The “Quantum Soul”: A Scientific Hypothesis
book chapter in Exploring frontiers of the mind-brain relationship
Stuart Hameroff & Deepak Chopra, 2012
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The concept of consciousness existing outside the body (e.g. near-death and out-of body experiences, NDE/OBEs, or after death, indicative of a ‘soul’) is a staple of religious traditions but shunned by conventional science because of an apparent lack of rational explanation. However conventional science based entirely on classical physics cannot account for normal in-the-brain consciousness. The Penrose-Hameroff ‘Orch OR’ model is a quantum approach to consciousness, connecting brain processes (microtubule quantum computations inside neurons) to fluctuations in fundamental spacetime geometry, the fine-scale structure of the universe. Recent evidence for significant quantum coherence in warm biological systems, scale-free dynamics and end-of-life brain activity support the notion of a quantum basis for consciousness which could conceivably exist independent of biology in various scalar planes in spacetime geometry. Sir Roger Penrose does not necessarily endorse such proposals which relate to his ideas in physics. Based on Orch OR, we offer a scientific hypothesis for a ‘quantum soul’.
5.1. Brain, Mind, and Near-Death Experiences
The idea that conscious awareness can exist after bodily death, generally referred to as the “soul,” has been inherent in Eastern and Western religions for thousands of years. In some traditions, memories and awareness may be transferred after death to other lifetimes: reincarnation. In addition to beliefs based on religion, innumerable subjects have reported conscious awareness seemingly separating from the subject’s brain and physical body; this occurs in conjunction with so-called near death experiences (NDEs), most typically in patients who have been resuscitated after cardiac arrest (e.g., van Lommel et al. 2001; Parnia et al. 2007). Such patients describe remarkably consistent phenomenology including visions of a white light, being in a tunnel, feelings of serenity, conversing with deceased loved ones, life review and, in some cases, floating out of the body (out-of-body experiences – OBEs). Frequently, NDE/OBE patients also report a subsequent loss of the fear of death, and tend to be more serene and accepting of life’s vicissitudes (Chopra 2006).
Somewhat comparable experiences have been reported in various types of meditative and altered states, as well as traumatic psychological events, or seemingly without cause. A Gallup poll estimated some ten million Americans have reported some form of NDE/OBE (Chopra 2006). The drug ketamine, used as a “dissociative” anesthetic, can produce subjective reports of conscious awareness outside the body (Jansen 2000), as can various other psychoactive drugs. But subjective reports of drug-induced effects are distinctly different from those of NDEsl OBEs (Greyson 1993).
Unable to explain NDEs/OBEs, modern science on the whole ignores and derides such reports as unscientific folly, illusions due to stimulation of particular brain regions (Blanke et al. 2004), or hallucination due to hypoxia (lack of oxygen; Blackmore 1998). But in response one can point out: (1) subjective reports of illusions of body image are quite limited and completely different from NDE/OBE descriptions, (2) hypoxic patients are agitated, not serene, and do not form memory, and (3) modem science cannot explain normal, in-the-brain consciousness.
This last point is critical. NDEs/OBEs are particular types of subjective conscious awareness, in some way akin to our everyday conscious experience (including dreams). How the brain produces consciousness remains unknown.
The prevalent modem scientific approach to consciousness casts the brain as a biological computer, with 100 billion neurons and their axonal firings and synaptic connections acting as information networks of “bit” states and switches. Variability in synaptic strengths mediated by chemical neurotransmitters shapes network activity and enables learning and intelligent functions (Hebb 1949; Crick and Koch 2001; 2004). This “brain-as-computer” view is able to account for complex noncon-scious cognitive functions including perception and control of behavior. Such non-conscious cognitive functions are described as “zombie modes,” “auto-pilot,” or “easy problems” (Koch and Crick 2001; Hodgson 2007; Chalmers 1996). The “easiness” derives from the apparent cause-and-effect between specific computational functions of brain neurons, and actions and behavior which do not involve conscious will or phenomenal experience.
