A cartography of consciousness – researchers map where subjective feelings are located in the body
"How do you feel?" is a simple and commonly asked question that belies the complex nature of our conscious experiences. The feelings and emotions we experience daily consist of bodily sensations, often accompanied by some kind of thought process, yet we still know very little about exactly how these different aspects relate to one another, or about how such experiences are organised in the brain.
Now, reporting their results in PNAS, a team of researchers in Finland, led by neuroscientist Lauri Nummenmaa of the University of Turku, has produced detailed maps of what they call the "human feeling space", showing how each of dozens of these subjective feelings is associated with a unique set of bodily sensations.
In 2014, Nummenmaa and his colleagues published bodily maps of emotions showing the distinct bodily sensations associated with six basic emotions, such as anger, fear, happiness and sadness, and seven complex emotional states, such as anxiety, love, pride, and shame.
Building on this earlier work, for their new research they recruited 1,026 participants and asked them to complete an online survey designed to assess how they perceive 100 "core" subjective feelings, compiled from the American Psychological Association's Dictionary of Psychology, ranging from homeostatic states such as hunger and thirst, to emotional states such as anger and pleasure, and cognitive functions such as imagining and remembering.
The participants were shown a list of the 100 core feelings on the computer screen, and asked to drag and drop each one into a box, placing similar feelings close to each other (try it for yourself). They also had to rate each feeling according to how much it is experienced in the body, how much of it is psychological, how pleasant it feels, and how much control they think they have over it.
Their descriptions of the core feelings clustered into five distinct groups, based on similarity: Positive emotions, such as happiness and togetherness; negative emotions, such as fear and shame; thought processes, such as hearing and memorising; homeostatic sensations, such as hunger and thirst; and sensations associated with illness, such as coughing and sneezing.
In another online experiment, Nummenmaa and his colleagues asked the participants to indicate exactly where in the body they felt each state, by colouring in a blank body shape, allowing them to map the bodily sensations associated with the each of the 100 core feelings.
The researchers then pooled these data to create "bodily sensation maps" for each of the core feelings (see image, above). For example, the participants localised the feeling of anger to the head, chest, and hands; feelings of hunger and thirst to the stomach and throat, respectively; and the feelings of 'being conscious', imagining, and remembering entirely to the head.
The maps showed that, despite the similarities, each core feeling was associated with a unique set of bodily sensations. For example, participants reported perceiving anger mostly in the head and hands, anxiety mostly in the chest; and sadness in the chest and head. Although similar feelings produced similar body maps, the intensity and precise distribution of bodily sensations associated with each was unique.
That both anger and fear were associated with intense bodily sensations in the head and chest adds to past work showing that both these emotions involve remarkably similar physiological changes to the body, and further explains why we usually have to depend on context to help us interpret the emotional meaning of our sensations.
The new results provide yet more evidence for the emerging idea that the body plays a crucial role in cognitive and emotional processes – something which has, until very recently, been overlooked. "In other words," says study co-author Riita Hari, "the human mind is strongly embodied."
Post written by Mo Costandi (@Mocost) for the BPS Research Digest. Mo trained as a developmental neurobiologist and now works as a freelance writer specialising in neuroscience. He wrote the Neurophilosophy blog, hosted by The Guardian, and is the author of 50 Human Brain Ideas You Really Need to Know, and Neuroplasticity.
- The meaning of the word 'confidence' seems obvious. But it's not the same as self-esteem.
- Confidence isn't just a feeling on your inside. It comes from taking action in the world.
- Join Big Think Edge today and learn how to achieve more confidence when and where it really matters.
If you're lacking confidence and feel like you could benefit from an ego boost, try writing your life story.
In truth, so much of what happens to us in life is random – we are pawns at the mercy of Lady Luck. To take ownership of our experiences and exert a feeling of control over our future, we tell stories about ourselves that weave meaning and continuity into our personal identity.
Researchers hope the technology will further our understanding of the brain, but lawmakers may not be ready for the ethical challenges.
- Researchers at the Yale School of Medicine successfully restored some functions to pig brains that had been dead for hours.
- They hope the technology will advance our understanding of the brain, potentially developing new treatments for debilitating diseases and disorders.
- The research raises many ethical questions and puts to the test our current understanding of death.
The image of an undead brain coming back to live again is the stuff of science fiction. Not just any science fiction, specifically B-grade sci fi. What instantly springs to mind is the black-and-white horrors of films like Fiend Without a Face. Bad acting. Plastic monstrosities. Visible strings. And a spinal cord that, for some reason, is also a tentacle?
