Bachelor thesis – Melanie Wolf
Melanie Wolf
Analysis of the EEG-measured speech-FFRs of Musicians and Non-Musicians [PDF]
finished 2024-04
supervised by Tobias Reichenbach and Michael Schmiedeberg
Abstract
Abstract For this bachelor thesis, the aim was to analyse EEG-measured speech-FFRs of musicians and non- musicians. During the EEG measurements, the participants were simultaneously presented two audiobooks, to determine whether there would be differences between the neural responses when a certain narrator was attended or ignored. Furthermore, it was investigated whether the two groups of musicians and non-musicians exhibit different brain responses in general, and in regards to the attentional modulation. The provided EEG data was used together with two acoustic features, which were derived from the audiobooks, to compute Temporal Response Functions (TRFs). These Temporal Response Functions (TRFs) describe the relationship between the auditory stimulus and the EEG recordings. Then, the magnitudes of the Temporal Response Functions (TRFs) were determined and statistical tests were performed on the results concerning the different attentional modes (attended and ignored) and the two participant groups (musicians and non-musicians). It was found, that on the population average level of all considered participants, the neural responses to both acoustic features showed a tendency to be stronger in the ignored mode than in the attended mode, which was statistically backed for certain latencies after the auditory stimulation. At the considered latencies after the auditory stimulus, no significant differences could be determined between the strengths of the brain responses of the musicians and the non-musicians. This applies to the responses to both used acoustic features. Within the group of the non-musicians, the differences between the responses in the two attentional modes were insignificant for most of the considered latencies after the auditory stimulus. Within the group of the musicians, the differences between the responses when attending or ignoring the narrator seemed greater. At the certain latencies, where significant differences were found, the ignored response was again stronger than the attended response. This was observed for both acoustic features, respectively. Lastly, two different approaches to the calculation of the magnitudes of the TRFs were tried, by changing the order of the averaging steps in the computation process. The approaches led to two slightly different outcomes.
Abstract For this bachelor thesis, the aim was to analyse EEG-measured speech-FFRs of musicians and non- musicians. During the EEG measurements, the participants were simultaneously presented two audiobooks, to determine whether there would be differences between the neural responses when a certain narrator was attended or ignored. Furthermore, it was investigated whether the two groups of musicians and non-musicians exhibit different brain responses in general, and in regards to the attentional modulation. The provided EEG data was used together with two acoustic features, which were derived from the audiobooks, to compute Temporal Response Functions (TRFs). These Temporal Response Functions (TRFs) describe the relationship between the auditory stimulus and the EEG recordings. Then, the magnitudes of the Temporal Response Functions (TRFs) were determined and statistical tests were performed on the results concerning the different attentional modes (attended and ignored) and the two participant groups (musicians and non-musicians). It was found, that on the population average level of all considered participants, the neural responses to both acoustic features showed a tendency to be stronger in the ignored mode than in the attended mode, which was statistically backed for certain latencies after the auditory stimulation. At the considered latencies after the auditory stimulus, no significant differences could be determined between the strengths of the brain responses of the musicians and the non-musicians. This applies to the responses to both used acoustic features. Within the group of the non-musicians, the differences between the responses in the two attentional modes were insignificant for most of the considered latencies after the auditory stimulus. Within the group of the musicians, the differences between the responses when attending or ignoring the narrator seemed greater. At the certain latencies, where significant differences were found, the ignored response was again stronger than the attended response. This was observed for both acoustic features, respectively. Lastly, two different approaches to the calculation of the magnitudes of the TRFs were tried, by changing the order of the averaging steps in the computation process. The approaches led to two slightly different outcomes.