The “hard problem” (Chalmers 1996) is the question of how cognitive processes are accompanied or driven by phenomenal conscious experience. Despite detailed understanding of neuronal firings, synaptic transmissions, neurotransmitter chemistry, and neuronal computation, there is no accounting for conscious experience, the “self,” free will or “qualia” – the essence of experienced perceptions. How can the redness, texture, and fragrance of a rose, the experiential world, derive from data streams and electrochemical activity?
The answer according to most views in modern science is that consciousness emerges from a critical (but unspecified) level of neuronal computational complexity. In nonlinear dynamics, new properties do emerge in hierarchical systems, but such systems abound in nature and technology without consciousness. (e.g., weather patterns, the internet). The notion that computational complexity per se can account for consciousness may be mere wishful thinking.
The brain-as-neuronal-computer view has three problems.
- Because brain synaptic computation correlating with sensory processing often occurs after we have responded to that sensory input (seemingly consciously), the conventional view in modern science is that consciousness occurs after-the-fact and that conscious control is an illusion, consciousness is merely along for the ride (Dennett 1991; Wegner 2002). Apparently, we are, as T.H. Huxley (1893) famously said, “helpless spectators”.
- The best measurable correlate of consciousness (gamma synchrony EEG) does not derive from synaptic computation. Synchronized electroencephalography (EEG) in the gamma range of 30-90 cycles per second (Hertz, “Hz”) occurs in various brain regions at different times concomitant with consciousness (Gray and Singer 1989a,b; Engel et al. 1991; Singer 1995; 1999). Gamma synchrony requires networks of neurons interconnected not only by axon-to-dendrite chemical synapses, the basis for recognized neuronal computation, but by dendrite-to-dendrite gap junction electrical synapses (Christie and Westbrook 2006; Dermietzel 1998). One unconventional view is that gap junctions in various neurons open and close, enabling mobile zones of gamma synchrony to move about the brain, mediating consciousness (Hameroff 2006; 2010).
- As cells, neurons are far more complex than simple switches. Consider the uni-cellular Paramecium which can swim around, find food and mates, avoid obstacles, learn and have sex, all without a single synaptic connection. Artificial intelligence (AI) efforts to simulate brain function have yet to simulate anything as intelligent and nimble. Paramecium utilizes intelligent organizational functions of cytoskeletal lattice polymers called microtubules (Sherrington 1953). These same microtubules form the internal structure of brain neurons, regulate synapses and disintegrate in Alzheimer’s disease (e.g. Brunden et al. 2011). Microtubule information processing may underlie neuronal function.
Unable to explain consciousness in the brain, conventional science ignores apparent evidence for NDEs/OBEs, rejecting even the possibility of their occurrence. There are, however, unconventional but scientifically valid approaches to consciousness, which may address the three problems described above, and accommodate NDEs/OBEs as well as possible conscious awareness after bodily death. Such approaches explore strata of nature at an even finer scale than the chemical reactions and electrical signals relied upon by neuroscience, seeking convincing answers at the quantum level instead.
5.2. The Quantum World and Fine Scale of the Universe
Physics circumvents the strangeness of quantum mechanics by strictly dividing the macro/classical and micro/quantum, keeping the two worlds apart. However, consciousness somehow bridges the macro/classical and micro/quantum domains, equivalent to the subject-object split. Consciousness exists precisely on the edge between quantum and classical.
Quantum theory tells us that physical processes occur in discrete, quantized steps, or levels. The laws that govern the quantum differ strangely from the predictable reality of our everyday “classical” world. At small scales, and sometimes at large scales, the bizarre laws of quantum mechanics reign. For example, atoms and sub-atomic quantum particles can exist in two or more states or places simultaneously, more like waves than particles, and existing as multiple coexisting possibilities known as quantum superposition, governed by a quantum wave function. Another quantum property is “nonlocal entanglement,” in which components of a spatially separated system remain unified and connected (Penrose 1989).
In our conscious experience, we do not see superpositions – coexisting wave-like possibilities. We see objects and particles as material things in specific locations and states. This is partly due to scale. A humpback whale leaps out of the sea whole, despite the fact that the atoms and subatomic particles comprising the whale may occupy uncertain or even multiple positions in the invisible realm of possibilities. But even when small quantum systems are measured or observed they somehow choose definite states.