Kohrs Christin, Angenstein Nicole, Scheich Henning, Brechmann André
Special Lab Non-Invasive Brain Imaging, Leibniz Institute for Neurobiology Magdeburg, Germany.
Front Hum Neurosci. 2012 Aug 30;6:243. doi: 10.3389/fnhum.2012.00243. eCollection 2012.
The temporal contingency of feedback during conversations is an essential requirement of a successful dialog. In the current study, we investigated the effects of delayed and omitted registering feedback on fMRI activation and compared both unexpected conditions to immediate feedback. In the majority of trials of an auditory task, participants received an immediate visual feedback which merely indicated that a button press was registered but not whether the response was correct or not. In a minority of trials, and thus unexpectedly, the feedback was omitted, or delayed by 500 ms. The results reveal a response hierarchy of activation strength in the dorsal striatum and the substantia nigra: the response to the delayed feedback was larger compared to immediate feedback and immediate feedback showed a larger activation compared to the omission of feedback. This suggests that brain regions typically involved in reward processing are also activated by non-rewarding, registering feedback. Furthermore, the comparison with immediate feedback revealed that both omitted and delayed feedback significantly modulated activity in a network of brain regions that reflects attentional demand and adjustments in cognitive and action control, i.e., the posterior medial frontal cortex (pMFC), right dorsolateral prefrontal cortex (dlPFC), bilateral anterior insula (aI), inferior frontal gyrus (Gfi), and inferior parietal lobe (Lpi). This finding emphasizes the importance of immediate feedback in human-computer interaction, as the effects of delayed feedback on brain activity in the described network seem to be similar to that of omitted feedback.
对话过程中反馈的时间偶然性是成功对话的一项基本要求。在当前的研究中，我们调查了延迟和省略记录反馈对功能磁共振成像激活的影响，并将这两种意外情况与即时反馈进行了比较。在一项听觉任务的大多数试验中，参与者会收到即时视觉反馈，该反馈仅表明按钮按下已被记录，但不表明反应是否正确。在少数试验中，也就是意外情况下，反馈被省略或延迟了500毫秒。结果揭示了背侧纹状体和黑质中激活强度的反应层次：与即时反馈相比，对延迟反馈的反应更大，与省略反馈相比，即时反馈显示出更大的激活。这表明通常参与奖励处理的脑区也会被无奖励的记录反馈激活。此外，与即时反馈的比较表明，省略和延迟反馈均显著调节了一个脑区网络的活动，该网络反映了注意力需求以及认知和行动控制的调整，即后内侧前额叶皮质（pMFC）、右侧背外侧前额叶皮质（dlPFC）、双侧前岛叶（aI）、额下回（Gfi）和顶下小叶（Lpi）。这一发现强调了即时反馈在人机交互中的重要性，因为延迟反馈对所述网络中大脑活动的影响似乎与省略反馈的影响相似。
