Customer Reviews

How Brains Make Up Their Minds (Maps of the Mind S.)

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Walter Freeman packs a lot of his experience and knowledge of how the brain works in this fascinating little book.

Freeman's emphasis is a bit unique in that he focuses on the dynamics of how neurons communicate rather than on either the anatomy of the brain, or on either mental states or behavior.

By adopting this focus on neural dynamics, the author accomplishes some interesting things that other authors haven't been quite able to accomplish. He comes up with a multi-step mathematical model of how neurons organize themselves in order to function as a mind. His model is far more specific than most (such as the vague model in Susan Greenfield's "Private Life of the Brain" for example) and he links his model clearly and consistently to the pragmatist philosophy of mind.

The key to Freeman's unique approach is that he addresses from the outset the critical observation that makes hte "mind-brain problem" difficult. He recognizes that most models of brain function fail to address how top-down function in the brain could possibly work. How, in the classical model of brain function, can we have an expectancy that reliably alters basic perception, such as in hypnotic anesthesia and hallucinations ?

Materialist and cognitivist models of mind (in terms of simple flows of neural energy or information between neurons) simply have no way to explain why some behaviors should be "voluntary" and others "involuntary," or how meaning is somehow created from symbol processing. Representational models (which consider the brain to store "images" in some sense) still have some serious explanatory gaps.

If the brain simply links together sensory stimuli from the senses, and then somehow "taps into memory" to help interpret what we perceive, why should our initial perceptual gestalts themselves be altered by what we expect to perceive ?

The way attention and expectancy work - requires a different way to look at the brain, such as providing a continual staging process for awareness. The point is made succinctly and eloquently by Freeman, although readers interested in mroe of the background to this will find John McCrone's "Going Inside" a great read as well. Rather than discussing the background of this modern view of conscious awareness, Freeman links it to his own model of complex dynamics among populations of neurons and discusses various implications for philosophy of mind and brain.

Freeman's view is that consciousness is not itself a "cause" of neural effects, but a global linkage for smoothing chaotic fluctuations through interactions. The author borrows from a definition by Thomas Aquinas to make a point of defining intentionality in biological terms as a frame for problem solving rather than the weaker sense of "aboutness" used by analytic philosophers. He then builds a model of mind that uses chaotic attractor patterns to explain how we create meaning in individual brains by interacting usefully with the environment.

Walter Freeman is one of the scientists seriously trying to address such puzzling matters as _choice_, and how others can sometimes become aware of our own choices before we are, in both daily life and careful experiments. A lot of Freud's speculations in his theory of the Unconscious mind were intended to address this, but theorists today are in a better position to do it more scientifically. How can choice seemingly be "unconscious" and yet we have a very real sense of free will ? Is it an illusion ? Freeman makes a strong entry in the race to explain this in a way that works scientifically and yet explains what we actually experience. I read this at about the same time as John Taylor's "The Race for Consciousness," and found that it covers a lot of very similar ground, and often more elegantly.

While this book is surprisingly readable for having so much relevant technical detail in neuroscience and complexity maths, it will often frustrate readers who want to follow it in great detail unless they have some background in both neuroscience and nonlinear dynamics. In spite of this, I give it my highest recommendation because I think anyone who reads it will learn something interesting about the brain and its relationship to the mind.

This is one of several books in the last couple of years written by leading neuroscientists attempting to explain consciousness. Outstanding examples are Damasio's "The Feeling of What Happens" and Edelman and Tononi's "A Universe of Consciousness," which are both very worthwhile reading. Freeman takes a different tack, based on his years of research into the olfactory system. Though this short book appears to be aimed at the educated layman, many will be stopped short in their tracks by his "ten building blocks" of "how neural populations sustain the chaotic dynamics of intentionality," such as the ever-popular #8, "Attenuation of microscopic sensory-driven activity and enhancement of mesoscopic amplitude modulation patterns by divergent-convergent cortical projections underlying solipsm." These ten statements form the core of the book, and although they are ultimately explained with some degree of clarity, I found myself wishing for more specific examples from the neuroscientific literature beyond the very limited samples provided, which tended to be either very basic circuit diagram type drawings, or taken from his work in the olfactory system. I did find the application of chaos theory to brain dynamics fascinating, though for a critique of Freeman's approach and an alternative view see the article by Laurent et al in the 2001 Annual Review of Neuroscience. Overall, though, I found the book a stimulating and interesting read.

