The internal representation of head orientation differs for conscious perception and balance control
The internal representation of head orientation differs for conscious perception and balance control
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DOI：
10.1113/jp272998
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发表时间：
2017-04-15
影响因子：
5.5
通讯作者：
Blouin, Jean-Sebastien
中科院分区：
文献类型：
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作者：
Dalton, Brian H.;Rasman, Brandon G.;Blouin, Jean-Sebastien
用于平衡控制的前庭信号必须与其他感觉运动线索相结合，以允许根据身体结构的内部表征进行下行信号的转换。我们探索了感觉运动整合的两种替代模型，提出（1）头对脚方向的单一内部表征负责感知姿势方向和站立平衡或（2）有意识的感知和平衡控制由单独的内部表征驱动。在三个实验中，参与者安静地站着，同时被动或主动地保持长时间的转头姿势（> 10分钟）。在整个试验过程中，参与者间歇性地报告他们感知到的头部角度位置，随后提供电前庭刺激以引起全身平衡反应。视觉重新校准的头对脚的姿势，以确定是否静态视觉线索被用来更新的内部表示的身体配置感知方向和站立平衡。所有三个实验涉及的情况下，前庭诱发的平衡反应是不正交的感知头对脚的方向，无论提供的视觉信息。对于长时间的头转向姿势，平衡反应与实际的头对脚的姿势一致，只发生在积极的条件。我们的研究结果表明，有意识地感知头对脚的姿势和前庭控制的平衡不依赖于相同的内部表示，而是并行处理感觉运动线索，并可能得出不同的结论，头对脚的姿势。平衡系统似乎绕过静态视觉线索的姿势方向，并主要使用其他感觉运动信号的头上脚的位置，以转换前庭信号的头部运动，一种机制，适合于大多数日常活动。
Vestibular signals used for balance controlmust be integrated with other sensorimotor cues to allowtransformation of descending signals according to an internal representation of body configuration. We explored two alternative models of sensorimotor integration that propose (1) a single internal representation of head-on-feet orientation is responsible for perceived postural orientation and standing balance or (2) conscious perception and balance control are driven by separate internal representations. During three experiments, participants stood quietly while passively or actively maintaining a prolonged head-turned posture (> 10 min). Throughout the trials, participants intermittently reported their perceived head angular position, and subsequently electrical vestibular stimuli were delivered to elicit whole-body balance responses. Visual recalibration of head-on-feet posture was used to determine whether static visual cues are used to update the internal representation of body configuration for perceived orientation and standing balance. All three experiments involved situations in which the vestibular-evoked balance response was not orthogonal to perceived head-on-feet orientation, regardless of the visual information provided. For prolonged head-turned postures, balance responses consistent with actual head-on-feet posture occurred only during the active condition. Our results indicate that conscious perception of head-on-feet posture and vestibular control of balance do not rely on the same internal representation, but instead treat sensorimotor cues in parallel and may arrive at different conclusions regarding head-on-feet posture. The balance system appears to bypass static visual cues of postural orientation and mainly use other sensorimotor signals of head-on-feet position to transform vestibular signals of head motion, a mechanism appropriate for most daily activities.