What is Consciousness?

(Written for Beginners in Philosophy)

 

What do we mean by consciousness?

Awareness of our surroundings and awareness of self. Different organisms display varying levels of consciousness, and the most advanced organisms, namely humans, display the highest awareness. Under the integrated information theory of consciousness, awareness  level can be quantified by measuring the “amount of integrated information in a physical system, which is postulated to have an identity relationship with consciousness”4. This quantity is named phi (Φ), and is estimated by analyzing electroencephalograms to determine correlation between local electrical signals and local values of phi 4.

​

The Neuroscience Perspective

Consciousness manifests in the physical structure that we use to perceive the world-- the brain. To begin our discussion on consciousness, we must first consider what neuroscience has demonstrated about consciousness, and then use that as the basis for a philosophical description of what it entails. The brain receives a stimulus from the surroundings by taking it in through sensory organs, such as the eyes, touch receptors in the skin, and the ears. A stimulus will generate an action potential (a change in the voltage across a single neuron) that propagates along axons to other neurons nearby. The brain translates a stimulus to a bodily signal by increasing the voltage (depolarization) across the membrane of a neuron (brain cell)  and creates electrical potential. This depolarization spreads to many neurons around it, and the signal travels until it reaches an effector organ that will react to the stimulus. This could be a muscle movement or the secretion of chemicals by an organ. Scientists that study consciousness and diseases of consciousness are interested in the local field potential, which is the sum of the electric current in a group of neurons/neural tissue. They can make correlations between this electric activity and the different levels of awareness (Huang 2015). There are physical regions in the brain that contribute significantly to our conscious perception of the world, namely the prefrontal cortex, thalamus, and brainstem (reticular activating center)3. Global neuronal workspace and higher order theories involve the prefrontal cortex, described to be the brain’s decision making and behavioral center. The thalamus, located in the midbrain at the superior surface of the brain stem, the brain’s main integration center, and plays an important role for visual processing.  The thalamus is said to be the ‘gateway’ to consciousness because it filters information, and integrates the information needed to make us aware of our surroundings. The reticular activating system, located in the brainstem, plays a role in filtering over 99% of stimuli that enters the brain to direct our attention.

​

The Philosophy perspective

Philosophers have since considered the physical aspects of consciousness (although older philosophers like Kant did not know that the brain was responsible for it)  and combined them with their views about the non-physical, ineffable facets of conscious experience to formulate various theories of consciousness. It is important to note that every theory has a focal point, and that not all theories give a complete answer as to what consciousness is and how it manifests. When we put some of them together, we can begin to enrich our understanding of what makes us aware.  

​

The Global Workspace- A Cognitive Theory

Developed by Bernard Baars in the late 1990’s, this theory aims to connect conscious and unconscious processes, and describes conscious thought to be an inner domain where we “carry on the narrative of our lives” 1. This theory is often explained with the theater metaphor, in which your stream of consciousness is represented by a spotlight that draws attention to certain information. The dark surroundings represent the unconscious ‘audience’ watching the play1. This bright spot for sensory consciousness, for instance, can correspond to the activity of sensory neurons in the cerebral cortex1.

​

Qualitative Features of Consciousness

Despite the fact that consciousness is rooted in the physical structures of the brain that are shared among all of us, there is a facet of conscious experience that makes every experience unique to the individual. The hue of color that you perceive, or the taste of a fruit are sensory experiences that only you have knowledge of. The same goes for other conscious processes such as thought and judgement--only you can hear your thoughts. This ineffable subjectivity is a facet of consciousness is called qualia,  and was first proposed by Locke in 1688, and its significance to characterizing consciousness was described by Nagel  and Chalmers in the in the 1960s and 70s3. These philosophers believe that the existence of qualia in an organism is a major criterion for consciousness in that organism.

​

Phenomenal Structure and Phenomenal Consciousness-  

Phenomenal structure is different from qualitative structure in that it describes all kinds of “order and structure found within the domains of conscious experience”3. Qualia is a facet of the phenomenal structure of consciousness, but it is debated whether the cognitive state (thinking of objective facts) has qualia of its own, and qualia seems to go as far as describing the raw emotions and sensory perception 3. Other philosophers maintain that qualia can be a facet of cognitive processes beyond sensory perception, which is reflected by differences in our thought processes and the way we mentally represent that same (seemingly objective) concepts or facts. Infamous arguments for the existence of phenomenal consciousness include those proposed in Nagel’s What it's like to be a bat (1974), and Jackson’s Epiphenomenal Qualia (1982). Nagel proposes that although we understand how a bat perceives its surroundings (by echolocation) we cannot begin to understand the subjective facts about what it feels like to be one. Jackson takes a similar approach by imagining Mary, a color scientist that knows all objective information about color and the mechanisms behind its perception. If Mary has lived in a colorless (black and white) room her whole life, and sees a red rose for the first time, would she have learned anything new about color? Or would she have known exactly what to expect?

​

Access consciousness

This facet of consciousness maintains that  the mental state is accessible for use in reasoning and intentional behaviors3.One does not have to access it to be aware of their conscious state, but can still report on it.a conscious visual state, for example is one that the organism has access to and can mentally represent3.  Even though this state may not have phenomenal qualities, it is still considered conscious since the brain has access to it. Evidence for this type of consciousness is introspection, which is the act of thinking about our thoughts and actions.

​

Higher Order Theories of Consciousness

What makes a mental state a conscious mental state is that fact that it is accompanied by thoughts about that state (ie. a meta-mental state) whose contents are now about the original mental state3. Unconscious mental states do not have higher-order states about them. This theory is thought to explain the qualitative types of consciousness mentioned above. Higher order states are of two types, namely the higher order thought theory, and the higher order perception theories3.  Higher order thought theorists agree that we experience no sensory qualities other than those that are in our surroundings-- in other words, there is no ‘inner sense’ organs. This position is not taken by higher order perception theorists, rather, they agree that inner sense organs exist, and that the conscious mental state (higher order state) is non-inferential (such as a statement or belief) and exists simultaneously with the lower-level mental representation3.

 

Conclusion

It is important to recognize that this account of qualities of consciousness and theories of consciousness  is greatly simplified to make the concepts easier to grasp. There is much more information in the classroom resources and the syllabus going forward. All in all, we demonstrated the versatility of various theories in their application,made connections to the neuroscientific basis of consciousness, analyzed  the types of conscious awareness, and even looked at a specific theory of conscious perception.

​