This is clipart converted and broken apart that has been released into the public domain because the document says so, and its from NASA, a USA government agency. The publication is called "The Brain in Space:" http://www.nasa.gov/audience/foreducators/topnav/materials/listbytype/The.Brain.in.Space.html 美國國家航空航天局 空間 科學 58294main_The.Brain.in.Space-page-75-asian-kid-head-twist
set of cyclic, cycle concentric rings. revolved spirals, vortexes, whorls. abstract circular, radial loop shapes, elements 螺旋 向量 旋流 Spirals, swirl, twirls set. concentric, radial graphics
set of cyclic, cycle concentric rings. revolved spirals, vortexes, whorls. abstract circular, radial loop shapes, elements 螺旋 向量 旋流 Spirals, swirl, twirls set. concentric, radial graphics
set of cyclic, cycle concentric rings. revolved spirals, vortexes, whorls. abstract circular, radial loop shapes, elements 螺旋 向量 旋流 Spirals, swirl, twirls set. concentric, radial graphics
set of cyclic, cycle concentric rings. revolved spirals, vortexes, whorls. abstract circular, radial loop shapes, elements 螺旋 向量 旋流 Spirals, swirl, twirls set. concentric, radial graphics
set of cyclic, cycle concentric rings. revolved spirals, vortexes, whorls. abstract circular, radial loop shapes, elements 螺旋 向量 旋流 Spirals, swirl, twirls set. concentric, radial graphics