Mechanisms of spatial context learning through touch and vision

在日常场景中，搜索的目标并不是孤立出现的，而是嵌入到非目标或干扰项的配置中。如果目标相对于干扰物的位置是不变的，这种空间偶然性就会被学习并用来指导环境扫描(“语境线索”效应；(Chun&酱，1998；Geyer，Shih，&Müler，2010)。重要的是，这样的情境学习并不局限于视觉通道：我们最近使用了一种新的触觉搜索任务，表明重复的触觉语境有助于触觉搜索(AsSumpção，Shii，Zang，Müller，&Geyer，2015,2017)。然而，通过情境记忆引导搜索的研究几乎完全是在视觉和触觉的个体模式中进行的。因此，人们对空间语境学习中的跨通道可塑性知之甚少。本提案将使用行为和神经科学方法，除数学建模外，研究单峰搜索任务(仅由视觉或触觉搜索项目组成)和多模式搜索任务(由视觉和触觉搜索项目组成)中的背景学习。在这样做的时候，任何通常被称为跨模式可塑性的特定学习机制(表征)都应该被揭示出来。这三个主要的研究问题涉及(1)最终可能导致跨通道语境记忆的因素(例如，跨通道空间语境记忆的发展是否需要在多通道搜索任务上进行练习；(2)在单通道或多通道搜索任务中获得的语境记忆必须如何在ERP波形中表征(以及这些任务之间是否存在电生理成分的差异)；以及(3)如何使用随机贝叶斯模型来量化语境记忆对单通道和多通道搜索中反应时绩效的有利影响。

In everyday scenes, searched-for targets do not appear in isolation, but are embedded within configurations of non-target or distractor items. If the position of the target relative to the distractors is invariant, such spatial contingencies are learned and come to guide environmental scanning (“contextual cueing” effect; (Chun & Jiang, 1998; Geyer, Shi, & Müller, 2010). Importantly, such context learning is not limited to the visual modality: using a novel tactile search task, we recently showed that repeated tactile contexts aid tactile search (Assumpção, Shi, Zang, Müller, & Geyer, 2015, 2017). However, the guidance of search by context memory has almost entirely been investigated in the individual modalities of vision and touch. Thus, relatively little is known about crossmodal plasticity in spatial context learning. The present proposal will employ behavioural and neuroscience methods, in addition to mathematical modelling, to investigate context learning in unimodal search tasks (consisting of only visual or tactile search items), and multimodal search tasks (consisting of both visual and tactile search items). In doing so, any specific learning mechanisms (representations) commonly referred to as crossmodal plasticity should be revealed. The three leading research questions concern (1) the factors that may eventually give rise to crossmodal context memory (an example question is whether the development of crossmodal spatial context memory requires practice on a multimodal search task; (2) how context memory acquired in uni- or multimodal search tasks has to be characterized in ERP waveforms (and whether there are differences in electrophysiological components between these tasks); and (3), how the beneficial effects of context memory on reaction time performance in uni- and multimodal search can be quantified using stochastic Bayesian models.