Our senses often receive conflicting multisensory information, which our brain reconciles by adaptive recalibration. A classic example is the ventriloquism aftereffect, which emerges following both cumulative (long-term) and trial-wise exposure to spatially discrepant multisensory stimuli. Despite the importance of such adaptive mechanisms for interacting with environments that change over multiple timescales, it remains debated whether the ventriloquism aftereffects observed following trial-wise and cumulative exposure arise from the same neurophysiological substrate. We address this question by probing electroencephalography recordings from healthy humans (both sexes) for processes predictive of the aftereffect biases following the exposure to spatially offset audiovisual stimuli. Our results support the hypothesis that discrepant multisensory evidence shapes aftereffects on distinct timescales via common neurophysiological processes reflecting sensory inference and memory in parietal-occipital regions, while the cumulative exposure to consistent discrepancies additionally recruits prefrontal processes. During the subsequent unisensory trial, both trial-wise and cumulative exposure bias the encoding of the acoustic information, but do so distinctly. Our results posit a central role of parietal regions in shaping multisensory spatial recalibration, suggest that frontal regions consolidate the behavioral bias for persistent multisensory discrepancies, but also show that the trial-wise and cumulative exposure bias sound position encoding via distinct neurophysiological processes.

SIGNIFICANCE STATEMENT Our brain easily reconciles conflicting multisensory information, such as seeing an actress on screen while hearing her voice over headphones. These adaptive mechanisms exert a persistent influence on the perception of subsequent unisensory stimuli, known as the ventriloquism aftereffect. While this aftereffect emerges following trial-wise or cumulative exposure to multisensory discrepancies, it remained unclear whether both arise from a common neural substrate. We here rephrase this hypothesis using human electroencephalography recordings. Our data suggest that parietal regions involved in multisensory and spatial memory mediate the aftereffect following both trial-wise and cumulative adaptation, but also show that additional and distinct processes are involved in consolidating and implementing the aftereffect following prolonged exposure.

我们的感官通常会收到相互矛盾的多感觉信息，我们的大脑会通过自适应重新校准来调和这些信息。一个典型的例子是腹语后效，它是在累积（长期）和试验性地暴露于空间差异的多感觉刺激后出现的。尽管这种适应性机制与在多个时间范围内变化的环境进行交互的重要性，但仍存在争议，即在试验性和累积性暴露后观察到的腹语后效是否源于同一神经生理学底物。我们通过探测健康人（男女）的脑电图记录来解决这一问题，以预测暴露于空间偏移视听刺激后的后遗症偏向。我们的研究结果支持这样的假说，即不同的多感觉证据通过共同的神经生理过程在顶枕区域反映感觉推断和记忆，而在不同的时间尺度上形成后效应，而对一致差异的累积暴露又招募了额叶前过程。在随后的单感试验中，无论是试验方式还是累积暴露方式，都会对声音信息的编码产生偏见，但这样做显然不同。我们的研究结果提示壁区域在塑造多感觉空间重新校准中起着核心作用，表明额叶区域巩固了持续存在的多感觉差异的行为偏见，但同时也表明，通过不同的神经生理过程，试验性和累积性暴露偏向声音位置编码。

重要性声明我们的大脑可以轻松调和相互矛盾的多种感觉信息，例如在屏幕上看到一位女演员，同时戴着耳机听到她的声音。这些适应性机制对随后的单感觉刺激的感知产生持续影响，这被称为腹语后效。尽管这种后效是在多次接触或感觉差异后的试验性或累积性暴露后出现的，但尚不清楚两者是否均来自共同的神经基质。我们在这里使用人类脑电图记录来重新解释这个假设。我们的数据表明参与多感官和空间记忆的壁区域介导了试验和累积适应后的后效应，但也表明在长时间暴露后巩固和实施后效应中涉及额外的不同过程。