Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America.
Institute for Fiscal Studies, London, United Kingdom.
PLoS One. 2024 Jun 18;19(6):e0302852. doi: 10.1371/journal.pone.0302852. eCollection 2024.
In visual perception and information processing, a cascade of associations is hypothesized to flow from the structure of the visual stimulus to neural activity along the retinogeniculostriate visual system to behavior and action. Do visual perception and information processing adhere to this cascade near the beginning of life? To date, this three-stage hypothetical cascade has not been comprehensively tested in infants. In two related experiments, we attempted to expose this cascade in 6-month-old infants. Specifically, we presented infants with two levels of visual stimulus intensity, we measured electrical activity at the infant cortex, and we assessed infants' preferential looking behavior. Chromatic saturation provided a convenient stimulus dimension to test the cascade because greater saturation is known to excite increased activity in the primate visual system and is generally hypothesized to stimulate visual preference. Experiment 1 revealed that infants prefer (look longer) at the more saturated of two colors otherwise matched in hue and brightness. Experiment 2 showed increased aggregate neural cortical excitation in infants (and adults) to the more saturated of the same pair of colors. Thus, experiments 1 and 2 taken together confirm a cascade: Visual stimulation of relatively greater intensity evokes relatively greater levels of bioelectrical cortical activity which in turn is associated with relatively greater visual attention. As this cascade obtains near the beginning of life, it helps to account for early visual preferences and visual information processing.
在视觉感知和信息处理中，人们假设一连串的联想从视觉刺激的结构沿着视放射状系统流向神经活动，再到行为和动作。在生命早期，视觉感知和信息处理是否遵循这种级联？迄今为止，这种三阶段的假设级联尚未在婴儿中得到全面测试。在两项相关实验中，我们试图在 6 个月大的婴儿中揭示这种级联。具体来说，我们向婴儿呈现两种不同强度的视觉刺激，测量婴儿大脑皮层的电活动，并评估婴儿的偏好注视行为。色彩饱和度为测试级联提供了一个方便的刺激维度，因为较高的饱和度已知会激发灵长类动物视觉系统中增加的活动，并且通常被假设为刺激视觉偏好。实验 1 表明，与色调和亮度匹配的两种颜色中的另一种相比，婴儿更喜欢（看的时间更长）更饱和的颜色。实验 2 表明，对于同一对颜色中的较饱和颜色，婴儿（和成人）的总神经皮质兴奋增加。因此，实验 1 和实验 2 一起证实了一个级联：相对强度较大的视觉刺激会引起相对较大水平的生物电皮质活动，而这反过来又与相对较大的视觉注意力相关。由于这种级联在生命早期就存在，它有助于解释早期的视觉偏好和视觉信息处理。
