Data from: A robust and representative lower bound on object processing speed in humans

How early does the brain decode object categories? Addressing this question is critical to constrain the type of neuronal architecture supporting object categorization. In this context, much effort has been devoted to estimating face processing speed. With onsets estimated from 50 to 150 ms, the timing of the first face-sensitive responses in humans remains controversial. This controversy is due partially to the susceptibility of dynamic brain measurements to filtering distortions and analysis issues. Here, using distributions of single-trial event-related potentials (ERPs), causal filtering, statistical analyses at all electrodes and time points, and effective correction for multiple comparisons, we present evidence that the earliest categorical differences start around 90 ms following stimulus presentation. These results were obtained from a representative group of 120 participants, aged 18-81, who categorized images of faces and noise textures. The results were reliable across testing days, as determined by test-retest assessment in 74 of the participants. Furthermore, a control experiment showed similar ERP onsets for contrasts involving images of houses or white noise. Face onsets did not change with age, suggesting that face sensitivity occurs within 100 ms across the adult lifespan. Finally, the simplicity of the face-texture contrast, and the dominant midline distribution of the effects, suggest the face responses were evoked by relatively simple image properties and are not face specific. Our results provide a new lower benchmark for the earliest neuronal responses to complex objects in the human visual system.

大脑最早在何时对物体类别进行解码？解答这一问题，对于明确支撑物体分类的神经元架构类型至关重要。在此背景下，学界已投入大量精力估算面部加工速度。此前研究估计人类首次出现面部敏感响应的潜伏期在50至150毫秒之间，但该时间点仍存在争议。这一争议部分源于动态脑测量易受滤波失真与分析方法问题的影响。本研究采用单试次事件相关电位（event-related potentials, ERPs）分布、因果滤波、全电极与全时间点统计分析，以及多重比较有效校正方法，提供证据表明：最早的类别差异出现在刺激呈现后约90毫秒处。上述结果来自120名年龄在18至81岁之间的代表性受试群体，受试需对面部图像与噪声纹理图像进行分类任务。通过对其中74名受试进行重测评估，证实该结果在不同测试日中均具备可靠性。此外，一项对照实验显示，针对房屋图像与白噪声图像的对比任务，也得到了相似的ERP潜伏期结果。面部响应潜伏期未随年龄发生变化，表明在成年生命周期中，面部敏感性均出现在100毫秒以内。最后，面部-纹理对比范式的简洁性，以及效应显著的中线分布特征，表明面部响应由相对简单的图像属性诱发，并非面部特异性响应。本研究结果为人类视觉系统对复杂物体的最早神经元响应提供了新的下限基准。