Booth loves Bones.

So I was watching an episode of the Fox television show "Bones" a while back (I have yet to check out any of Kathy Reichs' books, she is the forensic anthropologist/author who is the inspiration for and producer of the show, but I do enjoy the show, and the overly rational, though exaggerated to the point of caricature, Temperance Brennan, a.k.a. "Bones").  Anyway, the other main character in the show is Booth (played by David Boreanaz), an ex-army sniper turned FBI agent who investigates murder cases with "Bones" and the rest of her forensics team.  Recently, Booth was diagnosed with a brain tumor and underwent surgery to have it removed, during the recovery, he was in a coma and dreamt that he was married to, and madly in love with, Bones.  Upon fully recovering, his amorous feelings followed him out of the dreamworld and into reality.  As evidence for the fact that Booth did, in fact, feel like he was in love with Bones, the FBI psychologist Dr. Sweets (played by John Francis Daley, who you may remember from the excellent, but short lived series Freaks and Geeks) shows Booth PET scans of his brain showing "activity" in the VTA, or Ventral Tegmental Area.  PET scans are somewhat similar to MRI scans, and if you follow the posts, I've described how fMRIs work in the past, but again, briefly, fMRIs measure bloodflow in the brain. When a particular area is being used, it needs more oxygen and glucose, thus, more blood.  But, here's the catch, everywhere in your brain needs oxygen and glucose, so a single MRI image wouldn't really tell you very much.  What you need to do is get a baseline, and then, while changing one thing (asking the person to think about something specific or to perform a specific task), you take another image.  When you subtract everything that is the same out of the two images, and look only at what is different, you get a functional MRI (fMRI), that is, an image showing exactly which areas of the brain seemed to be working harder while you were trying to do that specific task.  PET scans (or positron emission tomography) work in a similar fashion, except instead of measuring the iron (or oxygen) in the blood, PET scans work by measuring glucose (which has been tagged with a radioactive fluorine molecule to show up in the scan).  But the same principle holds if the PET scan is to be specific to a function, you have to have one image as a baseline, and another for the test condition.  In the case of Booth, I don't dispute that thinking about the one you love leads to increased bloodflow in the VTA and the caudate, There are several studies suggesting these 2 areas are involved in romantic love.  (One such study can be found here, or, for the popular press version, here.)  No, what I dispute is that a single PET scan image of Booth's brain would not likely show the VTA and caudate to be working overtime, unless Booth was specifically thinking about Bones while the scan was being done.  And even then, you would really only get an image like the one they showed if a baseline image had been taken.  A minor point I know, but when neuroscience comes up on a popular tv show, I can't help myself but to comment.  Actually, despite the minor error, I have to commend the producers and writers of Bones for introducing some pretty cool and pretty recent neuroscience info into the show.
And if you find it interesting too, here's a little more fodder for your brain: in many of these studies, for both the VTA and the caudate, it tends to be the right side of the brain that lights up, leading us to wonder what the VTA and the caudate in the left side of the brain are doing.  (And if you think that makes sense because the right side of the brain is supposedly the creative, artsy, and romantic side and the left brain is the rational side, you may have a point, or you may find a post about whether or not all that right brain/left brain stuff is really true sometime in the near future).  The really interesting conclusion of these studies however is that they suggest romantic love (as opposed to familial or brotherly love or platonic love, i.e. friendship) derives from motivational areas of the brain, not the ones involved in emotions like joy or sadness.  So, while relationships involve their fair share of joy and sadness, apparently falling in love is more like becoming addicted to cocaine...

By the way, if you're wondering why I didn't talk at all about Booth having visual hallucinations from a cerebellar tumor, it's because it is within the realm of possibility.  Though visual hallucinations are more commonly associated with tumors or lesions in the occipital lobe (in the back of the brain, where the visual cortex is located), they can occur in patients who have cerebellar tumors.  Though rare, cerebellar tumors can lead to visual hallucinations due to the fact that the cerebellum is also in the back of the brain, and a large growth can put pressure on the occipital lobe which is right next door.  Though, the more interesting thing is that Booth's hallucinations were actually visual and auditory, as he could hear and converse with his hallucinations, this is even more rare, as auditory processing occurs in the temporal lobe which is a little further forward in the brain, and auditory hallucinations are most commonly associated with tumors located there.  Just like the occipital lobe is heavily involved in visual processing, and the temporal is heavily involved in auditory (or hearing), the cerebellum is involved in motor movements, particularly those that require coordination (like running or playing sports).  As such, most cerebellar tumors are associated with "ataxia" which is the loss of coordinated movement in the limbs, often this is revealed by an unsteady gait or falling forward or to the side when walking, or by clumsiness when performing tasks that require coordinated movements of the hands or feet (see http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=cmed6.section.19621 for more symptoms of brain tumors).  It is odd that Booth wouldn't show any of these symptoms, and only have the much more rare hallucinations, but it is not impossible.  Everyone is different (and every tumor is different) this is what makes medicine (and finding a cure for cancer) so difficult, and while it is unlikely that a patient with a cerebellar astrocytoma would present with only the symptoms of having visual/auditory hallucinations, it can (and sometimes does) happen.