In a recent report, Nature addressed several studies on disembodied brains grown in the lab. One of those studies, published last year by Alysson Muotri of the University of California, San Diego, showed that brain organoids (organized clusters of brain cells) displayed electrical signals reminiscent of a twenty-five-week-old pre-term baby. the electrical activity continued for several months until the experiment was eventually stopped.
Experiments with such brain organoids have left many wondering whether we should be concerned about creating brains-in-a-dish.
Organoids, such as those made of kidney or liver cells, have been used to study drug development and disease. They are made either from embryonic stem cells—an ethically problematic source because they involve the destruction of an embryo—or induced pluripotent stem cells, which come from skin or other cells from a donor. Brain organoids from induced pluripotent stem cells from a donor who suffers from a neurological disease might help researchers understand how the disease develops and whether certain drugs or therapies can help. For example, researchers have observed that the electrical activity of brain organoids will dampen when exposed to drugs used to alleviate the effects of epilepsy.
These brain-like entities lack some very important neurological cell types that would make them truly “brains.” But many wonder whether we can make brains with human-like consciousness in a dish. Unfortunately, some conflate the mind with the brain and consciousness with brain activity, which creates confusion:
When Muotri suggested that his organoids’ firing patterns were just as complex as those seen in preterm infants, people were unsure what to make of that. Some researchers don’t consider the brain activity in a preterm infant to be complex enough to be classed as conscious. And organoids can’t blink or recoil from a painful stimulus, so they wouldn’t pass the clinical test for consciousness.Sara Reardon, “Can lab-grown brains become conscious?” at Nature
After the 2019 experiments had been published, the University of California at San Diego held a conference with the goal of establishing an ethical framework for experiments regarding brain organoids. It included neuroscientists, philosophers, and students and was open to the public. But the conference papers have not yet been published because of disagreements over the definition of consciousness:
The concerns over lab-grown brains have also highlighted a blind spot: neuroscientists have no agreed way to define and measure consciousness. Without a working definition, ethicists worry that it will be impossible to stop an experiment before it crosses a line.Sara Reardon, “Can lab-grown brains become conscious?” at Nature
The problems with defining consciousness are similar to the problems with defining sentience in the field of artificial intelligence. The assumption that we can create consciousness or sentience rests on the claim that by piecing together enough individual parts in the right way, we can somehow obtain all of the functions of the whole, including non-material (or what materialists call “emergent”) functions.
According to Insoo Hyun, a Case Western University bioethicist who sits on the NIH’s neuroethics panel, the current definition of consciousness is so flexible that everyone relies on their own meaning. “If it’s not clear we’re talking about the same thing, it’s a big problem for discourse.”
While experts can’t agree on the definition, as the Nature article points out, “Almost all scientists and ethicists agree that so far, nobody has created consciousness in the lab.”
Could the vintage radio program Donovan’s Brain helps us understand the issues?
The main characters are Dr. Cory, who conducts nefarious experiments in his home and an egotistical millionaire W. H. Donovan. When Donovan crashes his private plane near Dr. Cory’s home, Cory retrieves him from the wreckage. He cannot save Donovan, but he preserve the millionaire’s brain in a jar. He connects the brain to electrodes, thus stimulating brain activity. Things take a dark turn when Donovan’s brain telepathically takes over Dr. Cory’s body, eventually using Cory to plot a murder.
While cerebral organoids won’t become “Donovan’s Brain,” the story illustrates the need for a brain to inhabit a body in order to interact with the outside world. A brain without a body cannot receive sensory input or move about in the world (i.e., it has no motor output). Donovan’s brain needed Dr. Cory’s body in order to do anything. The brain is like a computer processor and hard drive. By itself, it is insufficient. It needs a mouse, keyboard, or touch screen from which to receive data, and it needs a screen on which to project output.
Donovan’s Brain also illustrates the materialist assumption that often lies behind discussions of cerebral organoids. Going back to the brain-as-a-computer analogy, even though the hard drive stores information and the processor processes it, neither creates information—at least not meaningful information. That requires a mind.
The Materialist’s Dilemma
In our post-Enlightenment era, science is assumed to be a materialist endeavor. Materialism is the philosophical belief that the physical world encompasses all of reality and therefore all of reality is explainable by and subject to physical laws. From this perspective, there is no immaterial world; thus the mind must be a product of physical processes. Thoughts are the result of synapses firing in the brain and consciousness emerges from the functioning brain.
Seen from this perspective, consciousness might be produced in the lab so long as all of the necessary physical parts to the brain are present and in their right places. This is the assumption behind most bioethical discussions about cerebral organoids—and their potential for becoming conscious. Often these discussions assume that as the organoids get “bigger,” they will become more brain-like.
When this issue is looked at from a non-materialist perspective, however, it becomes clear that organoids can never gain consciousness, even if they become the size of a human brain. Neurosurgeon Michael Egnor, who writes often about consciousness and the difference between the mind and brain here at Mind Matters News, says that even a whole brain can’t have consciousness (i.e., intentionality) without sense organs. He points out that even if scientists could “manufacture” intentionality in a lab by creating a full-sized brain with sensory organs, that brain will not display abstract thought. It might be animal-like, but it will never be human-like, because it will not have a spirit, which can only come from God.
Even if one chafes at Egnor’s use of spiritual language, our lived experience testifies that, rather than brains-in-a-vat, humans are embodied beings, whose identity is found in the whole person, not in any of the individual parts.
Murky Ethical Waters
While brain organoids probably will not become conscious, there are still several ethical concerns with research on human brain cells. In an experiment mentioned in Nature, neuroscientist Nenad Sestan from Yale University revitalized the brain of a pig that had died several hours earlier. When his group noted coordinated EEG activity, indicative of widespread brain activity rather than individual neurons, they stopped the project. While they didn’t create consciousness, Sestan’s group was advised by both a specialist and the NIH to anesthetize the brains thereafter. (In animal research, ethical practices call for anesthetizing animals so they do not suffer needlessly.)
Pigs can serve as helpful models for humans because they are mammals and their organs are roughly the size of human organs. Sestan’s group was working on pigs in hopes of learning how to reanimate dead human organs. Their research has implications for the current definition of brain death.
Then there is the issue of transplanting brain tissue, which may one day include brain organoids, into non-human organisms. This would theoretically place the organoids within a context that allows for sensory input and motor output. While the resulting chimeric animal would not necessarily become conscious in a human sense, it might nevertheless perceive and interact with its environment in ways that it would not have otherwise.
There are also also questions of confidentiality and discrimination. Geneticists have wrestled with the question of whether they should let people know about “incidental findings,” such as the APO marker for Alzheimer’s disease or the BRCA genes for breast cancer, when doing unrelated genetic studies. Similarly, what if organoid research using a particular patient’s cells, shows that the person has abnormal brain development? What if, for example, that person might be expected to be autistic based on their brain development, but has never displayed symptoms?
It’s doubtful that scientists will create human consciousness from brain organoids or that they will create truly sentient machines. But there are still some troubling aspects to this kind of research. Ethical norms and best practices make for good science, but they must begin with definitions that take into account non-material aspects of the human person.
Note: Portions of this article first appeared in Salvo, Issue #52, as “Mindless Attempts”. Other articles by Heather Zeiger are also available at the link.
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