Matching Items (996)
Description
Head movement is known to have the benefit of improving the accuracy of sound localization for humans and animals. Marmoset is a small bodied New World monkey species and it has become an emerging model for studying the auditory functions. This thesis aims to detect the horizontal and vertical rotation of head movement in marmoset monkeys.
Experiments were conducted in a sound-attenuated acoustic chamber. Head movement of marmoset monkey was studied under various auditory and visual stimulation conditions. With increasing complexity, these conditions are (1) idle, (2) sound-alone, (3) sound and visual signals, and (4) alert signal by opening and closing of the chamber door. All of these conditions were tested with either house light on or off. Infra-red camera with a frame rate of 90 Hz was used to capture of the head movement of monkeys. To assist the signal detection, two circular markers were attached to the top of monkey head. The data analysis used an image-based marker detection scheme. Images were processed using the Computation Vision Toolbox in Matlab. The markers and their positions were detected using blob detection techniques. Based on the frame-by-frame information of marker positions, the angular position, velocity and acceleration were extracted in horizontal and vertical planes. Adaptive Otsu Thresholding, Kalman filtering and bound setting for marker properties were used to overcome a number of challenges encountered during this analysis, such as finding image segmentation threshold, continuously tracking markers during large head movement, and false alarm detection.
The results show that the blob detection method together with Kalman filtering yielded better performances than other image based techniques like optical flow and SURF features .The median of the maximal head turn in the horizontal plane was in the range of 20 to 70 degrees and the median of the maximal velocity in horizontal plane was in the range of a few hundreds of degrees per second. In comparison, the natural alert signal - door opening and closing - evoked the faster head turns than other stimulus conditions. These results suggest that behaviorally relevant stimulus such as alert signals evoke faster head-turn responses in marmoset monkeys.
Experiments were conducted in a sound-attenuated acoustic chamber. Head movement of marmoset monkey was studied under various auditory and visual stimulation conditions. With increasing complexity, these conditions are (1) idle, (2) sound-alone, (3) sound and visual signals, and (4) alert signal by opening and closing of the chamber door. All of these conditions were tested with either house light on or off. Infra-red camera with a frame rate of 90 Hz was used to capture of the head movement of monkeys. To assist the signal detection, two circular markers were attached to the top of monkey head. The data analysis used an image-based marker detection scheme. Images were processed using the Computation Vision Toolbox in Matlab. The markers and their positions were detected using blob detection techniques. Based on the frame-by-frame information of marker positions, the angular position, velocity and acceleration were extracted in horizontal and vertical planes. Adaptive Otsu Thresholding, Kalman filtering and bound setting for marker properties were used to overcome a number of challenges encountered during this analysis, such as finding image segmentation threshold, continuously tracking markers during large head movement, and false alarm detection.
The results show that the blob detection method together with Kalman filtering yielded better performances than other image based techniques like optical flow and SURF features .The median of the maximal head turn in the horizontal plane was in the range of 20 to 70 degrees and the median of the maximal velocity in horizontal plane was in the range of a few hundreds of degrees per second. In comparison, the natural alert signal - door opening and closing - evoked the faster head turns than other stimulus conditions. These results suggest that behaviorally relevant stimulus such as alert signals evoke faster head-turn responses in marmoset monkeys.
ContributorsSimhadri, Sravanthi (Author) / Zhou, Yi (Thesis advisor) / Turaga, Pavan (Thesis advisor) / Berisha, Visar (Committee member) / Arizona State University (Publisher)
Created2014
Description
This study consisted of several related projects on dynamic spatial hearing by both human and robot listeners. The first experiment investigated the maximum number of sound sources that human listeners could localize at the same time. Speech stimuli were presented simultaneously from different loudspeakers at multiple time intervals. The maximum of perceived sound sources was close to four. The second experiment asked whether the amplitude modulation of multiple static sound sources could lead to the perception of auditory motion. On the horizontal and vertical planes, four independent noise sound sources with 60° spacing were amplitude modulated with consecutively larger phase delay. At lower modulation rates, motion could be perceived by human listeners in both cases. The third experiment asked whether several sources at static positions could serve as "acoustic landmarks" to improve the localization of other sources. Four continuous speech sound sources were placed on the horizontal plane with 90° spacing and served as the landmarks. The task was to localize a noise that was played for only three seconds when the listener was passively rotated in a chair in the middle of the loudspeaker array. The human listeners were better able to localize the sound sources with landmarks than without. The other experiments were with the aid of an acoustic manikin in an attempt to fuse binaural recording and motion data to localize sounds sources. A dummy head with recording devices was mounted on top of a rotating chair and motion data was collected. The fourth experiment showed that an Extended Kalman Filter could be used to localize sound sources in a recursive manner. The fifth experiment demonstrated the use of a fitting method for separating multiple sounds sources.
