Pooping Legos

Yeah, alright… uhm… how exactly should I approach this paper? I’d better just dive into it (oh boy! I shouldn’t have said that).

The authors of this paper were adult health-care professionals in the pediatric field. These three males and three females were also the participants in the study. They kept a poop-diary noting the frequency and volume of bowel movements (Did they poop directly on a scale or did they have to scoop it out in a bag?). The researchers/subjects developed a Stool Hardness and Transit (SHAT) metric to… um.. “standardize bowel habit between participants” (p. 1). In other words, to put the participants’ bowel movements on the same level (please, no need to visualize, I am still stuck at the poop-on-a-scale phase), the authors looked – quite literally – at the consistency of the poop and gave it a rating. I wonder if they checked for inter-rater reliability… meaning did they check each other’s poops?…

Then the researchers/subjects ingested a Lego figurine head, on purpose, somewhere between 7 and 9 a.m. Then they timed how much time it took to exit. The FART score (Found and Retrieved Time) was 1.71 days. “There was some evidence that females may be more accomplished at searching through their stools than males, but this could not be statistically validated” due to the small sample size, if not the poops’. It took 1 to 3 stools for the object to be found, although poor subject B had to search through his 13 stools over a period of 2 weeks to no avail. I suppose that’s what you get if you miss the target, even if you have a PhD.

The pre-SHAT and SHAT score of the participants did not differ, suggesting that the Lego head did not alter the poop consistency (I got nothin’ here; the authors’ acronyms are sufficient scatological allusion). From a statistical standpoint, the one who couldn’t find his head in his poop (!) should not have been included in the pre-SHAT score group. Serves him right.

I wonder how they searched through the poop… A knife? A sieve? A squashing spatula? Gloved hands? Were they floaters or did the poop sink at the base of the toilet? Then how was it retrieved? Did the researchers have to poop in a bucket so no loss of data should occur? Upon direct experimentation 1 minute ago, I vouchsafe that a Lego head is completely buoyant. Would that affect the floatability of the stool in question? That’s what I’d like to know. Although, to be fair, no, that’s not what I want to know; what I desire the most is a far larger sample size so some serious stats can be conducted. With different Lego parts. So they can poop bricks. Or, as suggested by the authors, “one study arm including swallowing a Lego figurine holding a coin” (p. 3) so one can draw parallels between Lego ingestion and coin ingestion research, the latter being, apparently, far more prevalent. So many questions that still need to be answered! More research is needed, if only grants would be so… regular as the raw data.

The paper, albeit short and to the point, fills a gap in our scatological knowledge database (Oh dear Lord, stop me!). The aim of the paper was to show that ingested objects by children tend to pass without a problem. Also of value, the paper asks pediatricians to counsel the parents to not search for the object in the faeces to prove object retrieval because “if an experienced clinician with a PhD is unable to adequately find objects in their own stool, it seems clear that we should not be expecting parents to do so” (p. 3). Seems fair.

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REFERENCE: Tagg, A., Roland, D., Leo, G. S., Knight, K., Goldstein, H., Davis, T. and Don’t Forget The Bubbles (22 November 2018). Everything is awesome: Don’t forget the Lego. Journal of Paediatrics and Child Health, doi: 10.1111/jpc.14309. ARTICLE

By Neuronicus, 27 November 2017

Apathy

Le Heron et al. (2018) defines apathy as a marked reduction in goal-directed behavior. But in order to move, one must be motivated to do so. Therefore, a generalized form of impaired motivation also hallmarks apathy.

The authors compiled for us a nice mini-review combing through the literature of motivation in order to identify, if possible, the neurobiological mechanism(s) of apathy. First, they go very succinctly though the neuroscience of motivated behavior. Very succinctly, because there are literally hundreds of thousands of worthwhile pages out there on this subject. Although there are several other models proposed out-there, the authors’ new model on motivation includes the usual suspects (dopamine, striatum, prefrontal cortex, anterior cingulate cortex) and you can see it in the Fig. 1.

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Fig. 1 from Le Heron et al. (2018). The red underlining is mine because I really liked how well and succinctly the authors put a universal truth about the brain: “A single brain region likely contributes to more than one process, but with specialisation”. © Author(s) (or their employer(s)) 2018.

After this intro, the authors go on to showcasing findings from the effort-based decision-making field, which suggest that the dopamine-producing neurons from ventral tegmental area (VTA) are fundamental in choosing an action that requires high-effort for high-reward versus a low-effort for low-reward. Contrary to what Wikipedia tells you, a reduction, not an increase, in mesolimbic dopamine is associated with apathy, i.e. preferring a low-effort for low-reward activity.

