School of Philosophy, Psychology and Language Sciences, University of Edinburgh, Edinburgh, EH8 9JZ, UK.
Nat Commun. 2019 Jan 31;10(1):515. doi: 10.1038/s41467-019-08519-0.
The ability to speak coherently is essential for effective communication but declines with age: older people more frequently produce tangential, off-topic speech. Little is known, however, about the neural systems that support coherence in speech production. Here, fMRI was used to investigate extended speech production in healthy older adults. Computational linguistic analyses were used to quantify the coherence of utterances produced in the scanner, allowing identification of the neural correlates of coherence for the first time. Highly coherent speech production was associated with increased activity in bilateral inferior prefrontal cortex (BA45), an area implicated in selection of task-relevant knowledge from semantic memory, and in bilateral rostrolateral prefrontal cortex (BA10), implicated more generally in planning of complex goal-directed behaviours. These findings demonstrate that neural activity during spontaneous speech production can be predicted from formal analysis of speech content, and that multiple prefrontal systems contribute to coherence in speech.
连贯地讲话的能力对于有效的沟通至关重要，但随着年龄的增长而下降：老年人更频繁地产生离题、跑题的言论。然而，关于支持言语产生连贯性的神经系统知之甚少。在这里，使用 fMRI 研究了健康老年人的扩展言语产生。使用计算语言学分析来量化在扫描仪中产生的话语的连贯性，从而首次确定了连贯性的神经相关性。高度连贯的言语产生与双侧下额前皮质（BA45）的活动增加有关，BA45 区域涉及从语义记忆中选择与任务相关的知识，以及双侧额极外侧前额皮质（BA10）的活动增加有关，BA10 更普遍地参与复杂目标导向行为的计划。这些发现表明，从言语内容的正式分析可以预测自发言语产生过程中的神经活动，并且多个前额叶系统有助于言语的连贯性。