ContributorsZhong, Xuan (Author) / Yost, William (Thesis advisor) / Zhou, Yi (Committee member) / Dorman, Michael (Committee member) / Helms Tillery, Stephen (Committee member) / Arizona State University (Publisher)
Created2015
Description
Sound localization can be difficult in a reverberant environment. Fortunately listeners can utilize various perceptual compensatory mechanisms to increase the reliability of sound localization when provided with ambiguous physical evidence. For example, the directional information of echoes can be perceptually suppressed by the direct sound to achieve a single, fused auditory event in a process called the precedence effect (Litovsky et al., 1999). Visual cues also influence sound localization through a phenomenon known as the ventriloquist effect. It is classically demonstrated by a puppeteer who speaks without visible lip movements while moving the mouth of a puppet synchronously with his/her speech (Gelder and Bertelson, 2003). If the ventriloquist is successful, sound will be “captured” by vision and be perceived to be originating at the location of the puppet. This thesis investigates the influence of vision on the spatial localization of audio-visual stimuli. Participants seated in a sound-attenuated room indicated their perceived locations of either ISI or level-difference stimuli in free field conditions. Two types of stereophonic phantom sound sources, created by modulating the inter-stimulus time interval (ISI) or level difference between two loudspeakers, were used as auditory stimuli. The results showed that the light cues influenced auditory spatial perception to a greater extent for the ISI stimuli than the level difference stimuli. A binaural signal analysis further revealed that the greater visual bias for the ISI phantom sound sources was correlated with the increasingly ambiguous binaural cues of the ISI signals. This finding suggests that when sound localization cues are unreliable, perceptual decisions become increasingly biased towards vision for finding a sound source. These results support the cue saliency theory underlying cross-modal bias and extend this theory to include stereophonic phantom sound sources.
ContributorsMontagne, Christopher (Author) / Zhou, Yi (Thesis advisor) / Buneo, Christopher A (Thesis advisor) / Yost, William A. (Committee member) / Arizona State University (Publisher)
Created2015
Description
Music training is associated with measurable physiologic changes in the auditory pathway. Benefits of music training have also been demonstrated in the areas of working memory, auditory attention, and speech perception in noise. The purpose of this study was to determine whether long-term auditory experience secondary to music training enhances the ability to detect, learn, and recall new words.
Participants consisted of 20 young adult musicians and 20 age-matched non-musicians. In addition to completing word recognition and non-word detection tasks, each participant learned 10 nonsense words in a rapid word-learning task. All tasks were completed in quiet and in multi-talker babble. Next-day retention of the learned words was examined in isolation and in context. Cortical auditory evoked responses to vowel stimuli were recorded to obtain latencies and amplitudes for the N1, P2, and P3a components. Performance was compared across groups and listening conditions. Correlations between the behavioral tasks and the cortical auditory evoked responses were also examined.
No differences were found between groups (musicians vs. non-musicians) on any of the behavioral tasks. Nor did the groups differ in cortical auditory evoked response latencies or amplitudes, with the exception of P2 latencies, which were significantly longer in musicians than in non-musicians. Performance was significantly poorer in babble than in quiet on word recognition and non-word detection, but not on word learning, learned-word retention, or learned-word detection. CAEP latencies collapsed across group were significantly longer and amplitudes were significantly smaller in babble than in quiet. P2 latencies in quiet were positively correlated with word recognition in quiet, while P3a latencies in babble were positively correlated with word recognition and learned-word detection in babble. No other significant correlations were observed between CAEPs and performance on behavioral tasks.
These results indicated that, for young normal-hearing adults, auditory experience resulting from long-term music training did not provide an advantage for learning new information in either favorable (quiet) or unfavorable (babble) listening conditions. Results of the present study suggest that the relationship between music training and the strength of cortical auditory evoked responses may be more complex or too weak to be observed in this population.
