多感觉整合测量范式中存在的影响因素探讨

An Investigation on the Effect Factors in the Paradigm of Multisensory Integration

已有的多感觉整合研究范式多采用不同单通道刺激和双通道刺激随机呈现的方式进行测量。在这种范式中混有通道转换效应,该效应可能导致多感觉整合的测量结果不准确。因此,分析清楚实验范式中通道转换效应的影响因素,并以此为依据设计合理的整合测量范式,是进行多感觉整合研究的一个必要前提。本文首先通过实验一验证了在经典的整合测量范式中通道转换效应的影响方式;进而,在实验二中通过控制前后刺激的信号强度的一致性,分析了通道转换效应的特点。综合分析显示,通道转换效应是由前一刺激差异所造成的对当前刺激通道加工的注意资源分配和警觉水平的变化所导致。该结果表明,在多感觉行为测量中,需先根据前一刺激通道分类后再进行分析。

The existing research paradigms of multisensory integration usually involve the random presentation of stimuli of unisensory modalities and bi-sensory modality. Such kind of paradigms, however, exists the modality shift effect which could lead to inaccurate measurement of multisensory integration. Therefore, it is necessary to exam the modality shift effect and separate it from the tests in order to analyze the results of multisensoryintegration. Experiment one examined whether modality shift effect affected the audiovisual integration in the previous paradigms of multisensory integration. The visual, auditory, and audiovisual stimuli were randomly presented. Subjects were suggested to respond to those stimuli as quickly as they could. Results showed that the modality types of pre-stimuli affected the response to the post-stimuli. The race modal is invalid only when the pre-stimuli were from the audiovisual or visual modality. Experiment two manipulated the intensity of pre-and-post stimuli so as to examine whether modality shift effect was caused by the suppression of reaction during the switch of modalities or by the priming on the same modality. The subjects were asked to response when detected visual or auditory stimulus. Through the analysis of the subjects＇ reactions, we found that the intensity of pre-stimuli affected the response to the post-stimuli. Therefore, we concluded that among the paradigms of multisensory integration, two factors had effects on the measurement of multisensory integration： First, dynamic adjusting on distribution of attention affected by the pre-stimuli; second, dynamic adjusting on the alertness of present reaction caused by the intensity of pre-stimuli. To get the pure results in multisensory measuring, these two influence factors should be eliminated in the measurement of multisensory integration.