Naked Science Forum
Life Sciences => Physiology & Medicine => Topic started by: EvaH on 01/06/2020 13:44:23
-
Jerry wants to know:
This is a topic which absolutely blows my socks off. How in the universe do flesh, blood and chemicals (neurotransmitters) form thoughts? What is a thought? How is it possible to have a thought? Or, a whole bunch of them? It doesn't matter to me, how many, just how can inanimate particles create a thought/thinking? My elbow doesn't use language. My ankles don't dream. My back doesn't come up with ideas. My kneecap can't carry on a conversation. How does what's inside our skulls, the tissues that comprise our brains, build, construct, develop, design, manufacture, thoughts? And how does it know how to do it and how is it done?
What do you think?
-
just how can inanimate particles create a thought/thinking?
In much the same way that a group of inanimate steel components can form a moving car, or inanimate components make a calculator. In the case of a brain the components are animated by chemical reactions and electrical signals (to over simplify it).
-
I'm not sure that anyone really knows how to explain consciousness yet, but I am personally convinced that it won't turn out to be anything more magical than a lot of electrochemical activity in a very large biological computer.
-
I'm not sure that anyone really knows how to explain consciousness yet, but I am personally convinced that it won't turn out to be anything more magical than a lot of electrochemical activity in a very large biological computer.
You have limited the scope to biological thought. In general, the computer who perform thinking process doesn't have to be biological.
-
AFAIK nobody has ever produced a useful definition of consciousness, so anything approaching an "explanation" is way over the horizon.
Functionally, the brain has a remarkable associative memory compared with any artificial device, but the difference seems to be quantitiative rather than qualitative.
-
AFAIK nobody has ever produced a useful definition of consciousness, so anything approaching an "explanation" is way over the horizon.
Functionally, the brain has a remarkable associative memory compared with any artificial device, but the difference seems to be quantitiative rather than qualitative.
How do you define "useful"? Is dictionary's definition not useful enough?
-
AFAIK nobody has ever produced a useful definition of consciousness, so anything approaching an "explanation" is way over the horizon.
Functionally, the brain has a remarkable associative memory compared with any artificial device, but the difference seems to be quantitiative rather than qualitative.
How do you define "useful"? Is dictionary's definition not useful enough?
At the time John Maddox's wrote What Remains to Be Discovered, there wasn't even a definition of life, and I don't think there is now either. There are a few words that everyone has an intuitive understanding of, but that are all but impossible to define formally. The dictionary is usually fatuous and circular:
Life: the state of being living rather than dead.
Energy: capacity to do work (Work: using energy)
Time: passing from the past into the future (Future: time yet to come)
Consciousness: awareness (Aware: cognizant, Cognizant: aware)
-
I think, therefore I am
The process of thought is what matters; you don't have to understand how it happens.
...but I agree it would be very interesting!
See: https://en.wikipedia.org/wiki/Cogito,_ergo_sum
We are a way for the universe to know itself.
-
Dictionary definitions tend to be of legal rather than scientific value. Hence such goodies as "a female bovine quadruped" or "a rigid planar surface supported on a multiplicity of legs". When talking about abstract qualities such as life or consciousness, a useful definition is one that distinguishes functionally between objects that possess it and those that don't. Life is fairly easy - it's something to do with transpiration and homeostasis, which are observable and testable. But consciousness seems beyond the grasp of those who use the term.
-
AFAIK nobody has ever produced a useful definition of consciousness, so anything approaching an "explanation" is way over the horizon.
Functionally, the brain has a remarkable associative memory compared with any artificial device, but the difference seems to be quantitiative rather than qualitative.
How do you define "useful"? Is dictionary's definition not useful enough?
At the time John Maddox's wrote What Remains to Be Discovered, there wasn't even a definition of life, and I don't think there is now either. There are a few words that everyone has an intuitive understanding of, but that are all but impossible to define formally. The dictionary is usually fatuous and circular:
Life: the state of being living rather than dead.
Energy: capacity to do work (Work: using energy)
Time: passing from the past into the future (Future: time yet to come)
Consciousness: awareness (Aware: cognizant, Cognizant: aware)
Many words which seem obvious and widely used may turn out to be not as well defined as we think they are, e.g:
- human
- red (color)
- mass
- temperature
-
Life is fairly easy - it's something to do with transpiration and homeostasis, which are observable and testable. But consciousness seems beyond the grasp of those who use the term.
The definition of transpiration and homeostasis themselves are related to life.
noun: transpiration
(of a plant or leaf) the exhalation of water vapour through the stomata.
noun: homeostasis
the tendency towards a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes.
adjective: physiological
relating to the branch of biology that deals with the normal functions of living organisms and their parts.
"physiological research on the causes of violent behaviour"
relating to the way in which a living organism or bodily part functions.
