Afraz Arash, Boyden Edward S, DiCarlo James J
Departments of Brain and Cognitive Sciences and McGovern Institute for Brain Research, and
Departments of Brain and Cognitive Sciences and McGovern Institute for Brain Research, and Biological Engineering, MIT Media Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139.
Proc Natl Acad Sci U S A. 2015 May 26;112(21):6730-5. doi: 10.1073/pnas.1423328112. Epub 2015 May 7.
Neurons that respond more to images of faces over nonface objects were identified in the inferior temporal (IT) cortex of primates three decades ago. Although it is hypothesized that perceptual discrimination between faces depends on the neural activity of IT subregions enriched with "face neurons," such a causal link has not been directly established. Here, using optogenetic and pharmacological methods, we reversibly suppressed the neural activity in small subregions of IT cortex of macaque monkeys performing a facial gender-discrimination task. Each type of intervention independently demonstrated that suppression of IT subregions enriched in face neurons induced a contralateral deficit in face gender-discrimination behavior. The same neural suppression of other IT subregions produced no detectable change in behavior. These results establish a causal link between the neural activity in IT face neuron subregions and face gender-discrimination behavior. Also, the demonstration that brief neural suppression of specific spatial subregions of IT induces behavioral effects opens the door for applying the technical advantages of optogenetics to a systematic attack on the causal relationship between IT cortex and high-level visual perception.
三十年前，在灵长类动物的颞下（IT）皮质中发现了对人脸图像的反应比对非人脸物体的反应更强烈的神经元。尽管有假设认为，面部之间的感知辨别取决于富含“面部神经元”的IT子区域的神经活动，但这种因果联系尚未直接确立。在这里，我们使用光遗传学和药理学方法，可逆地抑制了执行面部性别辨别任务的猕猴IT皮质小亚区域的神经活动。每种干预类型都独立表明，富含面部神经元的IT亚区域的抑制会导致面部性别辨别行为的对侧缺陷。对其他IT亚区域进行相同的神经抑制，行为上未产生可检测到的变化。这些结果确立了IT面部神经元亚区域的神经活动与面部性别辨别行为之间的因果联系。此外，对IT特定空间亚区域的短暂神经抑制会诱发行为效应的证明，为将光遗传学的技术优势应用于系统研究IT皮质与高级视觉感知之间的因果关系打开了大门。
