Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy; NeuroMi, Milan Centre for Neuroscience, Milan, Italy.
Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.
Physiol Behav. 2023 Jun 1;265:114142. doi: 10.1016/j.physbeh.2023.114142. Epub 2023 Mar 6.
A growing body of research has shown that a unilateral alteration in the sense of limb ownership is associated with the cooling of a limb's temperature. However, the recent emergence of contradictory results calls into question the existence of a relationship between this physiological reaction and the sense of body ownership. In the light of evidence that the malleability of the sense of hand ownership differs based on the preferential motor use of the hand to which the illusion is applied, one might observe the same lateralised pattern in the skin temperature cooling. In particular, if skin temperature change is a signature of body ownership, we expected a stronger illusion and reduction in skin temperature when altering ownership alteration of the left hand compared to the right hand in dextral individuals. To test this hypothesis, we selectively perturbated body ownership of the left or right hand in 24 healthy participants in different experimental sessions using the Mirror-Box Illusion (MBI) paradigm. Participants were asked to tap synchronously or asynchronously at a constant rhythm with their left and right index fingers against two parallel mirrors while looking at their reflected right/left hand. Skin temperature was measured before and after each MBI application, and explicit judgments of ownership and proprioceptive drift were collected. The results showed a consistent cooling of the hand's temperature only when the illusion was performed on the left hand. Proprioceptive drift exhibited the same pattern. In contrast, the explicit judgment of ownership of the reflected hand was similar across the two hands. These data provide evidence in favor of a specific laterality effect of the physiological response to an induced alteration of body part ownership. Moreover, they highlight the possibility of a direct link between proprioception and skin temperature.
越来越多的研究表明，单侧肢体所有权感觉的改变与肢体温度的降低有关。然而，最近出现的矛盾结果质疑了这种生理反应与身体所有权之间存在关系的可能性。鉴于手的所有权的可塑性能根据所应用的错觉的手的优先运动使用而有所不同的证据，人们可能会在手的温度冷却中观察到相同的偏侧化模式。特别是，如果皮肤温度变化是身体所有权的标志，我们预计在惯用右手的个体中，与改变右手相比，改变左手的所有权改变会产生更强的错觉和皮肤温度降低。为了检验这一假设，我们在不同的实验中使用镜像箱错觉（MBI）范式选择性地改变了 24 名健康参与者的左手或右手的身体所有权。要求参与者用食指同时或不同时地与两个平行的镜子敲击，同时看着他们反射的右手/左手。在每次 MBI 应用前后测量皮肤温度，并收集对所有权和本体感觉漂移的明确判断。结果表明，只有当错觉作用于左手时，手的温度才会持续降低。本体感觉漂移也呈现出相同的模式。相比之下，对反射手的所有权的明确判断在两只手上是相似的。这些数据为生理反应对诱导的身体部位所有权改变的特定偏侧性效应提供了证据。此外，它们还强调了本体感觉和皮肤温度之间可能存在直接联系。