"slow down your body's physiological response to anger by breathing deeply"
-
Here is some update of scientific research on human consciousness.
https://www.nature.com/articles/d41586-019-02207-1#ref-CR8
Decoding the neuroscience of consciousness
Newly developed techniques for measuring brain activity are enabling scientists to refine their theories about what consciousness is, how it forms in the brain and where the boundaries lie between being conscious and unconscious. And as our understanding of consciousness improves, some researchers are beginning to build strategies for its manipulation, with the possibility of treating brain injuries, phobias and mental-health conditions such as post-traumatic stress disorder (PTSD) and schizophrenia.
A succession of breakthroughs followed, including the case of a 23-year-old woman who sustained a severe brain injury in a car accident in July 2005, which left her in a non-responsive state, also known as wakeful unawareness. She could open her eyes and exhibited cycles of sleep and wakefulness, but did not respond to commands or show signs of voluntary movement. She was still unresponsive five months later. In a first-of-its-kind study, Adrian Owen, a neuroscientist then at the University of Cambridge, UK, and now at Western University, and his colleagues observed the woman using fMRI while giving her a series of verbal commands1. When the team asked her to imagine playing tennis, they observed activity in a part of her brain called the supplementary motor area. When they asked her to imagine walking through her home, activity ramped up instead in three areas of the brain that are associated with movement and memory. The researchers observed the same patterns in healthy volunteers who were given identical instructions.
(https://media.nature.com/lw800/magazine-assets/d41586-019-02207-1/d41586-019-02207-1_16961074.jpg)
It has become increasingly clear, however, that consciousness is not confined to only one region of the brain. Various cells and pathways are engaged, depending on what is being perceived or the type of perception that is involved. Investigating the coordination of neural signalling might help researchers to find reliable signatures of consciousness. In a 2019 study that collected fMRI data from 159 people, researchers found that, compared with people in minimally conscious states and those under anaesthesia, the brains of healthy individuals had more complex patterns of coordinated signalling that also changed constantly5.
Plenty of unknowns remain. Scientists disagree about how study results should be interpreted, and measuring whether a person is ‘in’ or ‘out’ of consciousness is a challenge that differs from looking at what happens in the brain as it becomes aware of different types of information. Nevertheless, studies of brain function at various levels of consciousness are starting to offer alternative ways of looking at the brain at a mechanistic level. The hope, says Seth, is that consciousness researchers can “move to a more twenty-first century sort of psychiatry, where we can intervene more specifically in the mechanisms to resolve specific symptoms”.
-
Plenty of unknowns remain. Scientists disagree about how study results should be interpreted, and measuring whether a person is ‘in’ or ‘out’ of consciousness is a challenge that differs from looking at what happens in the brain as it becomes aware of different types of information
This kind of problem is an example of classification problems, which essentially compress information from many bits of input into fewer bits of output. In this case, the input has many bits, but the output is just 1 bit.
A simpler example with fewer bits of input can be seen in color classification.
(https://www.osa-opn.org/opn/media/Images/Articles/2019/1901/Features/Partha-img6.jpg)
Given a few bits representing RGB color, determine if it is considered as red.
We can treat those problems above using fuzzy logic instead of Boolean logic.
https://en.wikipedia.org/wiki/Fuzzy_logic
-
scientific research on human consciousness.
Naked Neuroscience podcast had a story this week about testing human consciousness using the sense of smell.
- When presented with attractive or repulsive smells, breathing patterns change.
- When those changes in breathing don't happen, that does not bode well for a return to consciousness
The smell neurones in our noses feed directly into the lower part of the brain, which controls many instinctive and autonomic functions.
See: https://www.thenakedscientists.com/articles/interviews/sniff-test-determine-consciousness
https://en.wikipedia.org/wiki/Olfactory_system#Central
However, this low-level awareness operates in many species, and does not help with high-level consciousness - one that can think about thinking, for example.
-
The definition of transpiration and homeostasis themselves are related to life.
noun: transpiration
(of a plant or leaf) the exhalation of water vapour through the stomata.
noun: homeostasis
the tendency towards a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes.
You should have stopped there. Things that don't transpire or respire aren't alive. Dead things do not actively attempt to restore equilibrium. "especially...." leads you to the most common usage of the noun, not a definition of it.
We have tests to determine whether a patient is clinically unconscious, i.e. incapable of voluntary action but still capable of autonomic function, but the philosophical use of "consciousness" remains undefined.
-
Life is fairly easy - it's something to do with transpiration and homeostasis
Transpiration:
"Exhalation through the skin or surface of the body; formerly, also, evaporation." begs a definition of a body.
"The exhalation of watery vapour from the surface of the leaves and other parts of plants" begs a definition of plants and excludes non plants.
My central heating boiler emits water vapour.
Homeostasis:
"The maintenance of a dynamically stable state within a system by means of internal regulatory processes that tend to counteract any disturbance of the stability by external forces."
Any of the circuits I've designed with negative feedback exhibit homeostasis.
-
An old colleague was asked to define a medical device. He said "something you can hit with a golf club, that makes sick people better". At some point you need to apply common sense. However you define "body" (and in physics it is anything that you can hit with a golf club) it is still meaningless to someone who doesn't speak English.
It is absolutely true that inanimate objects can exhibit homeostasis, but a generalised NFB circuit doesn't - the output is a function of the input, determined by the inverse transfer function of the feedback loop.
