Strogatz 2003 provides various examples of resonance from physics, biology, chemistry and neuroscience to illustrate “sync” (synchrony), including:
 
·      Fireflies of certain species start flashing their little fires in sync in large gatherings of fireflies
·      Large-scale neuron firing can occur in human brains at specific frequencies, with mammalian consciousness thought to be commonly associated with various kinds of neuronal synchrony
·      Lasers are produced when photons of the same power and frequency are emitted together
·      The moon’s rotation is exactly synced with its orbit around the Earth such that we always see the same face
 
Let’s delve a little deeper into the idea of resonance.
 

II.             What is resonance, what is sync?

 
What’s happening in these examples just provided? Again, resonance/sync is a tendency for different processes to move together – to oscillate – at the same or similar frequency. The science of sync – sometimes called complex network theory or harmonic oscillator theory – is concerned with how coupled oscillators behave in relation to each other. We discuss these theoretical approaches further below.
 
The mystery in many examples of resonance is two-fold: 1) how do the constituents of each resonating structure (a term we’ll use to refer to any collection of resonating constituents) communicate with each other, and; 2) how do these constituents achieve resonance once that communication occurs?
 
Let’s look at each mystery in turn, focusing mostly on the first two examples we listed above: 1) Fireflies synchronizing their flashes; and 2) Large-scale neuronal synchrony in mammalian brains.
 

A.   How do resonating structures communicate?

 
The nature of communication between each resonating structure will depend on what example we’re considering. Looking at fireflies as one of two illustrative examples of complex resonating structures, we know that visual cues are available to each fly but there are probably also olfactory and other chemical cues available, and maybe even electrical or magnetic clues. This kind of sync will require empirical investigation to rule out candidates for communication in order to home in on the channels that are in fact being used by fireflies. From empirical research to date it seems likely that sync in firefly populations that coordinate their bioluminescent flashing relies mostly on visual perception (Strogatz 2003).
 
The nature of the communication between each neuron in the case of neuronal synchrony in brains is less clear. Walter Freeman has argued, based on his extensive work on rabbit and cat brains, that gamma synchrony, a particular type of neuronal sync, is achieved too quickly to depend only on electrochemical neuronal signaling, and must thus also depend on electrical field signaling. Freeman and Vitiello 2006 states:
 
High temporal resolution of EEG signals … gives evidence for diverse intermittent spatial patterns … of carrier waves that repeatedly re-synchronize in the beta and gamma ranges in very short time lags over very long distances. The dominant mechanism for neural interactions by axodendritic synaptic transmission should impose distance-dependent delays on the EEG oscillations owing to finite propagation velocities and sequential synaptic delays. It does not.
 
Hameroff 2010 mirrors this conclusion: “The seemingly instantaneous depolarization of gap-junction-linked excitable membranes (i.e., despite the relative slowness of dendritic potential waves or spikelets) suggests that even gap junction coupling cannot fully account for the precise coherence of global brain gamma synchrony.”
 
Additional research is necessary to further examine the communication channels responsible for achieving gamma and beta synchrony (a less rapid type than gamma synchrony), but as will be discussed data already available strongly suggest that shared resonance is key for human and other mammalian consciousness.  We discuss further below the various types of resonance patterns in mammalian brains, including electrical field resonance, and other recent developments in this scientific field.
 

B.    How do resonating structures achieve shared resonance?

 
We have introduced the first mystery, without offering any broad solutions at this point. Our second mystery is even deeper: How do resonating entities that are in mutual communication adjust their resonance frequencies to achieve resonance with each other? Entities start out of sync and somehow, in many cases, become synced. What forces are at work in these processes?
 
With respect to fireflies, we may analogize to human conscious actions. For example, when we want to lift our finger we achieve this intended result through a chain of neural pulses from our brain to our finger, and the motion is achieved. Similarly, it is plausible to speculate that fireflies intend to flash their little light; after they do so an electrochemical pulse travels from the fly brain to its abdomen, and then the physiological and chemical processes responsible for its bioluminescence kick into gear.[3]
 
It may seem strange to some readers to ascribe intention to fireflies. To us, it seems intuitive and logical that fireflies would experience intentions and conscious control of at least some of their bodily processes – particularly significant processes involving large organs like their light-making organ. Their behavior is complex and displays many “behavioral correlates of consciousness.” We don’t need to suggest, however, that fireflies have anything like the richness of human consciousness to acknowledge, by examining the various neuronal and behavioral analogies to humans and other mammals, that the firefly probably enjoys a rather basic level of conscious awareness.
 