Participants consisted of 20 young adult musicians and 20 age-matched non-musicians. In addition to completing word recognition and non-word detection tasks, each participant learned 10 nonsense words in a rapid word-learning task. All tasks were completed in quiet and in multi-talker babble. Next-day retention of the learned words was examined in isolation and in context. Cortical auditory evoked responses to vowel stimuli were recorded to obtain latencies and amplitudes for the N1, P2, and P3a components. Performance was compared across groups and listening conditions. Correlations between the behavioral tasks and the cortical auditory evoked responses were also examined.
No differences were found between groups (musicians vs. non-musicians) on any of the behavioral tasks. Nor did the groups differ in cortical auditory evoked response latencies or amplitudes, with the exception of P2 latencies, which were significantly longer in musicians than in non-musicians. Performance was significantly poorer in babble than in quiet on word recognition and non-word detection, but not on word learning, learned-word retention, or learned-word detection. CAEP latencies collapsed across group were significantly longer and amplitudes were significantly smaller in babble than in quiet. P2 latencies in quiet were positively correlated with word recognition in quiet, while P3a latencies in babble were positively correlated with word recognition and learned-word detection in babble. No other significant correlations were observed between CAEPs and performance on behavioral tasks.
These results indicated that, for young normal-hearing adults, auditory experience resulting from long-term music training did not provide an advantage for learning new information in either favorable (quiet) or unfavorable (babble) listening conditions. Results of the present study suggest that the relationship between music training and the strength of cortical auditory evoked responses may be more complex or too weak to be observed in this population.
ContributorsStewart, Elizabeth (Author) / Pittman, Andrea (Thesis advisor) / Cone, Barbara (Committee member) / Zhou, Yi (Committee member) / Arizona State University (Publisher)
Created2017
Description
Auditory scene analysis (ASA) is the process through which listeners parse and organize their acoustic environment into relevant auditory objects. ASA functions by exploiting natural regularities in the structure of auditory information. The current study investigates spectral envelope and its contribution to the perception of changes in pitch and loudness. Experiment 1 constructs a perceptual continuum of twelve f0- and intensity-matched vowel phonemes (i.e. a pure timbre manipulation) and reveals spectral envelope as a primary organizational dimension. The extremes of this dimension are i (as in “bee”) and Ʌ (“bun”). Experiment 2 measures the strength of the relationship between produced f0 and the previously observed phonetic-pitch continuum at three different levels of phonemic constraint. Scat performances and, to a lesser extent, recorded interviews were found to exhibit changes in accordance with the natural regularity; specifically, f0 changes were correlated with the phoneme pitch-height continuum. The more constrained case of lyrical singing did not exhibit the natural regularity. Experiment 3 investigates participant ratings of pitch and loudness as stimuli vary in f0, intensity, and the phonetic-pitch continuum. Psychophysical functions derived from the results reveal that moving from i to Ʌ is equivalent to a .38 semitone decrease in f0 and a .75 dB decrease in intensity. Experiment 4 examines the potentially functional aspect of the pitch, loudness, and spectral envelope relationship. Detection thresholds of stimuli in which all three dimensions change congruently (f0 increase, intensity increase, Ʌ to i) or incongruently (no f0 change, intensity increase, i to Ʌ) are compared using an objective version of the method of limits. Congruent changes did not provide a detection benefit over incongruent changes; however, when the contribution of phoneme change was removed, congruent changes did offer a slight detection benefit, as in previous research. While this relationship does not offer a detection benefit at threshold, there is a natural regularity for humans to produce phonemes at higher f0s according to their relative position on the pitch height continuum. Likewise, humans have a bias to detect pitch and loudness changes in phoneme sweeps in accordance with the natural regularity.
