This Mental Construction Overview touches upon the highlights of the impact of neural organization of reality on our thinking. Neuron functioning organizes chaotic reality into patterns. First, abstraction of multi featured data of various types arises from the neural threshold and its all-or-none discharge. Then, as the patterns are passed up the brain’s neural pathways, the neural learning rule is applied to fix mental maps in the cortex. These mental maps allow easy associations across a wide domain—current situation, past memories, emotional states, and future goals.
The journey from sense datum to thought starts with the neural threshold and the Almost Gate.
The neuron’s All-of-None firing property gives rise to the Almost Gate, where very closely similar inputs will produce the same output. Different inputs are treated identically. In addition, the looseness of the Almost Gate allows completions that can be creative, yet lead us astray at other times.
From individual neurons, subject to the Almost Gate, larger groups of neurons accept masses of sensory input and organize themselves into patterns. Self-Organizing Maps (SOMs) eliminate arguments that require a homunculus, a little person in the head, directing things.
The brain we use is built upon earlier brains, which developed and worked before speech. A breakdown of pre-Homo sapiens has three significant stages, which are useful in understanding our brains, since the structures are preserved, albeit modified from their original incarnations.
- The old brain, the spinal cord and brainstem, responds to the world immediately. In humans, we call the goal, homeostasis, maintenance of the organism’s internal environment at levels where its biological processes flourish.
- The midbrain lies atop the old brain and adds features to it. Its limbic components support remembering significant events. This is done implicitly. It remembers only events with the potential to affect one’s safety, access to food, or pleasure.
- The new brain, atop the midbrain, has a cortical cap which takes the raw sensory input and merges it with the limbic’s emotional assessment. It extracts more sensory information, while also integrating the various sensory inputs into a model of the world, our environment. The new brain is often called the mammalian brain. No language yet, not until the prefrontal brain expands enormously in Homo sapiens.
The human brain has a vastly expanded cortical frontal lobe, to process the output of the mammalian brain. With the brain’s expansion, we can experience self-aware consciousness and the appearance of choice.
- Its wiring makes it a general-purpose rule extractor.
- The Self-Organized Maps of the sensory world, merged with their emotional content, theories relating them, and past occurrences, are sifted for further relationships.
- Words are the packages that culture has found useful in organizing our worldview. We apply these words to products of older-brain structures that developed prior to the existence of words.
As our patterns move further from immediate sense data, they increase in abstraction and tie in with our memories and knowledge. We have language that channels our perceptions into culturally organized chunks.
The 100-Step Rule arises from the observations that it takes 0.5 s for a sensory information to reach consciousness and each neuron take several milliseconds to fire. This coarse estimate gives some scaffolding for the path of a sensation to a conscious thought in the prefrontal cortex.
Psychological evidence, like the data yielded by common word association tests, suggests that meaning (semantic) maps cluster our knowledge into a reality of our organization.
Surprisingly, only 0.1% of all cortical neurons connect to the outside world, either through sensory or motor output. That implies that the processed sense data goes through many steps to our executive region of the frontal lobe and then through a correspondingly lengthy chain until the motor nerves trigger an action. All the steps in the chain are subject to the looseness of the Almost Gate.
- Mathematically, if the Almost Gate is 99% high, the likelihood of two identical inputs arriving at the executive region as the same is only 60% because of loose linkages with memories and emotional content.
- Another way to look at this is to consider two people having an identical sensory experience. There is only a three-fifths chance that they will have the same input into their executive region.
Simple logic develops naturally from repeated experience. Automatic pattern categorization, compared with memory of past occurrences, develops into logic. The first step requires noticing stable objects, followed by resulting conditions. However, before we develop our own logic, we learn language that has built-in logical terms—and, or, not, implies, true, and false—and use them to logically organize our world. The result of a simplified neural network is appropriate assignment of truth values to logical operators, through experience with no outside oversight.
These implications are sometimes made explicit in this website. Some have clear consequences, but it was too distracting to mention during the development of the overall argument.
- We think deductively with words, but we also think inductively with patterns.
- Individuality. Idiosyncratic genetic and biological factors. Unique individualistic experiences.
- The Almost Gate and its looseness allow for creativity, but also produce errors.
- Philosophical oppositions, like subjectivity-objectivity and universals-experiential, are productively understood with the Almost Gate filtering our experience.
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