Motor Cognition Group, Max Planck Institute for Neurological Research, Gleueler Straße 50, 50931 Cologne, Germany.
Hum Brain Mapp. 2012 Aug;33(8):1812-20. doi: 10.1002/hbm.21325. Epub 2011 Jun 14.
While neural signatures of breaches of expectancy and their immediate effects have been investigated, thus far, temporally more remote effects have been neglected. The present fMRI study explored neural correlates of temporally remote destabilization of prediction following rare breaches of expectancy with a mean delay of 14 s. We hypothesized temporally remote destabilization to be reflected either in an attenuation of areas related to long-term memory or in an increase of lateral fronto-parietal loops related to the encoding of new stimuli. Monitoring a deterministic 24-digit sequence, subjects were asked to indicate occasional sequential omissions by key press. Temporally remote destabilization of prediction was expected to be revealed by contrasting sequential events whose equivalent was omitted in the preceding sequential run n-1 (destabilized events) with sequential events without such history (nondestabilized events). Temporally remote destabilization of prediction was reflected in an attenuation of activity in the dorsal frontomedian cortex (Brodmann Area (BA) 9) bilaterally. Moreover, activation of the left medial BA 9 was enhanced by contrasting nondestabilized events with breaches. The decrease of dorsal frontomedian activation in the case of destabilized events might be interpreted as a top-down modulation on perception causing a less expectation-restricted encoding of the current stimulus and hence enabling the adaptation of expectation and prediction in the long run.
虽然已经研究了违反预期及其即时效应的神经特征,但迄今为止,还忽略了时间上更遥远的效应。本 fMRI 研究探讨了罕见的违反预期后,经过平均 14 秒的延迟,预测的时间上更遥远的不稳定性的神经相关性。我们假设,时间上的不稳定性可以通过衰减与长期记忆相关的区域来反映,或者通过增加与新刺激编码相关的外侧额顶叶环来反映。在监测一个确定性的 24 位数字序列时,要求受试者通过按键来指示偶尔出现的序列遗漏。通过对比在前一个序列运行 n-1 中省略的等效序列事件(不稳定事件)与没有这种历史的序列事件(稳定事件),可以揭示预测的时间上的不稳定性。预测的时间上的不稳定性反映在双侧背侧额前皮质(Brodmann 区(BA)9)的活动减弱。此外,通过对比稳定事件和违反事件,左内侧 BA9 的激活增强。在不稳定事件的情况下,背侧额前皮质的激活减少可以解释为对感知的自上而下的调制,导致当前刺激的期望限制编码减少,从而能够长期适应期望和预测。