UPDATED Apr. 2023 - I'm excited by ChatGPT's possibilities in terms of facilitating advanced learning.
For example, I got enlightening answers to questions that I had
confronted when I first studied neuroscience. The examples below are
taken from a very recent session I had with ChatGPT (mid Jan. 2023.)
 |
| Source: https://neurosciencestuff.tumblr.com |
In case you're not familiar with ChatGPT, it's a very sophisticated "chatbot" - though, if you call it that way, it'll correct you! 'I am not a "chatbot", I am a language model, a sophisticated type of AI algorithm trained on vast amounts of text data to generate human-like text'.
For a high-level explanation of how ChatGPT actually works - which also gives immense insight into its weaknesses, there's an excellent late Jan. 2023 talk by Stephen Wolfram, the brilliant author of the Mathematica software and of Wolfram Alpha, a product that could be combined with ChatGPT to improve its factual accuracy and math skills. (Apr. 2023 : for another excellent explanation that is neither too technical nor too simple, check out this video by YouTube's creator Arvin Ash.)
Mar. 2023 UPDATE: this article focuses on some of the impressive abilities of ChatGPT. For a good glimpse of its weaknesses, in the context of poor intuition about Physics, as well as Math errors, check out this great short video: ChatGPT does PhysicsI was planning to write a separate article about miscellaneous WRONG ANSWERS I got from ChatGPT... but with version 4 coming out, I'll wait. I just posted a couple of examples as an addendum to this article, at the very end.
The following is the transcript of my mid-Jan. 2023 session
Notice how our chats, below, starts with broad generalities... and then, at my prodding, we get into the 'nitty-gritty details'. In some cases, I asked leading questions, hoping to get to a particular answer...(Disclaimer: I have not reviewed every small single detail for correctness.)
What makes the "human thought process" different from that of a "machine learning model"?
The human thought process is the result of the complex interactions between the brain, the body, and the environment. The brain is a highly sophisticated organ that allows us to perceive, think, feel, and make decisions. It also allows us to have consciousness, self-awareness, emotions and intentions. Human thought process is influenced by a variety of factors, including genetics, upbringing, personal experiences, and cultural background.
On the other hand, a machine learning model, like me, is an artificial system that is trained on large amounts of data to perform a specific task, such as image recognition, language translation, or text generation. The process of training a machine learning model involves feeding it with labeled data and adjusting the model's parameters so that it can make accurate predictions. The output of a machine learning model is based on the patterns it has learned from the data, but it does not involve consciousness, self-awareness, emotions, or intentions. It does not have the ability to experience the world or to perceive it in the same way that humans do.
let's get more technical, please, about the "human thought process", at a neural level. What can you tell me?
The human thought process is a complex phenomenon that is still not fully understood by scientists. However, it is believed to be the result of the activity of the brain's neurons, which are the basic units of the nervous system.
At a neural level, the human thought process is thought to involve the communication and processing of information by neurons through electrical and chemical signals. Neurons are connected to each other through structures called synapses, and they communicate with each other by sending electrical impulses called action potentials. When an action potential reaches the end of a neuron (the axon terminal), it triggers the release of chemicals called neurotransmitters, which then bind to receptors on the next neuron, transmitting the impulse.
This communication between neurons forms networks in the brain, which are thought to be the neural basis of mental processes such as perception, memory, emotion, and decision-making. Different regions of the brain are specialized for different functions, such as vision, hearing, touch, and motor control, and different regions are interconnected, allowing for the integration of information from different senses and the formation of complex thoughts and actions.
Scientists have also found that the human brain has the ability to adapt and change, a property called neuroplasticity, which allows it to learn and form new connections, this property is thought to be behind the process of learning, memory, and the ability to adapt to new situations.
It's important to note that this is a simplified explanation of a complex phenomenon, and much is still not known about how the brain works and how it gives rise to the mind.
Can you elaborate on spacial {oops, I meant "spatial"} vs. temporal integration of signals in neurons, as they converge to the "trigger zone"?
