Archive for the 'Neuroscience' Category

Nov 17 2017

The Ethics of Head Transplants

sergio-canaveroNewsweek, who has been following the story of Italian Neurosurgeon, Sergio Canavero, now reports: “Human Head Transplants Are About to Happen in China: But Where Are the Bodies Coming From?”

I have already discussed the scientific aspects of this claim. They are highly implausible and I doubt that such a transplant is about to happen at all. If it does I predict it will be a dismal failure, and ethically dubious. First, I have to reiterate, that it is far more accurate to call such a procedure a body transplant. The head donor will wake up with a new body. The body donor is, I suspect, dead.

There are three basic hurdles that need to be overcome in order to have a successful body transplant – the surgical attachment, suppression of rejection, and regeneration of the attached neurological tissue. Given that Canavero is a surgeon, I suspect he is excited about the first issue. He may think he has made some advances because he improved his technique for making the attachment. This was never, however, the primary hurdle.

We are already making great advances with organ transplantation and controlling rejection. However, this is still a huge issue. Donor and recipient have to be closely matched, and lifelong drugs are required. Still, the amount of tissue being transplanted here will be a challenge. It opens up, for the first time, the possible effects of tissue rejection on an entire brain. While this is a significant hurdle, our current treatments mean it is not necessarily a deal breaker (it might be, but research would be needed to see).

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Nov 03 2017

Consistency Bias

Published by under Neuroscience

“Oceania was at war with Eurasia; therefore Oceania had always been at war with Eurasia.”

– George Orwell

persistence-of-memory-486x309In Orwell’s classic book, 1984, the totalitarian state controlled information and they used that power to obsessively manage public perception. One perception they insisted upon was that the state was consistent – never changing its mind or contradicting itself. This desire, in turn, is based on the premise that changing one’s mind is a sign of weakness. It is an admission of prior error or fault.

Unsurprisingly our perceptions of our own prior beliefs are biased in order to minimize apparent change, a recent study shows. The exact reason for this bias was not part of the study.

Researchers surveyed subjects as to their beliefs regarding the effectiveness of corporal punishment for children. This topic was chosen based on the assumption that most subjects would have little knowledge of the actual literature and would not have strongly held beliefs. Subjects were then given articles to read making the case for the effectiveness or ineffectiveness of spanking (either consistent with or contrary to their prior beliefs), and then their beliefs were surveyed again.

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Oct 24 2017

The Mandela Effect

Published by under Neuroscience

mandelaeffect1Do you remember when Nelson Mandela was killed in prison in the 1980s? Apparently there are a lot of people who, for some reason, had this memory. Of course, Mandela was not killed in prison, he survived and went on to become president of South Africa.

This false memory, however, gave rise to the term, “The Mandela Effect,” which refers to remembering some detail of the past that is simply not true. There is a disconnect between our memory and reality.

This should not be surprising to anyone, especially anyone even slightly familiar with memory research. Our memories are constantly changing, they merge, details shift, and entire memories can be confabulated. If there is a conflict between our memory and documented reality, it is clearly our memory that is at fault.

Despite this obvious answer, there are groups of people who feel that the Mandela effect represents something else. The disconnect between our memories and reality is due, they argue, to a shifting in reality, perhaps due to a crossing of the streams between parallel universes. Alternatively it can be a glitch in the Matrix that happens when they apply a new patch or expansion.  Between physical reality and memory I would say that memory is the one that is slippery and changing, not reality.

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125 responses so far

Oct 17 2017

What Is Artificial Intelligence

AI-1A recent article by Peter Yordanov claims that Artificial Intelligence (AI) is nothing but misleading clickbait. This is a provocative way to state it, but he has a point, although I don’t think he expressed it well.

Yordanov spends most of the article describing his understanding of human intelligence, partly by walking through the evolution of the central nervous system. His basic conclusion, if I am reading it correctly, is that what we have today and call AI is nothing like biological intelligence.

This is certainly true, but it seems like he takes a long time to make what is essentially a semantic argument. The core problem is that the word “intelligence” means many things. Lack of a consistent operational definition plagues the use of the term is pretty much every context, and certainly in computer AI.

