Your conditions: 王迪
  • Spatial generalization of serial dependence in visual duration perception

    Subjects: Psychology >> Cognitive Psychology submitted time 2023-12-05

    Abstract: To establish a stable and sensitive experience of the world, the brain tends to use recent history when forming perceptual decisions. This results in serial dependence in perception, by which previous trials affect the current perception. The serial dependence effect can be divided into (at least) two categories: the effect of previous stimuli (i.e., the stimulus serial dependence effect) and the effect of previous decisions (i.e., the decisional serial dependence effect) on the current perception. Although separate stimulus and decisional serial dependence effects have been demonstrated in duration perception, their spatial selectivity is unclear. In the present study, we investigated whether and how serial dependence in duration perception generalizes across different visual positions of stimuli.
    The modified temporal bisection task was used in three experiments. Specifically, 24 naïve volunteers participated in Experiment 1. During the experiment, the visual stimulus (a white Gaussian blob) was pseudorandomly presented in the central or peripheral (10° from the left fixation) visual field. Participants were asked to judge whether the duration of the test stimulus (i.e., 300, 395, 520, 684, or 900 ms) was shorter or longer than a reference stimulus of intermediate duration (i.e., 520 ms) once the test stimulus disappeared. A group of 23 new volunteers were recruited for Experiment 2. The task of Experiment 2 was similar to that of Experiment 1, except that the visual stimulus was pseudorandomly located at either 5° to the left or 5° to the right of the central fixation. A new set of 24 volunteers participated in Experiment 3, in which the positions of both the fixation and the visual stimulus were changed; there were thus four types of positional relationships between stimuli across trials (i.e., identity, retinal position change, external position change, and both changes).
    The results showed that previous stimulus duration and previous choice exerted opposing effects on serial dependence of duration perception: specifically, a repulsive stimulus serial dependence and an attractive decisional serial dependence. In other words, current duration estimates were repelled away from the previous trial’s stimulus duration but attracted toward the previous choice. We found these effects in both the central and peripheral visual fields. More importantly, we found that the stimulus serial dependence effect was not constrained by the visual position of the stimuli: the effects were comparable between contexts in which the stimulus positions of previous and current trials were the same and when they were different. The effects fully transferred across the central and peripheral visual fields, across the left and right visual hemifields, and across different external spaces. However, we found that the decisional serial dependence effect was larger in the position-consistent context than in the position-inconsistent context. This indicates that the decisional serial dependence effect could only be partially transferred across different visual positions regardless of the types of positions (i.e., spatiotopic vs. retinotopic).
    These results provide evidence that both previous stimuli duration and previous choices affect subsequent perceptual decisions about duration, resulting in repulsive and attractive serial dependence effects, respectively. The repulsive stimulus serial dependence effect fully generalizes across different visual positions, suggesting it occurs primarily in higher-level visual areas. This also implies the existence of fast-duration adaptation. The attractive decisional serial dependence effect suggests that there is decision inertia in perceptual choices. Moreover, this effect is partly contingent on the visual position, which may result from the category organization function of higher-order brain areas. This suggests that the brain takes advantage of the visual position context when forming the decisional prior. These findings are helpful for understanding the plasticity of duration perception.

  • Study of Users’ Differences of Needs for University Libraries’ Digital Scholarship Services: From a Perspective of Research Lifecycle

    Subjects: Library Science,Information Science >> Library Science submitted time 2023-06-28

    Abstract: [Objective] This study focuses on the differences of needs of users with different research roles and from a variety of disciplines for digital scholarship services (DSS).
    [Methods] This study built a university library DSS framework covering all stages of research lifecycle based on the literature analysis. By using the framework, this study designed a questionnaire and applied KANO method to compare the differences of needs for DSS of users with different research roles and discipline backgrounds.
    [Results] Users of different research roles and discipline backgrounds have significant different needs for DSS in different stages of research lifecycle. The attractive and one-dimensional needs gather in research process and publication stages. Most of the services for research ideas stage belong to must-be needs. No reverse needs exist in DSS.
    [Limitations] This study has limitations in the number of research samples. It also focuses only on the research roles and discipline backgrounds of users, but did not consider other demographic characteristics.
    [Conclusions] In future, university libraries can focus more on users' attractive and one-dimensional needs,providing personalized DSS and cover more stages of research lifecycle.

  • 大数据环境中交互式查询差分隐私保护模型

    Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-04-12 Cooperative journals: 《计算机应用研究》

    Abstract: With the arrival of the era of big data, data mining technology is widely used, and the most basic and frequent operation of the technology, linear query, whose privacy protection occupies an extremely important position in data analysis and data release privacy protection. The data processed become more when querying in an interactive linear queries way, and it is less efficient when using the traditional privacy protection models. In order to solve the problem of differential privacy protection for interactive queries in big data environment, the model reduced the redundant information through data correlation analysis, decomposed the query load matrix by adopting alternating direction multiplier method, produced a reasonable amount of noise required for differential privacy protection using the adaptive noise injection technology, and a parallel processing method designed calculated it against the characteristics of interactive linear query differential privacy protection for large-scale data set. Experiment compared the model proposed to previous works. The result showed that the model proposed promoted the accuracy of privacy protection and algorithm performance greatly. Therefore, the model is feasible.