ContributorsPatten, K. Jakob (Author) / Mcbeath, Michael K (Thesis advisor) / Amazeen, Eric L (Committee member) / Glenberg, Arthur W (Committee member) / Zhou, Yi (Committee member) / Arizona State University (Publisher)
Created2017
Description
This paper considers what factors influence student interest, motivation, and continued engagement. Studies show anticipated extrinsic rewards for activity participation have been shown to reduce intrinsic value for that activity. This might suggest that grade point average (GPA) has a similar effect on academic interests. Further, when incentives such as scholarships, internships, and careers are GPA-oriented, students must adopt performance goals in courses to guarantee success. However, performance goals have not been shown to correlated with continued interest in a topic. Current literature proposes that student involvement in extracurricular activities, focused study groups, and mentored research are crucial to student success. Further, students may express either a fixed or growth mindset, which influences their approach to challenges and opportunities for growth. The purpose of this study was to collect individual cases of students' experiences in college. The interview method was chosen to collect complex information that could not be gathered from standard surveys. To accomplish this, questions were developed based on content areas related to education and motivation theory. The content areas included activities and meaning, motivation, vision, and personal development. The developed interview method relied on broad questions that would be followed by specific "probing" questions. We hypothesize that this would result in participant-led discussions and unique narratives from the participant. Initial findings suggest that some of the questions were effective in eliciting detailed responses, though results were dependent on the interviewer. From the interviews we find that students value their group involvements, leadership opportunities, and relationships with mentors, which parallels results found in other studies.
ContributorsAbrams, Sara (Author) / Hartwell, Lee (Thesis director) / Correa, Kevin (Committee member) / Department of Psychology (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Many factors are at play within the genome of an organism, contributing to much of the diversity and variation across the tree of life. While the genome is generally encoded by four nucleotides, A, C, T, and G, this code can be expanded. One particular mechanism that we examine in this thesis is modification of bases—more specifically, methylation of Adenine (m6A) within the GATC motif of Escherichia coli. These methylated adenines are especially important in a process called methyl-directed mismatch repair (MMR), a pathway responsible for repairing errors in the DNA sequence produced by replication. In this pathway, methylated adenines identify the parent strand and direct the repair proteins to correct the erroneous base in the daughter strand. While the primary role of methylated adenines at GATC sites is to direct the MMR pathway, this methylation has also been found to affect other processes, such as gene expression, the activity of transposable elements, and the timing of DNA replication. However, in the absence of MMR, the ability of these other processes to maintain adenine methylation and its targets is unknown.
To determine if the disruption of the MMR pathway results in the reduced conservation of methylated adenines as well as an increased tolerance for mutations that result in the loss or gain of new GATC sites, we surveyed individual clones isolated from experimentally evolving wild-type and MMR-deficient (mutL- ;conferring an 150x increase in mutation rate) populations of E. coli with whole-genome sequencing. Initial analysis revealed a lack of mutations affecting methylation sites (GATC tetranucleotides) in wild-type clones. However, the inherent low mutation rates conferred by the wild-type background render this result inconclusive, due to a lack of statistical power, and reveal a need for a more direct measure of changes in methylation status. Thus as a first step to comparative methylomics, we benchmarked four different methylation-calling pipelines on three biological replicates of the wildtype progenitor strain for our evolved populations.
While it is understood that these methylated sites play a role in the MMR pathway, it is not fully understood the full extent of their effect on the genome. Thus the goal of this thesis was to better understand the forces which maintain the genome, specifically concerning m6A within the GATC motif.
To determine if the disruption of the MMR pathway results in the reduced conservation of methylated adenines as well as an increased tolerance for mutations that result in the loss or gain of new GATC sites, we surveyed individual clones isolated from experimentally evolving wild-type and MMR-deficient (mutL- ;conferring an 150x increase in mutation rate) populations of E. coli with whole-genome sequencing. Initial analysis revealed a lack of mutations affecting methylation sites (GATC tetranucleotides) in wild-type clones. However, the inherent low mutation rates conferred by the wild-type background render this result inconclusive, due to a lack of statistical power, and reveal a need for a more direct measure of changes in methylation status. Thus as a first step to comparative methylomics, we benchmarked four different methylation-calling pipelines on three biological replicates of the wildtype progenitor strain for our evolved populations.
While it is understood that these methylated sites play a role in the MMR pathway, it is not fully understood the full extent of their effect on the genome. Thus the goal of this thesis was to better understand the forces which maintain the genome, specifically concerning m6A within the GATC motif.
