Browsing by Subject "Electroencephalography"
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Item A study of the effect of pitch interval during pitch identification on the electroencephalogram using Fast Fourier Transform(Texas Tech University, 1975-12) Wang, Cecilia ChuThe major concern in this study was to investigate brain wave alterations as evidenced on the electroencephalogram during a specific task of pitch discrimination. Another objective is to provide guidelines for future reference in the research of the brain in relation to music. The author sincerely hopes that the study will encourage both musicians and scientists in joint pursuits, especially in the area of neurophysiology.Item An attentional mediation theory of the relationship between alpha and hypnotic susceptibility(Texas Tech University, 1977-08) Post, David SNot availableItem An electrocortical model of bimodal vigilance performance.(Texas Tech University, 1975-05) Schiflett, Samuel G.The purpose of this dissertation is to develop a model that is based upon physiological processes that accurately reflect changes in an organism's state that are correlated with different aspects of performance of a vigilance task. The utility of the model will then be assessed by predicting a priori effects on electrocortical activity manipulating independent variables that have well established outcomes on vigilance performance, e.g. signal/nonsignal probability ratios. The model is based primarily on the sensory evoked response averaged fron the electroencephalogram.Item EEG signal analysis for seizure detection(Texas Tech University, 1996-05) Qin, DongyingBiological tissue obeys Ohm's law for small current densities [6]. Bioimpedance can be measured with four electrodes: two for current injection and two for voltage measurement. The magnitude of the impedance is given by the ratio of the magnitude of the measured voltage and the magnitude of the injected current. There seems to be a slow increase in measured impedance several minutes prior to the onset of seizure activity. This result may be caused by ionic (Ca^^) shifts prior to seizure formulation [13]. However, whether the result is common for most epilepsy patients is still unknown. Besides, there are also some difficulties in determining a suitable warning threshold, and the procedures for bioimpedance measurement are more complicated than that for an EEG [13]. An EEG is the recording of electrical cerebral potentials [6]. AU chemical and physical processes that take place in living cells produce electrical energy. The energy can be recognized by changes in potential of the cell membrane [11]. The potential of one cell is very small, but when a larger group of cells acts simultaneously, the potential is higher and can be recorded with suitable amplification. Many techniques have been developed for EEG signal analysis. Some techniques have been used for seizure detection or prediction, but there have been no conclusive findings. In this thesis, EEG analysis is used as a tool for seizure detection or prediction. Several different signal analysis techniques are examined. The objective is to determine which technique is the best for seizure detection or prediction.Item Infants' neural processing of facial attractiveness(2014-12) Jankowitsch, Jessica Michelle; Langlois, Judith H.The relationship between infants’ neural processing of and visual preferences for attractive and unattractive faces was investigated through the integration of event-related potential and preferential looking methods. Six-month-olds viewed color images of female faces previously rated by adults for attractiveness. The faces were presented in contrasting pairs of attractiveness (attractive/unattractive) for 1.5-second durations. The results showed that compared to attractive faces, unattractive faces elicited larger N290 amplitudes at left hemisphere electrode sites (PO9) and smaller P400 amplitudes at electrode sites across both hemispheres (PO9 and PO10). There were no significant differences between infants’ overall looking times based on attractiveness, however, a significant relationship was found between amplitude and trial looking time; larger N290 amplitudes were associated with longer trial looking times. The results suggest that compared to attractive faces, unattractive faces require greater cognitive resources and longer initial attention for visual processing.Item Millennial consumers’ perceptions of corporate social responsibility(2012-05) Smith, Shelly; Fowler, Deborah C.; Kim, JungsunThe purpose of this study was to measure consumer response to Corporate Social Responsibility (CSR). In recent years the adoption of CSR has become popularized by many companies, however little academic or industry related data has been collected to determine the relationship between consumer perception of CSR with purchasing and patronage. For this study, the well-known companies of Walmart, Starbucks, and Marriott web-sites were chosen, as these companies are geo-graphically diverse recognizable consumer brands which all have well-developed and award winning Corporate Social Responsibility programs. The sample sought in this study was the web-site surfing college-aged-members of Generation Y, a rapidly growing group of consumers whose purchasing power will play a role in the future direction of companies (i.e., online retailing, online marketing). The primary data sought in this study was the subconscious response of Generation Y when presented a web-site inspired PowerPoint containing the Corporate Social Responsibility initiatives of all three companies. As purchasing of goods is often a subconscious response and relies more on emotion rather than reasoning, obtaining subconscious data is crucial to understanding the minds of consumers. In order to test consumers’ subconscious responses, the neuroimaging instrument of Electroencephalography (EEG) was used . The EEG scan was conducted in NeuroImaging Cognition and Engineering Lab of within Texas Tech University. Prior to EEG scanning, a pre-survey was administered online to gather baseline participant responses to each of the companies and gather consumer opinion of each company’s CSR perception. After the EEG, a post survey was given to determine participant retention of the PowerPoint and future purchase intentions. Using the survey instruments described above, this study operates on the test-retest experimental research method and the theoretical framework known as Stimulus-Organism-Response (SOR), which investigated the relationship between web-site stimulus of CSR and the internal emotional perception of consumers evidenced in the outcome or behavioral response. Data collection was gathered for three days in April of 2012 and consisted of a sample size of 6 females and 5 males. From the sample, no definitive results can be drawn from the EEG results. The results, or brain scan readings, were distorted with artifacts, (i.e., outside noise, physiological movement, etc...), so no definitive brain response analysis could link the stimulus to the response. Therefore, a convenience sample of students was gathered and completed the study without the use of EEG equipment. The second sample consisted of 49 participants, 45 female and 4 male. The methodology remained the same from the initial study; however the emotional and subconscious data were unable to be obtained. The most significant results of the study were descriptive statistics relating to whether or not the participants believed each company possessed the socially responsible behaviors. The participant mean responses increased, indicating the perception that after being presented with the CSR stimulus, people’s perception of the company was more favorable.Item The effect of a pitch matching task on the vertex EEG of trained musicians(Texas Tech University, 1982-12) Rhodes, Hugh HarvleyNot availableItem The influence of calcium and potassium ions on certain electrical phenomena associated with nervous tissue, lipid emulsions, and the influence of potassium ions on the electroencephalogram of the cortex(Texas Tech University, 1953-05) Fain, PatriciaNot availableItem The relationship between conditioned alpha rhythm and psychological variables(Texas Tech University, 1973-08) Grauke, Clyde ErwinThis study proposed to investigate the effect of conditioned alpha rhythm on the psychological variables of locus of control, ego-strength, and anxiety. Hypotheses were proposed which predicted movement along these dimensions in the direction of increased inner-directedness, increased ego-strength, and lessened anxiety as a result of the gain of control over alpha activity. Control of the alpha rhythm was accomplished by biofeedback instrumentation, whereas movement along the psychological dimensions was determined by utilization of appropriate objective tests.