Under this assumption – that fireflies enjoy a rudimentary type of consciousness, at least in comparison to human consciousness – we may explain the question (how are flashes synchronized?), at a high level, ignoring the complexities of the sub-level mechanisms. This allows for a parsimonious explanation in keeping with how we would explain any conscious action in a human, dog, cat, etc.: the brain/mind wills it and the body responds.
 
We can also, however, explain firefly flashing sync without recourse to consciousness or intelligence. This is Strogatz’s approach and he and his colleagues first explained the then-mystery of firefly sync by positing internal biological oscillators that automatically sync with neighbors (Strogatz 2003).  
 
But what about resonance between individual neurons, looking at our second example of synchrony? It would be hard to make the case that individual neurons “intend” anything, and we are not suggesting such. So how do neurons sync up so quickly and so frequently? This is a mystery that may rival the mystery of how these global frequencies are communicated. We don’t know yet how this communication is manifested in each neuron in a way that rapidly changes the electrical cycles in each neuron to match rapidly changing macroscopic patterns.
 
Keppler 2013 focuses on the phase transitions observed in mammalian brains and the fact that these brains seem to exist generally in a state of “criticality,” which makes them very sensitive to small changes:
 
From this perspective, the brain mechanisms behind conscious processes can be regarded as a complex system that operates near a critical point of a phase transition. While displaying spontaneous activity and irregular dynamics in the disordered phase, an appropriate stimulus can transfer the brain to the ordered phase that exhibits long-range correlations and stable attractors.
 
The concept of “phase transition” is potentially quite important in this context. A good analogy to a phase transition is water turning into ice, or water vapor condensing into drops as mentioned above. Small changes in temperature can tip cold water into forming ice crystals that rapidly spread. Similarly, these authors are suggesting that brain states (and the neural states that comprise brain states) can oscillate back and forth quickly, based on relatively modest stimuli. We discuss this further below.
 
Fries 2015, a major update to Fries’ now well-known “communication through coherence” hypothesis described Fries 2005, frames a cognitive frequency triad of various brain wave types as follows:
 
The experimental evidence presented and the considerations discussed so far suggest that top-down attentional influence are mediated by beta-band synchronization, that the selective communication of the attended stimulus is implemented by gamma-band synchronization, and that gamma is rhythmically reset by a 4 Hz theta rhythm.
 
The brief overview of resonance in nature just provided is meant to introduce a number of key ideas that we’ll flesh out below: 1) all aspects of nature are processes rather than static things; 2) all processes/things resonate at various frequencies; 3) processes that resonate in proximity to each other will in some cases sync up and resonate together after a certain time.
 
These are all components in our approach to resolving the “easy party” of the Hard Problem, otherwise known as the combination problem, which is the main focus of this paper. Before we flesh out this solution further, however, we will briefly focus on the “hard part” of the Hard Problem in the next section.
 

III.           The “hard part” of the Hard Problem

 
Chalmers 1996 described what he thought would be required of the eventual “psychophysical laws” governing the relationship between mind and matter – which would collectively comprise the ultimate solution to the “hard problem” of consciousness:
 
[T]he cornerstone of a theory of consciousness will be a set of psychophysical laws governing the relationship between consciousness and physical systems. … [A]n account of these laws will tell us just how consciousness depends on physical processes. Given the physical facts about a system, such laws will enable us to infer what sort of conscious experience will be associated with the system, if any.[4]
 
Chalmers’ suggested psychophysical laws would constitute a solution to what he described as the “hard problem” of consciousness (now generally capitalized), which is a new name for the classic mind/body problem.
 
Hunt 2011 proposed a set of psychophysical laws that would describe the relationship between consciousness and physical systems. The present paper is a follow-up to the earlier work, also elaborated in Schooler, Hunt and Schooler 2011, and an elaboration of the manner in which resonance plays a key role in achieving macro-scale consciousness through the combination of many micro-conscious entities.
 
