Tag Archives: neuroscienze

The Carney Landis Experiment

Suppose you’re making your way through a jungle, and in pulling aside a bush you find yourself before a huge snake, ready to attack you. All of a sudden adrenaline rushes through your body, your eyes open wide, and you instantly begin to sweat as your heartbeat skyrockets: in a word, you feel afraid.
But is your fear triggering all these physical reactions, or is it the other way around?
To make a less disquieting example, let’s say you fall in love at first sight with someone. Are the endorphines to be accounted for your excitation, or is your excitation causing their discharge through your body?
What comes first, physiological change or emotion? Which is the cause and which is the effect?

This dilemma was a main concern in the first studies on emotion (and it still is, in the field of affective neurosciences). Among the first and most influential hypothesis was the James-Lange theory, which maintained the primacy of physiological changes over feelings: the brain detects a modification in the stimuli coming from the nervous system, and it “interprets” them by giving birth to an emotion.

One of the problems with this theory was the impossibility of obtaining clear evidence. The skeptics argued that if every emotion arises mechanically within the body, then there should be a gland or an organ which, when conveniently stimulated, will invariably trigger the same emotion in every person. Today we know a little bit more of how emotions work, in regard to the amygdala and the different areas of cerebral cortex, but at the beginning of the Twentieth Century the objection against the James-Lange theory was basically this — “come on, find me the muscle of sadness!“

In 1924, Carney Landis, a Minnesota University graduate student, set out to understand experimentally whether these physiological changes are the same for everybody. He focused on those modifications that are the most evident and easy to study: the movement of facial muscles when emotion arises. His study was meant to find repetitive patterns in facial expressions.

To understand if all subjects reacted in the same way to emotions, Landis recruited a good number of his fellow graduate students, and began by painting their faces with standard marks, in order to highlight their grimaces and the related movement of facial muscles.
The experiment consisted in subjecting them to different stimuli, while taking pictures of their faces.

At first volunteers were asked to complete some rather harmless tasks: they had to listen to jazz music, smell ammonia, read a passage from the Bible, tell a lie. But the results were quite discouraging, so Landis decided it was time to raise the stakes.

He began to show his subjects pornographic images. Then some medical photos of people with horrendous skin conditions. Then he tried firing a gunshot to capture on film the exact moment of their fright. Still, Landis was having a hard time getting the expressions he wanted, and in all probability he began to feel frustrated. And here his experiment took a dark turn.

He invited his subjects to stick their hand in a bucket, without looking. The bucket was full of live frogs. Click, went his camera.
Landis encouraged them to search around the bottom of the mysterious bucket. Overcoming their revulsion, the unfortunate volunteers had to rummage through the slimy frogs until they found the real surprise: electrical wires, ready to deliver a good shock. Click. Click.
But the worst was yet to come.

The experiment reached its climax when Landis put a live mouse in the subject’s left hand, and a knife in the other. He flatly ordered to decapitate the mouse.
Most of his incredulous and stunned subjects asked Landis if he was joking. He wasn’t, they actually had to cut off the little animal’s head, or he himself would do it in front of their eyes.
At this point, as Landis had hoped, the reactions really became obvious — but unfortunately they also turned out to be more complex than he expected. Confronted with this high-stress situation, some persons started crying, others hysterically laughed; some completely froze, others burst out into swearing.

Two thirds of the paricipants ended up complying with the researcher’s order, and carried out the macabre execution. In any case, the remaining third had to witness the beheading, performed by Landis himself.
As we said, the subjects were mainly other students, but one notable exception was a 13 years-old boy who happened to be at the department as a patient, on the account of psychological issues and high blood pressure. His reaction was documented by Landis’ ruthless snapshots.

Perhaps the most embarassing aspect of the whole story was that the final results for this cruel test — which no ethical board would today authorize — were not even particularly noteworthy.
Landis, in his Studies of Emotional Reactions, II., General Behavior and Facial Expression (published on the Journal of Comparative Psychology, 4 [5], 447-509) came to these conclusions:

1) there is no typical facial expression accompanying any emotion aroused in the experiment;
2) emotions are not characterized by a typical expression or recurring pattern of muscular behavior;
3) smiling was the most common reaction, even during unpleasant experiences;
4) asymmetrical bodily reactions almost never occurred;
5) men were more expressive than women.

Hardly anything that could justify a mouse massacre, and the trauma inflicted upon the paritcipants.

After obtaining his degree, Carney Landis devoted himself to sexual psychopatology. He went on to have a brillant carreer at the New York State Psychiatric Institute. And he never harmed a rodent again, despite the fact that he is now mostly remembered for this ill-considered juvenile experiment rather than for his subsequent fourty years of honorable research.

There is, however, one last detail worth mentioning.
Alex Boese in his Elephants On Acid, underlines how the most interesting figure of all this bizarre experiment went unnoticed: the fact that two thirds of the subjects, although protesting and suffering, obeyed the terrible order.
And this percentage is in fact similar to the one recorded during the infamous Milgram experiment, in which a scientist commanded the subjects to inflict an electric shock to a third individual (in reality, an actor who pretended to receive the painful discharge). In that case as well, despite the ethical conflict, the simple fact that the order came from an authority figure was enough to push the subjects into carrying out an action they perceived as aberrant.