What we have now and is generally referred to as AI are computer algorithms that display functions that resemble intelligence or duplicate certain components of intelligence. Computers are good at crunching numbers, running algorithms, recognizing patterns, and searching and matching data. Newer algorithms are also capable of learning – of changing their behavior based on data input.

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Sep 26 2017

Brain Stimulation in Coma

Published by under Neuroscience

VNA for comaThe link to the article from the BBC Science News page reads, “Therapy “Wakes” Vegetative-State Patient.” The headline of the article was a bit more conservative, “Vegetative-state patient responds to therapy.” Annoying click-bait aside, what is actually going on here?

Like every such case so far, the improvement in neurological function in this patient with severe coma is extremely limited. This is mostly a proof of concept study, and the results are interesting, but the term “wakes,” even is quotations, is not even close to being justified.

Here is the case report: Restoring consciousness with vagus nerve stimulation. Even that title is a bit misleading – they aren’t saying they actually restored consciousness, just that vagus nerve stimulation might be a viable approach to develop. For background, a vegetative state is one in which basic neurological functions, like breathing, having a sleep-wake cycle, and some automatic movements, are retained. However, the conscious part of the cortex does not appear to be working. By definition there is no reaction to the environment.

By contrast a minimally conscious state has, as the name implies, minimal response to the environment. Patients in this state might blink to threat, or turn to a voice, but cannot communicate or participate in their daily activities. There is a continuum of neurological function from this minimal state to fully conscious.

As I have discussed before, researchers are trying to improve out ability to tell how impaired individual people are who clinically appear to be vegetative or minimally conscious. The challenge is that the neurological exam is limited. If the patient cannot follow commands, we have a limited ability to directly test which circuits in the brain are functioning. The patient may be more conscious than they appear to be because they are paralyzed or deaf, for example. Using functional MRI scanning and EEGs have enhanced our ability to assess brain function in these cases. Continue Reading »

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Sep 08 2017

How People Thrive

Published by under Neuroscience

happy-facesThere is a science to happiness and to what we might call thriving (sometimes called flourishing) – not just surviving, but being happy and fulfilled. Obviously any such phenomenon is going to be very complex and variable, but some clear patterns are emerging in the psychological literature. A recent study by Brown et al reviews that literature in an attempt to summarize what we know about thriving.

Brown identifies a number of factors that contribute to thriving, but the core seems to come down to two things: being confident and being good at something. Other researchers looking at the same question have had a slightly different emphasis, but I think are essentially saying the same thing. Thriving correlates with living with purpose, for example. Other studies emphasize community and having a belief system (which may just be a proxy for having a purpose). Having a purpose in life has even been associated with better physical health in older adults.

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Jul 31 2017

The Goldwater Rule Revisited

Published by under Neuroscience

goldwaterIn 1964 Fact Magazine published an article titled: “1,189 Psychiatrists say Goldwater is Psychologically Unfit to be President!”  They were later sued successfully for defamation. This incident led the The Goldwater rule – Section 7 in the American Psychiatric Association’s (APA) Principles of Medical Ethics, which states it is unethical for psychiatrists to give a professional opinion about public figures they have not examined in person, and from whom they have not obtained consent to discuss their mental health in public statements.

This rule has held sway for the last 50 years. However, recently the American Psychoanalytic Association (APsaA) e-mailed its members to inform them that they are not constrained by the Goldwater rule. So which stance is correct?

There are two competing ethical principles at stake. The first is the ethical responsibility of professionals not to cause harm to someone else by making public statements they have no business making. This is especially true when it comes to psychiatric diagnoses, because they carry a heavy and (in my opinion) unjustified stigma. The mere fact of being a public figure does not mean that medical professionals are free to bypass confidentiality and consent to make public speculations about your mental health.

