Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy; Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK.
Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy.
Curr Biol. 2023 Oct 23;33(20):R1038-R1040. doi: 10.1016/j.cub.2023.08.062.
Primary visual cortex (V1) retains a form of plasticity in adult humans: a brief period of monocular deprivation induces an enhanced response to the deprived eye, which can stabilize into a consolidated plastic change despite unaltered thalamic input. This form of homeostatic plasticity in adults is thought to act through neuronal competition between the representations of the two eyes, which are still separate in primary visual cortex. During monocular occlusion, neurons of the deprived eye are thought to increase response gain given the absence of visual input, leading to the post-deprivation enhancement. If the decrease of reliability of the monocular response is crucial to establish homeostatic plasticity, this could be induced in several different ways. There is increasing evidence that V1 processing is affected by voluntary action, allowing it to take into account the visual effects of self-motion, important for efficient active vision. Here we asked whether ocular dominance homeostatic plasticity could be elicited without degrading the quality of monocular visual images but simply by altering their role in visuomotor control by introducing a visual delay in one eye while participants actively performed a visuomotor task; this causes a discrepancy between what the subject sees and what he/she expects to see. Our results show that homeostatic plasticity is gated by the consistency between the monocular visual inputs and a person's actions, suggesting that action not only shapes visual processing but may also be essential for plasticity in adults.
初级视皮层（V1）在成年人类中保留了一种形式的可塑性：短暂的单眼剥夺会导致对被剥夺眼睛的反应增强，尽管丘脑输入不变，但这种增强可以稳定为巩固的塑性变化。这种形式的成人同源性可塑性被认为是通过两只眼睛的代表之间的神经元竞争来发挥作用的，而在初级视皮层中，两只眼睛的代表仍然是分开的。在单眼遮挡期间，由于缺乏视觉输入，被剥夺眼睛的神经元被认为会增加反应增益，从而导致剥夺后增强。如果单眼反应的可靠性降低对于建立同源性可塑性至关重要，那么这可以通过几种不同的方式来诱导。越来越多的证据表明，V1 处理受到自愿动作的影响，从而使其能够考虑到自身运动的视觉效果，这对于有效的主动视觉很重要。在这里，我们询问是否可以在不降低单眼视觉图像质量的情况下诱发眼优势同源性可塑性，而只需通过在参与者主动执行视觉运动任务时在一只眼睛中引入视觉延迟来改变其在视觉运动控制中的作用；这会导致主体看到的与他/她期望看到的之间出现差异。我们的结果表明，同源性可塑性由单眼视觉输入与一个人的动作之间的一致性来控制，这表明动作不仅塑造了视觉处理，而且对于成年人的可塑性也可能是必不可少的。
