Monday, May 21, 2018

The Yin-Yang Brain: Even Faster Learning Using Spike Timing

The First and the Last

In September of last year, I wrote an article to describe a fast method used by the brain to learn elementary patterns using spike timing. I just want to show in this quick post that pattern learning can be much faster if we take advantage of the Yin-Yang or complementary nature of the brain. The reason is that, if everything in the brain comes in complementary-opposite pairs, learning one component of a pair automatically learns its complement. The trick is to always create and connect everything in pairs. Thus every sensor or pattern detector belongs to a dual entity. For example, a sensor that detects the onset (first signal) of a stimulus is paired with another that detects the offset (last signal) of the same stimulus. Likewise, a pattern neuron that detects the movement of an edge in one direction is paired with another pattern neuron that detects the opposite movement.

He Who Overcomes Will Not Be Hurt by the Second Death

The title of this paragraph comes from the occult book of Revelation where I get a huge part of my understanding of intelligence. It is a good idea to think of paired entities as a single object or complementary unit (CU). This way, instead of connecting a sensor to a pattern neuron, we can connect a sensory CU to a pattern CU, thereby killing two birds with one stone, so to speak. This is where it gets interesting. During learning, both connections can fail the concurrency test but if one of them passes, there is no need to continue testing the other connection. One successful test is enough to certify both connections. In other words, two failures (two deaths) are needed to disconnect the CU but a single success is not nullified by the failure of the other connection. I could be wrong but this is my current interpretation of the metaphorical message to the Church in Smyrna.

A similar approach is used in the cortex where all columns are organized in complementary pairs. The end result is that, since not all connections have to be tested, pattern learning in both the thalamus and the cortical columns is much faster than it would be otherwise.
Complementary organization of cortical columns in the visual cortex
Note: I have been thinking of writing an article to explain the true purpose of the cortex and its 100 million cortical columns. I am currently weighing the pros and cons. Hang in there.

See Also:

Fast Unsupervised Pattern Learning Using Spike Timing
Message to The Church in Smyrna
Solving the Mysteries of Reciprocal Corticothalamic Feedback and Cortical Learning
Fast Cortical Learning Using Spike Timing
The Yin-Yang Brain Revisited: Stephen Grossberg's Work

Saturday, May 12, 2018

The Yin-Yang Brain Revisited: Stephen Grossberg's Work

A Funny Thing Happened this Morning

In December of last year, I wrote a two-part article on how I came to understand the Yin-Yang organization of the brain. I have known for a long time that the Yin-Yang principle was the basis of reality and I came to understand that complementarity was absolutely essential to the organization of the brain. Thanks to my research in deciphering the meaning of certain occult texts, I discovered that each hemisphere of the brain consists of two separate but complementary hierarchies. These are symbolized by two olive trees.

I had assumed (wrongly, as it turned out) that I was the only person to have arrived at this understanding. This morning, one of my readers (Spent Death) left a comment on my blog to recommend the work of cognitive neuroscientist Stephen Grossberg. After a quick search on Google, I was blown away by what I found. In 2000, Grossberg published a paper titled, THE COMPLEMENTARY BRAIN Unifying Brain Dynamics and Modularity (pdf) in which he describes a revolutionary model of the brain based on complementarity. This post is not intended to be a review or a critique of Grossberg's work. I merely wish to point out the commonality between his views and mine. Here is what he wrote in the paper's abstract (emphasis added):
How are our brains functionally organized to achieve adaptive behavior in a changing world? This article presents one alternative to the computer metaphor suggesting that brains are organized into independent modules. Evidence is reviewed that brains are organized into parallel processing streams with complementary properties. Hierarchical interactions within each stream and parallel interactions between streams create coherent behavioral representations that overcome the complementary deficiencies of each stream and support unitary conscious experiences. This perspective suggests how brain design reflects the organization of the physical world with which brains interact. Examples from perception, learning, cognition, and action are described, and theoretical concepts and mechanisms by which complementarity is accomplished are presented.
In the same paper, Grossberg offers a hypothesis to explain how the brain handles sensory uncertainty using parallel streams and multiple stages or levels in the hierarchy. I propose a somewhat similar solution which also uses multiple levels and parallel streams but is implemented via feedback pathways in the cortex and the thalamus. If you have any interest in how the brain works, I heartily recommend that you read Grossberg's work on complementarity.

Needless to say, nobody in mainstream AI is thinking along these lines even though some of them claim to base their research on neuroscience. They are lost in a lost world. AGI will not come from the mainstream.

See Also:

Solving the Mysteries of Reciprocal Corticothalamic Feedback and Cortical Learning
Fast Cortical Learning Using Spike Timing
The Two Olive Trees and the Yin-Yang Brain: How My Understanding of the Cortex Evolved Over the Years