Understanding Consciousness
Consciousness is a fundamental aspect of human experience, yet it still remains difficult to understand in science and philosophy. Consciousness helps us focus, perceive, decide, and interact—enabling us to direct our attention and engage meaningfully with the world and reality.
Consciousness is the “I think, therefore I am”; being in a state of awareness and able to think about one’s own existence, thoughts, and surroundings. It involves awareness, but awareness is not necessary consciousness. Awareness is the ability to perceive the environment, and the recognition of oneself as an individual, though these are distinct: a creature might be aware of its surroundings without reflecting on itself.
Consciousness is often split into two types:
- Phenomenal consciousness: the experience, “the feeling of what happens”, “what it’s like” , such as the taste of coffee (also called qualia).
- Access consciousness: the thought process, “the perception of what passes in a man’s own mind”, the decision making, processing information as to determine a conscious action.
Much of the brain’s activity is actually unconscious; managing routine tasks and freeing conscious attention for more complex reasoning. When learning to play the piano or drive, we begin with deliberate, conscious control—thinking through each action. With practice, control shifts to unconscious systems, enabling fluid, automatic performance. Yet consciousness re-engages instantly when something unexpected occurs, like a mistake in music or a hazard while driving. Our unconscious can manage multiple tasks simultaneously, whereas conscious thought tends to only able to focus on one thing at a time.
Where does consciousness come from?
Consciousness is closely tied to brain activity. Specific brain regions, such as the prefrontal cortex (linked to self-awareness and decision-making) and the thalamus (involved in alertness and sensory processing), play key roles in the conscious experience, but scientists are still unable to identify a single point that is responsible.
When resting, our “Default Mode Network” (DMN) is active, and is linked to patterns of conscious thought. Scientists can see DMN brain activity using scanners, but they still don’t know how this creates our personal, inner experience.
Brain surgeons, while removing tumours, have conducted experiments by stimulating various parts of the brain while the patient is awake. They are able to induce muscle movements through this stimulation; however, patients consistently report being aware of the difference between initiating a movement themselves and having the movement induced by the surgeon. This has led some surgeons to believe that consciousness may not be a physical component of the brain. However, epiphenomenalist science says that consciousness is real, but just a by-product of physical brain activity.
The ‘Hard Problem’ of Consciousness?
David Chalmers’ hard problem asks why physical brain processes result in subjective experiences (qualia), like why red feels “red.” The “easy problems”—functions like memory or perception—are more tractable, but the subjective gap persists. Thought experiments like Mary’s Room (where a scientist learns about colour without experiencing it) highlight this challenge, but very recent brain scans appear to show that the people do perceive colours the same so do likely have the same subjective experiences (qualia).
Is Consciousness Unique to Humans?
Consciousness is not exclusive to humans. Animals like chimpanzees, dolphins, and elephants show self-awareness in mirror tests, while birds and octopuses display complex behaviours—such as problem-solving and emotional responses—indicating some level of consciousness. Evolutionarily, this may have supported survival through social coordination, with species having complex nervous systems, like primates and octopuses, showing signs of consciousness studied via comparative cognition. However, humans possess a unique form characterised by advanced language, abstract thought, and self-reflection. The problem of other minds—the philosophical challenge of proving whether other beings (human or animal) are truly conscious—complicates this question, as we can only scientifically infer consciousness from behaviour, however, it’s likely that any animal possessing a nervous system has a level of consciousness.
People who have experienced strokes, struggle to move, to use language, and unable to form understanding, but after the experience say they were still fully aware and conscious while being frustrated by the brain not being able to perform normally (cite:Jill Bolte). It could be argued that complex brain activity or thoughts are not required for consciousness, suggesting that many simpler species, such as ants, and possibly plants, might be conscious.
Disorders like coma, locked-in syndrome, or vegetative states show that consciousness can persist despite extreme loss of motor or cognitive function, suggesting it is not solely tied to behaviour.
Also, many people who have had near-death experiences (NDEs) say they were having a fully conscious (out of body) experiences, even while surgeons say they were clinically dead during that time. Scientifically, there is no current empirical evidence that consciousness exists without brain activity, but many have reported very similar (out of body) experiences, leading the individuals to believe that conscious experience is something outside of the brain.
Consciousness as an evolved biological process
Recent brain research shows that consciousness comes from many parts of the brain working together. It is not just from one area, such as the cerebral cortex (the wrinkled outer layer that covers the top of the brain, handling complex thinking).
A 2025 scientific review looked at brain scans, electrical stimulation tests, damage cases, and people or animals born without much cortex. It found that three main parts play a role in being conscious:
- The cortex (outer wrinkled layer).
- The subcortex (deeper middle areas, including the brainstem at the bottom connecting to the spinal cord, and the thalamus which relays signals).
- The cerebellum (smaller rounded part at the back bottom, best known for balance and movement).
The deeper subcortex alone can support basic consciousness, like feeling pain, fear, or hunger. This comes from cases where humans or animals lack most of the outer cortex but still show signs of basic feelings and awareness through behaviour.
The cerebellum (back bottom part), often ignored in consciousness talks, also affects how experiences feel and shows up strongly in brain scans of conscious states.
This fits with how consciousness evolved in different animals. Birds lack our thick wrinkled cortex but have a brain area called the nidopallium caudolaterale that does similar jobs to our front thinking part.
