Diomedi Stefano, Vaccari Francesco E, Filippini Matteo, Fattori Patrizia, Galletti Claudio
Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
iScience. 2020 Sep 28;23(10):101616. doi: 10.1016/j.isci.2020.101616. eCollection 2020 Oct 23.
The activity of neurons of the medial posterior parietal area V6A in macaque monkeys is modulated by many aspects of reach task. In the past, research was mostly focused on modulating the effect of single parameters upon the activity of V6A cells. Here, we used Generalized Linear Models (GLMs) to simultaneously test the contribution of several factors upon V6A cells during a fix-to-reach task. This approach resulted in the definition of a representative "functional fingerprint" for each neuron. We first studied how the features are distributed in the population. Our analysis highlighted the virtual absence of units strictly selective for only one factor and revealed that most cells are characterized by "mixed selectivity." Then, exploiting our GLM framework, we investigated the dynamics of spatial parameters encoded within V6A. We found that the tuning is not static, but changed along the trial, indicating the sequential occurrence of visuospatial transformations helpful to guide arm movement.
猕猴内侧顶叶后区V6A神经元的活动受伸手任务诸多方面的调节。过去，研究大多集中于调节单个参数对V6A细胞活动的影响。在此，我们使用广义线性模型（GLMs）在固定到伸手任务期间同时测试多个因素对V6A细胞的贡献。这种方法为每个神经元定义了一个代表性的“功能指纹”。我们首先研究了这些特征在群体中的分布情况。我们的分析突出显示几乎没有仅对一个因素严格选择性的单元，并揭示大多数细胞具有“混合选择性”特征。然后，利用我们的GLM框架，我们研究了V6A内编码的空间参数的动态变化。我们发现这种调谐不是静态的，而是在试验过程中发生变化，这表明有助于引导手臂运动的视觉空间转换是依次发生的。
