Transducer models of head-centred motion perception
Transducer models of head-centred motion perception
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DOI：
10.1016/s0042-6989(01)00159-6
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发表时间：
2001-09-01
期刊：
影响因子：
1.8
通讯作者：
Freeman, TCA
中科院分区：
文献类型：
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作者：
Freeman, TCA
通过添加视网膜和追踪眼球运动速度，可以确定对象相对于头部的运动。视觉系统通过将视网膜外的眼睛速度信号与视网膜运动信号相加来执行类似的计算似乎是可能的。因此，感知到的以头部为中心的运动可以通过这些信号编码速度的方式的差异来确定。例如，如果视网膜外信号提供较低的速度估计，则移动对象在被追踪时将显得较慢（Aubert-Fleischl现象），并且静止对象将与眼睛运动相反地移动（Filehne错觉）。大多数以前的工作提出，这些错觉的存在，因为视网膜信号编码视网膜运动准确，而视网膜外信号低估眼速。一个更一般的模型，其中两个信号可能是错误的。两种类型的输入/输出速度的关系进行检查。第一种使用线性速度传感器，第二种使用非线性速度传感器，后者基于幂律。结果表明，奥伯特-弗莱舍现象和Filehne错觉的研究揭示了增益比或功率比单独。我们还考虑了一般的速度匹配，并表明，在理论上匹配功能是有限的增益比的线性情况。然而，在非线性的情况下，各个换能器的形状被揭示，尽管高达一个未知的比例因子。实验表明，增益比小于1的线速度传感器可以很好地描述Aubert-Fleischl现象和Filehne错觉。对于某些观察者来说，这也是一般速度匹配实验的情况。然而，对于其他观察者，行为是非线性的，并且根据传感器模型，表明速度编码中存在扩展的非线性。这一令人惊讶的结果进行了讨论，与其他理论的头部为中心的运动知觉和可能的策略，一些观察员可能会采取判断刺激运动时，在眼球运动。(C)2001爱思唯尔科技有限公司版权所有。
By adding retinal and pursuit eye-movement velocity one can determine the motion of an object with respect to the head. It would seem likely that the visual system carries out a similar computation by summing extra-retinal, eye-velocity signals with retinal motion signals. Perceived head-centred motion may therefore be determined by differences in the way these signals encode speed, For example, if extra-retinal signals provide the lower estimate of speed then moving objects will appear slower when pursued (Aubert-Fleischl phenomenon) and stationary objects will move opposite to an eye movement (Filehne illusion). Most previous work proposes that these illusions exist because retinal signals encode retinal motion accurately while extra-retinal signals under-estimate eye speed. A more general model is presented in which both signals could be in error. Two types of input/output speed relationship are examined. The first uses linear speed transducers and the second non-linear speed transducers, the latter based on power laws. It is shown that studies of the Aubert-Fleischl phenomenon and Filehne illusion reveal the gain ratio or power ratio alone. We also consider general velocity-matching and show that in theory matching functions are limited by gain ratio in the linear case. However, in the non-linear case individual transducer shapes are revealed albeit up to an unknown scaling factor. The experiments show that the Aubert-Fleischl phenomenon and Filehne illusion are adequately described by linear speed transducers with a gain ratio less than one. For some observers, this is also the case in general velocity-matching experiments. For other observers, however, behaviour is non-linear and, according to the transducer model, indicates the existence of expansive non-linearities in speed encoding. This surprising result is discussed in relation to other theories of head-centred motion perception and the possible strategies some observers might adopt when judging stimulus motion during an eye movement. (C) 2001 Elsevier Science Ltd. All rights reserved.