Saccade target selection in the superior colliculus: A signal detection theory approach
Saccade target selection in the superior colliculus: A signal detection theory approach
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DOI：
10.1523/jneurosci.5424-07.2008
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发表时间：
2008-03-19
影响因子：
5.3
通讯作者：
Basso, Michele A.
中科院分区：
文献类型：
--
作者：
Kim, Byounghoon;Basso, Michele A.
大脑如何从多个选项中选择一个动作是未知的。信号检测理论（SDT）的一个主要原则是，感觉刺激被表示为嘈杂的信息通道。因此，选择的准确性可以通过区分代表替代物的神经元活动的程度来预测。在这里，我们应用SDT框架的运动系统记录从上级丘（SC）神经元在执行的颜色，oddball选择任务。我们同时记录了四个神经元的集合，四个神经元中的每一个代表四个可能的目标之一。由于电极放置限制了刺激在视野中的位置，因此刺激的排列在实验中有所不同。这种变化的刺激安排导致的变化，使我们能够探索SC神经元的活动和性能的准确性之间的关系的选择。SC靶神经元有更高的放电水平比SC干扰神经元在子集的试验时，选择性能是非常准确的。在试验的子集时，性能差，放电水平下降，在目标神经元和分心神经元增加。准确的表现与神经元活动与目标和干扰物之间的较大分离相关，如通过受试者工作特征（ROC）面积和d'（可辨别性指数）量化的。靶神经元和干扰神经元活动的分离程度越小，则表现越好。ROC面积和d'与性能准确度近似线性缩放。此外，ROC面积和d'随着眼跳开始的临近而增加。总之，结果表明，SC积聚神经元活动信号扫视眼球运动的决定。
How the brain selects one action from among multiple options is unknown. A main tenet of signal detection theory (SDT) is that sensory stimuli are represented as noisy information channels. Therefore, the accuracy of selection might be predicted by how well neuronal activity representing alternatives can be distinguished. Here, we apply an SDT framework to a motor system by recording from superior colliculus (SC) neurons during performance of a color, oddball selection task. We recorded from sets of four neurons simultaneously, each of the four representing one of the four possible targets. Because the electrode placement constrained the position of the stimuli in the visual field, the stimulus arrangement varied across experiments. This variability in stimulus arrangement led to variability in choices allowing us to explore the relationship between SC neuronal activity and performance accuracy. SC target neurons had higher levels of discharge than SC distractor neurons in subsets of trials when selection performance was very accurate. In subsets of trials when performance was poor, the discharge level decreased in target neurons and increased in distractor neurons. Accurate performance was associated with larger separations between neuronal activity from targets and distractors as quantified by the receiver operating characteristic (ROC) area and d' (an index of discriminability). Poorer performance was associated with less separation of target and distractor neuronal activity. ROC area and d' scaled approximately linearly with performance accuracy. Furthermore, ROC area and d' increased as saccade onset approached. Together, the results indicate that SC buildup neuronal activity signals the saccadic eye movement decision.