Chapter 8

Theorem X: Mental Interactions are Physical Processes

A mother, seeing her beloved child wandering into the street and about to be hit by a speeding car, decides without hesitation to save her child by jumping into the street to protect her child even if that means risking her own life. Obviously, her love for the child must be able to affect her thinking, planning, and decision making and cause her to carry out such a life-risking act. But how can the feeling of love affect other mental processes, such as thinking, planning, and decision making? The obvious mechanism is that, as mental processes are the information-processing processes of neural processes, interactions between mental processes occur by information transmissions between the involved neural processes via their synapses.

8.1. Mental Force

However, another possible mechanism that has long been suspected to exist and that some people still believe in is that mental processes interact between themselves directly, without utilizing the neural synaptic transmissions, by using a force that is not one of the four fundamental physical forces. This force may be called mental force or mental power. Let’s examine this force in more detail of how it probably works and what happens if it works.

To be a mental force, the force must be directly executable by mental processes and must affect other mental processes directly by itself. As a mental process, which is the information-processing process of a neural process, is the counterpart of the electrical/electrochemical-signal-processing process of that neural process (Chapter 2), when the mental process is affected by the mental force, the electrical/electrochemical-signal-processing process must be affected similarly too so that they remain in accordance with each other. This means that the mental force must affect the electrical/electrochemical- signal-processing process physically too. In detail, this means that the mental force must affect membrane channels and synaptic channels of millions of neurons and move billions and billions of sodium, potassium, calcium, and/or chloride ions at the correct channels in a correct way (such as a correct amount of sodium, calcium, etc. ions are moved at the correct rate, in the correct direction, and at the correct time, in each and every channel in a concerted pattern) accurately so that appropriate polarizations or depolarizations occur at the right time and result in timely and appropriate action potentials or no action potentials of each of the millions of neurons in the involved neural circuit [1,2,3] so that the correct signaling pattern occurs in the neural circuit.

The main questions about this mental force are

  1. What is the nature of this mental force?
  2. How can it affect various kinds of neuronal membrane and synaptic channels and move different kinds of ions?
  3. In affecting the membrane and synaptic channels and moving ions across channels, energy must be expended or gained. Where does this force draw energy from or channel the gained energy to, and how does it do that?
  4. How can this force know what the exact signaling pattern (such as what the exact signaling pattern of a decision to save a child) is to be created in what neural circuit in order that the desired mental process and qualia (such as a decision to save the child) occur? And how can this force know which neurons of the 100 billion neurons in the brain are the neurons of the neural circuit that is to be affected?
  5. How can this force affect millions/billions of neuronal membrane and synaptic channels in the neural circuit correctly, both spatially and temporally, so that the desired signaling pattern (in 4.) is created?

Evidently, to create a suitable signaling pattern in a correct neural circuit for a certain mental process to occur is not a simple physical process. But the mental force, if it really exists, must be able to do this. Up to the present time, however, there are no answers to how it can do this, and there is no physical evidence for this force either.

8.2. Mental process interactions

On the contrary, a lot of evidence supports that mental process interactions occur by signal transmissions through neural synaptic connections between the involved neural processes. Let’s examine how mental process interactions occur by this mean in more details. When one mental process (such as seeing a child in danger) occurs, the signaling pattern that is the information of this visual perception will be sent through synaptic connections to other neural processes of other mental processes. These signal-receiving neural processes will process this information and generate signaling patterns that are their specific information (i.e., a decision to save a child, emotion of fright, retrieval of relevant past knowledge and experiences of how to save the child, etc.). The generated signaling patterns, which are the generated information, will likewise be sent to related neural processes via neural synaptic transmissions and create successive signaling patterns that are successively processed information that will be sent to other related neural processes, and so on. Overall, because neural circuits are connected in some specific patterns and because synaptic junctions are capable of processing transmitted signals [2, 4-13], neural synaptic transmissions can “not only transmit but also process” information through the neural circuits and synapses. Thus, coherent mental process functions can occur via neural processes and neural synaptic transmissions.

