15 research outputs found
Spectral Sound Gap Filling
No full textWe present a new method for automatically filling in gaps of textural sounds. Our approach is to transform the signal to the time-frequency space, fill in the gap, and apply the inverse transform to reconstruct the result. The complex spectrogram of the signal is partitioned into separate overlapping frequency bands. Each band is fragmented by segmentation of the time-frequency space and a partition of the spectrogram in time, and filled in with complex fragments by example. We demonstrate our method by filling in gaps of various types of textural sounds
A Neural Edge-Detection Model for Enhanced Auditory Sensitivity in Modulated Noise
No full textPsychophysical data suggest that temporal modulations of stimulus amplitude envelopes play a prominent role in the perceptual segregation of concurrent sounds. In particular, the detection of an unmodulated signal can be significantly improved by adding amplitude modulation to the spectral envelope of a competing masking noise. This perceptual phenomenon is known as “Comodulation Masking Release ” (CMR). Despite the obvious influence of temporal structure on the perception of complex auditory scenes, the physiological mechanisms that contribute to CMR and auditory streaming are not well known. A recent physiological study by Nelken and colleagues has demonstrated an enhanced cortical representation of auditory signals in modulated noise. Our study evaluates these CMR-like response patterns from the perspective of a hypothetical auditory edge-detection neuron. It is shown that this simple neural model for the detection of amplitude transients can reproduce not only the physiological data of Nelken et al., but also, in light of previous results, a variety of physiological and psychoacoustical phenomena that are related to the perceptual segregation of concurrent sounds.
Functional reorganization of upper-body movement after spinal cord injury
No full textSurvivors of spinal cord injury need to reorganize their residual body movements for interacting with assistive devices and performing activities that used to be easy and natural. To investigate movement reorganization, we asked subjects with high-level spinal cord injury (SCI) and unimpaired subjects to control a cursor on a screen by performing upper-body motions. While this task would be normally accomplished by operating a computer mouse, here shoulder motions were mapped into the cursor position. Both the control and the SCI subjects were rapidly able to reorganize their movements and to successfully control the cursor. The majority of the subjects in both groups were successful in reducing the movements that were not effective at producing cursor motions. This is inconsistent with the hypothesis that the control system is merely concerned with the accurate acquisition of the targets and is unconcerned with motions that are not relevant to this goal. In contrast, our findings suggest that subjects can learn to reorganize coordination so as to increase the correspondence between the subspace of their upper-body motions with the plane in which the controlled cursor moves. This is effectively equivalent to constructing an inverse internal model of the map from body motions to cursor motions, established by the experiment. These results are relevant to the development of interfaces for assistive devices that optimize the use of residual voluntary control and enhance the learning process in disabled users, searching for an easily learnable map between their body motor space and control space of the device
Auditory edge detection: A neural model for physiological and psychoacoustical responses to amplitude transients
No full textedge detection: a neural model for physiological and psychoacoustical responses to amplitude transients. J Neurophysiol 85: 2303–2323, 2001. Primary segmentation of visual scenes is based on spatiotemporal edges that are presumably detected by neurons throughout the visual system. In contrast, the way in which the auditory system decomposes complex auditory scenes is substantially less clear. There is diverse physiological and psychophysical evidence for the sensitivity of the auditory system to amplitude transients, which can be considered as a partial analogue to visual spatiotemporal edges. However, there is currently no theoretical framework in which these phenomena can be associated or related to the perceptual task of auditory source segregation. We propose a neural model for an auditory temporal edge detector, whose underlying principles are similar to classical visual edge detector models. Our main result is that this model reproduces published physiological responses to amplitude transients collected at multiple levels of the auditory pathways using a variety of experimental procedures. Moreover, the model successfully predicts physiological responses to a new set of amplitude transients, collected in cat primary auditory cortex and medial geniculate body. Additionally, the model reproduces several published psychoacoustical responses to amplitude transients as well as the psychoacoustical data for amplitude edge detection reported here for the first time. These results support the hypothesis that the response of auditory neurons to amplitude transients is the correlate of psychoacoustical edge detection
Neural model for physiological responses to frequency and amplitude transitions uncovers topographical order in the auditory cortex
No full textmodel for physiological responses to frequency and amplitude transitions uncovers topographical order in the auditory cortex. J Neurophysiol 90: 3663–3678, 2003. First published August 27, 2003; 10.1152/jn.00654.2003. We characterize primary auditory cortex (AI) units using a neural model for the detection of frequency and amplitude transitions. The model is a generalization of a model for the detection of amplitude transition. A set of neurons, tuned in the spectrotemporal domain, is created by means of neural delays and frequency filtering. The sensitivity of the model to frequency and amplitude transitions is achieved by applying a 2-dimensional rotatable receptive field to the set of spectrotemporally tuned neurons. We evaluated the model using data recorded in AI of anesthetized ferrets. We show that the model is able to fit the responses of AI units to variety of stimuli, including single tones, delayed 2-tone stimuli and various frequency-modulated tones, using only a small number of parameters. Furthermore, we show that the topographical order in maps of the model parameters is higher than in maps created from response indices extracted directly from the responses to any single stimulus. These results suggest a possible ordered organization of a simple rotatable spectrotemporal receptive field in the mammalian AI
