Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London, WC1N 3AR, UK.
J Cogn Neurosci. 2011 Apr;23(4):961-77. doi: 10.1162/jocn.2010.21491. Epub 2010 Mar 29.
This study investigated links between working memory and speech processing systems. We used delayed pseudoword repetition in fMRI to investigate the neural correlates of sublexical structure in phonological working memory (pWM). We orthogonally varied the number of syllables and consonant clusters in auditory pseudowords and measured the neural responses to these manipulations under conditions of covert rehearsal (Experiment 1). A left-dominant network of temporal and motor cortex showed increased activity for longer items, with motor cortex only showing greater activity concomitant with adding consonant clusters. An individual-differences analysis revealed a significant positive relationship between activity in the angular gyrus and the hippocampus, and accuracy on pseudoword repetition. As models of pWM stipulate that its neural correlates should be activated during both perception and production/rehearsal [Buchsbaum, B. R., & D'Esposito, M. The search for the phonological store: From loop to convolution. Journal of Cognitive Neuroscience, 20, 762-778, 2008; Jacquemot, C., & Scott, S. K. What is the relationship between phonological short-term memory and speech processing? Trends in Cognitive Sciences, 10, 480-486, 2006; Baddeley, A. D., & Hitch, G. Working memory. In G. H. Bower (Ed.), The psychology of learning and motivation: Advances in research and theory (Vol. 8, pp. 47-89). New York: Academic Press, 1974], we further assessed the effects of the two factors in a separate passive listening experiment (Experiment 2). In this experiment, the effect of the number of syllables was concentrated in posterior-medial regions of the supratemporal plane bilaterally, although there was no evidence of a significant response to added clusters. Taken together, the results identify the planum temporale as a key region in pWM; within this region, representations are likely to take the form of auditory or audiomotor "templates" or "chunks" at the level of the syllable [Papoutsi, M., de Zwart, J. A., Jansma, J. M., Pickering, M. J., Bednar, J. A., & Horwitz, B. From phonemes to articulatory codes: an fMRI study of the role of Broca's area in speech production. Cerebral Cortex, 19, 2156-2165, 2009; Warren, J. E., Wise, R. J. S., & Warren, J. D. Sounds do-able: auditory-motor transformations and the posterior temporal plane. Trends in Neurosciences, 28, 636-643, 2005; Griffiths, T. D., & Warren, J. D. The planum temporale as a computational hub. Trends in Neurosciences, 25, 348-353, 2002], whereas more lateral structures on the STG may deal with phonetic analysis of the auditory input [Hickok, G. The functional neuroanatomy of language. Physics of Life Reviews, 6, 121-143, 2009].
这项研究调查了工作记忆和语音处理系统之间的联系。我们使用 fMRI 中的延迟伪词重复来研究语音工作记忆 (pWM) 中次词汇结构的神经相关性。我们在隐蔽复述的条件下（实验 1），通过改变听觉伪词的音节和辅音簇的数量来正交变化，并测量这些操作的神经反应。一个以颞叶和运动皮层为主的左优势网络显示出对较长项目的活动增加，而只有在添加辅音簇时，运动皮层才显示出更大的活动。个体差异分析显示，在角回和海马体的活动与伪词重复的准确性之间存在显著的正相关关系。因为 pWM 的模型规定，其神经相关性应该在感知和产生/复述期间被激活[Buchsbaum, B. R., & D'Esposito, M. 寻找语音存储：从循环到卷积。认知神经科学杂志，20, 762-778, 2008； Jacquemot, C., & Scott, S. K. 语音短期记忆和语音处理之间有什么关系？认知科学趋势，10, 480-486, 2006；Baddeley, A. D., & Hitch, G. 工作记忆。在 G. H. Bower（编辑）的《学习与动机心理学：研究与理论进展》（第 8 卷，第 47-89 页）。纽约：学术出版社，1974]，我们在一个单独的被动听力实验（实验 2）中进一步评估了这两个因素的影响。在这个实验中，音节数量的影响集中在双侧颞上回的后内侧区域，尽管没有证据表明对添加的簇有显著的反应。总之，结果确定颞平面是 pWM 的关键区域；在这个区域内，在音节水平上，代表可能采用听觉或听动“模板”或“块”的形式[Papoutsi, M., de Zwart, J. A., Jansma, J. M., Pickering, M. J., Bednar, J. A., & Horwitz, B. 从音位到发音代码：fMRI 研究 Broca 区在言语产生中的作用。大脑皮层，19, 2156-2165, 2009；Warren, J. E., Wise, R. J. S., & Warren, J. D. 声音可做：听觉-运动转换和颞后平面。神经科学趋势，28, 636-643, 2005；Griffiths, T. D., & Warren, J. D. 颞平面作为计算中心。神经科学趋势，25, 348-353, 2002]，而 STG 上更外侧的结构可能处理听觉输入的语音分析[Hickok, G. 语言的功能神经解剖学。生命物理学评论，6, 121-143, 2009]。
