Establishing consistent relationships between neural activity and behavior is a challenge in human cognitive neuroscience research. We addressed this issue using variable time constraints in an oddball frequency-sweep design for visual discrimination of complex images (face exemplars). Sixteen participants viewed sequences of ascending presentation durations, from 25 to 333 ms (40–3 Hz stimulation rate) while their electroencephalogram (EEG) was recorded. Throughout each sequence, the same unfamiliar face picture was repeated with variable size and luminance changes while different unfamiliar facial identities appeared every 1 s (1 Hz). A neural face individuation response, tagged at 1 Hz and its unique harmonics, emerged over the occipito-temporal cortex at 50 ms stimulus duration (25–100 ms across individuals), with an optimal response reached at 170 ms stimulus duration. In a subsequent experiment, identity changes appeared non-periodically within fixed-frequency sequences while the same participants performed an explicit face individuation task. The behavioral face individuation response also emerged at 50 ms presentation time, and behavioral accuracy correlated with individual participants’ neural response amplitude in a weighted middle stimulus duration range (50–125 ms). Moreover, the latency of the neural response peaking between 180 and 200 ms correlated strongly with individuals’ behavioral accuracy in this middle duration range, as measured independently. These observations point to the minimal (50 ms) and optimal (170 ms) stimulus durations for human face individuation and provide novel evidence that inter-individual differences in the magnitude and latency of early, high-level neural responses are predictive of behavioral differences in performance at this function.

在神经活动和行为之间建立一致的关系是人类认知神经科学研究的一个挑战。我们在一个奇怪的频率扫描设计中使用可变时间约束来解决这个问题，以对复杂图像（人脸样本）进行视觉区分。16 名参与者查看了从 25 到 333 毫秒（40–3 Hz 刺激率）的递增呈现持续时间序列，同时记录了他们的脑电图 (EEG)。在每个序列中，相同的陌生面部图片以可变的大小和亮度变化重复出现，而不同的陌生面部特征每 1 秒（1 Hz）出现一次。在 50 ms 刺激持续时间（个体间为 25-100 ms）时，在枕颞皮层上出现标记为 1 Hz 的神经面部个性化反应及其独特的谐波，在 170 ms 刺激持续时间达到最佳反应。在随后的实验中，身份变化在固定频率序列中非周期性出现，而相同的参与者执行了明确的面部个性化任务。行为面部个性化反应也在 50 ms 呈现时间出现，行为准确性与个体参与者在加权中间刺激持续时间范围（50-125 ms）的神经反应幅度相关。此外，独立测量的在 180 到 200 毫秒之间达到峰值的神经反应的延迟与个人在这个中间持续时间范围内的行为准确性密切相关。