生物谷报道：英国科学家2月27日日发布一项研究结果，表明他们已确定了一个大脑区域的位置，这个区域对于形成照料和抚养婴儿这种为人父母的本能至关重要。相关论文发表在《公共科学图书馆·综合》（PLoS ONE）上。
据路透社报道，牛津大学的研究人员说，这个发现有助于解释人们为何认为婴儿需要特殊照顾这一进化问题，并可以有助于医生更准确地诊断遭受产后抑郁症折磨的病人。
这项研究的负责人之一、神经系统科学家莫滕·克林格尔巴赫说：“这个发现很重要，因为我们为什么会照料自己的孩子，以确保我们这个物种延续下去，这一定是有原因的。这个观点可以追溯到达尔文那里。”
克林格尔巴赫和他的同事艾伦·斯坦证明了大脑中一个被称为内侧眶前脑皮层的区域在见到婴儿的面孔时会兴奋，而见到成人面孔则不会。
科学家相信这个区域紧挨着眼球上方，与辨认面孔的重要区域相连接，是大脑中控制情感的重要部位。研究人员利用成像扫描技术测量了志愿者的大脑活动情况。试验过程中，志愿者按照要求会在眼前的屏幕更换色彩时按动按钮。其间，陌生的婴儿和成人面孔会在屏幕上闪动。
研究人员说，在看到成人面孔时，大脑没有反应；但看到婴儿面孔时，一秒钟之内大脑活动水平就会提高。这是一种本能的信号，说明婴儿是特殊的。
研究中涉及的男性、女性和没有孩子的志愿者对婴儿的父性母性反应是相似的。这就证明了这种反应是与生俱来的。（新华网）
生物谷推荐原始出处：
（《公共科学图书馆·综合》（PLoS ONE），doi:10.1371/journal.pone.0001664，Morten L. Kringelbach, Alan Stein）
A Specific and Rapid Neural Signature for Parental Instinct
Morten L. Kringelbach1,2,8,9*, Annukka Lehtonen1, Sarah Squire1, Allison G. Harvey3, Michelle G. Craske4, Ian E. Holliday5, Alexander L. Green8, Tipu Z. Aziz2,8, Peter C. Hansen6, Piers L. Cornelissen7, Alan Stein1
1 Department of Psychiatry, University of Oxford, Oxford, United Kingdom, 2 Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom, 3 Department of Psychology, University of California, Berkeley, California, United States of America, 4 Department of Psychology, University of California Los Angeles, Los Angeles, California, United States of America, 5 The Wellcome Trust Laboratory for MEG Studies, School of Life and Health Sciences, Aston University, Birmingham, United Kingdom, 6 School of Psychology, University of Birmingham, Birmingham, United Kingdom, 7 Department of Psychology, York University, York, United Kingdom, 8 Department of Neurosurgery, John Radcliffe Hospital, Oxford, United Kingdom, 9 Center of Functionally Integrative Neuroscience (CFIN), Aarhus University, Aarhus, Denmark
Abstract
Darwin originally pointed out that there is something about infants which prompts adults to respond to and care for them, in order to increase individual fitness, i.e. reproductive success, via increased survivorship of one's own offspring. Lorenz proposed that it is the specific structure of the infant face that serves to elicit these parental responses, but the biological basis for this remains elusive. Here, we investigated whether adults show specific brain responses to unfamiliar infant faces compared to adult faces, where the infant and adult faces had been carefully matched across the two groups for emotional valence and arousal, as well as size and luminosity. The faces also matched closely in terms of attractiveness. Using magnetoencephalography (MEG) in adults, we found that highly specific brain activity occurred within a seventh of a second in response to unfamiliar infant faces but not to adult faces. This activity occurred in the medial orbitofrontal cortex (mOFC), an area implicated in reward behaviour, suggesting for the first time a neural basis for this vital evolutionary process. We found a peak in activity first in mOFC and then in the right fusiform face area (FFA). In mOFC the first significant peak (p<0.001) in differences in power between infant and adult faces was found at around 130 ms in the 10–15 Hz band. These early differences were not found in the FFA. In contrast, differences in power were found later, at around 165 ms, in a different band (20–25 Hz) in the right FFA, suggesting a feedback effect from mOFC. These findings provide evidence in humans of a potential brain basis for the “innate releasing mechanisms” described by Lorenz for affection and nurturing of young infants. This has potentially important clinical applications in relation to postnatal depression, and could provide opportunities for early identification of families at risk.
Figure 1. Significant differences between viewing infant and adult faces.
The group SAM analysis revealed a significant peak in the medial orbitofrontal cortex in the 10–30 Hz band in the 0–250 ms (first two columns), 100–350 ms (third column) and 200–450 ms (fourth column) windows when participants viewed infant (upper row) and not when they viewed adult faces (lower row). The fifth column shows the integrated z-map over the three time windows (with Z>3.1) with all active brain regions listed in Table 1. In order to see the extent of the spread of activity over the fusiform cortices elicited by faces, the group activity is superimposed on a ventral view of the human brain (with the cerebellum removed).
全文链接：http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0001664