Spatial integration in neurons refers to the process by which input from multiple sources is combined and integrated at the level of a single neuron. This happens when a neuron receives input from multiple synapses located at different points on its dendrites (the tree-like branches that receive input from other neurons). When an action potential reaches the end of a neuron (the axon terminal), it triggers the release of chemicals called neurotransmitters, which then bind to receptors on the next neuron, transmitting the impulse.
This process is important because it allows neurons to integrate information from multiple sources and make decisions based on the combined input. For example, in the visual system, input from multiple retinal ganglion cells is integrated by a single neuron in the primary visual cortex, allowing it to detect patterns in the visual scene.
Temporal integration, on the other hand, refers to the process by which a neuron integrates input over time. This can happen when a neuron receives inputs at different frequencies or at different phases of an oscillation. For example, a neuron in the auditory system might integrate input from multiple hair cells in the inner ear over time to detect the frequency of a sound.
The integration of signals from multiple sources in space and time is thought to be critical for the generation of complex patterns of activity in the brain, which are thought to underlie mental processes such as perception, memory, emotion, and decision-making.
The trigger zone is a term used to describe the point of integration in a neuron, it's the place where input signals are integrated, and where the decision is made whether to generate an action potential or not. It's usually considered to be the initial segment of the axon, where the voltage-gated ion channels are located. The trigger zone is where the electrical signals are converted into chemical signals, allowing the information to be transmitted to the next neuron via the release of neurotransmitters.
neurotransmitters can be both inhibiting and I forget what the opposite term is. What is it?
Neurotransmitters can be either excitatory or inhibitory, depending on their effects on the electrical activity of the postsynaptic neuron.
Excitatory neurotransmitters are those that increase the likelihood of an action potential occurring in the postsynaptic neuron, by depolarizing the membrane potential. They do this by binding to receptors that increase the influx of positively charged ions, such as sodium or calcium, into the cell. Examples of excitatory neurotransmitters include glutamate and acetylcholine.
Inhibitory neurotransmitters, on the other hand, decrease the likelihood of an action potential occurring in the postsynaptic neuron, by hyperpolarizing the membrane potential. They do this by binding to receptors that increase the efflux of positively charged ions, such as chloride, out of the cell or decrease the influx of positively charged ions. Examples of inhibitory neurotransmitters include GABA and glycine.
The balance between excitatory and inhibitory neurotransmission is crucial for the proper function of the nervous system. It allows for the generation of complex patterns of activity in the brain, which are thought to underlie mental processes such as perception, memory, emotion, and decision-making.
Can the same neurotransmitter be both excitatory AND inhibitory? What would determine its modality?
Yes, the same neurotransmitter can be both excitatory and inhibitory depending on the type of receptors it binds to. The modality of neurotransmitter action is determined by the type of receptors it binds to on the postsynaptic neuron.
For example, acetylcholine (Ach) is an excitatory neurotransmitter that binds to nicotinic acetylcholine receptors (nAChRs) and muscarinic acetylcholine receptors (mAChRs) in the nervous system. nAChRs are ionotropic receptors that allow the influx of positively charged ions, such as sodium, into the cell, leading to depolarization and excitation of the postsynaptic neuron. mAChRs are metabotropic receptors that activate intracellular signaling pathways leading to excitation of the postsynaptic neuron, but it does not involve the direct influx of ions.
On the other hand, some studies have shown that Ach can act as an inhibitory neurotransmitter in certain situations. For example, in the hippocampus, a brain region involved in learning and memory, Ach can bind to muscarinic receptors on interneurons, leading to hyperpolarization and inhibition of these cells.
In summary, the same neurotransmitter can have different effects on the postsynaptic neuron, depending on the type of receptors it binds to. The modality of neurotransmitter action is determined by the balance between excitatory and inhibitory neurotransmission, which is crucial for the proper function of the nervous system.
 |
| Source: www.researchgate.net/figure/Dendritic-spines-of-RGCs-They-are-the-primary-postsynaptic-site-of-excitatory_fig3_5293556 |
'dendritic spine' (depicted in the above diagram) is the term I'm fishing for, in my next questions to ChatGPT.
what's the name of the structure where a dendrite makes contact with an axon?