Further, psychiatric diagnoses are especially complex and subjective. In order to make a accurate diagnosis you need a lot of background information about a person, and you need some professional interaction. This should ideally be a personal examination, however watching a video of another professional conducting an examination could suffice. But even then, the purpose of psychiatric diagnoses is to guide therapy. They are still fuzzy and subjective entities. It seems profoundly unethical to turn them against an individual, and use a formal diagnosis to medicalize their personality and behavior for non-therapeutic purposes.

When dealing with politicians, it is further very difficult for professionals to filter out their own ideology or personal feelings. It becomes too easy to use the tools of medicine for political fighting.

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Jul 10 2017

Why Are We Conscious?

Published by under Neuroscience

brain3While we are still trying to sort out exactly what processes and networks in the brain create consciousness, we are also still uncertain why we are conscious in the first place. A new study tries to test one hypothesis, but before we get to that let’s review the problem.

The question is – what is the evolutionary advantage, if any, of our subjective experience of our own existence? Why do we experience the color red, for example – a property philosophers of mind call qualia?

One answer is that consciousness is of no specific benefit. David Chalmers imagined philosophical zombies (p-zombies) who could do everything humans do but did not experience their own existence. A brain could process information, make decisions, and engage in behavior without actual conscious awareness, therefore why does the conscious awareness exist?

This idea actually goes back to soon after Darwin proposed his theory of evolution. In 1874 T.H. Huxley wrote an essay called, “On the Hypothesis that Animals are Automata.”  In it he argued that all animals, including humans, are automata, meaning their behavior is determined by reflex action only. Humans, however, were “conscious automata” – consciousness, in his view, was an epiphenomenon, something that emerged from brain function but wasn’t critical to it. Further he argued that the arrow of cause and effect led only from the physical to the mental, not the other way around. So consciousness did nothing. We are all just passengers experiencing an existence that carries on automatically.

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Jul 07 2017

Conspiracy Thinking and the Need for Certainty

conspiracy1The world is horrifically complicated and humans have developed a number of strategies to deal with that complexity. These strategies are necessary but imperfect. There is also always a trade-off, sacrificing detail and nuance for understandability.

One such strategy I have written about often is the need for simplicity. A saying, attributed to Albert Einstein with good references, goes: “Everything should be as simple as it can be, but not simpler.” He was talking about the art of making complex scientific knowledge accessible without making it wrong. Unfortunately, the desire for simplicity often leads to oversimplification, with important details and concepts lost or distorted.

There is another related strategy psychologist call the need for cognitive closure. One reference defines this need as:

“As a dispositional construct, the need for cognitive closure is presently treated as a latent variable manifested through several different aspects, namely, desire for predictability, preference for order and structure, discomfort with ambiguity, decisiveness, and close-mindedness.”

It is easy to see the trade-offs here. On the one hand it is good to be intellectually flexible, open-minded, and comfortable with ambiguity and uncertainty. Yet, this disposition can predispose one to indecisiveness, the “paralysis of analysis.” At some point we have to commit, even if tentatively. Structure and order in thought can also be positive things.

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Jul 06 2017

The Brain’s Wiring

Published by under Neuroscience

connectome5Cardiff University has released its latest scans of the wiring of the human brain. This now adds to a similar project in the US funded by the NIH.

The result is a stunning image of all the axons in the human brain – the wires that conduct signals and form networks and connections to other parts of the body. In addition to these wires there are also the neurons, which are the cell bodies of which the axons are part, and the glia, which are other cells in the brain that serve support functions but also play a role in modulating neuronal function.

These wiring images are part of various connectome projects – attempts at fully mapping all the connections within the human brain and their functions. These latest images from Cardiff are the result of the Siemens 3 Tesla Connectome MRI system. Essentially we are seeing the result of advances in both hardware and software technology.

The MRI scanners themselves are on the more powerful side. The “3 Tesla” refers to the power of the magnet. A typical hospital MRI scanner operates at 1.5 Tesla or 3 Tesla. There is a 10.5 Tesla MRI unit at the University of Minnesota which is used for the NIH connectome project. So 3 Tesla is a powerful MRI scanner, but no more so than the more powerful typical clinical MRI scanners.

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