Klein S K, Kurtzberg D, Brattson A, Kreuzer J A, Stapells D R, Dunn M A, Rapin I, Vaughan H G
Case Western Reserve University, USA.
Brain Lang. 1995 Dec;51(3):383-405. doi: 10.1006/brln.1995.1067.
The present study examined the extent to which verbal auditory agnosia (VAA) is primarily a phonemic decoding disorder, as contrasted to a more global defect in acoustic processing. Subjects were six young adults who presented with VAA in childhood and who, at the time of testing, showed varying degrees of residual auditory discrimination impairment. They were compared to a group of young adults with normal language development matched for age and gender. Cortical event-related potentials (ERPs) were recorded to tones and to consonant-vowel stimuli presented in an "oddball" discrimination paradigm. In addition to cortical ERPs, auditory brainstem responses (ABRs) and middle latency responses (MLRs) were recorded. Cognitive and language assessments were obtained for the VAA subjects. ABRs and MLRs were normal. In comparison with the control group, the cortical ERPs of the VAA subjects showed a delay in the N1 component recorded over lateral temporal cortex both to tones and to speech sounds, despite an N1 of normal latency overlying the frontocentral region of the scalp. These electrophysiologic findings indicate a slowing of processing of both speech and nonspeech auditory stimuli and suggest that the locus of this abnormality is within the secondary auditory cortex in the lateral surface of the temporal lobes.
本研究考察了言语听觉失认症（VAA）在多大程度上主要是一种音素解码障碍，这与听觉处理方面更全面的缺陷形成对比。研究对象是六名在儿童期出现VAA的年轻成年人，在测试时，他们表现出不同程度的残余听觉辨别损伤。将他们与一组年龄和性别匹配、语言发育正常的年轻成年人进行比较。在“oddball”辨别范式中，记录了对音调以及辅音 - 元音刺激的皮层事件相关电位（ERP）。除了皮层ERP外，还记录了听觉脑干反应（ABR）和中潜伏期反应（MLR）。对VAA受试者进行了认知和语言评估。ABR和MLR正常。与对照组相比，VAA受试者的皮层ERP显示，在颞叶外侧皮层记录到的N1成分对音调和语音的反应均延迟，尽管在头皮额中央区域上方N1潜伏期正常。这些电生理结果表明，言语和非言语听觉刺激的处理速度减慢，提示这种异常的部位位于颞叶外侧表面的二级听觉皮层内。
