Department of Biological and Vision Sciences, State University of New York College of Optometry, New York City, New York, United States.
Department of Optometry, School of Medical & Allied Sciences, G.D. Goenka University, Gurugram, India.
J Neurophysiol. 2024 Mar 1;131(3):548-555. doi: 10.1152/jn.00355.2023. Epub 2024 Jan 31.
It has been suggested that, during difficult visual search tasks involving time pressure and multiple saccades, inhibitory tagging helps to facilitate efficient saccade target selection by reducing responses to objects in the scene once they have been searched and rejected. The superior colliculus (SC) is a midbrain structure involved in target selection, and recent findings suggest an influence of inhibitory tagging on SC activity. Precisely how, and by how much, inhibitory tagging influences target selection by SC neurons, however, is unclear. The purpose of this study, therefore, was to characterize and quantify the influence of inhibitory tagging on target selection in the SC. Rhesus monkeys performed a visual search task involving time pressure and multiple saccades. Early in the fixation period between saccades in the context of this task, a subset of SC neurons reliably discriminated the stimulus selected as the next saccade goal, consistent with a role in target selection. Discrimination occurred earlier and was more robust, however, when unselected stimuli in the search array had been previously fixated on the same trial. This indicates that inhibitory tagging both speeds and strengthens saccade target selection in the SC during multisaccade search. The results provide constraints on models of target selection based on SC activity. An important aspect of efficient behavior during difficult, time-limited visual search tasks is the efficient selection of sequential saccade targets. Inhibitory tagging, i.e., a reduction of neural activity associated with previously fixated objects, may help to facilitate such efficient selection by modulating the selection process in the superior colliculus (SC). In this study, we characterized and quantified this modulation and found that, indeed, inhibitory tagging both speeds and strengthens target selection in the SC.
有人提出，在涉及时间压力和多次眼跳的困难视觉搜索任务中，抑制性标记通过减少对已搜索和拒绝的场景中的物体的反应，有助于促进有效的眼跳目标选择。上丘（SC）是参与目标选择的中脑结构，最近的发现表明抑制性标记对 SC 活动有影响。然而，确切地说，抑制性标记通过 SC 神经元对目标选择的影响有多大，尚不清楚。因此，本研究的目的是表征和量化抑制性标记对 SC 中目标选择的影响。恒河猴执行了一项涉及时间压力和多次眼跳的视觉搜索任务。在该任务的眼跳之间的固定期早期，一组 SC 神经元可靠地区分了作为下一个眼跳目标选择的刺激，这与目标选择的作用一致。然而，当搜索数组中未选中的刺激在前一个试验中被固定时，这种区分更早且更稳健。这表明，在多眼跳搜索过程中，抑制性标记既加快又增强了 SC 中的眼跳目标选择。结果为基于 SC 活动的目标选择模型提供了限制。在困难的、限时的视觉搜索任务中，高效行为的一个重要方面是对顺序眼跳目标的高效选择。抑制性标记，即与先前注视的物体相关的神经活动减少，可能有助于通过调节上丘（SC）中的选择过程来促进这种高效选择。在这项研究中，我们对这种调制进行了表征和量化，确实发现，抑制性标记既加快又增强了 SC 中的目标选择。
