Tag Archives: neural networks

10/27/17

Ability to Choose … Within Limits

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It’s not too difficult to discover where Sam Harris stands on whether or not humans have free will. We unequivocally don’t. “Free will is an illusion.” In a lecture Harris gave for Skeptic Magazine that was based on his book, Free Will, he added that if the scientific community were to publically declare free will to be an illusion, “it would precipitate a culture war.” Science has revealed that we are “biochemical puppets” and “The universe is pulling your strings.”

Free will is an illusion. Our wills are simple not of our own making. Thoughts and intentions emerge from background causes of which we are unaware and over which we exert no conscious control. We do not have the freedom we think we have.

This illusion of free will is based on two false assumptions, according to Harris. The first is that we can behave differently than we did in the past. But since we live in a world of cause and effect, our wills are determined by a long chain of prior causes, “and we’re not responsible for them.” Alternately, what we perceive as free will is the product of chance; and again, we’re not responsible. Or there could be some combination of chance and cause and effect, but still no personal agency. Whichever way we conceive it, free will is an illusion in a world ruled by chance and cause and effect.

The second false assumption is that we are the conscious source of our thoughts and actions. “We presume an authorship over our own thoughts and actions that is illusory.” There is no self, no ego, no soul to generate thoughts and actions, according to Harris. They just emerge in our consciousness. And if we cannot control our thoughts, if we don’t know what our next thought will be until it consciously emerges, where is our free will?

How can we be free as conscious agents, if everything we consciously intend was caused by events in our brain, which we did not intend, and over which we had no control?

Sam Harris is an author, philosopher and neuroscientist who has written several popular books in addition to Free Will. Along with Richard Dawkins, Daniel Dennett and Christopher Hitchens, he has been referred to as one of the “Four Horsemen of New Atheism.” The reference draws on the title of a 2-hour unmoderated discussion between the four that is available here on the website for the Richard Dawkins Foundation for Reason and Science. They discussed the public reaction to some of their books critical of religion, and some common misrepresentations of them and their beliefs.

Harris’s position on free will assumes the universe is a closed system of cause and effect. Since there are no creator gods, everything that now exists is the result of what has come from “a long chain of prior causes.” The theologian Francis Schaeffer referred to the understanding of science that comes from this view of the universe as modern, modern science—science rooted in naturalistic philosophy. The uniformity of natural causes, which is an essential starting point for scientific investigation, must be understood as occurring entirely within the natural order of the universe. Nature is closed to any causal intervention from outside.

There is no Creator; no First Cause. There is only chance or cause and effect. Not only physics, but psychology, social science and human nature must be explained within the confines of this closed system. The biologist and neuroscientist Robert Sapolsky believes that every bit of human behavior has multiple layers of causality. He said what we call “free will” is simply biology that hasn’t been discovered yet. “It’s just another way of stating that we’re biological organisms determined by the physical laws of the universe.” See “Ruling Over Our Genes” for more on Sapolsky.

In Escape From Reason, Schaeffer concluded this materialist unity of all things leaves us afloat on a deterministic sea with no shore. The only way this unity can be achieved is by ruling out freedom. “The result of seeking for a unity on the basis of the uniformity of natural causes in a closed system is that freedom does not exist.” Free will is therefore an illusory cognitive construct.  The nonmaterial mind or soul is also an illusion.

However, Harris and Sapolsky aren’t the only neuroscientists to ever consider the possibility of free will. Harvey McMahon is a staff scientist and group leader at the Medical Research Council Laboratory of Molecular Biology in Cambridge. He is also a member of The Royal Society, the world’s oldest independent scientific academy. Past members of the Society have included Isaac Newton, Albert Einstein and Charles Darwin. Current members include Richard Dawkins and Stephen Hawking.

McMahon discussed free will in: “How Free Is Our Free-Will?” He opened his essay by noting science has provided evidence that free-will may be an illusion. Yet free-will was fundamental to our sense of wellbeing, and underwrote our sense of morality, our judicial system, and our Judeo-Christian faith. “We may not be as free as we would like to think, but within boundaries shaped by our individual histories, our genetics, and our environment we can make decisions that determine our character, relationships and future.”

He noted the paradoxical nature of freedom. For example, if we marry we limit the relationships we will have with others, while at the same time opening up new avenues of freedom from being settled in our choice of partner. This principle, McMahon said, applies to all our choices. We change our future possibilities by the choices we make today. “Thus freedom is not unconstrained choice, for with each choice we limit our freedom, and in so doing shape our environment and ourselves.”

These constraints are from our culture, our relationships, our jobs and our families, and other influences. Added to these is the subconscious working of our brain, processing cues of which we are not aware. “Thus the brain may even be making decisions for us.” Do we really have a choice? Here McMahon acknowledged Harris’ above noted argument (and book), that free-will was an illusion. But rather than an illusion, he thought it better to say it was constrained by many factors.