The Milgram experiment took place in 1961, almost forty years after the Landis experiment. “It is often this way with experiments — says Boese — A scientis sets out to prove one thing, but stumbles upon something completely different, something far more intriguing. For this reason, good researchers know they should always pay close attention to strange events that occur during their experiments. A great discovery might be lurking right beneath their eyes – or beneath te blade of their knife.“

On facial expressions related to emotions, see also my former post on Guillaume Duchenne (sorry, Italian language only).

Stoned spiders

1948, University of Tubingen, Germany.
Zoologist H. M. Peters was frustrated. He was conducting a photographic research on the way orb-weaver spiders build their web, but he had encountered a problem: the arachnids he was studying insisted on performing this task of astounding engineering only during the night hours, very early in the morning. This schedule, besides forcing him to get up at an ungodly hour, made photographic documentation quite hard, as the spiders preferred to move in total darkness.
One day Peters decided to call on a collegue, young pharmacologist Dr. Peter N. Witt, for assistance. Would it be possible to somehow drug the spiders, so they would change this routine and start weaving their webs when the sun was already up?

Witt had never had any experience with spiders, but he soon realized that administering tranquilizers or stimulants to the arachnids was easier than he thought: the little critters, constantly thirsty for water, quickly learned to drink from his syringe.
The results of this experiment, alas, turned out to be pretty worthless to zoologist Peters. The spiders kept on building their webs during the night, but that was not the worst part of it. After swallowing the medicine, they weren’t even able to weave a decent web: as if they were drunk, the arachnids produced a twisted mesh, unworthy of being photographed.
After this experience, a disheartened Peters abandoned his project.
In Dr. Witt’s mind, instead, something had clicked.

Common spiders (Araneidae) are all but “common” when it comes to weaving. They build a new web every morning, and if byt he end of the day no insect is trapped, they simply eat it. This way, they are able to recycle silk proteins for weeks: during the first 16 days without food, the webs look perfect. Whe nthe spider gets really hungry, it begins sparing the energy by building a wider-meshes web, suitable to catch only larger insects (the spider is in need of a substantial meal).
After all, for a spider the web isn’t just a way to gather food, but an essential instrument to relate with the surrounding world. Most of these arachnids are almost totally blind, and they use the vibrations of the strands like a radar: from the perceived movements they can understand what kind of insect just snagged itself on the web, and if it is safe for them to approach it; they can notice if even a single thread has broken, and they confidently head in the right direction to repair it; they furthermore use the web as a means of communication in mating rituals, where the male spider remains on the outer edges and rythmically pinches the strings to inform the female of its presence, in order to seduce her without being mistaken for a juicy snack.

peter-witt

During his experimentation with chemicals, Dr. Witt noticed that there seemed to be a significative correspondence between the administered substance and the aberrations that the spiderweb showed. He therefore began feeding the spiders different psychoactive drugs, and registering the variations in their weaving patterns.
Dr. Witt’s study, published in 1951 and revised in 1971, was limited to statistical observation, without attempting to provide further interpretations. Yet the results could lead to a fascinating if not very orthodox reading: it looked like the spiders were affected in much the same way humans react to drugs.

webs

Under the influence of weed, they started regularly building their web, but were soon losing interest once they got to the outer rings; while on peyote or magic mushrooms, the arachnids movements became slower and heavier; after being microdosed with LSD, the web’s design became geometrically perfect (not unlike the kaleidoscopic visions reported by human users), while more massive doses completely inhibited the spiders’ abilities; lastly, caffeine produced out of control, schizoid results.

Spiderweb after high doses of LSD-25.

Clearly this “humanized” interpretation is not scientific to say the least. In fact, what really interested Witt was the possibility of using spiders to ascertain the presence of drugs in human blood or urine, as they had proved sensitive to minimal concentrations, which could not be instrumentally detected at the time. His research continued for decades, and Witt went from being a pharmacologist to being an entomology authority. He was able to recognize his little spliders one by one just by looking at their webs, and his fascination for these invertebrates never faded.
He kept on testing their skills in several other experiments, by altering their nervous system through laser stimulation, administering huge quantities of barbiturics, and even sending them in orbit. Even in the absence of gravity, in what Witt called “a masterpiece in adaptation”, after just three days in space the spiders were able to build a nearly perfect web.

Near the end of the Seventies, Witt discontinued his research. In 1984 J. A. Nathanson re-examined Witt’s data, but only in relation to the effects of caffeine.
In 1995 Witt saw his study come back to life when NASA successfully repeated it, with the help of statistic analysis software: the research showed that spiders could be used to test the toxicity of various chemicals instead of mice, a procedure that could save time and money.

Anyway, there is not much to worry regarding the fate of these invertebrates.
Spiders are among the very few animals who survived the biggest mass extinction that ever took place, and they are able to resist to atmospheric conditions which would be intolerable to the majority of insects. Real rulers of the world since millions of years, they will still be here a long time — even after our species has run its course.