| Brain-computer interfaces (BCIs) are defined as communication and control systems that do not depend on the brain’s normal output channals of peripheral nerves and muscles. The researches of BCIs would not only improve the undstanding of the brain mechanisms, but also provide some important approaches for human computer interaction. Steady-state visual evoked potentals based BCI (SSVEP-based BCI) had been frequently studied due to higher signal-nosie ratio, higher information transfer ratio and needing less practice. The present study aimed to inverstigate the attential mechanism of the SSVEP and set up a one-dimention (1D) control system and a Chinese character stroke spell system based on SSVEP.This study was composed of two parts. The first part investigated the modulation of the SSVEP by object-based attention (Experiment1), the deployment of the attention (Experiment2), attentional enchancement and inhibition (Experiment3) and attention in dynamic situation (Experiment4). In the second part, we developed a SSVEP-based BCI which contained function module, data analysis module and application module. We experimentally determined the parameters of the BCI (Experiment5), and then set up a1D control system (Experiment6) and a preliminary Chinese character stroke spell system (Experiment7).The main findings of the present study were as follows:(1) Object-based attention is related to early sensory enhancement, and enhancement is reflected in human early visual cortex;(2) Spatial attention involves neural suppression surrounding the classic ’spotlight’;(3) SSVEPs is modulated by attention not fixation, and is related to deployment of the attentional resources;(4) The design of flickers of SSVEP-based BCI can be dynamic;(5) The1D control system (PsychBCI) can satisfy basic needs for human-computer communication;(6) The preliminary Chinese character stroke system can input certain Chinese characters successfully. |
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