Free-will, McMahon thought, “is a cognitive concept, involving the mind.” It is the ability to choose deliberately between options. “It cannot be regarded as the opposite of determinism, where events have cause and effect outside human control.” He illustrated what he meant with the following diagram. Free-will only applied to cognitive processes where we use our minds to make choices—in between the two extremes. Although not stated by McMahon, I’d say completely free choice is only possible within the mind of God.

Human free-will is then not completely determined, nor is it completely free. McMahon suggested free-will occurred within the boundaries of predetermined factors, where there was little or no freedom to choose. These factors could be biological or genetic. They could also be family, culture, or environmental factors. See the diagram below.

Within an outer sphere of predetermined boundaries, lies a continuum of interaction between prior free-will and proximal free-will. Prior free-will is where an immediate decision is constrained by past decisions and history. Going to work on a given day is more the result of a past decision than one made when you woke up that day. You can re-assess the decision and not go to work for some reason, “yet the choice does not have to be constantly re-evaluated.” In-the-moment or proximal decisions can be inconsequential, like choosing between tea or coffee, or involve active cognition, as when we weigh our options. “Both of these give a strong sense of free-will in the moment.”

Plasticity refers to the fact that our brains are moldable. “We are constantly learning new information, meeting new people and acquiring new skills, which all require that our brains are ‘plastic’.” New synapses can be formed or existing synapses can be modified or lost. “At a molecular level there can be changes in the expression of various proteins which in turn influence the excitability of a given synapse or circuit.”

The choices we make influence the behavior patterns we develop, which are laid down as neuronal pathways. In turn, these pathways influence other choices. “So in this sense we are masters of our own destiny… all because we have a ‘plastic’ brain (i.e. not completely preprogrammed).” Although there is difficulty in the process, we can change. If we make certain choices repetitively, they lay down neuronal pathways and turn into learned behaviors.

Plasticity is thus key to the possibility of free-will [see the above diagram]. While memories of past experiences may not be completely eradicated, they can be scaled back by the new experiences that occupy our minds as we choose to dwell on other things.

Jeffery Schwartz and Rebecca Gladding coauthored You Are Not Your Brain, a self-help book that applies the principles of neuroplasticity discussed above. Like McMahon, Schwartz and Gladding affirm the reality of the human mind and the existence of free-will. Dr. Schwartz is one of the world’s leading experts in neuroplasticity. You can read more about him and his books on his web page here.

McMahon said the relationship between this conception of free-will and intentionality is complex. To the extent we willfully choose and can foresee certain outcomes, ”we can be held responsible for the outcome.” However, if we could not foresee the potential consequences of decisions, to what extent can we say their outcome was intentional? Furthermore, what about when reason has been suppressed for some reason, or if it has been erroneously applied (if we haven’t reasonably weighed our potential thoughts or actions), and non-intended consequences result.

Despite the caveats, in general each of us is responsible today for what we did yesterday because these were acts of free-will, or actions resulting from an absence of self-control. The responsibility for evil can be lessened by considering our circumstances but it never excuses us because at some point in the past we have actively participated in shaping who we are today.

McMahon goes on to describe how he believes our brains and free-will interact with each other. He suggested that while individual neurons do not have free-will, “it is an emergent property of neuronal networks.” He suggested free-will sits upon a tripod of past memories, present inputs (combined with the ability to compute and learn) and future predictions and aspirations within the plasticity of the brain.

There is more to read and think about in his article. McMahon also shares his thoughts on how God constrains us and yet frees us. He wrestles with the question of whether free-will is compatible with divine sovereignty. Read more on how he applies the above discussion to this theological dilemma. His conclusions are worth repeating here.

With the above in mind the following definition of free-will can be offered: Free-will is the ability to choose intentionally within limits placed by a sovereign God, with resulting human responsibility. Free-will is not the opposite of determinism: one can have free-will within the limits set by determinism. Indeed our relationships and our decisions are not absolutely predetermined, and this is a reflection of the freedom given to us by being made in the image of God. So, we have the best of both worlds, where we have freedom to make decisions and yet our personal future and that of the world are secure.

The above understanding of free-will indicates we are less free than we may like to think we are at any given moment, because of prior decisions and predetermined factors. And while neuroscience hasn’t extinguished free-will, it does help us see why we do the things we do. So we are not biochemical puppets, but biology constrains us. “We are not determined by our past, but certainly influenced by it.”

02/25/15

Deep Brain Jolts

© Brain Energy Pulse by idesign | stockfresh.com

© Brain Energy Pulse by idesign | stockfresh.com

Michael J. Fox is probably the most well known person with Parkinson’s disease. Viewing the progression of his Parkinson’s between 1991 and an interview he did on Oprah in 2010 gives you an indication of how debilitating it can become. There is a treatment called Deep Brain Stimulation (DBS) that effectively silences the tremors. The dramatic therapeutic difference can be seen in this YouTube video of a New Zealand man named Andrew Johnson who has Early Onset Parkinson’s. The difference is dramatic and it is easy to see why he would agree to the procedure. What’s not to like about it and why would Michael and others put off trying it? It involves surgery that implants electrodes into your brain.

