Department of Psychology, Durham University, Durham, UK.
Behav Res Methods. 2024 Apr;56(4):2842-2858. doi: 10.3758/s13428-023-02227-w. Epub 2023 Sep 20.
Studying how sensory signals from different sources (sensory cues) are integrated within or across multiple senses allows us to better understand the perceptual computations that lie at the foundation of adaptive behaviour. As such, determining the presence of precision gains - the classic hallmark of cue combination - is important for characterising perceptual systems, their development and functioning in clinical conditions. However, empirically measuring precision gains to distinguish cue combination from alternative perceptual strategies requires careful methodological considerations. Here, we note that the majority of existing studies that tested for cue combination either omitted this important contrast, or used an analysis approach that, unknowingly, strongly inflated false positives. Using simulations, we demonstrate that this approach enhances the chances of finding significant cue combination effects in up to 100% of cases, even when cues are not combined. We establish how this error arises when the wrong cue comparator is chosen and recommend an alternative analysis that is easy to implement but has only been adopted by relatively few studies. By comparing combined-cue perceptual precision with the best single-cue precision, determined for each observer individually rather than at the group level, researchers can enhance the credibility of their reported effects. We also note that testing for deviations from optimal predictions alone is not sufficient to ascertain whether cues are combined. Taken together, to correctly test for perceptual precision gains, we advocate for a careful comparator selection and task design to ensure that cue combination is tested with maximum power, while reducing the inflation of false positives.
研究来自不同来源（感官线索）的感觉信号如何在多个感觉内或跨多个感觉进行整合，使我们能够更好地理解作为适应性行为基础的感知计算。因此，确定是否存在精度增益——线索组合的经典标志——对于描述感知系统及其在临床条件下的发展和功能非常重要。然而，为了区分线索组合和替代感知策略，需要通过经验测量精度增益来进行，这需要仔细考虑方法学。在这里，我们注意到，大多数测试线索组合的现有研究要么省略了这一重要对比，要么使用了一种分析方法，无意识地导致了大量的假阳性。通过模拟，我们证明即使线索没有组合，这种方法也能在高达 100%的情况下增加发现显著线索组合效应的机会。我们确定了当选择错误的线索比较器时，这种错误是如何产生的，并推荐了一种替代分析方法，这种方法易于实施，但相对较少的研究采用了这种方法。通过将组合线索的感知精度与为每个观察者单独确定的最佳单线索精度进行比较，而不是在群体水平上进行比较，研究人员可以提高其报告效应的可信度。我们还注意到，仅测试偏离最佳预测的情况不足以确定线索是否组合。总之，为了正确测试感知精度增益，我们提倡仔细选择比较器和任务设计，以确保以最大的能力测试线索组合，同时减少假阳性的膨胀。
