Kruijne Wouter, Meeter Martijn
Department of Experimental and Applied Psychology, Faculty of Behavioural and Movement Sciences, Vrije Universiteit, Amsterdam, The Netherlands.
PLoS One. 2017 Nov 22;12(11):e0187556. doi: 10.1371/journal.pone.0187556. eCollection 2017.
Our visual brain makes use of recent experience to interact with the visual world, and efficiently select relevant information. This is exemplified by speeded search when target- and distractor features repeat across trials versus when they switch, a phenomenon referred to as intertrial priming. Here, we present fAIM, a computational model that demonstrates how priming can be explained by a simple feature-weighting mechanism integrated into an established model of bottom-up vision. In fAIM, such modulations in feature gains are widespread and not just restricted to one or a few features. Consequentially, priming effects result from the overall tuning of visual features to the task at hand. Such tuning allows the model to reproduce priming for different types of stimuli, including for typical stimulus dimensions such as 'color' and for less obvious dimensions such as 'spikiness' of shapes. Moreover, the model explains some puzzling findings from the literature: it shows how priming can be found for target-distractor stimulus relations rather than for their absolute stimulus values per se, without an explicit representation of relations. Similarly, it simulates effects that have been taken to reflect a modulation of priming by an observers' goals-without any representation of goals in the model. We conclude that priming is best considered as a consequence of a general adaptation of the brain to visual input, and not as a peculiarity of visual search.
我们的视觉大脑利用近期经验与视觉世界进行交互,并有效地选择相关信息。当目标和干扰项特征在不同试验中重复出现与切换时,快速搜索就体现了这一点,这种现象被称为试验间启动。在此,我们提出了fAIM,这是一个计算模型,它展示了如何通过整合到一个既定的自下而上视觉模型中的简单特征加权机制来解释启动现象。在fAIM中,特征增益的这种调制是广泛存在的,而不仅仅局限于一个或几个特征。因此,启动效应源于视觉特征对当前任务的整体调整。这种调整使模型能够再现针对不同类型刺激的启动,包括针对典型刺激维度(如“颜色”)以及形状的“尖刺度”等不太明显维度的启动。此外,该模型解释了文献中的一些令人困惑的发现:它展示了如何在不明确表示关系的情况下,针对目标 - 干扰项刺激关系而非其绝对刺激值本身发现启动现象。同样,它模拟了被认为反映观察者目标对启动的调制的效应——而模型中没有任何目标表示。我们得出结论,启动最好被视为大脑对视觉输入的一般适应的结果,而不是视觉搜索的特性。