When Is A Photo Not A Photo?

You might be forgiven for thinking that the image to the right is a photograph.  Strictly speaking it is, in the sense that it is the replication of visual data by digital photographic means.  That is why the credit that goes with it often calls it a photograph.  But there is potential for confusion here.  The image is in fact of an fMRI scan – functional magnetic resonance imaging.  It shows digitally a vertical section of the brain with certain structural details but the coloured areas have been created from coded data and show, I understand, greater or lesser brain activity compared to a notional baseline.  Clearly, no brain is this colour in reality - and only a post-mortem dissection could reveal such a section anyway.  What the image shows is a set of data in visual form to make it more easily comprehensible. It could be reproduced in tables or as a graph but then who would look? 

The boundary between a true photograph and digital images of other kinds is becoming more and more blurred. I thought of this again when the recent image of a black hole produced by Event Horizon Telescope was shown in the press recently (below).  Obviously, this is not a photograph of a black hole, since a black hole is invisible.  It is pretty amazing, though. The magazine New Scientist describes it as “a tinted representation of colourless radio frequency photons”.  A 21st century hand-tint!  Apparently it is culled from five petabytes of data (one petabyte is a million gigabytes.)  The technology of reducing that to one image is mind-spinning. 

The whole field of infographics (data in visual forms) seems to be a growth area: I’ve seen several courses advertised to help you use data visualisation in various ways: as visual storytelling, as hand-drawing and as infographics. The reliability of the results presumably depends on the methodology of turning the data into an image, though. That is where doubt creeps in. If you were unfortunate enough to find yourself in court and charged with an offence which you denied – how happy would you be for an fMRI scan of your brain to be used by the prosecution as evidence that you were lying? No, me neither - but how would you challenge it?

Ooops, I seem to be back on my digital hobbyhorse here…..  I’m just saying though: great pictures, but they are just as much imagination as science.