ContributorsBoyer, Gwyneth (Author) / Lynch, Michael (Thesis director) / Behringer, Megan (Committee member) / Geiler-Samerotte, Kerry (Committee member) / School of Life Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
This paper emphasizes how vital prosthetic devices are as tools for both congenital and acquired amputees in order to maximize this population's level of societal productivity, but several issues exist with the current technological focus of development by the prosthetic industry that creates unnecessary hurdles that amputees must surpass in order to truly benefit from these tools. The first major issue is that these devices are not readily available to all amputees. The astronomical cost of most prosthetic devices is a variable that restricts low income amputee populations from obtaining these vital tools regardless of their level of need, thus highlighting the fact that amputees who are not financially stable are not supported in a fashion that is conducive to their success. Also, cost greatly affects children who suffer from a missing appendage due to the fact that they are in constant need of prosthetic replacement because of physical growth and development. Another issue with the current focus of the prosthetic industry is that it focuses on acquired amputees because this population is much larger in comparison to congenital amputees and thus more lucrative. Congenital amputees' particular needs are often entirely ignored in terms of prosthetic innovation. Finally, low daily utilization is a major issue amongst the amputee population. Several variables exist with the use of prosthetic devices that cause many amputees to decide against the utilization of these tools, like difficulty of use and lack of comfort. This paper will provide solutions to cost, discrimination, issues in development, and daily utilization by emphasizing on how lowering the cost through alternative designs and materials, transitioning the focus of technological development onto the entire amputee population rather than targeting the most lucrative group, and advancing the design in a fashion to which promotes daily utilization will provide the largest level of societal support, so that the amputee population as a whole can maximize their level of productivity in a manner that will allow this group to conquer the hardships that are introduced into their lives due to a missing appendage.
ContributorsO'Connor, Casey Charles (Author) / Popova, Laura (Thesis director) / Graff, Sarah (Committee member) / Department of Psychology (Contributor) / School of Social Work (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
This study examines Glamour magazine to determine the messages the publication sends to its readers and to evaluate if such messages align with modern feminist goals. The articles of Glamour's 12 issues from the year of 2016 are analyzed using a framework adapted from previous research on women's magazines. Articles are coded as either positive (feminist, anti-traditional, promotes equality) or negative (anti-feminist, traditional, promotes inequality). Distinct content themes (appearance, dating, home, self-development, career development, politics/world issues, and entertainment) are also examined individually. After the presentation of data, I examine my findings through a feminist lens to determine the nature of the messages being sent to women through the magazine's editorial content, followed by an assessment of the value of women's magazines and how they could potentially shape the beliefs and roles of a 2017 woman. It is found that about half of the articles in Glamour could be considered as having feminist messages, with strong themes of personal choice, individual empowerment, and political involvement or activism in these articles and throughout the magazine. The content also has many blatantly feminist messages, including consistent use of the word itself. Another 40% of the articles are found to be neutral (no clear message to reader), and the remaining are negative. The sexism inherent in these negative articles is critically examined. Finally, the main takeaways of the findings and their ramifications are discussed from both a media consumer and a media producer perspective, with arguments for why it is important to be critical of a magazine's editorial content.
ContributorsAllnatt, Libby Paige (Author) / Pucci, Jessica (Thesis director) / Dove-Viebahn, Aviva (Committee member) / School of Social Transformation (Contributor) / Department of Psychology (Contributor) / Walter Cronkite School of Journalism and Mass Communication (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Spousal loss is a common, significant life event that can negatively affect multiple facets of individual health and psychological adjustment. Social support is one factor that is shown to improve adjustment following spousal loss, but much less is known regarding which facet of social support is most predictive of positive adjustment outcomes following spousal loss. This study examined the course of changes in mental health and well-being following spousal loss and which facets of social support are associated with better outcomes following spousal loss. Latent growth curve modeling was applied to data from 265 widowed individuals, ages 65 and older, across four assessments (baseline, and 6-, 18-, and 48- months following spousal loss). I examined the following research questions: (1) adjustment following spousal loss will follow a trajectory of an increase in depressive symptoms and anxiety and decrease in well-being with a leveling-off over time, with between-person differences, and (2) emotional support and instrumental support given will lead to more positive adjustment outcomes over time. Depressive symptoms followed the hypothesized trajectory but anxiety and well-being showed relative stability before and after spousal loss. Instrumental support was the most beneficial facet of social support, such that receiving more instrumental support was associated with lower levels of depressive symptoms and anxiety 6-months following spousal loss. Giving more instrumental support led to an increase in well-being following spousal loss. Instrumental support given and received led to increases in well-being as a function of spousal loss. The discussion focuses on whether and how these findings can help to identify ways through which support and help can be given to individuals to improve adjustment to spousal loss and fully recover.
ContributorsSullivan, Colleen Elizabeth (Author) / Infurna, Frank (Thesis director) / Luthar, Suniya (Committee member) / Davis, Mary (Committee member) / Department of Psychology (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12