1,721,001 research outputs found
Olfactory and haptic crossmodal perception in a visual recognition task
No full textOlfactory perception is affected by cross-modal interactions between different senses. However, although the effect of cross-modal interactions for smell have been well investigated, little attention has been paid to the facilitation expressed by haptic interactions with a manipulation of the odorous object’s shape. The aim of this research is to investigate whether there is a cortical modulation in a visual recognition task if the stimulus is processed through an odorous cross-modal pathway or by haptic manipulation, and how these interactions may have an influence on early visual-recognition patterns. Ten healthy non-smoking subjects (25 years ± 5 years) were trained to have a haptic manipulation of 3-D models and olfactory stimulation. Subsequently, a visual recognition task was performed during an electroencephalography recording to investigate the P3 Event Related Potentials components. The subjects had to respond on the keyboard according to their subjective predominant recognition (olfactory or haptic). The effects of haptic and olfactory condition were assessed via linear mixed-effects models (LMMs) of the lme4 package. This model allows for the variance related to random factors to be controlled without any data aggregation. The main results highlighted that P3 increased in the olfactory cross-modal condition, with a significant two-way interaction between odor and left-sided lateralization. Furthermore, our results could be interpreted according to ventral and dorsal pathways as favorite ways to olfactory crossmodal perception
A cerebral bridge from olfactory cognition to spatial navigation
Full text linkAn evolutionary paradox is the variability of the olfactory bulb size, in contrast to the other brain regions, which are sized proportionally to the peripheral function. This variability seems to be the result of selection for the olfactory function. This disagreement may derive from considering smell as a sense linked to odorous discrimination. In many vertebrates and in terrestrial and marine mammals, the sense of smell has evolved into functions related to the eco-localization. So, if the olfactory function involves spatial perception and navigation, this, couldexplain the proportional discrepancy between the olfactory bulb and olfactory cortex. Humans are able to discriminate a spatial position as a function of olfactory cues. Vice versa, in neurodegenerative syndromes the orientation capacity and olfactory perception are impaired. This leads us to think that could be a common cross-modal processing, of phylogenetic origin, which links olfactory perception and spatial orientation. Starting from these theoretical assumptions, we conducted a basic research, on 100 healthy subjects, investigating, through both behavioral and electroencephalographic data, the connection between spatial memory span and olfactory spatial memory span. Subjects were assessed through a three-condition task: normal Corsi Block Test (CBT), ‘Olfactory’ Block Test (OBT) and a ‘Semantic-Olfactory’ Block Test (SOBT). CBT consisted in a test on spatial memory span; OBT consisted in a presentation a spatial sequences of 9 different odorants (i.e., Eucalyptol, Carvone, Eugenol, Isoamyl Acetate, Geraniol, Phenethyl Alcohol, Acetophenone, Cinnamon, Hexanal) instilled on paper square not recognizable by any sign, positioned on a CBT, and showed in a spatial navigation way, and SOBT consisted of a semantic labelled of olfactory spatial navigation. A GLM repeated measure highlighted significant differences during the three conditions. Subjects had different SPANs due to different conditions. The Semantic olfactory memory SPAN was inferior respect Olfactory span and Spatial Span. Furthermore was found a significant positive correlation between the three condition. The 5 subjects with higher SPAN scores, 5 with medium scores and the 5 subjects with lower SPAN scores were recruited to investigate ERP components elicited during the cross-modal task. Subjects had to perform, during a high-density EEG recording, an olfactory task (administered through the device US2017127971 (A1) “? 2017-05-11), an EEG Posner spatial cueing task and a go/no-go olfactory semantic categorization task. The results of this study will be discussed in light of a theoretical connection between these three aspects of cortical functions that seem strongly interconnected
Neuroprosthetic Haptic Interface and Haptic Stimulation: Neuromorphic Microtransduction and EEG Alpha Variations
Full text linkAccording to the recent studies on the psychophysiology of touch, a haptic effector designed in a neuromorphic way was projected, designing an electronic card as to be able to deliver variable signals over time and in intensity. The two-dimensional arrays of micro-actuators were made either with planar geometry or with three-dimensional, semi-spherical or “dome” geometry. Subsequently, on both the behavioral and the electrophysiological level the haptic sensation received by the effector was evaluated on 6 subjects and compared to real stimulations of different grains (Paper). During the various stimulations the subject was in a state of Resting State (RS). Each stimulation had a frequency range ranging from 2 to 500 Hz on 2 and 5 s. Analysis of behavioral responses and the alpha rhythm in RS showed significant differences for low frequencies vs Paper. RS highlighted differences in ROIs on the various frequency distributions, especially low frequencies in Frontal ROI. This pilot study indicates that the best frequencies for a haptic simulation are between a range from 20 Hz to 166 Hz
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
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
- …
