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I recently watched a discussion with a neuroscientist who was explaining the left brain-right brain difference, as it's currently understood. He said the left h

I recently watched a discussion with a neuroscientist who was explaining the left brain-right brain difference, as it's currently understood. He said the left hemisphere evolved to focus its attention on a small field of perception, mainly to find food. The right hemisphere evolved to detect threats from the entire field of perception. The way we train LLMs, to my understanding, is to predict the next word. That's a narrow task, and in my interpretation is a left brain dominant task. What can happen with the left brain is that it can become so focused on the task at hand, and so wedded to the mental models used to accomplish that task, that it loses touch with reality as broadly perceived by the right brain. The neuroscientist claimed schizophrenia is a disorder of too little inhibition of left brain inferences by the right brain. (I am taking him at his word on this.) The left brain's mental models lose touch with ground truth. This can result in hallucinations. If I am correct that LLMs act like the left brain in that they are relying on models that they developed during training and focusing on a single task, absent sensory experience, then hallucination may actually be a good term. I do think that the use of anthropomorphic terms is problematic because it suggests the same phenomenon, rather than an analogous phenomenon.

heavyset_go 3y ago
> The neuroscientist claimed schizophrenia is a disorder of too little inhibition of left brain inferences by the right brain. This sounds very "bicameral mind"-y[1] to me, and it's worth noting that schizophrenia's causes haven't been pinned down accurately yet. There are a ton of hypotheses around how schizophrenia develops/works, but none are conclusive. I bring it up because when you hear relatively simple explanations about the left and right brain and the tasks they're "assigned" or "designed" to process, or how their perceived differences contribute to mental illness, it should be taken with a grain of salt. Similarly, I'd hesitate to compare LLMs or any NNs to actual human brains. Their similarities are entirely superficial, and beyond the very basic topology of NNs that were inspired by specific types of neurons, the similarities end there. [1] https://en.wikipedia.org/wiki/Bicameral_mentality#The_Origin_of_Consciousness https://en.wikipedia.org/wiki/Bicameral_mentality#The_Origin...
im3w1l 3y ago
Heavyset_go wrote a good answer from one point of view, I would like to add another. Namely that "hallucination" the word means quite different things for a human and an llm. For a human a hallucination roughly refers to a sensory experience where you experience something that isn't there. For an LLM it refers to making something up when answering a question. A closer phenomenon to that would be a false memory, but even that isn't quite the same thing. The thing is that we want LLM's to learn patterns, we want them to generalize from its training data to a certain extent. Hallucinations are basically undesirable instances of this. The user expects to hear about somethign that does exist, but the answer they get is rather about somethign that the LLM has extrapolated might exist.

heavyset_go 3y ago

> The neuroscientist claimed schizophrenia is a disorder of too little inhibition of left brain inferences by the right brain. This sounds very "bicameral mind"-y[1] to me, and it's worth noting that schizophrenia's causes haven't been pinned down accurately yet. There are a ton of hypotheses around how schizophrenia develops/works, but none are conclusive. I bring it up because when you hear relatively simple explanations about the left and right brain and the tasks they're "assigned" or "designed" to process, or how their perceived differences contribute to mental illness, it should be taken with a grain of salt. Similarly, I'd hesitate to compare LLMs or any NNs to actual human brains. Their similarities are entirely superficial, and beyond the very basic topology of NNs that were inspired by specific types of neurons, the similarities end there. [1] https://en.wikipedia.org/wiki/Bicameral_mentality#The_Origin_of_Consciousness https://en.wikipedia.org/wiki/Bicameral_mentality#The_Origin...

im3w1l 3y ago

Heavyset_go wrote a good answer from one point of view, I would like to add another. Namely that "hallucination" the word means quite different things for a human and an llm. For a human a hallucination roughly refers to a sensory experience where you experience something that isn't there. For an LLM it refers to making something up when answering a question. A closer phenomenon to that would be a false memory, but even that isn't quite the same thing. The thing is that we want LLM's to learn patterns, we want them to generalize from its training data to a certain extent. Hallucinations are basically undesirable instances of this. The user expects to hear about somethign that does exist, but the answer they get is rather about somethign that the LLM has extrapolated might exist.