IRCCS Fondazione Stella Maris, Calambrone, Pisa, Italy, 56128.
Department of Psychology, Vita-Salute San Raffaele University, Milan, Italy, 20132.
J Neurosci. 2023 May 24;43(21):3825-3837. doi: 10.1523/JNEUROSCI.0837-22.2023. Epub 2023 Apr 10.
Behavioral studies suggest that motion perception is rudimentary at birth and matures steadily over the first few years. We demonstrated previously that the major cortical associative areas serving motion processing, like middle temporal complex (MT+), visual cortex area 6 (V6), and PIVC in adults, show selective responses to coherent flow in 8-week-old infants. Here, we study the BOLD response to the same motion stimuli in 5-week-old infants (four females and four males) and compare the maturation between these two ages. The results show that MT+ and PIVC areas show a similar motion response at 5 and 8 weeks, whereas response in the V6 shows a reduced BOLD response to motion at 5 weeks, and cuneus associative areas are not identifiable at this young age. In infants and in adults, primary visual cortex (V1) does not show a selectivity for coherent motion but shows very fast development between 5 and 8 weeks of age in response to the appearance of motion stimuli. Resting-state correlations demonstrate adult-like functional connectivity between the motion-selective associative areas but not between primary cortex and temporo-occipital and posterior-insular cortices. The results are consistent with a differential developmental trajectory of motion area respect to other occipital regions, probably reflecting also a different development trajectory of the central and peripheral visual field. How the cortical visual areas attain the specialization that we observed in human adults in the first few months of life is unknown. However, this knowledge is crucial to understanding the consequence of perinatal brain damage and its outcome. Here, we show that motion selective areas are already functioning well in 5-week-old infants with greater responses for detecting coherent motion over random motion, suggesting that very little experience is needed to attain motion selectivity.
行为研究表明，运动感知能力在出生时基本存在，并在最初几年内稳步发展。我们之前已经证明，成年人中用于运动处理的主要皮质联合区域，如颞中复合体（MT+）、视觉皮层区 6（V6）和 PIVC，对 8 周大婴儿的连贯流具有选择性反应。在这里，我们研究了在 5 周大婴儿（4 名女性和 4 名男性）中对相同运动刺激的 BOLD 反应，并比较了这两个年龄段之间的成熟度。结果表明，MT+和 PIVC 区域在 5 周和 8 周时表现出相似的运动反应，而 V6 中的反应在 5 周时对运动的 BOLD 反应减少，并且在这个年轻的年龄，楔前联合区域无法识别。在婴儿和成人中，初级视觉皮层（V1）对连贯运动没有选择性，但在 5 至 8 周之间对运动刺激的出现表现出非常快速的发展。静息状态相关性表明，运动选择性联合区域之间具有成人样的功能连接性，但初级皮层与颞枕和后岛叶皮层之间没有功能连接性。结果与运动区域相对于其他枕叶区域的不同发展轨迹一致，这可能也反映了中央和外周视野的不同发展轨迹。皮质视觉区域如何获得我们在生命的头几个月中在人类成年人中观察到的专业化尚不清楚。然而，这一知识对于理解围产期脑损伤及其后果至关重要。在这里，我们表明，运动选择性区域在 5 周大的婴儿中已经很好地发挥作用，对检测连贯运动的反应更大，这表明只需要很少的经验就能获得运动选择性。