The first step in any resolution of the Hard Problem requires taking a position with respect to the interaction of mind and matter. As mentioned, our preferred approach, accepts that all matter has some associated mind. This position is often described as panpsychism or panexperientialism (Hunt 2011, Schooler, Hunt and Schooler 2011, Hunt 2014, Schooler 2015, Goff 2017). In the vast majority of matter this associated mind is very rudimentary – perhaps just a little humming of simple awareness in, for example, an electron or an atom. But in some types of collections of matter, such as the complex biological life forms we are intimately familiar with, consciousness takes off and becomes more rich in comparison to the vast majority of matter. 
 
Based on the observed behavior of the entities that surround us, from electrons to atoms to molecules to bacteria to paramecia to mice, bats, rats, etc., all things should be viewed as at least a little conscious. Panpsychism represents the counterpoint to the emergentist viewpoint, which argues that consciousness emerged at a particular point in the development of each species that enjoys consciousness, and also emerged at a particular point in the development of each organism that enjoys consciousness, where it wasn’t before.
 
The panpsychist argues, rather, that mind did not emerge; it’s always associated with matter and vice versa (they are two coequal sides of the same coin), but the mind that is associated with all matter is generally extremely rudimentary. An electron or an atom enjoy just a tiny amount of consciousness. But as matter complexifies, so mind complexifies, and vice versa. It is not, however, any kind of increase in complexity that matters in this context. It is, rather, a function of greater resonant interconnections, both internally and externally. Hunt 2019 (in progress) fleshes out the mathematical framework first described in Hunt 2011, focusing on how resonant connections lead to larger-scale conscious entities and how such entities may be characterized and quantified.
 
We won’t delve too deeply into the many arguments in favor of panpsychism here, but see Hunt 2011 and 2014, Schooler, Hunt and Schooler 2011, Schooler, 2015; Griffin 1998, Goff 2017. Christof Koch, a pioneer in the scientific investigation of the neural basis of consciousness, wrote a short piece in 2014 explaining his “coming out” as a panpsychist (Koch 2014):
 
Elementary particles either have some charge, or they have none. Thus, an electron has one negative charge, a proton has one positive charge and a photon, the carrier of light, has zero charge. As far as chemistry and biology are concerned, charge is an intrinsic property of these particles. Electrical charge does not emerge from noncharged matter. It is the same, goes the logic, with consciousness. Consciousness comes with organized chunks of matter. It is immanent in the organization of the system. It is a property of complex entities and cannot be further reduced to the action of more elementary properties. We have reached the ground floor of reductionism.
 
Koch has also partnered with Giulio Tononi in developing the Integrated Information Theory of consciousness, which is panpsychist in its assumptions. (Oizumi, et al. 2014, Tononi 2012, Tononi and Koch 2015).
 
Koch and Tononi (2015) are incorrect in arguing that other approaches to panpsychism have not suggested a rigorous framework for analyzing consciousness (a number of authors have attempted just this, including Griffin 1998 and Hunt 2011), but they are correct that none of these other efforts are well-known.
 
We think of this philosophical stance – that all matter has at least some associated consciousness – as the “hard part of the Hard Problem” because it requires a conclusion about the basic ontology of the world: how do matter and mind relate to each other? Coming to this conclusion is no easy task for most scholars and debate continues to be robust between materialist, emergentist, panpsychist and even dualist and idealist, approaches.
 
We won’t dwell on this debate, however, in this paper. Rather, we will focus on the “easy part” of the Hard Problem – the combination problem, described further in the next section.
 
Our preferred stance is panpsychist because we recognize the major difficulties with emergentist materialism (the prevailing view among philosophers and physicists; though the tide is turning toward panpsychism) and it seems more plausible that, just as life evolves smoothly from one form to another, so mind evolves smoothly from one form to another – in fact these processes are concurrent and inter-related.
 
Summing up: arriving at some version of panpsychism constitutes a solution to the “hard part” of the Hard Problem that we find more convincing than the alternatives.
 

