Département de Réadaptation, Faculté de Médecine, Université Laval, 1050 Avenue de La Médecine, Office 4109, Quebec City, QC, G1V 0A6, Canada.
CERVO Brain Research Centre, Quebec City, QC, Canada.
Exp Brain Res. 2020 Oct;238(10):2307-2321. doi: 10.1007/s00221-020-05886-9. Epub 2020 Jul 30.
It has been proposed that the maintenance of phonological information in verbal working memory (vWM) is carried by a domain-specific short-term storage center-the phonological loop-which is composed of a phonological store and an articulatory rehearsal system. Several brain regions including the left posterior inferior frontal gyrus (pIFG) and anterior supramarginal gyri (aSMG) are thought to support these processes. However, recent behavioral evidence suggests that verbal and non-verbal auditory information may be processed as part of a unique domain general short-term storage center instead of through specialized subsystems such as the phonological loop. In the current study, we used a single-pulse transcranial magnetic stimulation (TMS)-delayed priming paradigm with speech (syllables) and acoustically complex non-speech sounds (bird songs) to examine whether the pIFG and aSMG are involved in the processing of verbal information or, alternatively, in the processing of any complex auditory information. Our results demonstrate that TMS delivered to both regions had an effect on performance for speech and non-speech stimuli, but the nature of the effect was different. That is, priming was reduced for the speech sounds because TMS facilitated the detection of different but not identical stimuli, and accuracy was decreased for non-speech sounds. Since TMS interfered with both speech and non-speech sounds, these findings support the existence of an auditory short-term storage center located within the dorsal auditory stream.
有人提出，言语工作记忆（vWM）中语音信息的维持是由特定于领域的短期存储中心——语音环——组成的，它由语音存储和发音复述系统组成。包括左后下额回（pIFG）和前上缘回（aSMG）在内的几个大脑区域被认为支持这些过程。然而，最近的行为证据表明，言语和非言语听觉信息可能作为独特的、通用的短期存储中心的一部分进行处理，而不是通过语音环等专门的子系统进行处理。在当前的研究中，我们使用了单脉冲经颅磁刺激（TMS）延迟启动范式，结合言语（音节）和声学复杂的非言语声音（鸟鸣），来检验 pIFG 和 aSMG 是否参与言语信息的处理，或者是否参与任何复杂听觉信息的处理。我们的结果表明，TMS 刺激这两个区域都会对言语和非言语刺激的表现产生影响，但影响的性质是不同的。也就是说，由于 TMS 促进了不同但不相同的刺激的检测，因此语音声音的启动减少，而非言语声音的准确性降低。由于 TMS 干扰了言语和非言语声音，这些发现支持了位于背侧听觉流中的听觉短期存储中心的存在。
