Hollywood actress Natalie Portman I first remarked in the Mike Nichols 2004 film Closer. According to rumor on the Internet a few years before Closer she co-authored a functional neuroimaging scientific article called Frontal lobe activation during object permanence: data from near-infrared spectroscopy. She was attributed as Natalie Hershlag.
I have written before of data mining a co-author graph for the Erdös number and “Hayashi” number, and I wondered if it would be possible to find a co-author path from Portman to me. And indeed yes.
Abigail A. Baird first-authored Portman’s article, and the article Functional magnetic resonance imaging of facial affect recognition in children and adolescents has Abigail Baird and psychiatry professor Bruce M. Cohen among the authors. Bruce M. Cohen and Nicholas Lange is among the co-authors on Structural brain magnetic resonance imaging of limbic and thalamic volumes in pediatric bipolar disorder and Lange and I are linked through our Plurality and resemblance in fMRI data analysis, — an article that contrasted different fMRI analysis methods.
So the co-author path between Portman and me is: Portman – Baird – Cohen – Lange – me, which bring my “Portman number” to 4.
Navigating a graph is a general problem if you only know the local connections. There has even been written scientific articles about it, e.g., Jon Kleinberg‘s Navigating in a small world. When a human (such as I) navigate a social graph such as the co-author graph of scientific articles one can utilize auxillary information, here the information about where a researcher has worked, what his/her interest are and how prominent the researcher is (how many co-authors s/he has). As Portman worked from Harvard a good guess would be to start looking among my co-authors that are near Harvard. Nicholas Lange is from Harvard and we collaborated in the American funded Human Brain Project. I knew that radiology professor Bruce R. Rosen was/is a central figure in Boston MRI researcher, so I thought that there might be a productive connection from him, — both to Lange and to Portman. Portman’s co-author Baird is professor and has written some neuroimaging papers, so among Portman’s co-authors Baird was probably the one that could lead to a path. While searching among Lange and Baird co-authors I confused Bruce Rosen and Bruce Cohen (their Hamming distance is not great). This error proved fertile.
If I didn’t run into Cohen and really wanted to find a path between Portman and me then I think a more automated and brute force method could have been required. One way would be to query PubMed and put the co-author graph into NetworkX which is a Python package. It has a shortest path algorithm. Joe Celko in his book SQL for Smarties: Advanced SQL programming shows a shortest path algorithm in SQL. That might be an alternative to NetworkX.