Visual categorization shapes feature selectivity in the primate temporal cortex.

The way that we perceive and interact with objects depends on our previous experience with them. For example, a bird expert is more likely to recognize a bird as a sparrow, a sandpiper or a cockatiel than a non-expert. Neurons in the inferior temporal cortex have been shown to be important in the representation of visual objects; however, it is unknown which object features are represented and how these representations are affected by categorization training. Here we show that feature selectivity in the macaque inferior temporal cortex is shaped by categorization of objects on the basis of their visual features. Specifically, we recorded from single neurons while monkeys performed a categorization task with two sets of parametric stimuli. Each stimulus set consisted of four varying features, but only two of the four were important for the categorization task (diagnostic features). We found enhanced neuronal representation of the diagnostic features relative to the non-diagnostic ones. These findings demonstrate that stimulus features important for categorization are instantiated in the activity of single units (neurons) in the primate inferior temporal cortex.     

什么时间该去机场？

如果你从来没有误过飞机,那么你很有可能在机场浪费了太多时间。这听上去有违直觉——为什么有人甘愿冒险错过航班？——但自有逻辑在里面。这个说法最先由诺贝尔奖得主、经济学家乔治·斯蒂格勒（George Stigler）提出,现在,数学教授乔丹·埃伦伯格（Jordan Ellenberg）在他的新书《怎么不出错：数学思考的力量》（How Not to Be Wrong：The Power of Mathematical Thinking）一书中对此作了阐述。埃伦伯格指出,什么时候到机场这个问题归根结底是＂效用＂的问题,在经济学里常用这个概念来衡量某人做某事的收益和成本,效益可正可负。     

Social evolution: kin preference in a social microbe

Kin recognition helps cooperation to evolve in many animals, but it is uncertain whether microorganisms can also use it to focus altruistic behaviour on relatives. Here we show that the social amoeba Dictyostelium purpureum prefers to form groups with its own kin in situations where some individuals die to assist others. By directing altruism towards kin, D. purpureum should generally avoid the costs of chimaerism experienced by the related D. discoideum.     

Lymphatic vascular defects promoted by Prox1 haploinsufficiency cause adult-onset obesity

Multiple organs cooperate to regulate appetite, metabolism, and glucose and fatty acid homeostasis. Here, we identified and characterized lymphatic vasculature dysfunction as a cause of adult-onset obesity. We found that functional inactivation of a single allele of the homeobox gene Prox1 led to adult-onset obesity due to abnormal lymph leakage from mispatterned and ruptured lymphatic vessels. Prox1 heterozygous mice are a new model for adult-onset obesity and lymphatic vascular disease.