Department of Cognitive Neuroscience, Universität Bielefeld, Bielefeld, Germany.
Department of Neurophysiology & Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
PLoS One. 2023 Aug 22;18(8):e0290461. doi: 10.1371/journal.pone.0290461. eCollection 2023.
Multisensory integration and recalibration are two processes by which perception deals with discrepant signals. Both are often studied in the spatial ventriloquism paradigm. There, integration is probed by the presentation of discrepant audio-visual stimuli, while recalibration manifests as an aftereffect in subsequent judgements of unisensory sounds. Both biases are typically quantified against the degree of audio-visual discrepancy, reflecting the possibility that both may arise from common underlying multisensory principles. We tested a specific prediction of this: that both processes should also scale similarly with the history of multisensory discrepancies, i.e. the sequence of discrepancies in several preceding audio-visual trials. Analyzing data from ten experiments with randomly varying spatial discrepancies we confirmed the expected dependency of each bias on the immediately presented discrepancy. And in line with the aftereffect being a cumulative process, this scaled with the discrepancies presented in at least three preceding audio-visual trials. However, the ventriloquism bias did not depend on this three-trial history of multisensory discrepancies and also did not depend on the aftereffect biases in previous trials - making these two multisensory processes experimentally dissociable. These findings support the notion that the ventriloquism bias and the aftereffect reflect distinct functions, with integration maintaining a stable percept by reducing immediate sensory discrepancies and recalibration maintaining an accurate percept by accounting for consistent discrepancies.
多感觉整合和再校准是感知处理不一致信号的两种过程。这两种过程通常在空间错觉范式中进行研究。在该范式中，通过呈现不一致的视听刺激来探测整合，而在后续的单感觉声音判断中，再校准表现为一种后效。这两种偏差通常都根据视听差异的程度进行量化，反映了这两种偏差可能都源于共同的基本多感觉原则。我们检验了这个假设的一个具体预测：这两种过程也应该与多感觉差异的历史相似地进行缩放，即几个先前的视听试验中的差异序列。通过分析来自十个具有随机变化空间差异的实验的数据，我们确认了每个偏差都依赖于当前呈现的偏差的预期依赖性。并且，与后效是一个累积过程一致，这种依赖性与至少三个先前的视听试验中呈现的差异相匹配。然而，错觉偏差并不依赖于多感觉差异的三试验历史，也不依赖于先前试验中的后效偏差——这使得这两种多感觉过程在实验上可以分离。这些发现支持了这样的观点，即错觉偏差和后效反映了不同的功能，整合通过减少即时感觉差异来维持稳定的感知，而再校准通过考虑一致的差异来维持准确的感知。