IV.          The “easy part” of the Hard Problem

 
The “easy part” of the Hard Problem is, as discussed above, more generally known as the “combination problem” or the “binding problem” (Chalmers 2013). The combination problem refers to the question of how different micro-entities combine to form a higher-level macro-conscious entity. That is, how do the purported experiences in, say, individual neurons, or regions of the brain, combine together to create a larger-scale experience that is still individual and unitary?
 
Goff 2017 states the problem well: “We feel we have some kind of grip on how . . . parts of a car engine make up an engine, but we are at a loss trying to make sense of lots of ‘little’ (proto) minds forming a big mind.”
 
This “combination problem” is not unique to panpsychism, as is often suggested. It is a problem in every reductionistic answer to the Hard Problem, whether we are materialist or panpsychist in our approach. This is the case because any reductionist explanation of consciousness must explain how the components of a given brain or mind (or brain/mind) combine to form a seemingly unitary consciousness. None of these approaches has achieved any consensus with respect to this basic problem.
 
William James first described what is now known generally as the combination problem or the boundary problem in his 1895 book The Principles of Psychology:
 
Where the elemental units [of our theory of mind] are supposed to be feelings, the case is in no wise altered. Take a hundred of them, shuffle them and pack them as close together as you can (whatever that may mean); still each remains the same feeling it always was, shut in its own skin, windowless, ignorant of what the other feelings are and mean. There would be a hundred-and-first feeling there, if, when a group or series of such feelings were set up, a consciousness belonging to the group as such should emerge. And this 101st feeling would be a totally new fact; the 100 original feelings might, by a curious physical law, be a signal for its creation, when they came together; but they would have no substantial identity with it, nor it with them, and one could never deduce the one from the others, or (in any intelligible sense) say that they evolved it.
 
Resonance theory and empirical data suggest, however, that these “elemental units” in James’ passage aren’t “windowless”: all processes are constantly interacting with other processes nearby; they do in fact have “windows” that allow for such interaction, and when full resonance occurs these windows are maximally open.
 
We suggest, based on the growing body of data described sketchily above, that a shared resonance frequency is the key to resolving the combination problem, the “easy part” of the Hard Problem. Resonating entities bind/combine together in various ways when they resonate at the same frequency. Depending on the entities being considered, such shared resonance and binding can in certain circumstances lead to a combination of mental qualities into a larger whole.
 
What is it about shared resonance that would allow such a combination or binding of mental qualities? It is clear today that the Democritean/Newtonian notion of matter as akin to little billiard balls careening around in space is highly incomplete as a model of reality. We know from quantum mechanical theory and abundant data over the last century that matter is more like a tight little standing wave of concentrated energy. Each of these waves are more or less localized in space and time.
 
When we see matter as fundamentally wave-like, it is not hard to see why shared resonance leads to faster information flows and macro-conscious entities. All physical processes are different types of waves, so when various entities resonate at the same frequency the waves work together, instead of in opposition. This allows for significantly higher bandwidth and speed in the information flows between the constituents of whatever resonating structure we’re looking at. The resonating wave forms of the micro-conscious entities are then coherent and information flows combine into a larger entity, a larger harmonic, rather than occurring out of phase (decoherently).
 
Fries 2015 provides a helpful example in the context of neuronal resonance/coherence: “In the absence of coherence, inputs arrive at random phases of the excitability cycle and will have a lower effective connectivity.” Conversely, inputs that arrive synced to the same excitability cycle will propagate faster and with greater bandwidth. We look further at Fries’ model below.
 
Biological organisms have leveraged faster information exchange through various biophysical pathways. These faster and richer information flows allow for more macro-scale levels of consciousness to occur than would occur in similar-scale structures like boulders or a pile of sand, simply because there is greater interconnectivity and thus more “going on” in biological structures than in a boulder or a pile of sand (Figure 2). However, as stated previously, the type of interconnectivity must be based on resonance mechanisms that, as a general matter, induce a step function in the speed of information flows due to the transition from incoherent structures to coherent structures. Boulders and piles of sand amount to “mere aggregates” or just collections of rudimentary conscious entities (perhaps at the atomic or molecular level only), rather than combinations of micro-conscious entities that combine into a higher level macro-conscious entity, as is the case with biological life.