Consciousness – Definition, Nature, Functions & Theories



We cannot underestimate the importance of the brain in our everyday lives. The brain has physical properties that are in a constant state of flux. Consciousness is an important aspect to study among other cognitive functions.

The brain never rests totally but is always teeming with electro-chemical activity. Thus, all cognitive functions such as consciousness, attention, memory, thinking, the use of language and many more are reflection of the modulated pattern of chemical activity among specialized cells i.e. neuron.

Nevertheless, we owe our entire cognitive universe to the functioning of these neurons which transmits information in the form of electrical waves.

Definition of Consciousness 

Consciousness is a phenomenon that is shared by nearly all people. It cannot be directly seen or touched. Yet it is real enough to most people.

It is the fundamental state that denotes the being as alive and gives the body the necessary information about the world outside it and about the body itself. 

In fact, It covers cognitive functions such as attention, sensory experiences, memory and states such as being awake or dreaming.

Several definitions of Consciousness have been proposed by different authors:

  • According to American Psychological Association (APA) – Consciousness is an organism’s awareness of something either internal or external to itself.
  • Consciousness consists of all the sensations, perceptions, memories and feelings you are aware of at any instance (Farthing, 1992). 
  • It is “the normal mental condition of the waking state of humans, characterized by the experience of perceptions, thoughts, feelings, awareness of the external world, and often in humans . . . self-awareness” (Colman, 2001, Tononi and Koch 2008)
  • According to Matlin, Consciousness means the awareness that people have about the outside world and about their perceptions, images, thoughts, memories, and feelings.

Nature of Consciousness

Consciousness has two sides: Consciousness includes a realization of environmental stimuli. For example one
might become mindful of an old tune, a headache, or visual recognition of an old friend. Consciousness also includes once cognizance of mental events – thoughts that results from memories.

Consciousness is a psychological construct – a concept i.e. devised to help us understand our observations or behaviors. The construct of consciousness has several meanings. 

As sensory awareness: our sense organs (Eyes, ears, nose etc.) enable us to become aware of the environment. 

Inner state: We are conscious of thoughts, images, emotions and memories within ourselves. Although they may not have physical occurrence of these aspects. 

The waking state: consciousness is also the waking state as opposed to sleep. 

Brain Areas Associated with Consciousness

Functional neuroimaging (fMRI) was used to assess activation in brain areas associated with face processing (the fusiform face area) and object processing (parahippocampal place area). They key finding was that it was possible
to predict the identity of the suppressed (unconscious) stimulus with almost 90% accuracy by studying the brain activation pattern in those brain areas. Thus, even suppressed stimuli were processed at high levels of the visual system.

In addition, McIntosh et al. found evidence that the left prefrontal cortex forms part of a much larger neural
system associated with conscious awareness including the right prefrontal cortex, bilateral superior temporal cortices, medial cerebellum, and occipital cortex.

Functions of Consciousness

  • Simplification and Selection of information
  • Guiding and overseeing actions
  • Setting priorities for action
  • Detecting and resolving discrepancies
  • Adaptation and learning function
  • Reflective and Self Monitoring Function
  • Error Detection and Editing Function
  • Decision-making

Theories of Consciousness

Global Workspace Theory

Baars and Franklin (2007) put forward a Global Workspace Theory.

  • One of the main assumptions of this theory is that we are only consciously aware of a small fraction of the information processing going on in our brain at any given moment.

We generally become aware of information that is of most importance to us, for example, because it is connected to our current goals.

Baars and Franklin (2007) used a theatre metaphor to clarify the nature of their global workspace theory. According to this metaphor, “Unconscious processors in the theater audience receive broadcasts from a conscious ‘bright spot’ on the stage. Control of the bright spot corresponds to selective attention” 

  • Another major assumption is that there are very close links between consciousness and attention. In everyday language, the words – “look”, “listen” involves attention. In fact, the words “see”, “hear” involves consciousness.
  • One more assumption is that much human information processing involves a large number of special-purpose processors that are typically unconscious.
  • In addition, one assumption is that, “Conscious contents evoke widespread brain activation”

Dehaene and Naccache’s theory

Dehaene and Naccache (2001) put forward a global workspace theory resembling Baars’ theoretical approach. However, they did it going beyond in identifying the main brain areas associated with conscious awareness.

They argued that  conscious awareness depends on simultaneous activation of several distant parts of the brain. 

They identified three major states that can occur when a visual stimulus is presented:

(1) Conscious state: There is much activation in areas involved in basic visual processing, and neurons in parietal, prefrontal. Moreover, cingulate cortex associated with attention are also activated.

(2) Pre-conscious state: There is sufficient basic visual processing to permit conscious awareness but there is insufficient top-down attention.

(3) Subliminal state: There is insufficient basic visual processing to permit conscious awareness regardless of the involvement of attention.

In other words, conscious visual awareness requires basic visual processing (bottom-up processing) and attention (top-down processing).


  •  Anderson, J. R. (2015). Cognitive psychology and its implications. New York: Worth Publishers
  • Galloti, K. M. (2004). Cognitive psychology in and out of the laboratory. USA: Thomson Wadsworth.
  • Matlin, M. (1994). Cognition. Bangalore: Harcourt Brace Pub.

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