Jacob—I read your 2015 essay. It is interesting and makes some fruitful points.
I am puzzled, though, about when nervous systems are supposed to have evolved this ‘Universal Learning Machine’ (ULM) capability. Did ULMs emerge with the transition from invertebrates to vertebrates? From rat-like mammals to social primates? From apes with 400 cc brains to early humans with 1100 cc brains?
Presumably bumblebees (1 million neurons) don’t have ULM capabilities, but humans (80 billion neurons) allegedly do. Where is the threshold between them—given that bumblebees already have plenty of reinforcement learning capabilities?
I’m also puzzled about how the ULM perspective can accommodate individual differences, sex differences, mental disorders, hormonal influences on cognition and motivation, and all the other nitty-gritty wetware details that seem to get abstracted away.
For example, take sex differences in cognitive abilities, such as average male superiority on mental rotation tasks and female superiority on verbal fluency—are you really arguing that men and women have identical ULM capabilities in their neocortexes that are simply shaped differently by their information inputs? And it just happens that these can be influenced by manipulating sex hormone levels?
Or, take the fact that some people start developing symptoms of schizophrenia—such as paranoid thoughts and auditory hallucinations—in their mid-20s. Sometimes this dramatic change in neocortical activity is triggered by over-use of amphetamines; sometimes it’s triggered by a relationship breakup; often it reflects a heritable family propensity towards schizotypy. Would you characterize the onset of schizophrenia as just the ULM getting some bad information inputs?
I am puzzled, though, about when nervous systems are supposed to have evolved this ‘Universal Learning Machine’ (ULM) capability.
The core architecture of brainstem, basal ganglia, thalamus and pallium/cortex is at least 500 million years old.
Where is the threshold between them
You are looking for some binary threshold which simply does not exist, the dominance of intra over inter lifetime learning is continuous and depends on brain size * lifespan or cumulative optimization power.
Likewise one could ask: What is the threshold between between Alexnet and VIT L/14@336px?
are you really arguing that men and women have identical ULM capabilities in their neocortexes that are simply shaped differently by their information inputs?
What would make you suspect I would argue that?
From the ULM post, the core hypothesis:
The universal learning hypothesis proposes that all significant mental algorithms are learned; nothing is innate except for the learning and reward machinery itself (which is somewhat complicated, involving a number of systems and mechanisms), the initial rough architecture (equivalent to a prior over mindspace), and a small library of simple innate circuits (analogous to the operating system layer in a computer). In this view the mind (software) is distinct from the brain (hardware). The mind is a complex software system built out of a general learning mechanism.
Significant mental algorithms are things like adding numbers, forming sentences, recognizing attractive vs unattractive mates, bipedal walking, courtship strategies, etc—essentially almost everything that infants can’t do at birth, which is nearly everything for humans.
Both the hardware and initial rough architecture—the architectural prior—are innate, which is where you see the genetic differences between individuals, families, races, sexes, species, etc.
And it just happens that these can be influenced by manipulating sex hormone levels?
“it just happens” is massively underselling how much effect the sex hormones have on which genetics activate, isn’t it? somewhere on here someone did an analysis of how genetically-defined mouse neurons train the recognition of mouse squeaks, or something like that, which would be a wonderful bridge between your field and practical brain understanding.
(slightly off topic question I’ve been wanting to ask—are you familiar with evolutionary game theory?)
My phrasing was slightly tongue-in-cheek; I agree that sex hormones, hormone receptors in the brain, and the genomic regulatory elements that they activate, have pervasive effects on brain development and psychological sex differences.
Off topic: yes, I’m familiar with evolutionary game theory; I was senior research fellow in an evolutionary game theory center at University College London 1996 − 2000, and game theory strongly influenced my thinking about sexual selection and social signaling.
Jacob—I read your 2015 essay. It is interesting and makes some fruitful points.
I am puzzled, though, about when nervous systems are supposed to have evolved this ‘Universal Learning Machine’ (ULM) capability. Did ULMs emerge with the transition from invertebrates to vertebrates? From rat-like mammals to social primates? From apes with 400 cc brains to early humans with 1100 cc brains?
Presumably bumblebees (1 million neurons) don’t have ULM capabilities, but humans (80 billion neurons) allegedly do. Where is the threshold between them—given that bumblebees already have plenty of reinforcement learning capabilities?
I’m also puzzled about how the ULM perspective can accommodate individual differences, sex differences, mental disorders, hormonal influences on cognition and motivation, and all the other nitty-gritty wetware details that seem to get abstracted away.
For example, take sex differences in cognitive abilities, such as average male superiority on mental rotation tasks and female superiority on verbal fluency—are you really arguing that men and women have identical ULM capabilities in their neocortexes that are simply shaped differently by their information inputs? And it just happens that these can be influenced by manipulating sex hormone levels?
Or, take the fact that some people start developing symptoms of schizophrenia—such as paranoid thoughts and auditory hallucinations—in their mid-20s. Sometimes this dramatic change in neocortical activity is triggered by over-use of amphetamines; sometimes it’s triggered by a relationship breakup; often it reflects a heritable family propensity towards schizotypy. Would you characterize the onset of schizophrenia as just the ULM getting some bad information inputs?
The core architecture of brainstem, basal ganglia, thalamus and pallium/cortex is at least 500 million years old.
You are looking for some binary threshold which simply does not exist, the dominance of intra over inter lifetime learning is continuous and depends on brain size * lifespan or cumulative optimization power.
Likewise one could ask: What is the threshold between between Alexnet and VIT L/14@336px?
What would make you suspect I would argue that?
From the ULM post, the core hypothesis:
Significant mental algorithms are things like adding numbers, forming sentences, recognizing attractive vs unattractive mates, bipedal walking, courtship strategies, etc—essentially almost everything that infants can’t do at birth, which is nearly everything for humans.
Both the hardware and initial rough architecture—the architectural prior—are innate, which is where you see the genetic differences between individuals, families, races, sexes, species, etc.
“it just happens” is massively underselling how much effect the sex hormones have on which genetics activate, isn’t it? somewhere on here someone did an analysis of how genetically-defined mouse neurons train the recognition of mouse squeaks, or something like that, which would be a wonderful bridge between your field and practical brain understanding.
(slightly off topic question I’ve been wanting to ask—are you familiar with evolutionary game theory?)
My phrasing was slightly tongue-in-cheek; I agree that sex hormones, hormone receptors in the brain, and the genomic regulatory elements that they activate, have pervasive effects on brain development and psychological sex differences.
Off topic: yes, I’m familiar with evolutionary game theory; I was senior research fellow in an evolutionary game theory center at University College London 1996 − 2000, and game theory strongly influenced my thinking about sexual selection and social signaling.