Spatial Learning and Spatial Attention

我们如何在新的环境中找到自己的方向？这项研究将使用电鱼模型将空间学习与注意力联系起来，并确定这种学习的神经基础。脉冲电鱼（Gymnotus sp.）在黑暗中使用电子器官放电（EOD）来感知它们的环境。这些鱼利用它们的电感觉来学习食物相对于地标的位置。他们每单位距离的爆炸物处理率（抽样密度，SD）是一种注意力的标志。SD与空间学习有关：当鱼第一次遇到地标或食物时，SD很高，但在学习后减少。SD增加也是由记忆引起的：当预期位置没有食物时，SD增加。为了确定食物相对于地标的位置，鱼必须估计它们之间的距离。我们最近的实验表明，鱼丘脑中的电感觉神经元计算与物体相遇之间的时间间隔：它们的放电频率将发出信号，指示遇到地标和食物之间的时间。我们假设这些神经元的反应，结合对鱼的速度的独立估计，可以用来估计从地标到食物的距离。我们建议测试的预测，从这个假设流与行为实验和记录从丘脑自由游动的鱼从事相同的导航任务中的行为研究。

How do we learn to find our way in a new environment? The proposed research will connect spatial learning to attention using an electric fish model and determine the neural bases for such learning. Pulse electric fish (Gymnotus sp.) use electric organ discharges (EOD) to sense their environment in the dark. These fish learn the location of food with respect to landmarks using their electrosense. Their EOD rate per unit distance (sampling density, SD) is a signature of attention. SD is associated with spatial learning: it is high when the fish first encounters landmarks or food but diminishes after learning. SD increases are also induced by memory: it increases when no food is present at its expected location. In order to locate the food with respect to a landmark, the fish has to estimate the distance between them. Our recent experiments have shown that electrosensory neurons in the fish’s thalamus compute the time interval between encounters with objects: their firing rate will signal the time between encountering a landmark followed by food. We hypothesize that the response of these neurons, combined with an independent estimate of the fish’s speed, could be used to estimate the distance from landmark to food. We propose to test the predictions that flow from this hypothesis with behavioural experiments and by recording from the thalamus of freely swimming fish engaged in the same navigational task examined in the behavioural studies.