Next, the authors focus on why are the apathetic… apathetic? Basically, they asked the question: “For the apathetic, is the reward too little or is the effort too high?” By looking at some cleverly designed experiments destined to parse out sensitivity to reward versus sensitivity to effort costs, the authors conclude that the apathetics are indeed sensitive to the reward, meaning they don’t find the rewards good enough for them to move.  Therefore, the answer is the reward is too little.

In a nutshell, apathetic people think “It’s not worth it, so I’m not willing to put in the effort to get it”. But if somehow they are made to judge the reward as good enough, to think “it’s worth it”, they are willing to work their darndest to get it, like everybody else.

The application of this is that in order to get people off the couch and do stuff you have to present them a reward that they consider worth moving for, in other words to motivate them. To which any practicing psychologist or counselor would say: “Duh! We’ve been saying that for ages. Glad that neuroscience finally caught up”.  Because it’s easy to say people need to get motivated, but much much harder to figure out how.

This was a difficult write for me and even I recognize the quality of this blogpost as crappy. That’s because, more or less, this paper is within my narrow specialization field. There are points where I disagree with the authors (some definitions of terms), there are points where things are way more nuanced than presented (dopamine findings in reward), and finally there are personal preferences (the interpretation of data from Parkinson’s disease studies). Plus, Salamone (the second-to-last author) is a big name in dopamine research, meaning I’m familiar with his past 20 years or so worth of publications, so I can infer certain salient implications (one dopamine hypothesis is about saliency, get it?).

It’s an interesting paper, but it’s definitely written for the specialist. Hurray (or boo, whatever would be your preference) for another model of dopamine function(s).

REFERENCE: Le Heron C, Holroyd CB, Salamone J, & Husain M (26 Oct 2018, Epub ahead of print). Brain mechanisms underlying apathy. Journal of Neurology, Neurosurgery & Psychiatry. pii: jnnp-2018-318265. doi: 10.1136/jnnp-2018-318265. PMID: 30366958 ARTICLE | FREE FULLTEXT PDF

By Neuronicus, 24 November 2018

No licorice for you

I never liked licorice. And that turns out to be a good thing. Given that Halloween just happened yesterday and licorice candy is still sold in USA, I remembered the FDA’s warning against consumption of licorice from a year ago.

So I dug out the data supporting this recommendation. It’s a review paper published 6 years ago by Omar et al. (2012) meant to raise awareness of the risks of licorice consumption and to urge FDA to take regulatory steps.

The active ingredient in licorice is glycyrrhizic acid. This is hydrolyzed to glycyrrhetic acid by intestinal bacteria possessing a specialized ß-glucuronidase. Glycyrrhetic acid, in turn, inhibits 11-ß-hydroxysteroid dehydrogenase (11-ß-HSD) which results in cortisol activity increase, which binds to the mineralcorticoid receptors in the kidneys, leading to low potassium levels (called hypokalemia). Additionally, licorice components can also bind directly to the mineralcorticoid receptors.

Eating 2 ounces of black licorice a day for at least two weeks (which is roughly equivalent to 2 mg/kg/day of pure glycyrrhizinic acid) is enough to produce disturbances in the following systems:

  • cardiovascular (hypertension, arrhythmias, heart failure, edemas)
  • neurological (stroke, myoclonia, ocular deficits, Carpal tunnel, muscle weakness)
  • renal (low potassium, myoglobinuria, alkalosis)
  • and others

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Although everybody is affected by licorice consumption, the most vulnerable populations are those over 40 years old, those who don’t poop every day, or are hypertensive, anorexic or of the female persuasion.

Unfortunately, even if one doesn’t enjoy licorice candy, they still can consume it as it is used as a sweetener or flavoring agent in many foods, like sodas and snacks. It is also used in naturopathic crap, herbal remedies, and other dangerous scams of that ilk. So beware of licorice and read the label, assuming the makers label it.

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Licorice products (Images: PD, Collage: Neuronicus)

REFERENCE: Omar HR, Komarova I, El-Ghonemi M, Fathy A, Rashad R, Abdelmalak HD, Yerramadha MR, Ali Y, Helal E, & Camporesi EM. (Aug 2012). Licorice abuse: time to send a warning message. Therapeutic Advances in Endocrinology and Metabolism, 3(4):125-38. PMID: 23185686, PMCID: PMC3498851, DOI: 10.1177/2042018812454322. ARTICLE | FREE FULLTEXT PDF

By Neuronicus, 1 November 2018