Haptic information can be used to create our perception of the stiffness of objects and to regulate grip force. Introducing noise into sensory inputs can create uncertainty, yet a method of creating haptic uncertainty without distorting the haptic information has yet to be discovered. Toward this end, in this article, we investigated the effect of varying haptic information between consecutive interactions with an elastic force field on stiffness perception and grip force control. In a stiffness discrimination task, participants interacted with force fields multiple times. Low, medium, and high variability levels were created by drawing the stiffness level applied in each consecutive interaction within a trial from normal distributions. Perceptual haptic uncertainty was created only by the medium variability level. Moreover, all the variability levels affected the grip force control: the modulation of the grip force with the load force decreased with repeated interactions with the force field, whereas no change in the baseline grip force was observed. Additionally, we ascertained that participants formed their perceived stiffness by calculating a weighted average of the different stiffness levels applied by a given force field. We conclude that the medium variability level can be effective in inducing uncertainty in both perception and action.

中文翻译：

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刚度变化对感知和握力调整的影响

触觉信息可用于创建我们对物体刚度的感知并调节抓地力。将噪声引入感官输入会产生不确定性，但尚未发现一种在不扭曲触觉信息的情况下产生触觉不确定性的方法。为此，在本文中，我们研究了在与弹性力场的连续交互之间变化的触觉信息对刚度感知和握力控制的影响。在刚度鉴别任务中，参与者多次与力场交互。低、中和高可变性水平是通过从正态分布绘制试验中每个连续相互作用中应用的刚度水平来创建的。感知触觉不确定性仅由中等可变性水平产生。而且，所有可变性水平都会影响握力控制：随着与力场的重复相互作用，握力与负载力的调制减少，而基线握力没有变化。此外，我们确定参与者通过计算给定力场施加的不同刚度水平的加权平均值来形成他们的感知刚度。我们得出结论，中等可变性水平可以有效地引起感知和行动的不确定性。我们确定参与者通过计算给定力场施加的不同刚度水平的加权平均值来形成他们的感知刚度。我们得出结论，中等可变性水平可以有效地引起感知和行动的不确定性。我们确定参与者通过计算给定力场施加的不同刚度水平的加权平均值来形成他们的感知刚度。我们得出结论，中等可变性水平可以有效地引起感知和行动的不确定性。