Brain symmetry index in healthy and stroke patients for assessment and prognosis

Quantitative neurophysiological signal parameters are of value in predicting motor recovery after stroke.Thenovel role of EEG-derived brain symmetry index formotor function prognostication in the subacute phase after stroke is explored. Ten male stroke patients and ten matched healthy controls were recruited. Motor function was first assessed clinically using the MRC score, its derivativeMotricity Index, and the Fugl–Meyer assessment score. EEG was subsequently recorded firstwith subjects at rest and then during hand graspingmotions, triggered by visual cues. Brain symmetry index (BSI) was used to identify the differences in EEG-quantified interhemispheric cortical power asymmetry observable in healthy versus cortical and subcortical stroke patients. Subsequently, any correlation between BSI and motor function was explored. BSI was found to be significantly higher in stroke subjects compared to healthy controls ( = 0.023). The difference in BSI was more pronounced in the cortical stroke subgroup ( = 0.016). BSI showed only a mild general decrease on repeated monthly recording. Notably, a statistically significant correlation was observed between early BSI and Fugl–Meyer score later in recovery ( < 0.050). Brain symmetry index is increased in the subacute poststroke phase and correlates with motor function 1-2 months after stroke.peer-reviewe

Users' representation of the machine in human-computer speech interaction

We report an experiment designed in order to study whether models of human-human voice dialogues could be applied successfully to human-computer communication using spoken natural language. Two groups of 6 subjects were asked to collect information about air travel, through dialoguing with a remote interlocutor. Subjects of the machine group were led to believe they were talking to a computer, subjects of the operator group were told they were interacting with a human operator. Both groups actually talked to the same human experimenter. The study focuses on subjects' representations of interlocutor's skills and knowledge, and differs from previous analogous experiments in several respects: - the task is more complex, giving rise to structured exchanges in natural language instead of question/answers pairs in a restricted language; - specific attention has been paid to the experimental protocol, in order to avoid the possible bias of other studies (in particular, conditions are strictly identical for both groups); - evolution over time has been considered (3 sessions, with a one-week interval). Some results confirm those of the literature, namely that subjects of the machine group tend to control and simplify their linguistic expression more than those in the operator group. However, most observations are either original or in contradiction with previous results: - subjects of the machine group are more talkative; no significant difference can be detected between the two groups with respect to most aspects of linguistic practice; - concerning evolution over time: both groups tend to get more concise; with respect to scenario processing (i.e. problem solving), the strategies of the operator group evolve significantly, whilst those of the machine group remain stable. These differences in the behaviors of the two groups are ascribed to different representations of the interlocutor's abilities

Atmospheric Pressure Plasma-Synthesized Gold Nanoparticle/Carbon Nanotube Hybrids for Photothermal Conversion

In this work, a room-temperature atmospheric pressure direct-current plasma has been deployed for the one-step synthesis of gold nanoparticle/carboxyl group-functionalized carbon nanotube (AuNP/CNT-COOH) nanohybrids in aqueous solution for the first time. Uniformly distributed AuNPs are formed on the surface of CNT-COOH, without the use of reducing agents or surfactants. The size of the AuNP can be tuned by changing the gold salt precursor concentration. UV–vis, ζ-potential, and X-ray photoelectron spectroscopy suggest that carboxyl surface functional groups on CNTs served as nucleation and growth sites for AuNPs and the multiple potential reaction pathways induced by the plasma chemistry have been elucidated in detail. The nanohybrids exhibit significantly enhanced Raman scattering and photothermal conversion efficiency that are essential for potential multimodal cancer treatment applications

Dialogue control strategies in oral communication

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