Neural Correlates of Predictive and Postdictive Switching Mechanisms for Internal Models
Neural Correlates of Predictive and Postdictive Switching Mechanisms for Internal Models
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DOI：
10.1523/jneurosci.1106-08.2008
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发表时间：
2008-10-15
影响因子：
5.3
通讯作者：
Kawato, Mitsuo
中科院分区：
文献类型：
--
作者：
Imamizu, Hiroshi;Kawato, Mitsuo
感觉运动任务的切换可分为基于情境信息的预测性切换和基于反馈与预测误差的后置性切换。我们使用功能性神经成像来研究涉及视觉运动旋转（视觉反馈的顺时针和逆时针旋转）的每种内部模型切换的大脑区域。运动开始前提示的颜色在指示条件下与反馈的旋转方向一致，而在非指示条件下则不一致。切换相关活性被确定为在旋转方向改变后短暂增加的活性。在指示条件下，当预测转换可能发生时，在顶叶上小叶（SPL）中观察到提示期的转换相关活动。然而，在非指示条件下，当预测误差对后置转换至关重要时，反馈期的转换相关活动在顶叶下叶（IPL）和前额叶皮层中被观察到。在指示条件下，SPL对小脑外侧的功能影响（即内部模型可能的神经关联）增加，但在非指示条件下，IPL对小脑的影响增加。我们观察到，在指示条件下，活动快速增加，而在非指示条件下，活动逐渐增加，主要集中在枕颞外侧皮层（LOTC）和辅助运动皮层（SMA）。这些结果与预测开关和后置开关的单独机制一致，并表明LOTC和SMA从适当的内部模型接收输出信号。
Switching of sensorimotor tasks may be classified into predictive switching based on contextual information and postdictive switching based on the error between sensorimotor feedback and predictions. We used functional neuroimaging to study the brain regions involved in each type of switching of internal models for visuomotor rotations ( clockwise and counterclockwise rotations of visual feedback). The color of a cue presented before movement initiation corresponded to direction of rotation of the feedback in an instructed condition, but not in a noninstructed condition. Switching-related activity was identified as activity that transiently increased after the direction of rotation was changed. The switching-related activity in cue periods in the instructed condition, when a predictive switch is possible, was observed in the superior parietal lobule (SPL). However, the switching-related activity in feedback periods in the noninstructed condition, when prediction error is crucial for the postdictive switch, was observed in the inferior parietal lobule (IPL) and prefrontal cortex. The functional influence of the SPL on the lateral cerebellum, namely, a possible neural correlate for internal models, increased in the instructed condition, but the influence of the IPL on the cerebellum was increased in the noninstructed condition. We observed a rapid activity increase in the instructed condition and a gradual activity increase in the noninstructed condition mainly in the lateral occipito-temporal cortices (LOTC) and supplementary motor cortex (SMA). These results are consistent with separate mechanisms for predictive and postdictive switches and suggest that the LOTC and SMA receive output signals from appropriate internal models.