中文摘要：

统计最优化理论认为,在多感觉信息整合的过程中,大脑是以加权平均的方式将多个感觉通道的信息整合为统一的感觉信息,通道信息的利用权重根据各通道信息的可靠性来确定。近期的几个行为研究结果则显示,有关通道估计可靠性的先验知识同样能够影响通道信息在整合过程中的利用权重。然而,这些研究结果不能确定先验知识对多感觉信息整合的影响是发生在认知加工的感知觉阶段还是决策阶段。当前研究致力于对此问题进行探讨。实验通过赋予两种颜色字母不同的视、听一致概率（高概率、低概率）,测量并分析被试在各概率水平下对视听一致刺激的反应时。实验数据显示不同的视听一致概率能够调制对视听一致刺激的反应时。该结果揭示通道估计可靠性先验知识在早期的知觉加工阶段影响多感觉信息整合。

英文摘要：

According to the statistically optimal integration theory,our brains weigh various sources of sensory information according to their reliabilities during multisensory integration.Recent behavioral studies have proposed that the prior knowledge about the reliability of different modalities can also play an important role in the weighting of different sensory information.The present study aimed to examine whether the prior knowledge affect multisensory integration in the early perceptual processing stage or in the post-perceptual processes stage.Fourteen participants （19-24 years old） were tested when a single letter （＂B＂ or ＂E＂） was presented simultaneously in both auditory and visual modalities.The letter was displayed in one of the two colors.In one condition the visual information presented was always （probability of 100%） congruent with auditory information and this is the same for either color presented （equal-probability condition）.In another condition,the probability in which the visual and auditory information was congruent was varied.The probability was 100% （high probability,HP） when the visual letter was in one color and the probability was 30% （low probability,HP） when the visual letter was in another color.Therefore different colors were associated with different probability （different-probability condition）.The participants were instructed to press the button 1 for letter B and button 2 for letter E regardless of the color of the visual stimuli and regardless of the auditory information.Each participant completed 240 trials during equal-probability condition and 1500 trials （consisting of 5 experimental blocks） during different-probability condition.Significantly different responses to the congruent audiovisual stimuli were found between HP and LP and the difference was only observed during block 4 and block 5 of difference-probability condition.These results suggested the different probabilities of auditory-visual congruency modulate the response time to audit