Department of Philosophy, Lund University Cognitive Science, Lund University Lund, Sweden.
Certec - Division of Rehabilitation Engineering Research, Department of Design Sciences, Lund University Lund, Sweden.
Front Hum Neurosci. 2014 Mar 28;8:166. doi: 10.3389/fnhum.2014.00166. eCollection 2014.
What would it be like if we said one thing, and heard ourselves saying something else? Would we notice something was wrong? Or would we believe we said the thing we heard? Is feedback of our own speech only used to detect errors, or does it also help to specify the meaning of what we say? Comparator models of self-monitoring favor the first alternative, and hold that our sense of agency is given by the comparison between intentions and outcomes, while inferential models argue that agency is a more fluent construct, dependent on contextual inferences about the most likely cause of an action. In this paper, we present a theory about the use of feedback during speech. Specifically, we discuss inferential models of speech production that question the standard comparator assumption that the meaning of our utterances is fully specified before articulation. We then argue that auditory feedback provides speakers with a channel for high-level, semantic "self-comprehension". In support of this we discuss results using a method we recently developed called Real-time Speech Exchange (RSE). In our first study using RSE (Lind et al., in press) participants were fitted with headsets and performed a computerized Stroop task. We surreptitiously recorded words they said, and later in the test we played them back at the exact same time that the participants uttered something else, while blocking the actual feedback of their voice. Thus, participants said one thing, but heard themselves saying something else. The results showed that when timing conditions were ideal, more than two thirds of the manipulations went undetected. Crucially, in a large proportion of the non-detected manipulated trials, the inserted words were experienced as self-produced by the participants. This indicates that our sense of agency for speech has a strong inferential component, and that auditory feedback of our own voice acts as a pathway for semantic monitoring. We believe RSE holds great promise as a tool for investigating the role of auditory feedback during speech, and we suggest a number of future studies to serve this purpose.
如果我们说出的话和我们听到的自己说的话不一样，那会是什么样子？我们会注意到有什么不对劲吗？还是我们会相信自己说出了我们听到的话？我们对自己说话的反馈是否仅用于检测错误，还是它也有助于指定我们所说的话的含义？自我监测的比较器模型倾向于第一种选择，认为我们的代理权是由意图和结果之间的比较给出的，而推理模型则认为代理权是一个更流畅的结构，取决于关于行动最可能原因的上下文推断。在本文中，我们提出了一个关于在演讲中使用反馈的理论。具体来说，我们讨论了推理模型的言语产生，这些模型质疑了言语含义在发音之前完全指定的标准比较器假设。然后，我们认为听觉反馈为说话者提供了一个用于高级语义“自我理解”的渠道。为了支持这一点，我们讨论了使用我们最近开发的一种称为实时言语交换（RSE）的方法的结果。在我们使用 RSE 的第一项研究中（Lind 等人，即将出版），参与者戴上耳机并执行计算机化的斯特鲁普任务。我们秘密记录了他们说的话，然后在测试中，我们在参与者说出其他话的同时，以完全相同的时间播放他们说的话，同时阻止他们的声音的实际反馈。因此，参与者说了一件事，但听到自己说了另一件事。结果表明，当时间条件理想时，超过三分之二的操作未被检测到。至关重要的是，在很大一部分未被检测到的操纵试验中，插入的单词被参与者体验为自己产生的。这表明我们对言语的代理权具有很强的推理成分，而我们自己声音的听觉反馈则是语义监控的途径。我们相信 RSE 作为一种研究言语过程中听觉反馈作用的工具具有很大的潜力，我们建议进行一些未来的研究来实现这一目标。
