Manhunter #21: A Medical Review
Manhunter #21 “Psychobabble, part 2: Mind over Morals”
Marc Andreyko, writer
Javier Pina, penciler
For what must only be the second time since starting this blog, I’m actually reviewing a comic the same week it came out…
The comic in question is Manhunter #21, the second issue of the “One Year Later” storyline. In this book, Kate Spencer finds herself defending the villainous Dr. Psycho in court, much to her disgust. The question before the court is whether or not Dr. Psycho used his mental powers to cause innocent bystanders to become homicidal maniacs. In one particular scene, Dr. Mid-Nite is on the stand.
Dr. Mid-Nite: If you do a side by side comparison of the MRIs, you can see the difference in electrical charges of a normal brain versus the brains of those from the Metropolis event.
Notice that the patterns of synaptic firing in the victims, all twenty-three of them, are exactly the same in the hours following. This is a statistical impossibility — unless one mind is overriding the inherent individuality and causing a “hive mind” effect.
Dr. Mid-Nite is wrong. While Magnetic Resonance Imaging (MRI) is excellent at showing the anatomy of the brain, ittells us absolutely nothing about the activity going on within the brain. A brain MRI of a living person and a recently deceased individual would be identical (unless, of course, the person died from severe head trauma).
If you want to look at the activity going on within the brain, a PET scan (positron emission technology) is your best bet. In this procedure, a faintly radioactive isotope in injected into the patient and tracked by a special machine. Areas of higher blood flow light up more than areas of lower blood flow. It is assumed that these areas of high blood flow are the parts of the brain where the most activity is occurring. In recent years PET scans have been used to determine which areas of the brain are used during certain activities or used to express emotions (studying, sleeping, love, hate, etc.). PET scans have also been used to study the brains of the mentally ill to look for differences from “normal” brains. (The Wikipedia article on PET scans is a little dry, but full of good information).
I also think Dr. Mid-Nite is wrong when he refers to a “statistical impossibility.” I’ll agree that it is extremely unlikely for the brain scans of 23 people to be identical, but I doubt that it is categorically impossible — just like DNA evidence is always stated as an odds ratio (6 million to 1, for instance), and never a 100% certainty.
UPDATE: Several commenters have mentioned Functional MRI (fMRI), and they’re right. It works much the same as a PET scan, measuring blood flow in the brain, so it would give some information about brain activity. It doesn’t do as much as Dr. Mid-Nite claims but it’s closer than a regular MRI.
April 21st, 2006 at 7:10 am
Aww, give him a break – he said “statistical impossibility” – which I take to mean “the odds against it are so great as to be meaningless for legal purposes”. He’s trying to make the assessment comprehensible to a judge or jury.
April 21st, 2006 at 8:43 am
Couldn’t he have been talking about a functional MRI? I’ve never worked with the imaging techniques, but my recollections from my intro Neuro class are that fMRI has higher resolution (around a couple mm) than PET. It does measure brain activity, in the form of blood flow to regions of the brain–which, although a poor temporal measurement, is the same thing that PET is ultimately measuring, isn’t it?
April 21st, 2006 at 10:38 am
There’s always fMRI (functional MRI, which is a really bad name. “Do you want a functional MRI?” No, I want one that doesn’t work.)
But anyway, an fMRI does something similar to a PET scan ie indicate relative metabolic activity in different regions. PET shows the accumulation of a radioisotope labeled sugar analog, fMRI tracks the volume of blood flow to different areas. Of course neither shows electrical activity aka ‘brainwaves’.
- PET and fMRI -> high spatial resolution, low temporal rez.
vs
- EEG or BEAM (electrical or magnetic detection of aggregate neural firing resp.) -> high resolution of events in time, but lower spatial resolution.
I assume EEGs and PET scans are much less exspensive than BEAM or an MRI.
April 21st, 2006 at 11:00 am
Also when were these scans, whatever they were, conducted? Surely these people didn’t all happen to be wondering around with portable EEG monitors at the time, so we’re looking at common aftereffects of psychic domination, presumably hours later.
Why is she defending Psycho anyway, I thought she was a prosecutor.
Oh and, ’synaptic firing’? Synaptic transmission is a purely chemical signal between cells, the electrical signals detected by an EEG are cumulative results from waves of ionic depolarization along the cell membranes of individual nerve cells.
April 21st, 2006 at 11:45 am
Official Comment
fMRI looks like it would work about the same as a PET scan, so I stand corrected there. I can’t speak for the cost of an fMRI, but I know a PET scan is pretty damn expensive.
I thought about EEG, but the images shown are definitely MRI images (and not fMRI images)
April 21st, 2006 at 1:59 pm
Official Comment
Seth,
You’re right, but that’s just the sort of thing I’d expect a defense attorney to jump all over, pointning out that “impossible” and” ridiculously improbable” are not quite the same thing — that whole “reasonable doubt” idea. On the other hand, as this issue shows Kate has other (and better) tricks up her sleeve.
April 21st, 2006 at 5:10 pm
Ah, you know, it strikes me that since this is an instance of using real-life medical science (or a comic book approximation thereof) to diagnose a made-up condition, for the purposes of the story it would have made no difference if Dr. Mid-Night had said that there was pixie dust involved and left it at that.
April 21st, 2006 at 9:02 pm
But if the defense attorney quibbles along those lines, it’s a set-up for Dr. Mid-Nite to then reply something like “The odds against it are [huge number]. If you think that’s a resonable doubt, I have some lottery tickets to sell you”. I suspect the smart move there by the defense attorney would be to let it pass, rather than give Dr. Mid-Nite another chance to re-emphasize the point.
April 21st, 2006 at 9:53 pm
M-She was a prosecutor, but the OYL solicit specifies that she’s switching sides. Which means, I guess (and did so earlier) that she’s a defense attorney now.
Which, I guess, means that she gets them off for the crime and then kills them.
April 28th, 2006 at 4:14 pm
I hate to be nitpicky, but as a PET technologist, I really don’t think I can navigate away from this page without saying something. I apologize for renoting an old entry.
PET brain scans do not show perfusion specifically. They show metabolism. The 18F is part of FlouroDeoxyGlucose (FDG). Wherever the glucose is being taken up, that’s the part of the brain that “lights up”.
Small, completely harmless mistake, but in my profession, there are so many misunderstandings that I try to correct them when I see them.
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