1,720,979 research outputs found
From horizontal to vertical: Human spatial representations in three-dimensional navigation
Full text linkPrevious research has provided a lot of evidence about spatial navigation on 2D surfaces whereas how animals represent space in 3D navigation involving vertical information is much less often investigated (Jeffery, Jovalekic, Verriotis, & Hayman, 2013; Jeffery, Wilson, Casali, & Hayman, 2015). The current dissertation work aims to investigate humans’ memory of localization and their heading updating in 3D navigation. In Chapter 1, I first review the previous research about these two topics (3D location memory and 3D heading) and briefly discuss the individual difference by evolutionary and individual histories. Chapter 2 presents Study 1 which examined 3D location memory and Chapter 3 presents Study 2 which examined 3D heading representation in spatial navigation. Both studies were conducted in immersive virtual reality environments. Chapter 4 summarizes the findings in the two studies and discusses the general cognitive mechanisms and principles in 3D navigation implied by the two studies.
Study 1 presented in Chapter 2 investigated whether humans’ localization is more variable vertically than horizontally in different locomotion modes. Participants localized targets on a vertical wall via self-locomotion. One group of participants flew three-dimensionally along their viewing direction towards the target (flying group). The second group only locomoted on the floor and the wall along the projection of the viewing direction onto the current travelling surface (climbing group). The third group pressed a button to be teleported from the floor to the wall and then locomoted on the wall (teleportation group). Both the flying and the climbing groups showed a horizontal advantage of location memory whereas the teleportation group showed a vertical advantage. Examining the trajectories of the participants in the three groups indicate a vertical advantage of locomotion on a vertical surface. The results suggest that locomotion mode does not account for the horizontal advantage for the surface-travelling
iii
animals. Therefore, the horizontal advantage is more likely to be species-specific rather than locomotion-mode specific.
Study 2 in Chapter 3 investigated whether humans can spontaneously extend their allocentric heading on the ground when locomoting to walls and the ceiling. Participants first learned a layout of objects on the ground. In testing phases, initially facing south (or north), they navigated to testing planes: south (or north) walls with the testing heading of Up or the ceiling with the testing heading of North (or South). They then either replaced the objects on that plane or did a Judgement of Relative Direction task (JRD task, “imagine standing at object A, facing B, point to C”) with imagined headings of south and north. The results from the object placement task showed that the participants more likely treated Up on two opposite walls, and the same direction (e.g., North) on the ceiling and on the ground as the same heading. Only a small portion of participants (about 20%) treated the same directions on the ground and on the ceiling as two opposite headings, indicating that they extended their allocentric heading through pitch rotations. The results of the JRD task showed that only these “extension” participants showed a reversed sensorimotor alignment effect, better performance when the imagined facing direction on the ground and physical facing direction on the ceiling were opposite than when they were the same. These results indicate that on a behavioral level, only a small portion of humans can spontaneously represent 3D allocentric headings (i.e., pitch) while most humans only represent 3D allocentric directions (e.g., North, Up). Therefore, the toroidal (extension) model proposed by findings in bats and rats (Finkelstein et al., 2015; Page et al., 2018; Taube et al., 2013) may not be applicable to humans. Supplemental material related to this thesis is available at https://era.library.ualberta.ca/collections/7p88ck40x
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Anticipation of a midsession reversal in humans
No full textIn a two-stimulus visual discrimination choice task with a reversal in reward contingencies midway through each session, pigeons produce a surprising number of anticipatory errors (i.e., responding to the second-correct stimulus before the reversal) based on failure to inhibit timing-based intrusion errors; limited prior research has suggested humans’ performance is qualitatively different. Here we illustrate a partial replication of previous findings in humans, but suggest based on our results that humans process these tasks in a manner similar to pigeons. Humans made relatively few but consistent errors across both simultaneous- and successive-choice experiments. Anticipation errors were limited when the identity of the first-correct stimulus alternated between sessions, consistent with the behaviour of pigeons. Subsequent experiments found evidence for anticipation on a purely temporal simultaneous choice task, and fewer errors with symmetrical reinforcement and punishment of responses on a sequential choice task. Interval timing causes conflicts with decision-making processes on the midsession reversal task that are consistent, but differ in magnitude, across species
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