Science sees consciousness working on a scale, from simple to complex. Older deep subcortical parts handle basic survival feelings, while the outer cortex and cerebellum add richer, more detailed experiences in normal brains.
In different animals, the level of consciousness depends on how their brain parts connect and develop, not just size or looking like a human brain.
When does consciousness arrive?
Through behavioural tests like the mirror self-recognition test, problem-solving tasks, and responses to novel stimuli or social cues, we can scientific measure the level of consciousness. Infants develop self-awareness around 18 months, as demonstrated by the mirror test. Some people claim to have memories from within the womb. It’s possible that consciousness begins when the brain first becomes active—around 24 weeks’ gestation—when zinc-dependent enzymes trigger a signal that suddenly lights up and activates neural circuits across the brain, which is quite a remarkable event to witness. There are some people who claim their consciousness was in and out of the body before they were born. The most likely occurrence is probably somewhere in between, likely around the time during birth.
Can Machines or AI Be Conscious?
No, machines/AI can be self-aware (as they are taught as to be able to reference itself), but they are not conscious. There is zero evidence that machines or AI possess consciousness based on our current technology. Current AI operates via algorithms and data processing, lacking subjective experience. Some people believe that if AI becomes conscious, it could become dangerous; however, AI does not require consciousness to perform ‘conscious-like’ decisions or actions. The line between consciousness and conscious-like is distinct, but will be become very difficult to discern in the future.
Consciousness during sleep
During sleep, consciousness goes to a different place but doesn’t disappear entirely. Our senses are disconnected from our consciousness—hearing goes mute, even for people with tinnitus; and eyesight goes blank, even for those who sleep with their eyes open. While laying unconsciousness, our subconscious does still appear to be listening, and is able to prompt consciousness back to life. It’s interesting how the senses are reconnected upon waking. Even though different senses are processed in different parts of the brain, they appear to restore at exactly the same moment, directly after becoming conscious again. We don’t hear out of one ear and then the other, just instantaneous.
During REM (Rapid Eye Movement) sleep, its known that the brain becomes a little more active, but still lacking real-world awareness or full control. Sleep studies using EEG show the brain cycles through distinct patterns usually every 45mins. The fact that we regain consciousness every morning, without needing to “reboot”, suggests that consciousness is not simply turned off during sleep but remains in a suspended or altered form.
During surgical operations under general anaesthesia, consciousness is deliberately suppressed through the use of anaesthetic drugs. This state is not the same as natural sleep—patients under anaesthesia are unresponsive, have no awareness of their surroundings at all, and typically do not form memories of the experience. Unlike sleep, where consciousness gradually fades and returns, anaesthesia effectively ‘switches off’ consciousness entirely for a period, though the exact mechanisms of how and why remain only partially understood. People who experience it don’t recall being asleep, but rather that the section of time simply never existed. It can be quite an eerie feeling.
Personal perspective…
Consciousness doesn’t need intelligence, and intelligence doesn’t need consciousness. I personally believe consciousness is not physical but somehow cohabitates within physical bodies to experience physical processes, which mostly aligns with a dualistic philosophy view. We think and feel that we have free will, but it is largely an illusion, as the choices we make have mostly already been shaped by prior events. Choices arise from a combination of the data at hand and the type of person you are – although not strictly determined, they are heavily influenced.
Stroke survivors tell us they were no less consciousness, just frustrated by their brain malfunctions, and interestingly, NDE survivors suggest that we don’t even need a body at all; they also say that who we are and what we wanted to experience was decided by ourselves before we were even born. There are things that can only be taught through experience, which is probably the whole purpose of living.
Classifications:
States of Consciousness
- Wakefulness: Full awareness and engagement.
- Sleep: Non-REM (minimal awareness) and REM (dreaming).
- Meditation: Enhanced or altered awareness.
- Altered states: From hypnosis or psychedelics.
- Unconscious states: Coma or anaesthesia.
Brain imaging tools like fMRI and EEG reveal distinct patterns for each state.
Philosophical Perspectives key theories on consciousness
- Dualism (Descartes): Mind and body are separate.
- Physicalism/Materialism: Consciousness is purely physical.
- Functionalism: Consciousness is about information processing.
- Panpsychism: Consciousness is universal.
- Idealism: Reality is mental.
These frameworks shape the debate, though none is proven.
Psychological Models of Consciousness
- Freud’s Model: Conscious, preconscious, and unconscious layers.
- Attention and Awareness: Consciousness depends on focus.
- Cognitive Psychology: Links consciousness to working memory (holding information) and perception (interpreting sensory input).
- Altered States: Hypnosis, meditation, and psychedelics reveal its flexibility.
Cultural & Religious views
- Hinduism: Atman (soul) and Brahman (universal consciousness).
- Buddhism: Anatta (no-self).
- Indigenous Australian: Ties consciousness to land and spirits.
- Christianity/Islam: Links it to the soul.
Historically, consciousness shifted from spiritual to scientific focus post-Enlightenment.
Measuring consciousness
- Glasgow Coma Scale: Assesses patient responsiveness.
- fMRI and EEG: Detect brain activity.
- Integrated Information Theory (IIT): Measures information integration.
- Global Workspace Theory (GWT): Views consciousness as information sharing.
Limitations persist in fully capturing subjective experience.
Listen to the podcast
