I have some news that might be a bit disappointing to…well, pretty much anyone who would find themselves on a blog dedicated to the mind and brain.  Bear with me (or not, if you’d like, really), but this is a post primarily about the heart.

I was recently introduced via a grad student in the (yes, neuroscience) lab I work in to the latest advancement in the race to perfect an artificial heart. That link is to an NPR article that really tells you everything you need to know…and you should absolutely read it.  But to summarize the details you need to know for my purposes here, the design is completely novel, and unlike previous designs, it doesn’t use nature as its inspiration.

All previous artificial hearts have attempted to mimic the beating of a natural heart, but the moving parts can wear down or cause problems such as blood clots.  Instead, this implant has only two moving rotors, spinning to move the blood continuously rather than in pulses.  Let that sink in for a second.  Yes, transplant recipients have no heartbeat.  And the first recipient lived for over a month in this state before dying of underlying problems, the “heart” still working perfectly.

So here, finally, is what all of this has to do with the brain.  The main message I took home from the NPR article and subsequent discussion (aside from, as the aforementioned grad student pointed out, the fact that one with such an implant should never accidentally fall asleep in public) is that while our instinct has previously been to imitate nature, that might not always be the most efficient logistical solution. Dr. Billy Cohn, one of the creators of the device, put it very well when he pointed out that many of the earliest attempts at flying machines had flapping wings before we realized that what works for birds and insects isn’t necessarily the best answer for us.

I decided to pass this information on to my mom, a cardiac catheterization lab RN, and someone as in love with the heart as I am with the brain.  Her eyes lit up when she realized that systole and diastole, that is, the heart’s pulsations serve no purpose aside from the maintenance of the heart itself, and the flow of blood—there’s no reason it can’t be continuous and steady if the heart itself is artificial.  “You might start seeing these soon,” I told her, “they’re the future of your field.”  “So what about you?” she replied, “How far off are artificial brains?”  I rolled my eyes at her joke.  Then it slowly occurred to me that, while still absurd for discussions of transplant purposes, just because something doesn’t function in the same way as its natural counterpart, doesn’t mean it isn’t the same thing.

So aren’t we already pretty close?

Lady Macbeth

For those of you who’ve forgotten or perhaps even repressed your memories of high school English class, the line in the title is the cry of the power-hungry and all-around homicidal maniac Lady Macbeth, the female lead in Shakespeare’s great tragedy, Macbeth. After having committed regicide so that her husband may become king, she becomes convinced that she cannot wash King Duncan’s blood from her hands.  Thoughts are soliloquized, guilt is manifested in madness, and archetypes are born.

Curtain.

If you are not a humanities major, you may ask yourself why you should care about Shakespeare, and even if you are, you might be asking yourself what place this topic has in a blog dedicated to mind and brain sciences…aside from the obvious madness thing.

To answer the first question exclusively, Shakespeare is awesome. So there’s that.  To more appropriately answer the first question and the second question as well, I submit that you might have more in common with Lady M than you think.

A paper titled “Washing Away Your Sins: Threatened Morality and Physical Cleansing” published in 2006 in the journal Science examined the connection between physical cleanliness and morality in presumably non-homicidal normal subjects.  Researchers found a strong link between feelings of guilt and various physical cleansing desires/behaviors and it has a name–The Lady Macbeth Effect.

Subjects in the study performed tasks such as recalling memories from their pasts in which they performed either a good or a bad deed.  They were subsequently told to fill in the missing letters in a list of incomplete words including “W_ _H,” “SH_ _ER” and   “S_ _P.”  Those who had been primed for guilt were 60% more likely to complete the list as “WASH,” “SHOWER,” and “SOAP” rather than more neutral possibilities such as “WISH” “SHAKER” and “SLIP.”

