Mind, Matter and Quantum Mechanics
Henry Stapp – Springer Verlag
Stapp starts by asking what sort of brain action corresponds to a conscious thought. He criticises the mainstream for assuming that Newtonian physics can be applied directly to the brain, and claims that a quantum framework is needed to understand the brain. The Copenhagen interpretation of quantum theory was the first mainstream version, and was pragmatic in recommending the theory as a system of rules that allowed the calculation of empirically verifiable relationships between observations. Stapp favours Heisenberg’s refinement of the original Copenhagen position. Heisenberg thought that the probability distribution of quantum theory really existed in nature, and that the evolution of this probability was punctuated by uncontrolled events, which are the events that actually occur in nature, and which at the same time eliminate the other probabilities.
The development of computing during the second half of the 20th century demonstrated that thought-like or cognitive processes required internal representations not allowed for in the then prevailing behaviourist concept. However, this still did not account for conscious experience, and in this period thinking or cognition came to be seen as something separate from consciousness.
Both Bohr and Heisenberg viewed quantum theory as a set of rules for making predictions about observations under experimental conditions. These predictions are incompatible with classical physics in respect of the prediction of non-locality. Heisenberg did not view the quanta as actual things, but as tendencies for certain types of events to occur. The orderly evolution of the system is deterministic, but this controls only the tendencies for things or propensity for events, and not the actual things or events themselves. The things are controlled by quantum jumps that do not individually conform to any natural law, but collectively conform to statistical rules.
Stapp bases his proposal for quantum consciousness on three observations. 1.) The brain’s representation of the body or body schema must be represented by some form of physical structure in the brain. 2.) Some brain processes such as the behaviour of calcium ions involved in synaptic transmission need to be treated quantum mechanically. Stapp also thinks that the sensitivity and non-linearity of the synaptic system, the involvement of calcium ions and the large number of metastable states into which the brain could evolve all point to a quantum mechanical system. 3.) Stapp suggests that the brain could evolve into a state analogous to the deterministic evolution of the quantum state from which an actual state must be selected.
Although Stapp pays a lot of attention to the synapses his is not actually a neuron based theory. Rather the event could be selected from the large scale excitation of the brain. The selection of events from a wide range of probabilities is seen as being particular adaptive where an organism needs to select from a range of future probabilities. Stapp wishes to establish the relationship between mind and matter, the relationship between reality and quantum theory, and also how relativity is reconciled with both experience and non-locality. The solution is suggested to be a series of creative events bringing into being one of a range of possibilities created by prior events. He suggests that consciousness exercises top-level control over neural excitations in the brain. The neural excitations are regarded as a code, and each human experience is regarded as a selection from this code. He sees the physical world as a structure of tendencies in the world of the mind. He finds it as unacceptable that there is an irreducible element of chance in nature as described by quantum theory, which is the most usual conclusion to be drawn from the randomness of the wave function collapse. The element of conscious choice is seen as removing chance from nature. He distinguishes between systems where an external representation and knowledge of the laws of physics can accurately predict how the system develops, and his own idea of a system that is internally determined in a way that cannot be represented outside the system.
The brain is viewed as a self-programming computer with self-sustaining neural patterns as the codes. It is necessary to integrate the code from sensory input, with the code from previous experience. This creates a number of probabilities, from which consciousness has to select. The conscious act is the selection of a piece of top-level code, which then exercises control over the flow of neural excitation. The unity of conscious thought comes from a unifying force in the conscious act itself. It selects a single code from amongst a multitude on offer in the brain. Raising an arm involves a conscious act selecting the top-level code that raises the arm. This is suggested to close the traditional explanatory gap between thought and classical physics, because here the conscious thought is the selection of the code that allows the physical act. P. Stapp goes on to discuss the conscious process of looking at pictures. According to him top-level codes instruct lower-level codes to produce new top level codes and to initiate their storage in memory. The experience of noticing something is deemed to be the process of initiation into memory. There are close connections between the top-level code and the memory structure. The lower level codes have to be functioning correctly i.e. not damaged, and to be focused on the incoming stimuli in order for it to be put into higher level code and to be registered in memory.
Stapp discusses what neural research would need to reveal if it were to support his theory. It would need to reveal the neural connections needed to support self-sustaining patterns of neural excitation. It is necessary to find the neurons providing the top level coding, then the mechanism for storing memory traces of this, and finally the mechanism by which these memories are involved in the production of new top-level codes. P. Each conscious experience is seen as a creative act represented in the physical world by the selection of a top level code from among the many generated by the laws of quantum theory. The conscious experiences are the initiation of processes that produce changes in the body schema and the external and internal reality schema. The conscious act is functionally equivalent to changes in the physical world as represented in quantum theory. In the Heisenberg version of quantum theory physical things are events and quantum theory gives the propensity for particular events to occur. This is seen as providing a link between conscious processes and brain processes. In the Heisenberg version it is the act of observation which leads to the selection of a particular propensity.
Stapp attaches great importance to the idea of the formation of a record. This is seen as analogous to the Geiger counter that registers a record of a quantum event. Every conscious experience is seen as recordable, because it is evidence of some form of brain process. The later retrievability of the experience is evidence of a record in the brain. A key process in brain dynamics is seen as persisting patterns of neural excitation producing physical changes in neurons that enable a particular pattern to be re-excited, and allow re-excited pattern to connect with new stimuli. This is seen as the basis of the brain’s associative memory.
The top-level brain process is viewed as a process of actualising symbols, composed of earlier symbols connected into a whole by neural links. The top-level process is seen as directing information gathering, planning and choice of particular plans, monitoring the execution of plans. This can be understood in terms of top-level direction of multiple neural processes. Because of the top-level directive role, its connection to associative memory and the multiple structure of the symbols involved it is suggested that each top-level event corresponds to a psychological event, and this in turn connects psychological events to the quantum level. Both the top-level brain event and the psychological event act as choosers of a possibility, or converters of potentialities into actualities. Each human conscious experience is seen as the feel of an event in the top-level of processing in the human brain, a sequence of Heisenberg actual events, actualising a quasi-stable pattern of neural activity. Activation of particular symbols creates a tendency for the activation of other related symbols. The body schema is the product of actualised events accumulated over the life of the body. The top-level symbols have compositional structure formed from other symbols. The Heisenberg events are seen as being capable of grasping a whole a pattern of activity, and this is seen as accounting for the unity of consciousness. The continuity or flow of time is explained by an overlap of symbols with the preceding mental event.