Prior to Dr. Suzana Herculano-Houzel’s research, scientists assumed that the brains of all mammals were built in the same way and that the overall brain mass as compared to body mass was the critical determinant of cognitive ability. It was to resolve these conundrums about brain mass, body mass, and intelligence that Herculano-Houzel turned to chainsaws, butchers’ knives, and kitchen blenders to concoct what she refers to as brain soup. As STEM-Talk co-hosts Ken Ford and Dawn Kernagis point out during their interview with Herculano-Houzel, epsisode 39 of the podcast turned out to be not only an enlightening conversation, but also one of the most fun STEM-Talk interviews to date. Herculano-Houzel is a Brazilian neuroscientist who devised a way to count the number of neurons in human and animal brains. She writes about this in her book, The Human Advantage: A New Understanding of How Our Brain Became Remarkable. Her method of counting the neurons of human and other animals' brains allowed her to study the relation between the cerebral cortex and the thickness and number of cortical folds in the brain. She is currently an associate professor of psychology and biological sciences in Vanderbilt University’s psychological sciences department and the Vanderbilt Brain Institute. She grew up in Brazil and received her undergraduate degree in biology at Federal University of Rio de Janeiro. She went to Case Western Reserve University in Cleveland, Ohio, to get her masters in neuroscience, and completed her Ph.D. in visual neurophysiology at the Max Planck Institute for Brain Research in Frankfurt, Germany. After completing her doctorate, Herculano-Houzel returned to Rio and went to work for the Museum of Life where she designed children’s activities. In 2002 she returned to her alma mater and began researching how human brains compared to other animals. In 2004, she devised a way of reducing brains to liquid as a means to count the number of neurons in them. It is technically known as the “isotropic fractionator.” In 2004 she won the Jose Reis Prize of Science, and in 2010 she received the James S. McDonell Foundation’s  Scholar Award in Understanding Human Cognition.  She is also the author of a biweekly newspaper column on the neuroscience of everyday life for Folha de São Paulo, the major newspaper in Brazil. Going into its 11th year, the column has appeared more than 270 times since 2006.  In addition to “The Human Advantage,” Herculano-Houzel is also the author of six books in Portuguese that focus on the neuroscience of everyday life. She also has a popular blog called “The Neuroscientist on Call,” which she describes as not-so-random thoughts about brains, the universe and everything. She lives in Nashville, TN, with her husband, son and two dogs. Links you may be interested in: “The Human Advantage”: http://amzn.to/2rtvNOY The Neuroscientist on Call blog: http://www.suzanaherculanohouzel.com Show notes: 5:32: Suzana talks about growing up in Rio and how she became interested in science. 7:07: Ken asks Suzana about her work at Rio’s Museum of Life. 12:55: Dawn asks Suzana when she firsts became interested in neuroscience. 16:00: Dawn follows up with a question about the composition of cells in the brain. 29:21: Suzana talks about how the brain represents just 2% of the average human mass, yet requires 25%of person’s energy. 33:14: Dawn tells Suzana she’s curious about Suzana’s method of counting neurons and asks her to talk about how she came up with the idea of brain soup. 38:58: Break 39:24: Dawn reads a portion of a book review that described how Suzana turned to chainsaws, butcher knifes and blenders to concoct brain soup and asks her to elaborate. 42:03: Suzana talks about some of the difficulty she had in locating brains for her research. 53:07: Suzana shares some of the lessons she’s learned from analyzing the brains of more than 100 species.