The researchers then decided to take the experiment a step further and examine any perceived efficacy of such behaviors.  The researchers again asked the participants to recall stories of past immoral or selfish behavior, and were offered various small, inexpensive items as a reward.  Unsurprisingly, amongst those offered the choice between a hand wipe and a pencil, the participants who recalled an unethical deed were more likely to choose hand wipes.

After presumably using the wipes to wash the metaphorical blood from their hands, these subjects were asked to perform a selfless deed such as donating money, the type of behavior established as increasing with feelings of guilt.  While the subjects who had not been offered cleanliness products volunteered  74% of the time, only 41% of those with clean hands, and thereby apparently clean consciences, donated.

These results, from an anthropological viewpoint, are not that surprising.  Many cultures make some association between evil and uncleanliness, and many religions advocate some form of ritual purification for both the body and the soul.  While it is somewhat counterintuitive that such complex, useful human capacities as guilt and remorse can be allayed by such trivial things, and disturbing that feelings of physical cleanliness can decrease potential charitable acts, these are by no means complete negating effects–for the mentally stable, a bar of soap isn’t going to magically erase from your mind whatever it is you have done.

Still, one wonders if Macbeth might have turned out differently if only Purell had existed in medieval Scotland.

It has been said “The most exciting phrase to hear in science, the one that heralds new discoveries, is not ‘Eureka!’ but ‘That’s funny…’” (Isaac Asimov), and a recent observation by a Harvard Medical School lab studying the brain chemistry of Bipolar Disorder has researchers uttering that precise phrase…as well as the one alluded to in the title of this post.

The initial study prompting such observations recruited patients suffering specifically from Bipolar Disorder, also known as Manic-Depression, for 20-minute brain scans in an MRI.  MRI scans subject patients to a harmless magnetic field and pulses of radio waves to create detailed structural images of various body parts, in this case, the brain.  While the procedure is painless and relatively short, it can be unpleasant for reasons wholly unrelated to the magnets and radio signals; patients frequently report unrelated bodily discomfort or claustrophobia.  For this reason it was all the more surprising, according to one researcher, that patients participating in the study started to report mood elevations (that for some lasted days or even a week) following the scan.  One patient even subtly suggested that the researchers had slipped her something without her permission.

Patient undergoing TMS treatment for depression

The use of magnets to improve the effects of depression is not uncharted territory in neuroscience and it might even sound familiar to some.  Transcranial magnetic stimulation, or TMS, is another technique that has recently been adapted to depression therapy, yet it is more akin to electroconvulsive, or “electroshock”, therapy (ECT) than MRI.

TMS uses a magnetic field to induce a relatively small electric current, without causing seizure or loss of consciousness, to stimulate the left prefrontal cortex, the area thought to be under-active in depression.  Whereas ECT treatments are utilized only in the most extreme depression cases because of the risk of seizure and necessity of sedation, TMS carries much fewer risks and can be used for more mild depression. While the exact mechanisms are still not known, particularly the roll of seizure for the antidepressant effects, both ECT and TMS have been cleared by the FDA.

But the magnet employed in MRI does not excite specific brain regions (if it did the entire imaging method of functional magnetic resonance imaging, fMRI, would be ineffective) and it is certainly not strong enough to induce seizures.  After observing the curious side-effects of their initial study, the aforementioned researchers set up a small preliminary study with both bipolar and normal controls who confirmed respectively that the effects were not placebo, and that even those without depression can experience the mood-boosting effects of MRI.

So could a new depression treatment soon be joining the ranks of such accidental scientific breakthroughs as penicillin and Post-It notes?  At this point it really is unclear.  The actual mechanism of the mood-boosting effects of MRI on depressed patients is not yet understood, nor have the effects been generalized to unipolar depression.  However, the safety of exposure to MRI has been confirmed by the FDA and a lack of total understanding regarding what causes the “miraculous” effects of that other magnet-based depression treatment, TMS, as well as a host of other medical treatments (including lithium for Bipolar Disorder) certainly has not prevented their use.

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