The English philosopher, John Locke, (1632 – 1704) described consciousness as “the perception of what passes in a man’s own mind”. He was, of course, a man of his age and, today, we would understand this definition to include all genders and some animals. More recently, Locke’s definition has been extended to include awareness of the external world but, unfortunately, this is a red herring. Even bacteria respond to stimuli in the external world and, so, are aware of it. However, we would not regard them as being conscious. Furthermore, the unconscious human mind is aware of the external world, which is why, for example, a noise will wake us from sleep. Finally, it is possible for a human being to be conscious in the complete absence of external stimuli. Locke’s original definition seems more apt, therefore.
As mentioned in the previous article, consciousness is probably an emergent property of our complex brains and caused by feedback loops. A highly simplified model of the human mind might be:
These “functions” and the concepts of the “conscious and unconscious mind” do not, of course, refer to specific regions of the brain, but rather to processes that it follows.
We perceive the consequences of our actual behaviour with our senses, and this provides external feedback. For example, when driving a car, we continuously observe our position in the road and correct it when necessary. With sufficient practice, this can be done almost unconsciously. However, we can also “know” proposed behaviour before we act. For example, we can “hear” words that we might speak before saying them, “hear” music that we might play without playing it and “see” actions that we might take before taking them. Sensory processing functions are, therefore, connected to and aware of behaviour processing functions. Awareness of our own minds and awareness of the external world can be similar because both are processed by the same sensory processing functions. This creates the potential for feedback, and it is this feedback which, in the author’s view, leads to the emergence of consciousness.
This is supported by Francis Crick and Christof Koch who, in their paper “A Framework for Consciousness”, note that there is substantial evidence that a top-down flow of neural activity from the frontal cortex, which governs behaviour, to the sensory areas, is more predictive of conscious awareness than the reverse, bottom-up flow. This top-down flow is labelled “internal feedback” in the diagram above.
Experiments carried out, in the 1970s by the American neuroscientist, Benjamin Libet (1916 – 2007), provide further support for this model. Libet found that unconscious electrical processes in the brain preceded the conscious decision to perform an act. Significantly, however, he also found that the conscious mind could veto those decisions.
Such internal feedback loops have several evolutionary advantages:
- They allow us to review the likely consequences of potential behaviour before engaging in it. For example, in the case of language, the internal oral/aural feedback loop enables us to review and refine the information we would communicate, and assess its potential impact on any recipients. The cognitive processing and decision-making function passes a form of words to the behaviour processing function. The sensory processing function hears these words internally. It then passes them back to the cognitive processing function, which reviews them from the standpoint of the recipient. In effect, this is a form of empathy, one of the skills that we have as social animals.
- The logical rules that we have learnt and that the cognitive processing function employs in arriving at its conclusions are reflected in the structure of spoken language, and vice versa. This enables us to pass these rules on subliminally.
- Short term memory can be regarded as residing in the conscious mind, i.e., in the feedback loop. Long-term memory, on the other hand, resides in the unconscious mind and is strongly linked to the cognitive processing function. Internal feedback enables us to internally “rehearse” a wide range of information and behaviour which, in turn, serves to reinforce long-term memory..
- In a feedback loop, the emergent property regulates the components. Thus, the loop which causes consciousness may regulate the mind and enable us to concentrate on specific problems. This includes regulation of the unconscious mind but, as we are unaware of this, it cannot be regarded as “conscious regulation of the unconscious”.
- When we relax our conscious efforts, the unconscious mind operates more freely and, for example, solutions to problems that we have been working on come more readily.
- Finally, it can offer a degree of control over intuitive behaviour, providing we think before we act.
There is a question over where consciousness resides in the brain. I am of the view that it resides in a large part of it. In fact, I would go as far as to say that parts of the brain can operate either consciously or unconsciously depending on how the various parts are interacting with one another. The most notable evidence is the fact that our unconscious minds are not as good at producing ideas when, consciously, we are very heavily focussed on a problem. We must let go of conscious thought to allow unconsciously generated thoughts to flow and, very often, it seems that this is necessary to solve a problem.
Where feedback loops come in is the way in which parts of the brain interact with one another. Going back to the analogy of a microphone in front of a loudspeaker, it cannot be said that the howl it produces lies in any one part of the system. Yes, there is a loud sound in the air between the microphone and the speaker. However, there is an equally strong electrical current within the microphone, amplifier, and loudspeaker. In a way, the whole system can be said to be howling. This is an emergent property of the system and the way that its parts interact and is analogous to consciousness. However, if we turn down the volume control on the amplifier, the emergent property disappears and the whole system becomes quiescent – both the sound and the electrical currents. This is analogous to unconsciousness.
The audio analogy cannot be taken too far, however. Firstly, because whatever happens in the brain is probably far more complex. Secondly, unlike the audio system, which is either howling or not, we appear to experience degrees of consciousness and unconsciousness.
It is certainly the case that some parts of the brain only act unconsciously. For example, even when conscious, we are not aware of what takes place in the cognitive processing and decision-making function. It is a part of the unconscious mind. Rather, we are only aware of how the decisions that it passes to the behaviour processing function are interpreted. Knowing the information on which these decisions are based we can, to a limited extent, deduce the processes behind them. However, this is not the same as being consciously aware of them. Such deductions can be coloured by our needs and are, therefore, often a rationalization of our true decision-making process.
When we are awake, the feedback loops are on, and we are conscious. While we are asleep, they are off, and we are unconscious. However, unlike the audio analogy, which is either howling or not, we experience degrees of consciousness and unconsciousness. Consciousness is at its strongest when we are concentrating on a problem and at its weakest when we are in the depths of sleep. Neither state prevents the cognitive processing function, from receiving input from the sensory processing functions. Nor does it prevent it from passing instructions to the behaviour processing functions. We are unconsciously aware of the external world and can wake or give it our conscious attention when necessary. We can also sleepwalk and act on “autopilot”. This implies that our level of consciousness is regulated by communication between the behaviour processing functions and the sensory processing functions, which is consistent with Crick and Koch’s findings. Notably, parts of the prefrontal cortex are deactivated during sleep. However, this does not necessarily mean that they are where consciousness resides. Rather it may only mean that they are analogous to the volume control and regulate the feedback loops. In the absence of regulation by consciousness, the cognitive processing function behaves more freely. We will, for example, dream. When we wake, we catch the tail end of dreams because that is what has been fed by the cognitive processing function to our behaviour processing functions while we slept. However, as soon as consciousness returns it regulates the cognitive processing function, and so, such dreams may become extinguished.
If this hypothesis is correct, then it has the following implications:
- Animals that use tools or simple forms of communication may be conscious.
- The strength of human consciousness must surely vary from individual to individual.
- We may be able to strengthen our conscious skills by practicing activities which require a high level of concentration.
- Due to its advantages, greater consciousness may still be evolving in humans and other creatures.
- Using similar feedback processes in machines of sufficient complexity, it might theoretically be possible to replicate consciousness.
- We can take in information or knowledge subliminally, i.e., without being consciously aware of it. This can occur when our consciousness is at a low level, when it is distracted by more pressing concerns, or when the information does not appear to require a response. Such knowledge can also be reinforced subliminally through repetition. It can then affect our beliefs and, also, our behaviour when faced with a relevant situation.
Cognitive processing relies, of course, on knowledge. In my next post I will, therefore, discuss the nature of our knowledge.