听视觉刺激对长期听力损失患者语言处理的影响

Effects of auditory and visual stimuli on speech processing of patients with long-term hearing loss

目的:研究听视觉刺激对听力损失患者大脑中与语言处理相关脑区神经活动的影响,为患者的康复治疗提供理论支撑。方法:募集12个听力损失患者和12个性别年龄匹配的正常听力受试者。首先构建每个参与者个体化虚拟数字脑,然后将虚拟视觉刺激信号施加到已构建虚拟数字脑的次级视觉皮层;将虚拟听觉刺激信号施加到已构建虚拟数字脑的初级听觉皮层。最后,观察这些刺激信号在听力损失患者脑皮层中所诱发的神经活动变化。结果:同正常受试者相比,虚拟视觉刺激信号抑制了听力损失患者听觉皮层和布洛卡区的神经活动,并通过最短因果路径削弱了布洛卡区的激活。相反,虚拟听觉刺激信号抑制了听力损失患者视觉皮层的激活,但通过最短因果路径增强了布洛卡区的神经活动。此外,听力损失患者也呈现了减弱的视觉诱发的威尼克区的激活。结论:目前的研究表明,视觉刺激通过削弱听觉皮层和布洛卡区的神经活动抑制了听力损失患者的语言处理。相反,听觉刺激通过抑制视觉皮层的活动,增强布洛卡区的神经活动,从而改善了听力损失患者的语言处理。

Objective To research the effects of auditory and visual stimuli on the neural activities of cerebral cortices associated with speech processing in patients with hearing loss(HL),thereby providing theoretical support for the rehabilitation treatment of HL patients.Methods Twelve patients with long-term bilateral HL and 12 gender-and age-matched normal-hearing controls were enrolled in the study.The individual virtual digital brain of each subject was firstly constructed.Then a stimulating signal of visual task was processed and then exerted to the secondary visual cortex of the constructed virtual digital brain.Similarly,a stimulating signal of auditory task was also processed and then exerted to the primary auditory cortex of the constructed virtual digital brain.Finally,the changes of brain region activations evoked by these stimulating signals in HL patients were observed.Results The visual stimulus inhibited the neural activities of auditory cortex and Broca's area,and through the shortest causal connectivity paths,further weakened the activation of Broca's area in HL patients compared with normal-hearing controls.In contrast,the auditory stimulus inhibited the activation of visual cortex in HL patients,but enhanced their neural activity of Broca's area through the shortest synchronous causal connectivity paths.Additionally,compared with normal-hearing controls,HL patients presented weaker visual-evoked activation inWernicke's area.Conclusion The findings suggest that the visual stimulus limits the HL patients'capacity of speech processing through inhibiting the neural activities of auditory cortex and Broca's area,and that the auditory stimulus improves the HL patients'capacity of speech processing through inhibiting the activation of visual cortex and enhancing the neural activity of Broca's area.