Freeman wraps up a long history (30 years, I believe) as a neurophysiologist with a good general overview of some interesting information and philosophy. The book starts with a general overview of the brain, using a salamander's brain structure as the building block from which to start the discussion.

Freeman's main area of study revolves around the olfactory sense which is not a very common area within the "mainstream" of currently in-vogue neural work. This might explain why his views are rather different from many of his colleagues as well as those who stand on the "edge" of the whole mind-brain debate such as the Churchlands and Dennett.

Freeman details how we usually represent problems in a linear fashion and how this type of philosophy is not at all appropriate for the study of the nervous system. Freeman does a great job of delving into circular causality (feedback systems) and why this naturally leads to some interesting conclusions about the interrelationship of the brain and mind.

Freeman refers to himself as a "pragmatist" in the book although I found this to be a bit confusing based on some of his views. He is clear that he is not a materialist (like the Churchlands and Searle) but also not a dualist (such as Penrose and Chalmers) but I think he should have gone a further step and really stepped outside of the constraint of calling himself a "pragmatist".

He has some good and easy-to-digest information about chaotic systems and how they tend to seek islands of stability (that is, there is emergent order in a sea of unpredictability) but he never really gets down to the nitty and gritty of tackling how the physical realm ultimately manages to link causally to the mental. Tallis' book has some better leads on this "problem" and it would be interesting if these two and Austin ("Zen and the Brain") could get together to discuss some ideas.

All in all a pretty good read that won't hurt anyone who doesn't have a background in science. But we have a long way to go understanding the "hard problem" still...

In this book, Prof. Freeman is trying to resolve a very difficult problem : if my brain operates as mechanically as a car, then how can I be free to make choices and be responsible for my decisions ? He makes a detail ( lengthy ) presentation on his proposed solution. Unfortunately, after reading the whole book, I think he fails to provide a clear answer to the question.

His main idea is that there is an important difference between human brain and other substances in the universe such as a car. The brain is a complicated nonlinear system and capable of self-organization. It does not respond directly to incoming stimuli like a reflex action, but it is continuously changing and constructing its own neural activity patterns in order to adapt to and synchronize with the external stimuli. The active involvement of the brain can be seen from the fact that we won't interpret the world as moving backward when we know we are walking on a street. This self-awareness and the real-time interactions between the brain and the environment form what he called the circular causality. He concludes that a behaviour comes from the final decision of the brain itself who therefore bears the responsibility.

However, I find that what he is talking about is how the brain works ( yes, the title of the book is correct ), but it doesn't follow that the nature+nurture determinism is wrong. Of course our decision depends on our history ( memory and experience ), but we should ask what then the history depends on ? Genetic makeup and continuous stimuli from environment are the only factors or sources that cause people different from each other, while chaos and self-organization are just the mechanism within ( the laws of nonlinear dynamics are universal ). As a result I consider his circular causality as a misleading myth, at least he has ignored the initial condition : genes.

Although I disagree with Prof. Freeman's idea, I respect him as the greatest neuroscientist in our times. Readers can find more of his information from his website at U C Berkeley...

Walter J. Freeman brought philosophy to his research into the neuroscience of biology, brains, and human nature in How Brains Make Up Their Minds (2000), and in his earlier Society of Brains (1995). He grounds his findings in neuroscience with an understanding of an organism's purpose using the philosophical idea of intentionality which was described by Thomas Aquinas in the 13th century. Meaning arises in and between minds when the brain creates intentional behaviors and then changes itself based on sensory feedback from those behaviors. Meanings exist in the minds of observers, and not in objects, events, and body motions.

