Jeff Prideaux - Comparison between Karl Pribram's "Holographic Brain Theory" and more conventional models of neuronal computation

Yesterday I posted an article from Neuroskeptic on the holographic brain and mentioned the work of Karl Pribram as one of the "fathers" of holonomic brain theory. In looking for additional information, I found this article from Jeff Prideaux of Virginia Commonwealth University that compares Pribram's brain model to other models of cognitive or neuronal computation.

It's a long article, but it's also very interesting. I am not expert enough to say how accurate it is. What I can say is that Pribram gets very little attention anymore in cognitive neuroscience. The holonomic model, to my knowledge, is not widely accepted.

On the other hand, Pribram was among the first to stop doing frontal lobotomies because he recognized the frontal cortex as the seat of executive function in the brain. He was also among the first to recognize neuroplasticity and neurogenesis.

It might be that brain science is only now starting to catch up to his theory of brain function.

Here is the beginning of the article (follow the title link to read the whole article):

Comparison between Karl Pribram's "Holographic Brain Theory" and more conventional models of neuronal computation

By Jeff Prideaux
jprideaux@gems.vcu.edu
Virginia Commonwealth University

TABLE OF CONTENTS (with HYPERLINKS)

CHAPTER 1 INTRODUCTION

CHAPTER 2 HOLOGRAMS

What is holography?

The Hologram Relationship

Holograms

CHAPTER 3 EUCLIDEAN-BASED GEOMETRIC MODEL

CHAPTER 4 HOLONOMIC BRAIN THEORY

Experimental Evidence

Other Aspects of the holonomic theory

The Uncertainty Principle

Quantum Physics

Communication theory

Dissipative Structures

CHAPTER 5 CONCLUSIONS

General Comments

Conclusions

WORKS CITED

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CHAPTER 1 INTRODUCTION

One of the problems facing neural science is how to explain evidence that local lesions in the brain do not selectively impair one or another memory trace. Note that in a hologram, restrictive damage does not disrupt the stored information because it has become distributed. The information has become blurred over the entire extent of the holographic film, but in a precise fashion that it can be deblurred by performing the inverse procedure.

This paper will discuss in detail the concept of a holograph and the evidence Karl Pribram uses to support the idea that the brain implements holonomic transformations that distribute episodic information over regions of the brain (and later "refocuses" them into a form in which we re-member). Particular emphasis will be placed on the visual system since its the best characterized in the neurosciences. Evidence will be examined that bears on the validity of Pribram's theory and the more conventional ideas that images are directly stored in the brain in the form of points and edges (without any transformation that distributes the information over large regions). Where possible, the same evidence (for the visual system) will be used to evaluate both theories.

1. Holonomic theory where Fourier-like transformations store information of the sensory modalities in the spectral (or frequency) domain. The sensory stimulus is spread out (or distributed) over a region of the brain. A particular example (in the case of vision) would be that particular cortical cells respond to the spatial frequencies of the visual stimulus.

2. The more conventional theory that particular features of the untransformed sensory stimulus is stored in separate places in the brain. A particular example (in vision) would be that particular visual cortical cells respond to edges or bar widths in the visual stimulus.

It will be necessary in this report to first explain the concepts of a hologram and Fourier transforms before the physiological experiments can be understood. Bear in mind that the discursion into these other fields serves a purpose for later in the report.

Karl Pribram's holonomic theory reviews evidence that the dendritic processes function to take a "spectral" transformation of the "episodes of perception". This transformed "spectral" information is stored distributed over large numbers of neurons. When the episode is remembered, an inverse transformation occurs that is also a result of dendritic processes. It is the process of transformation that gives us conscious awareness.

Chapter 2 will outline the basic concept of a hologram and start to introduce Pribram's holonomic brain theory.

Chapter 3 will briefly describe the conventional accepted view of the pathway of neural processing (with particular emphasis on the visual system). The main computational event in this view is the generation of the action potential.

Chapter 4 will review the evidence for the alternative holonomic view. The holonomic theory is based on evidence that the main computational event of neurons is the polarizations and hyper polarizations at the dendritic membranes of neurons. The evidence will be reviewed that supports the notion that these dendritic processes effectively take something close to a Fourier transform.

This is some geeky stuff - but I find it incredibly fascinating even when I feel I don't fully grasp the science.

Tags: Jeff Prideaux, Comparison, Karl Pribram, Holographic Brain Theory, conventional models, neuronal computation, Fourier transform, brain, Psychology, consciousness, holographic model, neuroscience, neurons, polarizations, hyper polarizations, dendritic membranes, neural processing, information distribution, brain regions