Evidence that mental process interactions occur via neural processes and neural synaptic transmissions is countless. Anything that affects neural transmission directly at the synapses or at the neural tracts that connect to the synapses can affect mental process interactions. Pharmacologically, CNS (central nervous system) active substances that interfere with neural synaptic transmissions, such as psychedelic drugs, CNS stimulants, and tranquilizers, alter mental processes according to which neural synaptic transmissions they affect and how they affect them, and the results can be hallucination, excitation, tranquility, etc. [14-17]. In patients with CNS diseases that have neural synaptic transmission dysfunction such as bipolar disorder, major depression, anxiety disorders, Alzheimer’s disease, and Parkinson’s disease, drugs that can help correct or improve the abnormal neural synaptic transmissions can correct or improve the functions of corresponding neural processes and mental processes, such as mood and cognition [18-24]. A transection of a CNS nerve tract can affect and be used to treat a mental disorder (such as depression), pain, epilepsy, etc. [25-28]. A corpus callosum transection, which is done in some cases of intractable epilepsy, has observable mental effects that is called “split-brain syndrome”, in which some mental processes on one side of the brain cannot communicate with mental processes on the other side of the brain and in which there is an impaired functional connectivity between some modules between the two hemispheres [29-34]. Diseases that damage neural tracts that connect neural processes disrupt signal communication between the involved neural processes (and thus the corresponding mental processes) and result in various syndromes depending on which connection is destroyed, such as a conduction aphasia, which occurs when the left hemisphere arcuate fasciculus (which connects the sensory and motor language areas) is destroyed [35,36](such as in the case of cerebral infarction), and pseudobulbar affect (uncontrollable crying or laughing), which occurs when the corticopontine–cerebellar circuits (which are the pathways of emotion control) are disrupted (such as in the case of stroke or motor neuron disease) [37]. Regarding neural processes, evidence that mental process interactions occur via neural processes has been discussed in section PM2.4, and PM2.5 Chapter 1.

(* Conduction aphasia also occurs from lesions at other sites, such as at the posterior-most portion of the left planum temporale and supramarginal gyrus [38,39].)

8.3. Theorem X

Therefore, it can be concluded that mental interactions between mental processes are neural process interactions via neural synaptic transmissions. As the generation and propagation of action potentials in neural processes (which involve the functioning of neuronal membrane channels and movement of ions across channels, etc.) and in neural synaptic transmissions (which involve the functioning of synaptic channels, releasing and binding of neurotransmitters, depolarizations or hyperpolarizations of the postsynaptic membranes, etc.) [3] are physical processes, it can be concluded that mental process interactions are physical processes. This theory asserts this as a theorem:

Theorem X: Mental interactions are physical processes.

8.4. Indications

This theorem indicates that mental process interactions or the activities of the mind can be described and predicted by physical laws. For example, the effects of love, hate, aspiration, etc. on other mental processes such as thinking, planning, or decision making are physical effects and can ultimately be described and predicted by physical laws. The predictions can be definite or probabilistic depending on the physical laws involved.

If all the factors involved in the processes of mental process interactions, such as the exact signaling patterns of the neural processes of the affecting mental processes and the exact response characteristics of the neural processes of the affected mental processes, are known, it will be predictable what the result is. For example, when a person is given a choice to choose between two things, such as a house or a car, if all the factors of the neural processes of the involve mental processes and all the factors of their interaction characteristics are known, it can be predicted, definitely or probabilistically, what he/she will choose.

8.5. Predictions

  1. Mental interactions can be created, identified, measured qualitatively and quantitatively, monitored, changed, or destroyed by performing the respective action to only their neural signal transmissions. These actions on the neural signal transmissions are both necessary and sufficient for the corresponding actions on the mental interactions to occur, and these actions on anything else without having the actions on the neural signal transmissions will not result in the corresponding actions on the mental interactions.
  2. In any event or experiment, all predictions that are valid for the neural signal transmissions will be valid for the mental interactions that are associated with the neural signal transmissions, and the changes that occur in neural signal transmission and that occur in the mental interaction will be identical in all aspects (quality, quantity, temporal pattern, etc.).


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Back to Chapter 7 – Theorem VI – IX


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