But like any good science fiction, it's only a matter of time before some manner of it seeps into our reality. This week's Nature published the findings of researchers who managed to restore function to pigs' brains that were clinically dead. At least, what we once thought of as dead.
What's dead may never die, it seems
The researchers did not hail from House Greyjoy — "What is dead may never die" — but came largely from the Yale School of Medicine. They connected 32 pig brains to a system called BrainEx. BrainEx is an artificial perfusion system — that is, a system that takes over the functions normally regulated by the organ. The pigs had been killed four hours earlier at a U.S. Department of Agriculture slaughterhouse; their brains completely removed from the skulls.
BrainEx pumped an experiment solution into the brain that essentially mimic blood flow. It brought oxygen and nutrients to the tissues, giving brain cells the resources to begin many normal functions. The cells began consuming and metabolizing sugars. The brains' immune systems kicked in. Neuron samples could carry an electrical signal. Some brain cells even responded to drugs.
The researchers have managed to keep some brains alive for up to 36 hours, and currently do not know if BrainEx can have sustained the brains longer. "It is conceivable we are just preventing the inevitable, and the brain won't be able to recover," said Nenad Sestan, Yale neuroscientist and the lead researcher.
As a control, other brains received either a fake solution or no solution at all. None revived brain activity and deteriorated as normal.
The researchers hope the technology can enhance our ability to study the brain and its cellular functions. One of the main avenues of such studies would be brain disorders and diseases. This could point the way to developing new of treatments for the likes of brain injuries, Alzheimer's, Huntington's, and neurodegenerative conditions.
"This is an extraordinary and very promising breakthrough for neuroscience. It immediately offers a much better model for studying the human brain, which is extraordinarily important, given the vast amount of human suffering from diseases of the mind [and] brain," Nita Farahany, the bioethicists at the Duke University School of Law who wrote the study's commentary, told National Geographic.
An ethical gray matter
Before anyone gets an Island of Dr. Moreau vibe, it's worth noting that the brains did not approach neural activity anywhere near consciousness.
The BrainEx solution contained chemicals that prevented neurons from firing. To be extra cautious, the researchers also monitored the brains for any such activity and were prepared to administer an anesthetic should they have seen signs of consciousness.
Even so, the research signals a massive debate to come regarding medical ethics and our definition of death.
Most countries define death, clinically speaking, as the irreversible loss of brain or circulatory function. This definition was already at odds with some folk- and value-centric understandings, but where do we go if it becomes possible to reverse clinical death with artificial perfusion?
"This is wild," Jonathan Moreno, a bioethicist at the University of Pennsylvania, told the New York Times. "If ever there was an issue that merited big public deliberation on the ethics of science and medicine, this is one."
One possible consequence involves organ donations. Some European countries require emergency responders to use a process that preserves organs when they cannot resuscitate a person. They continue to pump blood throughout the body, but use a "thoracic aortic occlusion balloon" to prevent that blood from reaching the brain.
The system is already controversial because it raises concerns about what caused the patient's death. But what happens when brain death becomes readily reversible? Stuart Younger, a bioethicist at Case Western Reserve University, told Nature that if BrainEx were to become widely available, it could shrink the pool of eligible donors.
"There's a potential conflict here between the interests of potential donors — who might not even be donors — and people who are waiting for organs," he said.
It will be a while before such experiments go anywhere near human subjects. A more immediate ethical question relates to how such experiments harm animal subjects.
Ethical review boards evaluate research protocols and can reject any that causes undue pain, suffering, or distress. Since dead animals feel no pain, suffer no trauma, they are typically approved as subjects. But how do such boards make a judgement regarding the suffering of a "cellularly active" brain? The distress of a partially alive brain?
The dilemma is unprecedented.
Setting new boundaries
Another science fiction story that comes to mind when discussing this story is, of course, Frankenstein. As Farahany told National Geographic: "It is definitely has [sic] a good science-fiction element to it, and it is restoring cellular function where we previously thought impossible. But to have Frankenstein, you need some degree of consciousness, some 'there' there. [The researchers] did not recover any form of consciousness in this study, and it is still unclear if we ever could. But we are one step closer to that possibility."
She's right. The researchers undertook their research for the betterment of humanity, and we may one day reap some unimaginable medical benefits from it. The ethical questions, however, remain as unsettling as the stories they remind us of.
A space memorial company plans to launch the ashes of "Pikachu," a well-loved Tabby, into space.
- Steve Munt, Pikachu's owner, created a GoFundMe page to raise money for the mission.
- If all goes according to plan, Pikachu will be the second cat to enter space, the first being a French feline named Felicette.
- It might seem frivolous, but the cat-lovers commenting on Munt's GoFundMe page would likely disagree.
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