The ‘power of the unconscious’ is a common phrase reflecting the popular notion that our minds are divided in two, conscious and the unconscious. We are either urged to unleash our unconscious potential or listen to what bubbles up in us, but we also learned to overrule our animal instincts and emotions with reason thanks to our conscious mind.

We link the conscious and the unconscious to mind and body: we often think as the conscious processes as mental ones (I’ve given it much thought) and the unconscious processes as embodied (I have a gut feeling)

The division of the mind can be traced back to ancient Egypt about sleep and dream and early Hindu texts. Plato also gave the soul three parts: Reason, Spirit, Appetite, all with their own goals and abilities.

Gradually this shifted from parts of mind to mechanisms and distinct types of processing within one brain. This can be traced back to Helm-Holtz’s idea of ‘unconscious inference’, to William James’s distinction between associative and true reasoning. Most theories suggest that one process is fast, automatic, inflexible, effortless and dependent on context, while the other is slow, effortful, controlled, flexible, requires working memory and independent of context. This has been rediscovered and reinvented time after time, the distinction is common because it is valid.

The question is this – what could the difference between conscious and unconscious processes be?

For this we will consider first perception, then action and finally how perception and action and conscious and unconscious may converge in the phenomena of intuition and creativity.

What is unconscious perception?

Simple everyday phenomenon, like only noticing the humming of a microwave when it stops, seem odd because it suggests perception without consciousness. You unconsciously hear the sound. The phenomena of unconscious perception have been known since the very early days of psychology. Whenever there is a talk of automatic behaviour, unconscious processed or subliminal effects, there is an implicit comparison with conscious processes, yet those remain entirely unexplained. In early experiments, conscious perception was defined in terms of what people said: if we say we are conscious or unconscious of something, then (unless deliberately lying) we are. Yet this is problematic in some ways:

One problem is that whether people say they have consciously seen (or felt or heard) something depends on how cautious that are being. This became clearer with the signal detection theory.

This requires tow variables to explain how people detect things like sounds, flashes of light, or touches on the skin. One variable is the person’s sensitivity (how good their eyes are), the other, β, is their response criterion (how willing they are to say ‘yes, I see it’ when they are unsure).  Most relevant is that without their realising it, and with the exact same sensitivity, people can differ in criterion. For example if a punishment or reward is added to them seeing a flash of light, they will have a higher or lower criterion. This means there is no fixed threshold that separates the things that are ‘really seen’ or ‘really experienced’ from those that are not.

Another problem stems from the behaviourist suspicion of verbal reports, with some wanting more reliable ‘objective’ measures of consciousness than what people say. But this is a curious idea: On the one hand making a verbal report (speaking or writing) is  just as much an objective action as pressing a button or pointing, but on the other hand, if all objective measures of discrimination are taken as evidence of conscious perception, then evidence seems to be ruled out by definition.

The basic requirement became to demonstrate a dissociation between two measures: a ‘direct’ measure, to indicate conscious perception and an ‘indirect’ measure to indicate unconscious perception.

This controversy was revolved when James Cheesman and Philip Merikle proposed a distinction between what they called ‘objective threshold’, defined as the detection level at which perceptual information is actually discriminated at a chance level and the ‘subjective threshold’, defined as the detection level at which subjects claim not to be able to discriminate perceptual information at better than chance level. Their question was whether primes presented so briefly as to be undetectable would affect reaction times. Their conclusion was that unconscious perception occurs primarily when information is presented below the subjective threshold but above the objective threshold. The objective threshold really is the level below which stimulus can have no effect of any kind, but there is a level above that at which a stimulus can have an effect even though the person denies being conscious of it.

The idea of two thresholds creates difficulties if we think that all processes must be either conscious or unconscious. We could go further and suggest that if human behaviour is controlled, then we might expect two different systems. The fear of the subliminal took a turn when James Vicary came with subliminal  advertising and subliminal messages, such as buy this brand.

Also popular is the idea that subliminal self-help programmes can reduce anxiety, improve self-esteem, health, memory or help people stop smoking or loosing weight. There already is software to send you subliminal messages during your sleep or when playing a game. There is also a placebo effect, which says it’s more important what the label says than what the message says.

The question become crucial in the case of anaesthesia. In medical practise one every one or two thousand patients has anaesthetic wrongly administered wrongly or experienced some awareness, in the worst case severe pain and fear, but can do nothing to make their state known (like locked in syndrome). Being unresponsive and amnesic under anaesthetic is not necessarily the same a being rendered unconscious.

What are Emotional and Social Effects?

Some of the most striking experiments on unconscious perception concern the emotional effects. It is well known that people prefer familiar things – including images they saw before. This is the ‘mere-exposure effect’ and works on subliminal stimuli too.

It may be tempting to ask which measure reveals what people are really conscious of. Things must either be in or out of consciousness. An alternative is to say there uis not ultimately correct measure of what is unconscious or conscious; there are just different process responses and ways to measure them.  This view has no answer to: ‘what was I really conscious of?’

We may unconsciously imitate other people’s expression, mannerisms, moods and tone of voice or make judgements about other people but not knowing why. This can also be caused by seeing a person’s face and then experiencing a positive or negative event.

