1,721,052 research outputs found
Il Sonniloquio come via d’accesso all’elaborazione cognitiva in sonno: uno studio elettrofisiologico sulle produzioni verbali notturne
Full text linkINTRODUCTION
Sleep Talking (ST) is defined as the utterance of speech during sleep. The available literature cannot address ST as a REM or NREM parasomnias. Rarely studied as an isolated phenomenon, we currently have no definite evidence of its neural correlates. Recently, psycholinguistic features of verbal production in ST has been investigated, pointing to coherence with formal features of the language in wakefulness. This evidence, within the hypothesis of an involvement of parasomnias in sleep-related cognitive processing, suggests the importance of understanding the neural mechanism underlying ST.
We aimed to investigate EEG correlates predictive of verbal activation (Verbal ST), with a comparison with Non-verbal ST (moaning, laughing, crying, etc...) with the general hypothesis of shared mechanisms with neural correlates of language processing and production.
METHOD
Six highly frequent ST (3M, 3F, age 19-27, mean 23.83±3.60) recruited through an online survey (general health assessment, PSQI for the self-declared quality of sleep, MUPS for self-declared presence and frequency of the phenomenon). Presence and frequency of ST, together with the compliance in maintaining a regular sleep schedule, has been further assessed through one week of home sleep/dream-logs and audio-activated recorder. The suitable participants have been recorded in the laboratory for at least 2-consecutive nights of video-PSG. We pursued the conditions of Verbal and Non-verbal ST, obtaining a total of 21 Verbal ST and 21 Non-verbal ST in Stage 2 NREM. Control comparison has been performed between Vocalizations (N=42 vocal activations, combining Verbal and Non-verbal) and Baseline (N=42 equivalent sleep interval, 2 mins preceding each ST), to assess time-locking and specificity of the observed EEG pattern, in relation with vocal production.
Artifacts were off-line rejected for the 20 seconds EEG preceding each Verbal and Non-verbal ST and Baseline, on a 4-seconds basis. EEG power spectra have been obtained throughout a Fast Fourier Transform (FFT) routine. The power spectra have been then averaged to obtain the canonical sleep EEG bands: delta (0.5-4.5Hz), theta (4.75-7.75Hz), alpha (8-11.75Hz), sigma (12-15.75Hz) and beta (16-24.75Hz), and subsequently log-transformed.
RESULTS
Statistical comparisons (t-Test) show a general decrement in power spectra for Verbal ST vs. Non-verbal ST for the theta and alpha EEG bands. This effect is strongly lateralized to the left hemisphere and specifically localized on centro-parietal-occipitals channels. A single left parietal channel (P7; theta t=-4.48, p=0.0002; alpha t=-3.29, p=0.0037) was significant also after the Bonferroni correction.
T-test comparisons (t=≥2.96; p≤0.0051) for Vocalizations vs. Baseline show a general increment in power spectra for delta on frontal, central and temporal channels, almost on the entire scalp for the alpha band; on Fc2 and C4 for the beta band.
CONCLUSIONS
Our results suggest shared neural mechanisms between Verbal ST and language programming during wakefulness. Specifically, the selective decrement for the theta band on the left parietal sites is coherent with the literature about linguistic planning in wakefulness, suggesting a possible functional overlapping. Moreover, the phenomenon seems time-locked to the interval of sleep preceding ST, as demonstrated throughout a comparison with a preceding sleep interval
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
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
Interaction of Pt-compounds with human albumin by FTIR and CD. XAS on Pt(II) model compounds
No full text- …