Freeman escapes the trap of subject-object dualism by embracing intentionality. Human civilization is an expression of the development of the intentional object type to communicate images between minds. Psychological, philosophical, and neurological discussion of the human mind and its brain must include the intentional object type, along with the real external and subjective internal object types. See Mortmer Adler's Philosophical Dictionary, and his critique of the Kantian philosophy that poured out the baby of intentionality with the bath water.

Freeman engages some of the same Jamesian ideas that Domasio handles so well in his latest Self Comes to Mind (2010). I rate Freeman's book highly because it is an early advocate for the knowledge category of intentionality to understand biological organisms.

1. The neuron has a membrane, a nucleus embedded in cytoplasm, and metabolic power packs called mitochondria.
2. The neuron has two types of threads: the dendrite and axon. Axons grow to great lengths.
3. There are two types of neurons: the projection neuron and the local neuron. The projections main dendrite branch extends towards the surface of the cortex. The basal trunk extend parallel to the surface to adjacent neurons. The axon of a projection neuron extends from one side of the brain to the other, and to targets in the brainstem and spinal cord.
4. The neuron has side branches called axon collaterals to other neurons nearby.
5. The local neuron or interneuron provides connections within a neighborhood of neurons; whereas, the projection neuron provides communication across the brain and to the spinal cord.
6. Most projection neurons in the forebrain are excitatory. Whereas, interneurons can be both excitatory or inhibitory. There are thousands of synapses on the dendrite tree of the neuron.
7. The success in finding and maintaining a connection depends on the synapse being active. If the synapses are not active then connections decay and the synapses disappear. Brains need exercise.
8. The State space refers to the different states of a neuron. An neuron is activity in various states, such as rest, and excited and inhibited. Neuron trajectory always returns to a resting state.
9. A neuron acts on another neuron by sending an electrical pulse to its dendrite by the synapse. The second neuron dendrite responds by generating a dendrite wave of electrical current that flows to the cell body, where it appears as a postsynaptic potential.
10. Axons express its state as the frequency of its action potential or pulse rate.
11. Dendrite expresses its state in the intensity of its synaptic current (wave amplitude).
12. Dendrites integrate the pulse inputs and transform the pulses to waves. Axons transmit the neuronal output as trains of pulses.
13. When the pulse reaches the synapse it releases a chemical neuro transmitter and the dendrite current starts to flow. Dendrites can have multiple currents from other synapse superposition to create a large wave of current.
14. The sum of currents that a neuron generates in response to electrical stimulus produces the postsynaptic potential. The strength of the postsynaptic potential decreases with distance between the synapse. The attenuation is compensated by greater surface area and more synapses on the distal dendrites. Dendrites make waves and axons make pulses. Synapse convert pulses to waves. Trigger zones convert waves to pulses.
15. The stronger the neuron gain the longer the oscillation. In the cortex excitatory neuron out number inhibitory neurons 10 to 1. An excitatory pulse increases actively level of the population but returns to the steady state level. The inhibitor decreases the activity briefly then returns the population to the steady state.

I found this short little book to be wordy, murky and unclear. No one knows how thought/meaning is conveyed in the brain. Freeman suggests that chaos, transistions, and repeating patterns have something to do with memory, learning and meaning, and that context is important, but so what. Those ideas have been suggested before, and I didn't find any highly compelling new arguments, either theoretical or experimental, in support for how or why these particular ideas should be correct. There are some interesting tidbits here and there when he explains some experiments in the field.

Freeman's five decades of research in neuroscience lends to a title which explains how different human brains react differently to stimulus. From the physical science of neural activity to how nonlinear dynamics reveals order in brain function, How Brains Make Up Their Minds probes the foundations of how people think and make choices.

This book, although clearly on a very interesting subject, is extremely difficult to read. It is not organized in clear chapters, the writing more like streams of consciousness than organized thought. Very disappointed.