Botvinik-Nezer Rotem, Geuter Stephan, Lindquist Martin A, Wager Tor D
Hebrew University of Jerusalem.
Dartmouth College.
bioRxiv. 2024 Oct 12:2024.10.10.617570. doi: 10.1101/2024.10.10.617570.
Bayesian accounts of perception, such as predictive processing, suggest that perceptions integrate expectations and sensory experience, and thus assimilate to expected values. Furthermore, more precise expectations should have stronger influences on perception. We tested these hypotheses in a paradigm that manipulates both the mean value and the precision of cues within-person. Forty-five participants observed cues-presented as ratings from 10 previous participants-with varying cue means, variances (precision), and skewness across trials. Participants reported expectations regarding the painfulness of thermal stimuli or the visual contrast of flickering checkerboards. Subsequently, similar cues were each followed by a visual or noxious thermal stimulus. While perceptions assimilated to expected values in both modalities, cues' precision mainly affected visual ratings. Furthermore, behavioral and computational models revealed that expectations were biased towards extreme values in both modalities, and towards low-pain cues specifically. fMRI analysis revealed that the cues affected systems related to higher-level affective and cognitive processes-including assimilation to the cue mean in a neuromarker of endogenous contributions to pain and in the nucleus accumbens, and activity consistent with aversive prediction-error-like encoding in the periaqueductal gray during pain perception-but not systems related to early perceptual processing. Our findings suggest that predictive processing theories should be combined with mechanisms such as selective attention to better fit empirical findings, and that expectation generation and its perceptual effects are mostly modality-specific and operate on higher-level processes rather than early perception.
贝叶斯感知理论，如预测加工理论，认为感知整合了期望和感官体验，因此会趋向于期望值。此外，更精确的期望对感知应该有更强的影响。我们在一个范式中对这些假设进行了测试，该范式在个体内部操纵线索的均值和精度。45名参与者观察了线索——呈现为之前10名参与者的评分——在不同试验中具有不同的线索均值、方差（精度）和偏度。参与者报告了对热刺激疼痛程度或闪烁棋盘视觉对比度的期望。随后，类似的线索之后分别跟随着视觉或有害热刺激。虽然在两种模态中感知都趋向于期望值，但线索的精度主要影响视觉评分。此外，行为和计算模型表明，期望在两种模态中都偏向于极端值，尤其偏向于低疼痛线索。功能磁共振成像分析表明，线索影响与高级情感和认知过程相关的系统——包括在内源性疼痛贡献的神经标记物和伏隔核中趋向于线索均值，以及在疼痛感知过程中导水管周围灰质中与厌恶预测误差样编码一致的活动——但不影响与早期感知加工相关的系统。我们的研究结果表明，预测加工理论应与选择性注意等机制相结合，以更好地符合实证研究结果，并且期望的产生及其感知效应大多是模态特异性的，作用于高级过程而非早期感知。
