A Computational Model of Stereoscopic Prey Capture in Praying Mantises"
A Computational Model of Stereoscopic Prey Capture in Praying Mantises"
复制标题
螳螂立体捕获猎物的计算模型"
DOI：
10.1101/2021.12.03.471070
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
O'Keeffe J
中科院分区：
文献类型：
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作者：
O'Keeffe J
我们提出了一个简单的模型，可以解释螳螂捕食性攻击的立体敏感性。该模型由一个单一的“视差传感器”组成：一个对立体视差敏感的双眼神经元，从而对与动物的距离敏感。该模型紧密基于螳螂立体视觉的已知行为和神经生理学特性。单眼对神经元的输入反映了时间的变化，对对比信号不敏感，使传感器对眼睛间的相关性不敏感。单眼感受区有一个兴奋中心和抑制周围，使它们的大小可调。视差传感器将来自两只眼睛的输入线性组合，施加阈值，然后应用指数输出非线性。传感器的活动代表了模型螳螂被击中的瞬时概率。我们在刺激持续时间内对此进行积分，以获得对具有不同立体视差、大小和垂直视差的移动目标的预期打击次数。我们优化了模型的参数，以使其预测与我们的平均罢工率作为刺激规模和差异的函数的经验数据相一致。事实证明，该模型能够再现螳螂攻击行为中相对宽泛的大小调谐和立体差异的缩小调谐。尽管该模型的每只眼睛只有一个中心环绕的感受野，但它定性地显示了大小和视差之间的相互作用，这与我们在真实螳螂中观察到的相同：随着模拟猎物距离增加到超过理想距离，首选大小增加。我们证明，这是因为一只眼睛的刺激前沿和另一只眼睛的尾部边缘之间的立体“假匹配”；还需要进一步的工作来找出这种假匹配是否发生在真正的螳螂身上。重要的是，该模型还显示了对具有垂直差异的刺激的真实反应，以及对提供“幽灵匹配”的相同刺激对的真实反应，尽管不符合这些数据。这是第一个昆虫立体视觉的图像可计算模型，并再现了神经生理学和攻击行为的关键特征。
We present a simple model which can account for the stereoscopic sensitivity of praying mantis predatory strikes. The model consists of a single “disparity sensor”: a binocular neuron sensitive to stereoscopic disparity and thus to distance from the animal. The model is based closely on the known behavioural and neurophysiological properties of mantis stereopsis. The monocular inputs to the neuron reflect temporal change and are insensitive to contrast sign, making the sensor insensitive to interocular correlation. The monocular receptive fields have a excitatory centre and inhibitory surround, making them tuned to size. The disparity sensor combines inputs from the two eyes linearly, applies a threshold and then an exponent output nonlinearity. The activity of the sensor represents the model mantis’s instantaneous probability of striking. We integrate this over the stimulus duration to obtain the expected number of strikes in response to moving targets with different stereoscopic disparity, size and vertical disparity. We optimised the parameters of the model so as to bring its predictions into agreement with our empirical data on mean strike rate as a function of stimulus size and disparity. The model proves capable of reproducing the relatively broad tuning to size and narrow tuning to stereoscopic disparity seen in mantis striking behaviour. Although the model has only a single centre-surround receptive field in each eye, it displays qualitatively the same interaction between size and disparity as we observed in real mantids: the preferred size increases as simulated prey distance increases beyond the preferred distance. We show that this occurs because of a stereoscopic “false match” between the leading edge of the stimulus in one eye and its trailing edge in the other; further work will be required to find whether such false matches occur in real mantises. Importantly, the model also displays realistic responses to stimuli with vertical disparity and to pairs of identical stimuli offering a “ghost match”, despite not being fitted to these data. This is the first image-computable model of insect stereopsis, and reproduces key features of both neurophysiology and striking behaviour.