161 |
Development of a Time-restricted Region-suppressed ER-SAM Beamformer and its Application to an Auditory Evoked Field StudyWong, Daniel 30 July 2008 (has links)
This study evaluated a time-restricted region-suppressed event-related synthetic aperture magnetoencephalography (TRRS-ER-SAM) beamformer algorithm against equivalent current dipole (ECD), and event-related synthetic aperture magnetoencephalography (ER-SAM) post-processing methods for magnetoencephalography data. This evaluation was done numerically and with auditory evoked field (AEF) data elicited by binaurally presented 500 Hz tones. The TRRS-ER-SAM beamformer demonstrated robustness to noise, and the ability to handle coherent sources.
The TRRS-ER-SAM algorithm was then applied to a study of N1m AEFs in 8 subjects aged 12-25 years. The study examined the effects of age, stimulus frequency, and right-sided monaural versus binaural stimulation on the N1m location, amplitude, and latency. It was found that age affected the N1m latency; stimulus frequency affected the N1m location, amplitude, and latency; and monaural versus binaural stimulation affected the N1m amplitude. In the context of these effects, the auditory pathway structure and neurophysiological changes due to maturation were discussed.
|
162 |
Auditory Search: The Deployment of Attention within a Complex Auditory SceneGillingham, Susan 20 November 2012 (has links)
Current theories of auditory attention are largely based upon studies examining either the presentation of a single auditory stimulus or requiring the identification and labeling of stimuli presented sequentially. Whether or not these theories apply in more complex ecologically-valid environments where multiple sound sources are simultaneously active is still unknown. This study examined the pattern of neuromagnetic responses elicited when participants had to perform a search in an auditory language-based `scene` for a stimulus matching an imperative target held in working memory. The analysis of source waveforms revealed left lateralized patterns of activity that distinguished target present from target absent trials. Similar source waveform amplitudes were found when the target was presented in the left or right hemispace. The results suggest that auditory search for speech sounds engage a left lateralized process in the superior temporal gyrus.
|
163 |
Auditory Search: The Deployment of Attention within a Complex Auditory SceneGillingham, Susan 20 November 2012 (has links)
Current theories of auditory attention are largely based upon studies examining either the presentation of a single auditory stimulus or requiring the identification and labeling of stimuli presented sequentially. Whether or not these theories apply in more complex ecologically-valid environments where multiple sound sources are simultaneously active is still unknown. This study examined the pattern of neuromagnetic responses elicited when participants had to perform a search in an auditory language-based `scene` for a stimulus matching an imperative target held in working memory. The analysis of source waveforms revealed left lateralized patterns of activity that distinguished target present from target absent trials. Similar source waveform amplitudes were found when the target was presented in the left or right hemispace. The results suggest that auditory search for speech sounds engage a left lateralized process in the superior temporal gyrus.
|
164 |
Development of a Time-restricted Region-suppressed ER-SAM Beamformer and its Application to an Auditory Evoked Field StudyWong, Daniel 30 July 2008 (has links)
This study evaluated a time-restricted region-suppressed event-related synthetic aperture magnetoencephalography (TRRS-ER-SAM) beamformer algorithm against equivalent current dipole (ECD), and event-related synthetic aperture magnetoencephalography (ER-SAM) post-processing methods for magnetoencephalography data. This evaluation was done numerically and with auditory evoked field (AEF) data elicited by binaurally presented 500 Hz tones. The TRRS-ER-SAM beamformer demonstrated robustness to noise, and the ability to handle coherent sources.
The TRRS-ER-SAM algorithm was then applied to a study of N1m AEFs in 8 subjects aged 12-25 years. The study examined the effects of age, stimulus frequency, and right-sided monaural versus binaural stimulation on the N1m location, amplitude, and latency. It was found that age affected the N1m latency; stimulus frequency affected the N1m location, amplitude, and latency; and monaural versus binaural stimulation affected the N1m amplitude. In the context of these effects, the auditory pathway structure and neurophysiological changes due to maturation were discussed.
|
165 |
Feature processing in human audition : the role of auditory cortex in perception, short-term memory and imageryLinke, Annika Carola January 2012 (has links)
No description available.
|
166 |
Electroencephalographic measures of auditory perception in dynamic acoustic environmentsMcMullan, Amanda R January 2013 (has links)
We are capable of effortlessly parsing a complex scene presented to us. In order to do
this, we must segregate objects from each other and from the background. While this
process has been extensively studied in vision science, it remains relatively less
understood in auditory science. This thesis sought to characterize the neuroelectric
correlates of auditory scene analysis using electroencephalography. Chapter 2 determined
components evoked by first-order energy boundaries and second-order pitch boundaries.
Chapter 3 determined components evoked by first-order and second-order discontinuous
motion boundaries. Both of these chapters focused on analysis of event-related potential
(ERP) waveforms and time-frequency analysis. In addition, these chapters investigated
the contralateral nature of a negative ERP component. These results extend the current
knowledge of auditory scene analysis by providing a starting point for discussing and
characterizing first-order and second-order boundaries in an auditory scene. / x, 90 leaves : col. ill. ; 29 cm
|
167 |
Temporal stimulus effects on the P300 /Van Gorden, Michelle K., January 1900 (has links)
Thesis (Au. D.)--Missouri State University, 2008. / "May 2008." Includes bibliographical references (leaves 49-53). Also available online.
|
168 |
Event-related brain potentials to changes in the acoustic environment during sleep and sleepinessSallinen, Mikael. January 1997 (has links)
Thesis--University of Jyväskylä, 1997. / Added t.p. with thesis statement inserted.
|
169 |
An investigation of the P300 event related potential across genderLombard, F. D. January 2005 (has links)
Thesis (M. (Communication Pathology))--University of Pretoria, 2005. / Includes bibliographical references.
|
170 |
Event-related brain potentials to changes in the acoustic environment during sleep and sleepinessSallinen, Mikael. January 1997 (has links)
Thesis--University of Jyväskylä, 1997. / Added t.p. with thesis statement inserted.
|
Page generated in 0.0472 seconds