Exploring Intelligence - Neocortex

Get out a deck of playing cards. Take six cards and stack them on top of each other. (Go ahead and do it.) See how thick those six cards are? That is the thickness of your neocortex. Stretched out flat your neocortex is about the size of a dinner napkin. Your neocortex is all wrinkled up, covering the surface of your brain.

A lot of stuff happens in the neocortex. The neurons are so tightly packed it is difficult to count them, but the current estimate is 30 billion.

30 billion is one of those numbers that is so big it is hard to imagine.

These neurons sometimes referred to as nerve cells, contain our memories, knowledge, skills, and life experience.

In other words, they have a big job to do. Understanding the neocortex and its neurons will help us sort out how the human brain learns, which can help us with simplifying the overabundance of theories and materials claiming to help kids learn.

So let’s dive even farther into this amazing layer of crumpled brain.

There is a hierarchical flow, but it is not a one-way deal. Information is fed both directions.

There are many types of neurons, pyramidal neurons (which happen to be shaped like pyramids), make up about 80%.

Every layer of the cortex except the top one contains these pyramidal neurons.

Each of these pyramidal neurons (remember there are 30 billion neurons and 80% of them are pyramidal?) contains 5,000-10,000 synapses. We are not sure exactly how many because it is hard to see and count things this tiny.

But let’s just underestimate and pretend there are only 1000 synapses on each of the pyramidal neurons.

That would mean our neocortex has 30 trillion synapses.

30 billion neurons, 30 trillion synapses, both unimaginable numbers.

One of the most interesting things about the neocortex is that it has the same structure throughout. We have often mapped the brain by function, hoping this would reveal information about the how the brain works. Although we can map different cognitive activities to different areas of the brain, we also know that the map is changeable.

For example, people born deaf use “auditory” portions of their brain for visual input. People born blind, use the “visual” portion of their brain to read braille, not the “motor-touch” area of the brain.

This leads to the question…Is brain mapping a physiologically correct idea? Does our brain even do different things with visual, auditory, and tactile input?

Vernon Mountcastle, a neuroscientist at John Hopkins put together an organizing principle of cerebral function based on the uniformity of the neocortex. It was a simple idea but has yet to be fully embraced. He proposed that the neocortex is doing the same thing with all input. It is a function or operation, and this is why the structure of the different areas that process visual, auditory and touch all look the same.

“Here was the Rosetta stone of neuroscience-a single paper and a single idea that united all the diverse and wondrous capabilities of the human mind. It united them under a single algorithm. In one step it exposed the fallacy of all previous attempts to understand and engineer human behavior as diverse capabilities.” - Jeff Hawkins, On Intelligence

Although Mountcastle published his paper, “An Organizing Principle for Cerebral Function” in 1978 it has remained mostly unknown and/or ignored by the scientific community at large.

The concept may be hard to believe but there is a growing amount of research that gives support to this idea. We have all heard about neuroplasticity, the ability of the brain to rewire itself. Newborn ferrets can be surgically rewired so that the animals’ eyes send signals to the area of the cortex where hearing normally develops. The result is that the ferrets see with the auditory area of their brain.

Could it be that cells are not born to specialize in vision, hearing, or touch, but that they learn based on need?

Environment forms our brain cells function.

“Genes dictate the overall architecture of the cortex including the specifics of what regions are connected together, but within that structure, the system is highly flexible.” Jeff Hawkins, On Intelligence

Information travels to our cortex in the same form, no matter how it entered our body. To our cortex, there is no ‘visual input’. There is just input. Our perception and knowledge are based on the patterns of input.

“Mountcastle was right. There is a single powerful algorithm implemented by every region of the cortex.” Jeff Hawkins

The brain itself has no senses. This is why brain surgery can be performed while a patient is not sedated, the brain does not feel.

All your brain receives spatial and temporal patterns on axons. Axons are a long spindly part of the cell that sends signals to other cells with electrochemical impulses.

Your brain receives spatial and temporal patterns through axons. What your brain ‘sees’ is not the keyboard in front of you, but the spatial patterns being sent upstairs.

“The only thing the cortex knows is the pattern streaming in on the input axons.” Jeff Hawkins

Because the only thing your brain knows are the spatial and temporal patterns, Jeff Hawkins says:

“Vision is more like a song than a painting.” 

If you find this hard to believe consider that Paul Bach y Rita, professor of biomedical engineering at the University of Wisconsin had developed a way to display visual patterns on a human tongue. The brain quickly learned to pick up these visual patterns from the tongue. If you are curious about this concept you can read more here.

“Brains are a pattern machine.” Jeff Hawkins

Join me as I blog through Jeff Hawkins book, On Intelligence to discover what all this knowledge about the brain tells us about how we learn. (This was a very truncated summary of chapter 3, if you are into this stuff I highly recommend picking the book up for yourself.)

I think the biggest take away from learning more about the neocortex for me is that your brain will adapt to whatever type of input it is receiving.

This means it does not matter what format of input we use to teach our kids. Whether it is auditory, visual, or tactile is not important from the standpoint of the neocortex. It is important only because of relevance, in other words, some material makes more sense to teach with visuals, such as geography, and other with audio tools. The other reason presenting things in different ways can be helpful is simply to add variety and keep a child’s attention. This does not mean, however, that a visual child will not be able to learn from auditory input.

So relax, you don’t have to use a different spelling program for each kid based on their preferred learning style. You can just pick a great program that uses all learning modes and is well organized to maximize progress.

Read this for more about why learning styles don’t matter as much as we have been led to believe.

One Response

  1. […] Exploring Intelligence - The Neocortex […]

Leave a Reply

Your email address will not be published.