Department of Clinical Neurophysiology, University of Turku, Turku, Finland; Turku Brain and Mind Centre, University of Turku, Turku, Finland.
Department of Psychology, University of Turku, Turku, Finland.
Clin Neurophysiol. 2020 Sep;131(9):2140-2147. doi: 10.1016/j.clinph.2020.05.038. Epub 2020 Jul 3.
Speech deficits are common in Parkinson's disease, and behavioural findings suggest that the deficits may be due to impaired monitoring of self-produced speech. The neural mechanisms of speech deficits are not well understood. We examined a well-documented electrophysiological correlate of speech self-monitoring in patients with Parkinson's disease and control participants.
We measured evoked electroencephalographic responses to self-produced and passively heard sounds (/a/ phonemes) in age-matched controls (N = 18), and Parkinson's disease patients who had minor speech impairment, but reported subjectively experiencing no speech deficits (N = 17).
During speaking, auditory evoked activity 100 ms after phonation (N1 wave) was less suppressed in Parkinson's disease than controls when compared to the activity evoked by passively heard phonemes. This difference between the groups was driven by increased amplitudes to self-produced phonemes, and reduced amplitudes passively heard phonemes in Parkinson's disease.
The finding indicates that auditory evoked activity is abnormally modulated during speech in Parkinson's patients who do not subjectively notice speech impairment. This mechanism could play a role in producing speech deficits in as the disease progresses.
Our study is the first to show abnormal early auditory electrophysiological correlates of monitoring speech in Parkinson's disease patients.
帕金森病患者常存在言语缺陷，行为学研究结果表明，这些缺陷可能是由于自身言语产生过程的监控受损所致。然而，言语缺陷的神经机制尚不清楚。我们检测了帕金森病患者和对照组参与者中一个有充分文献记录的言语自我监控的电生理相关指标。
我们在年龄匹配的对照组（N=18）和帕金森病患者（主观上无言语缺陷但存在轻度言语障碍，N=17）中测量了自发音和被动听音（/a/音）诱发的脑电反应。
与被动听音相比，在发声后 100 毫秒（N1 波），帕金森病患者的听觉诱发活动抑制减少。组间差异主要由帕金森病患者自发音的振幅增加和被动听音的振幅降低驱动。
该发现表明，在主观上未察觉到言语障碍的帕金森病患者中，言语过程中听觉诱发活动异常调节。随着疾病的进展，这种机制可能在产生言语缺陷中发挥作用。
本研究首次显示了帕金森病患者监测言语时异常的早期听觉电生理相关指标。
