What our brains do during normal conditions of love or lust must be like an enormous fireworks display - science cannot tell us what happens in the brain under proper normal circumstances - they've never seen it.
Its scientific gobbledegook really.
"Then there are the limitations of the functional magnetic resonance imaging (fMRI) technology that produces the pretty pictures. The scans don't directly tap into the brain, as one might imagine from the hype, they merely detect the increases in blood flow needed to deliver additional oxygen to busy neurons. But neuronal activity lasts milliseconds, Tallis points out, while detected changes in blood flow lag by at least two and as many as ten seconds. Furthermore, many millions of neurons have to be activated for this change in blood flow to be detected. So what we see in brain scans is what is happening in one particular area, some time after the activity has commenced.
Small groups of neurons whose activity elicits little change in blood flow, or a modest network of neurons linking large regions, or neurons acting more efficiently than others, may be of great importance but would be under-represented in the scan or not represented at all. In short, pretty well everything relevant to a given response at a given time might be invisible on an fMRI scan."From a review of the book :Aping Mankind: Neuromania, Darwinitis and the Misrepresentation of Humanity, by Raymond Tallis