视觉-体感觉刺激跨通道相互作用机制研究

Interaction mechanisms of visual-somatosensory crossmodal stimuli

目的研究视觉-体感觉跨通道刺激模式下通道间的相互作用与影响,探讨大脑对于跨通道信息的整合与处理机制。方法选择20例视力或矫正视力正常、躯体感觉正常且无任何大脑病史的志愿者,其中男性9例,女性11例;均为身体健康的在校学生,年龄20~27岁,平均年龄23.4岁,全部为右利手。分析志愿者在视觉、体感觉单独刺激和视觉-体感觉联合刺激下,事件相关电位(P2、P3成分的峰值和峰值潜伏期)、行为学数据(反应时间和错误率)和二者之间的关系,并对P2、P3进行源分析,获得源的位置和强度。结果跨通道体感靶刺激(Sv)的反应时间和错误率(反应时间548 ms±20 ms,错误率13.8%±2.7%)均显著低于单通道体感靶刺激(S)下的值(反应时间571 ms±22 ms,错误率18.2%±2.8%);跨通道视觉靶刺激(Vs)的P2峰值和峰值潜伏期(峰值4.6μV±1.7μV,峰值潜伏期208.0 ms±5.0 ms)均显著高于单通道视觉靶刺激(V)下的值(峰值3.9μV±1.0μV,峰值潜伏期199.0 ms±7.0 ms),Vs的P3峰值(11.8μV±1.6μV)显著低于V(12.5μV±2.0μV);Sv的P2峰值、P3峰值和峰值潜伏期(P2峰值6.7μV±1.2μV,P3峰值10.6μV±1.2μV,P3峰值潜伏期392.0 ms±8.4 ms)均显著低于S下的值(P2峰值7.4μV±1.0μV,P3峰值11.7μV±1.0μV,P3峰值潜伏期503.0 ms±21.0 ms);反应时间与P3峰值潜伏期具有显著正相关(R=0.96,P <0.001)。结论跨通道间背景刺激对目标刺激的影响具有动态特性,大脑对感觉信息的整合是跨通道易化与抑制共同作用的结果。

Objective To study the crossmodal interaction of visual-somatosensory stimuli, and discuss brain mechanisms of information integration and processing in crossmodal. Methods A total of 20 volunteers with normal vision and somatosensory function who without brain disease history were enrolled, which included 9 males and 11 females, aged 20-27 years old with mean age of 23.4 years old, all of them were right-handed. The event-related potentials(P2, P3 amplitudes and latencies) between crossmodal and unimodal visual and somatosensory stimuli, behavioral data(reaction time and error rate) and the relation-ship were analyzed. The source locations and intensities of P2, P3 components were also obtained by source analysis method.Results The reaction time and error rate of crossmodal somatosensory target stimuli(Sv)[reaction time(548 ± 20) ms, error rate(13.8 ± 2.7) %] were significantly shorter and lower than those of unimodal somatosensory target stimuli(S)[reaction time(571 ±22) ms, error rate(18.2 ± 2.8) %]. P2 amplitudes and peak latencies of crossmodal visual target stimuli(Vs)[amplitudes(4.6 ±1.7) μV, peak latencies(208.0 ± 5.0) ms] were significantly higher than those of single visual target stimuli(V)[amplitudes(3.9 ±1.0) μV, peak latencies(199.0 ± 7.0) ms], P3 amplitudes of Vs[(11.8 ± 1.6) μV] were significantly lower than those of V[(12.5 ±2.0) μV]. The Sv amplitudes of P2[(6.7 ± 1.2) μV] and P3[(10.6 ± 1.2) μV] and P3 peak latencies[(392.0 ± 8.4) ms] were lower than those of S[P2 amplitudes(7.4 ± 1.0) μV, P3 amplitudes(11.7 ± 1.0) μV, P3 peak latencies(503.0 ± 21.0) ms]. The reaction time and latencies of P3 were significantly positive correlated(R = 0.96, P < 0.001). Conclusion It is demonstrated that influence of cross channel background stimulus on target stimulus has dynamic characteristics, and sensory information integration of human brain is the interaction result of crossmodal facilitation and inhibition effects.