May 2019

A Hidden Markov Factor Analysis Framework For Seizure Detection In Epilepsy Patients, Mahboubeh Madadi

Graduate Theses and Dissertations

Approximately 1% of the world population suffers from epilepsy. Continuous long-term electroencephalographic (EEG) monitoring is the gold-standard for recording epileptic seizures and assisting in the diagnosis and treatment of patients with epilepsy. Detection of seizure from the recorded EEG is a laborious, time consuming and expensive task. In this study, we propose an automated seizure detection framework to assist electroencephalographers and physicians with identification of seizures in recorded EEG signals. In addition, an automated seizure detection algorithm can be used for treatment through automatic intervention during the seizure activity and on time triggering of the injection of a radiotracer to …

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Electroencephalogram As A Diagnostic Tool In Acquired Brain Injury, Michael Zarra Apr 2019

Electroencephalogram As A Diagnostic Tool In Acquired Brain Injury, Michael Zarra

Senior Theses and Projects

The ability of electroencephalogram (EEG) to be used as a diagnostic device for acquired brain injuries (ABI) has been conceptualized previously. Averaged event-related potentials (ERP) derived from an EEG are suitable as markers of dysfunction however, distinctive properties in the frequency domain have not been established previously. In the present study, we examined pre- existing EEG signal data of healthy adults (HA), mild ABI (mABI), and severe ABI (sABI) human groups. Through Fourier analysis performed in MATLAB, we found that individuals in our sample population (n=80) were able to be categorized into their respective group based on common neuronal activity …

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