As described by the NIMH, DBS surgery begins with shaving your head and attaching it with screws to a sturdy frame that prevents the head from moving during surgery. The patient is awake during the procedure to help the surgeon with feedback. Patients feel no pain, however, because their head is numbed with a local anesthetic. MRIs are taken of the brain to guide the surgeon during the operation.

Once the above prep work is completed, two holes are drilled into the head. The surgeon then threads a slender tube down into the brain in order to place electrodes on each side of a specific part of the brain. After the electrodes are implanted and the patient provides feedback about the placement, the patient is then put under general anesthesia. The electrodes are now attached to wires that run inside the person’s body down to the chest, where a pair of battery-operated generators are implanted.

Electrical impulses are then continuously delivered over the wires to the electrodes in the brain. After the device is fine tuned, it reduces tremor and uncontrollable movements, stiffness and walking problems related to Parkinson’s. You can see how this all works afterwards in the Andrew Johnson video. At this point, DBS has been used in more than 100,000 people worldwide.

Helen Shen wrote in Nature that the biological mechanism underlying DBS is still unknown. Michael Okun, a neuroscientist, said there has been a lot of guesswork done with DBS over the past twenty years. “It would be premature for anyone to claim they know how the therapy works.” There are some hypotheses, though. The current theory is that DBS somehow disrupts or represses pathological signals that reverberate through multiple brain regions, thus corrupting their communications.

This fits with the emerging view that Parkinson’s disease, depression and other neuropsychiatric conditions are best understood as neural network dysfunctions. At this time DBS is approved by the FDA to treat the following: essential tremor (1997), Parkinson’s (2002), dystonia [a neurological movement disorder] (2003) and OCD (2009). There is research being done to assess it applicability to addiction and depression.

Helen Shen described a new device from Medtronic that is now being used in DBS treatment. The Medtronic neurostimulator not only will send electricity into the brain, it will also read neural signals generated by the brain and send them out.

Until now, such data have been accessible only when a patient’s brain is exposed briefly during surgery. But being able to make long-term neural recordings from human patients may become increasingly important — especially because researchers are experimenting with using DBS as a treatment for many other neurological conditions.

But the neural networks in these other neurological disorders are even less understood than those involved in Parkinson’s. Helen Mayberg, a neurologist at Emory University said devices like the Medtronic neurostimulator could change that, but “Every disease will be different and one size won’t fit all. . . .  [However] the new technology is going to enable progress exponentially.” Helen Bronte-Stewart, a neuroscientist, said this was an exciting time. “This is the first time we’re really getting a window into the brain.”

Others, such as medical ethicist Joseph Fins, urged caution. He also indicated that while the sensiorimotor network involved in Parkinson’s disease is mapped out in great detail, the other disorders have much less guidance available. “There has got to be a biological rationale for what you’re intending to do.” Others argue that controlled testing of DBS in humans doesn’t need to wait for complete or near complete understanding of the relevant networks.  Benjamin Greenberg, a psychiatrist at Brown University said that as a clinician, that wasn’t an important question. “The real questions are: do these treatments help people? Are they safe?”

The NIMH indicated, “DBS carries risks associated with any type of brain surgery.” The side effects or complications could include: stroke or bleeding in the brain; infection; disorientation or confusion; unwanted mood changes; movement disorders (isn’t DBS supposed to treat these?); lightheadedness; trouble sleeping. And DBS does not halt the progressive neurodegeneration of Parkinson’s. In the long run, patients will succumb to symptoms not effectively treated by DBS, like cognitive deterioration.

An article by Jeanene Swanson for The Fix referred to DBS surgery as a “relatively simple neurological procedure” (?) that could be used to treat a variety of disorders, including addiction, severe depression cluster headaches and obesity (None of these are approved DBS treatments at this time). DBS treatment for addiction was accidently “discovered” in 2006 by Jens Kuhn of the University of Cologne when Kuhn tried DBS as a treatment for panic disorder. “Recent valid animal studies show significant induced improvement in cocaine, morphine, and alcohol addiction behavior following DBS of the nucleus accumbens.”

Wayne Hall indicated that the interest in using DBS for treating addiction isn’t great. He suspected this was because it is an expensive, high technology intervention for a small minority of patients. He further noted that interest has declined for using DBS for depression because of poor trial results. However, that could be resurrected if more promising sites for stimulation were identified.

I would predict that if DBS is used for addiction in the future it will only be used in a minority of patients and will remain a niche treatment for addiction rather than becoming a mainstay form of treatment as it looks like it’s becoming for Parkinson’s disease and other movement disorders.

Dr. Nadar Pouratian of UCLA thinks it can be a promising treatment for addiction, but the earliest it could be available would be five years from now. “I think it’s a promising therapy for a spectrum of diseases, including addiction, but we need to be a little bit more methodical or careful—every time a trial does not work, the negative repercussions [do] far greater harm to the field.”

Could that be because DBS for addiction and depression is therapeutic overkill? Could it be because it’s dangerous when applied for addiction and depression? When the current state of knowledge doesn’t know how DBS works, and when the complexity of the neural networks for addiction and depression aren’t clearly understood, treating them with DBS seems like taking a huge risk.