-
We have tests to determine whether a patient is clinically unconscious, i.e. incapable of voluntary action but still capable of autonomic function, but the philosophical use of "consciousness" remains undefined.
Why do you keep saying that consciousness is undefined just because there is still no concensus about the clear cut boundary between conscious and non-conscious things? If that kind of strict requirement is applied consistently, then a lot of concepts would be undefined, even a simple one such as red color.
-
A feedback loop absolutely does exhibit homeostasis, it's why NFB reduces noise, distortion and gain variation in an amplifier, why a voltage regulator regulates, and why a PLL remains locked in the presence of a disturbance.
I can't remember the detail of what Maddox had to say now after 15 years, but he'd given the matter a lot more thought than you seem to have.
-
Here is an article clearly answers the question in this thread.
https://www.psychologytoday.com/us/blog/finding-purpose/201902/what-actually-is-thought-and-how-is-information-physical
Google the word “thought” and you will find this uninformative, circular definition: “an idea or opinion produced by thinking, or occurring suddenly in the mind.” The Merriam-Webster dictionary defines “think” in a similarly unhelpful way: “to form or have in the mind.” But what actually is a thought?
A thought is a representation of something. A representation is a likeness—a thing that depicts another thing by having characteristics that correspond to that other thing. For example, a picture, image, imprint or mold of an object is a representation of that object.
Modern information theory has taught us that information is a physical entity. Rolf Landauer, an IBM physicist, stated the case:
"Information is not an abstract entity but exists only through a physical representation, thus tying it to all the restrictions and possibilities of our real physical universe” “Information is inevitably inscribed in a physical medium."2
Elsewhere, Landauer explained further:
"Information is not a disembodied abstract entity; it is always tied to a physical representation. It is represented by engraving on a stone tablet, a spin, a charge [i.e. of elementary particles such as electrons], a hole in a punched card, a mark on paper, or some other equivalent."3
So too, no thought can occur without its neural substrate.
A map is an analog of the environment it is depicting—it corresponds to it. An analog is something that is similar to, or comparable to, something else either in general or in some specific detail. Maps can be regarded as a form of analogy-making (‘A’ is to ‘B’ as ‘X’ is to ‘Y’).
Cognitive scientist Douglas Hofstadter and psychologist Emmanuel Sander suggest that all thoughts are built from analogy-making. They propose that categorization through analogy-making is “the driving force behind all thought.”4 Our brains detect similarities or correspondences between newly and previously encountered situations, enabling the application of previously learned information to the new situation. “The very essence of an analogy is that it maps some mental structure onto another mental structure.”5
The sense of self begins with the nervous system’s map of its own body
The neuroscientist Antonio Damasio proposed a model for how the self emerges in gradations, in organisms of increasing evolutionary complexity. According to this model, a simple organism develops a rudimentary form of ‘self-awareness’ by forming a map of its body and its position in the physical space it occupies. Damasio calls the most basic representation of self the protoself—a nonconscious state that many species may have. It’s a very basic level of awareness comprised of neural patterns representing or mapping the body's physical structure.11
In summary: Information is physical and relational, and we are networks of information
Thoughts are not ethereal. They are representations of matter and are encoded in matter. They have shape and weight. Abstract ideas are analogically built from more concrete sensory representations. The sense of self is built from self-representations. Thoughts are forms of information, and all information is physical and relational. It ‘feels’ like something to ‘have’ a thought and to ‘be’ a self because we are that information, recursively reflecting on itself in an infinite regress.11
-
A feedback loop absolutely does exhibit homeostasis, it's why NFB reduces noise, distortion and gain variation in an amplifier, why a voltage regulator regulates, and why a PLL remains locked in the presence of a disturbance.
I can't remember the detail of what Maddox had to say now after 15 years, but he'd given the matter a lot more thought than you seem to have.
So your amplifier has no output? What is the point of it? Mine have loads of NFB so that the output is a function of the input, and my PLLs lock onto the chosen input. If the NFB loop is nonlinear, say an integrator or differentiator circuit, the output depends on the history, rate of change, peak, or whatever function you have chosen, of the input - it is by no means constant.
It is true that the classic operational amplifier analysis depends on maintaining a null at the summing junction, but the system as a whole is not homeostatic. I thought about little else for some 20 years, and still like to use analog systems for fun. I go back to the days of Ragazzini and Philbrick designs!
I guess any steamhead will point out that the Watt governor maintains constant speed against a variable load, so is a true homeostatic device, but a voltage stabiliser does so by comparing the output with a constant reference input, so isn't actually a homeostat so much as an opamp with a fixed input!
-
I guess any steamhead will point out that the Watt governor maintains constant speed against a variable load, so is a true homeostatic device, but a voltage stabiliser does so by comparing the output with a constant reference input, so isn't actually a homeostat so much as an opamp with a fixed input!
Don't you think that Watt governor also has a constant reference input, which is desired engine speed?
Voltage stabiliser also has to work against variable load, what makes it different?