Studies have shown that both positive and negative faces can produce significant changes in amygdala activation, even when stimuli are not consciously perceived. Perhaps at a certain level of activity the stimulus becomes conscious, or alternatively at the level the activity starts to have other effects within the brain and body.

if every impression produces effects in the brain, what is the difference between the ones that we are aware of and those we are not?

What is the difference between conscious and unconscious action?

We can divide actions into what our intuition suggests are five distinct types:

1. Always unconscious – growing hair, increase blood sugar level. Spinal reflexes that depend on neural connections outside the brain are always unconscious.
2. Usually unconscious – some actions can be brought under conscious control. Like when you feel your heart rate, you try to lower it by resting. We don’t know how it works, but it does.
3. Initially conscious – With practise skilled actions are learned and come easily and smoothly. You learned to cycle with the utmost conscious thought, but now do it fairly unconsciously.
4. Either conscious or unconscious – many well learned skills can be done either way. Sometimes you make tea, thinking about it, other times it is just an unconscious action.
5. Always conscious (Isn’t this obvious?) – always conscious, like when thinking about a forgotten name or a route to an unfamiliar city.

What are current theories?

Casual theories

Some theories have a clear casual role for consciousness, most obviously dualist theories, but they face the problem that for consciousness to have any effects it must interact with matter.

Descartes located this interaction in the pineal gland. William Benjamin carpenter proposed that in one direction physiological activity excites volition liberate the nerve-force with which appropriate part of the brain is charged. Popper and Eccles’s dualist interactionism faced the same problem. They later proposed that all mental events and experiences are composed of ‘psychons’ and every psychon interacts with one dendron in the brain.

Libet’s conscious mental field (CMF) also acts both ways, providing in one the direction the ‘mediator’ between the physical activities of nerve cells and the emergence of subjective experience and in the other a casual ability to affect or alter some neuronal functions.

Jeffrey Gray proposes that ‘the decision is made by the unconscious brain and enters conscious awareness only after the event. Conscious itself monitors features relevant to ongoing motor programmes and permits changes in the variable.

Finally the global workspace theory. Bernard Baars said:’consciousness is a supremely functional biological adaption. It is kind of a gate way: a facility for accessing, disseminaring and exchanging information’. According to him actions which are performed consciously are shaped by conscious feedback while unconscious actions are not.

Non-Casual Theories

Eliminative materialism denis that existence of consciousness as anything distinct from its material basis. Epiphenomanalism accepts the existence of consciousness but denies that it has any effects. IN it’s traditional form, this is a somewhat strange idea, implying a casual chain of events leading from sensory input to behaviour, with consciousness produces as a by-product that has no further action at all. This is highly counter-intuitive.

In Philosophy of mind there are two main theories: high order perception (HOP) and high order thoughts (HOT). According to HOP theory, being conscious of a mental state means monitoring first-order mental states in quasi-perceptual way – with something analogous to an ‘inner eye’or inner sense. According to HOT theories, a mental state is conscious if the person has a higher-order thought to the effect that they are in the state.

However, such theories face difficulties, such as deciding what counts as content of an HOP/HOT. They also mean denying consciousness to creatures incapable of HOTs, and have troyvke dealing with sates which seem to be conscious without thought or observer of any kind.

What is functionalism?

 Functionalism, is used un many different and sometimes contradictory ways. In philosophy it is the view that mental states are functional states. This means that any system which executed exactly the same functions as a human being in pain would also be in pain, so zombies are impossible. A common view is that functionalism woks well for explaining mental states, but is much less clear in accounting for phenomonal consciousness or qualia.

It is also used in discussion of artificial intelligence to mean that any system which could carry out exactly the same functions as a conscious system would also be conscious.

What is the Casual Efficacy of consciousness?

 In doing this simple task, the casual sequence seems to be 1) consciously perceive and 2) act on the basis of the conscious experience. This is known as the assumption of experience-based control.

It means two conversions: first the physical information in nerve firings in the visual system must somehow be turned into conscious experiences and then the conscious experience must somehow act back on the brain, causinf more nerve firings to direct the appropriate respons.

Susan Hurley’s Classical Sandwich model of the mind suggests: ‘The mind is a kinf od sandwich, and cognition is the filling’ You start with the bread of perception, then you have the filling of cognition and on top you have the bread of action.

Note that although the debate about mental causation goes back centuries, the question of consciousness is only a part.

In the 19th century, physiologists began to understand reflex arcs and nerve function. Shadworth Hodgson declared that feeling, however intensely felt, van have no causual efficacy whatever.  He compared the nervous system to a mosaic and the feelings to the colours of the stones.

James predicted that for years to come, we would have to infer what happens in the brain by making inferences from our feelings or behaviours. Later the brain imaging and other technological inventiobs have given us more insight, but bring a lot of new problems with them too. Information enters the nervous system through senses, flows through parallel pathways to various brain ares and ultimately affects a person’s actions.

For Max Velmans ‘conscious presents a Casual Paradox. As he points out: ‘Viewed from a first-person perspective, consciousness appears to be necessary for most forms of complex or novel processing, but viewd from a third person perspective, consciousness does not appear to be necessary fo any form of processing. An adequate theory of consciousness must make sense of these casual interactions and so resolve the paradox with out violating either out intuitions about our own experiences or the finding of science.