To our knowledge, this is the first MEG study to investigate the spatio-temporal and frequency characteristics between bilinguals and monolinguals, which provides us a new angle to better understand the language system in bilinguals' and monolingual's brain.

A simulation of pedestrian evacuation in room with affected visual field and absence of the direction of evacuation signs will be presented based on cellular automata (CA) in this paper. Evacuation room is divided into exit-visible area and exitinvisible area by pedestrian visual field radius. Two basic dynamic parameters in Dynamic Parameters Model (DPM) are used to simulate the varied movement characteristics of pedestrian in different evacuation areas including normal evacuation movement and blind random movement. The effect of pedestrian visual field radius on evacuation time is studied without evacuation signs on wall. It is observed that evacuation time is dependent not only on the pedestrian visual field radius but also on the initial density. It is also found that the evacuation time will tend to the level and remain unchanged with visual field radius rising.

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The present study investigated the spatial and frequency differences of neuromagnetic activities between the perception of open- and closed-class words by using a 275-channel whole head magnetoencephalography (MEG) system. Two groups of words, 110 open-class and 110 closed-class, were presented visually and auditorily simultaneously. The data of 12 healthy subjects were analyzed with synthetic aperture magnetometry (SAM) which can identify the frequency-dependent volumetric distribution of evoked magnetic fields (EMFs). Both vocabulary classes elicited spectral power changes in the left inferior frontal gyrus (Broca's area) and left posterior-superior temporal gyrus (Wernicke's area) within 70-120 Hz. However, the open-class words elicited event-related desynchronization (ERD) while the closed-class words elicited event-related synchronization (ERS) in the two areas within 70-120 Hz. In addition, the open-class words also elicited ERS in the right inferior frontal gyrus, right middle frontal gyrus and right inferior parietal lobe within 1-8 Hz, but the closed-class words only elicited ERD in the right inferior frontal gyrus within 1-8 Hz. Furthermore, there were ERD in the right posterior-superior temporal gyrus within 120-200 Hz for the open-class words, but not for the closed-class words. These results indicate that open- and closed-class words are processed differently in the brain, not only in the anatomical substrates, but also in the frequency range of neuromagnetic activity.