The structure where a dendrite makes contact with an axon is called a synapse. A synapse is the junction between two neurons, or between a neuron and a muscle or gland cell, where electrical signals are converted into chemical signals, allowing the information to be transmitted from one neuron to the next.
The dendrites of a neuron receive input from other neurons, and the axon sends output to other neurons, muscles or gland cells. When an action potential reaches the end of the axon, it triggers the release of chemical neurotransmitters from the axon terminal into the synapse. These neurotransmitters then bind to receptors on the dendrites of the postsynaptic neuron, transmitting the impulse.
The synapse is a complex structure that includes the presynaptic terminal, the postsynaptic membrane and the extracellular space between them, where neurotransmitters are released and bind to receptors. The activity at the synapse is regulated by a wide range of mechanisms that control the release, reuptake, degradation and synthesis of neurotransmitters, as well as the number and sensitivity of receptors.
In summary, a synapse is the point of contact between two neurons where electrical signals are converted into chemical signals and transmitted from one neuron to the next. The activity at the synapse is regulated by a wide range of mechanisms that control the release, reuptake, degradation and synthesis of neurotransmitters, as well as the number and sensitivity of receptors.
I was thinking of a term involving the word "spine", in that process you just described
I apologize for the confusion, the term you might have been thinking of is "spine" or dendritic spine, which is a small protrusion or knob that forms on the dendrites of neurons. Dendritic spines are the site of most excitatory synapses in the brain, where the majority of input from other neurons is received. They are small, specialized structures that contain neurotransmitter receptors and are thought to play an important role in the process of synaptic plasticity, which is the ability of the strength of synapses to be increased or decreased in response to changes in neural activity.
Dendritic spines are small, dynamic structures that can change shape and number in response to different forms of synaptic plasticity, such as long-term potentiation (LTP) and long-term depression (LTD). This allows for the formation of new synapses, the strengthening or weakening of existing synapses and the modulation of neural networks.
In summary, dendritic spines are small protrusions that form on the dendrites of neurons and are the site of most excitatory synapses in the brain, where the majority of input from other neurons is received. They are small, specialized structures that contain neurotransmitter receptors and are thought to play an important role in the process of synaptic plasticity, allowing for the formation of new synapses, the strengthening or weakening of existing synapses and the modulation of neural networks.
Feb. 2, 2023 addendum
A weakness of ChatGPT seems to be that it tends to sound confident, even at times when it shouldn't!
Asking the newly-updated "Jan. 30" version:
Q: why do so many medieval artwork pieces depict threatening giant snails?
A:
Medieval art often depicted giant snails as symbols of slow, steady progress and perseverance, especially in the context of spiritual journeys and moral lessons. Snails also had symbolic associations with the "hard shell" of sin, which could be "penetrated" by divine grace. The depiction of snails as giant and threatening was likely meant to evoke a sense of awe and reverence for the moral lessons they represented.
It sounds very self-assured, doesn't it? But asking that same question to Google brings up this top website (from the Smithsonian museum), with a variety of answers - and repeated admission that they're all just guesses!
Feb. 28, 2023 addendum
In college, I had one professor who, whenever he didn't really know the answer to something, he'd bullshit his way, trying to sound convincing! Alas, ChatGPT displays that same identical "personality" trait... Example:
"The Legend of Bagger Vance" was indeed a 2000 film... BUT it was directed by Robert Redford instead! What Jeremy Leven did was the screenplay. And Tom Hanks was NOT involved! Sources: IMDB , Rotten Tomatoes , Wikipedia
You can try out ChatGPT yourself at this link (free, but registration required) : ChatGPT
Thanks for the information and link.
ReplyDelete