Auditory Edge Detection: A Neural Model for Physiological and Psychoacoustical Responses to Amplitude Transients
No full text Primary segmentation of visual scenes is based on spatiotemporal edges that are presumably detected by neurons throughout the visual system. In contrast, the way in which the auditory system decomposes complex auditory scenes is substantially less clear. There is diverse physiological and psychophysical evidence for the sensitivity of the auditory system to amplitude transients, which can be considered as a partial analogue to visual spatiotemporal edges. However, there is currently no theoretical framework in which these phenomena can be associated or related to the perceptual task of auditory source segregation. We propose a neural model for an auditory temporal edge detector, whose underlying principles are similar to classical visual edge detector models. Our main result is that this model reproduces published physiological responses to amplitude transients collected at multiple levels of the auditory pathways using a variety of experimental procedures. Moreover, the model successfully predicts physiological responses to a new set of amplitude transients, collected in cat primary auditory cortex and medial geniculate body. Additionally, the model reproduces several published psychoacoustical responses to amplitude transients as well as the psychoacoustical data for amplitude edge detection reported here for the first time. These results support the hypothesis that the response of auditory neurons to amplitude transients is the correlate of psychoacoustical edge detection. </jats:p
Being observed magnifies action
No full textWe test the hypothesis that people, when observed, perceive their actions as more substantial because they add the audience’s perspective to their own perspective. We find that participants who were observed while eating (Study 1) or learned they were observed after eating (Study 2) recalled eating a larger portion than unobserved participants. The presence of others magnified both desirable and undesirable actions. Thus, observed (vs. unobserved) participants believed they gave both more correct and incorrect answers in a lab task (Study 3) and, moving to a field study, the larger the audience, the larger the contribution badminton players claimed toward their teams’ successes as well as failures (Study 4). In contrast to actions, inactions are not magnified, because they are unobservable; indeed, observed (vs. unobserved) participants believed they solved more task problems but did not skip more problems (Study 5). Taken together, these studies show that being observed fundamentally alters the subjective magnitude of one’s actions
Incentive designs with uncertainty: keep the hope alive
No full textM.Phil.Researchers suggested that adding uncertainty to incentive design boosts people’s motivation (Shen, Fishbach, and Hsee 2015). However, in a multi-stage reward program (e.g., purchase a cup of coffee to collect a stamp, redeem stamps for rewards), how can marketers best utilize uncertainty to maximize the effectiveness of the incentive? I propose a minimalistic model—namely, a labor chain of effort-score-payoff. Then I divided the labor chain and construct two incentive designs: an early-uncertainty design in which uncertainty occurs between “effort-score” and a later-uncertainty design in which uncertainty occurs between “score-payoff.” This thesis examines the optimization problem, querying whether the early-uncertainty or the later-uncertainty design motivates people to exert more effort. Four lab experiments demonstrated the effect that people work harder in a later-uncertainty design. Possible explanations such as medium maximization and magical thinking were not supported. I explain this effect with the notion of “keep the hope alive”—specifically, unresolved uncertainty leaves room for suspense and this suspense keeps one’s hope of achieving the best possible outcome. This research joins the judgment and decision literature involving uncertainty, discussing how to best utilize it. The findings also provide insights into designing cost-effective incentives for marketers and managers.研究者建議在激勵獎賞計劃中加入不確定性，以此鼓勵消費者 (Shen, Fishbach, and Hsee 2015)。然而，在涉及多個階段的獎賞計劃里（例如，買一杯咖啡得到一個獎章，集齊獎章兌換獎勵），市場營銷專員要怎樣來更好地利用不確定性以最大程度地保證激勵有效性？本文提出了一個簡約模型——即一條努力-分數-收益的勞動鏈。接著，我把這條勞動鏈分為兩個部分並且設計了兩種激勵方案：不確定性被放置於“努力-分數”階段的早期不確定性方案，以及不確定性被放置於“分數-收益”階段的晚期不確定性方案。本論文考察了一個優化問題，即早期不確定性方案還是晚期不確定性方案更有利於激勵人們付出更多努力。四組實驗結果證明，人們在晚期不確定性方案中會更加努力。中間值最大化效應及魔法思想效應的解釋並未被本文實驗結果支持。本文以“滿懷希望”來解釋此發現。具體說來即是，尚未揭示結果的不確定性留下了懸念存在的空間，而懸念讓人們滿懷得到最好結果的希望。本研究作為與不確定性相關的判斷與決策研究的其中一員，提供了怎樣更好利用不確定性的研究發現。本文的發現也為市場營銷專員及管理者提供成本效益高的激勵計劃設計思路。Luo, Xiyueyao.Thesis M.Phil. Chinese University of Hong Kong 2018.Includes bibliographical references (leaves 27-30).Abstracts also in Chinese.Title from PDF title page (viewed on …)
Attention deficit hyperactivity disorder: reframing “deficit” as creative strength
No full textCreative ideas are those that are both novel and useful. Creativity is considered to be a valuable social resource, which has supported the development of society in myriad domains. It has been suggested that behavioural indicators of creativity overlap with symptoms of Attention Deficit Hyperactivity Disorder (ADHD). Indeed, there is some preliminary evidence to suggest that individuals with ADHD may be more creative than individuals without ADHD. The first chapter of this thesis outlines the relevant research and theory and presents the ‘creative advantage hypothesis’. Specifically it is argued that defocused attention in individuals with ADHD increases the likelihood of unusual associations forming, thus increasing the likelihood of creative responses. The potential mediating roles of inhibition and delay aversion are also discussed. The second chapter of this thesis describes a study designed to test predictions of the creative advantage hypothesis. Parents of pupils in Year 8 were asked to rate their child’s level of inattentiveness and hyperactivity. Sixty six pupils completed a measure of figural creativity, inhibition and delay aversion in school. ADHD symptoms predicted creativity scores on one aspect of creativity, originality, and this effect was found in boys only. Inhibition and delay aversion were not found to mediate the relationship between ADHD symptomology and creativity in boys. Limitations and implications for Educational Psychologists and teachers are also discussed
