1,720,981 research outputs found
Performance predictions and postdictions in prospective memory of school-aged children
No full textProspective memory (PM) undergoes important developmental changes during the primary school years, particularly around 7 and 8 years of age. Recent studies have suggested that, as well as executive functions (EFs), PM development also benefits from age-related increments in metamemory (MM) abilities. The primary aim of the current study was to explore the role of MM monitoring and control processes (i.e., procedural MM) of 7- and 8-year-old children in a PM task including specific cues. Monitoring processes were assessed by asking children to judge their own PM performance before (predictions) and after (postdictions) in performing a PM task. In addition, children were asked to report the strategy they used to remember the PM task. Reactive effects of making predictions and using strategies were assessed via both an ongoing task (OT) and PM performance. EF and declarative MM performance was also examined. Results showed that children who were asked to predict PM performance had faster PM response times (RTs), but not higher accuracy rates, than children in a control group. However, strategy use affected both PM and OT performance, with those children reporting active strategy use obtaining higher PM accuracy rates and slower OT RTs. Finally, switching abilities were also predictive of OT performance. This investigation highlights the importance of studying MM monitoring and control processes in relation to children's PM
Travelling salesperson in an immersive virtual environment: Experimental evaluation of tracking system device
No full textNowadays Virtual Reality (VR) is an extremely versatile technology capable to cope with many areas of human life, and its fast development requires constant evaluation and validation. Cognitive models of human behavior play a central role in this evaluation, aiming at obtaining high quality, safe and usable products. A problem currently faced by VR users inside immersive Virtual Environments (iVEs) consists in the Simulator-induced Sickness (SS), a particular kind of motion sickness evoked by the simulated visual motion. SS can reduce subjects’ performances, and bias data collected with VR. Although Tracking Systems (TS) were thought to reduce SS symptoms, their effective contribution is not clear. A task based on the Traveling Salaperson was implemented in an iVE to investigate whether TS (a) evoked less SS symptoms and (b) facilitated performance in participants with respect to a control condition without TS. Results showed that TS allowed reduction of many SS symptoms, but this did not produced clear benefits on the cognitive performance, mainly true for female subjects. While TSs may facilitate enjoyment of iVE reducing SS, the higher susceptibility of females suggested that VR designers and producers should consider valuable a certain training before using the iVEs
Stereoscopy does not improve metric distance estimations in virtual environments
No full textStereoscopy is widely used to render depth and perceptual spatial cues information in Virtual Environments (VEs). In literature, the use of stereoscopy in VEs reported advantages but also disadvantages on perceptual skills such as metric evaluation of distances. The present study tests the influence of stereoscopy on a verbal metric and nonmetric evaluation of egocentric and allocentric distances task, in closed and open scenarios, correlating performance with Mental Rotation ability. Results show that stereoscopy could be helpful only for nonmetric estimates. More errors occurred in metric evaluation, modulated by gender
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
Spike-timing-dependent plasticity induction reveals dissociable supplementary– and premotor–motor pathways to automatic imitation
Full text linkHumans tend to spontaneously imitate others’ behavior, even when detrimental to the task at hand. The action observation network (AON) is consistently recruited during imitative tasks. However, whether automatic imitation is mediated by cortico-cortical projections from AON regions to the primary motor cortex (M1) remains speculative. Similarly, the potentially dissociable role of AON-to-M1 pathways involving the ventral premotor cortex (PMv) or supplementary motor area (SMA) in automatic imitation is unclear. Here, we used cortico-cortical paired associative stimulation (ccPAS) to enhance or hinder effective connectivity in PMv-to-M1 and SMA-to-M1 pathways via Hebbian spike-timing-dependent plasticity (STDP) to test their functional relevance to automatic and voluntary motor imitation. ccPAS affected behavior under competition between task rules and prepotent visuomotor associations underpinning automatic imitation. Critically, we found dissociable effects of manipulating the strength of the two pathways. While strengthening PMv-to-M1 projections enhanced automatic imitation, weakening them hindered it. On the other hand, strengthening SMA-to-M1 projections reduced automatic imitation but also reduced interference from task-irrelevant cues during voluntary imitation. Our study demonstrates that driving Hebbian STDP in AON-to-M1 projections induces opposite effects on automatic imitation that depend on the targeted pathway. Our results provide direct causal evidence of the functional role of PMv-to-M1 projections for automatic imitation, seemingly involved in spontaneously mirroring observed actions and facilitating the tendency to imitate them. Moreover, our findings support the notion that SMA exerts an opposite gating function, controlling M1 to prevent overt motor behavior when inadequate to the context
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
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
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