听觉-体感觉靶刺激诱发事件相关电位跨模增进效应研究

Cross-modal enhancement of auditory-somatosensory target stimuli based on event related potential

目的研究听觉一体感觉跨模靶刺激模式下双模增进作用，探讨大脑认知过程不同脑区间相互作用的神经机制。方法选择20例听力正常、躯体感觉功能正常、无任何大脑病史的在读研究生和大学生，其中男性8例，女性12例；年龄20～26岁．平均年龄22．5岁：均为右利手。以受试者的事件相关电位为考察对象，分析听觉一体感觉跨模靶刺激与单一听觉、体感觉靶刺激模式下受试者的行为学数据（反应时间、反应错误率）与事件相关电位（P3、P2幅值和潜伏期）的关系。结果单一听觉、体感觉靶刺激模式下受试者的反应时间[分别为（538±14）ms、（576±18）ms]、P3峰值潜伏期[分别为（455±17）ms、（479±18）m8]均显著大于听觉一体感觉双模靶刺激模式下的值[反应时间（461±20）ms，潜伏期（357±12）ms；P〈0．001]：单一听觉、体感觉靶刺激模式下受试者的反应错误率[分别为（5．1±1．2）％、（19．3±3．1）％]显著小于听觉一体感觉双模靶刺激模式下的值[（2．7±0．6）％；P〈0．001]，说明大脑不仅对听觉一体感觉双模靶刺激有更快的反应速度，而且探测的准确度明显优于单一靶刺激：不同靶刺激模式下．反应时间与P3峰值潜伏期具有显著相关性（r=0．58，P〈0．001），可以作为跨通道增进效应潜在神经过程的时间指标。结论双模靶刺激模式下存在明显的增进效应，大脑在跨模靶刺激模式下具有更优越的感觉信号神经整合机制。

Objective To study the cross-modal enhancement of auditory-somatosensory stimuli, and discuss neural mechanism of interaction between different brain regions during cognitive processing. Methods Twenty volunteers with normal hearing and somatosensory function and without any brain history were enrolled, included 8 males and 12 females, aged 20 - 26 years with mean age of 22.5, all of them were right-handed. Based on the event related potential, the relationship of behavioral（reaction time and error rate） and electroencephalographic （P3, P2 latency and amplitude） responses between cross-modal and uni-modal auditory and somatosensory stimuli were analyzed. Results Tile subject＇s reaction time under single auditory and somatosensory target stimulus mode [（538 ± 14） ms, （576 ± 18） ms], and the respective P3 peak latencies[（455 ± 17） ms, （479 ± 18 ） ms] were significantly longer than the auditory - somatosensory value of dual-target stimulus mode [reaction time （461 ± 20） ms, latencies （357 ± 12） ms; P 〈 0.001]. The error rates of the single auditory and somatosensory target stimulus patterns[（5.1 ± 1.2） %, （19.3 ± 3.1） %] were significantly higher than that of the auditory-somatosensory stimulation dual-target mode[（2.7 ± 0.6） %; P 〈 0.001], which suggested the brain responsed faster and had more accuracy under auditory-somatosensory target stimuli. The reaction time and latencies of P3 were significantly correlated（r = 0.58, P 〈 0.001） under different target stimuli, P3 may be used as time indicators of enhancement of cross-modal stimulation. Conclusion It is demonstrated that there are obvious enhancement under dual-modal target stimuli, the brain has superior integration mechanism of sensory neural signals in crossmodal target conditions.