Thinking Beyond Science

Human consciousness is one of the most complex and fascinating phenomena we can explore. It shapes how we experience reality—bringing together awareness, subjectivity, and self-recognition. Yet, the term “consciousness” means different things in different contexts. For neuroscientists, it often describes a physiological state, distinguishing being awake from being asleep or unconscious. For philosophers, it delves into deeper questions—how the experience of being “aware” differs in humans, animals, or even machines.

The Spectrum of Arousal and Alertness
The simplest way to understand consciousness is to think about states like wakefulness, sleep, and unconsciousness caused by anesthesia or injury. When someone is under anesthesia, they are clearly unconscious. But sleep occupies a nuanced middle zone—suspended awareness, but not total absence of it.

Neuropsychologists measure these states using physiological indicators such as heart rate, breathing, and brain activity through electroencephalograms (EEGs). These reflect a level of internal activation known as arousal or alertness.

There are two main forms of alertness:

• Phasic alertness: This is the short-term spike of awareness we feel when encountering a new or potentially threatening stimulus. For instance, hearing a sudden loud noise instantly sharpens your senses and prepares your body for action. However, when this stimulus repeats, your body “habituates,” conserving energy for genuine novelties.
• Tonic alertness: This represents the slower, more gradual shifts in internal arousal throughout the day—from drowsiness to full wakefulness. These cycles are controlled by a region in the brainstem called the reticular activating system (RAS). If this system is severed, the consequences are dramatic: cutting below it leaves an animal alert but paralyzed, while severing above it induces continuous deep sleep.

Understanding Sleep: The Rhythm of Restoration
Sleep stands as a unique state where consciousness is mostly suspended, and the brain and body undertake a vital form of restoration. During this period, the body relaxes, metabolism slows, and EEG readings reveal distinctive stages. Psychologists typically describe five stages of sleep—one REM (rapid eye movement) stage and four NREM (non-REM) stages—through which we cycle several times each night.

1. Transition to sleep (Hypnagogic period): Brain waves slow from high-frequency beta to more relaxed alpha waves.
2. Stage I NREM: Theta waves appear, muscles relax, and the sleeper is easily awakened.
3. Stage II NREM: Short bursts of brain activity, called sleep spindles, occur.
4. Stage III NREM: Delta waves begin; this is a deeper phase where heart rate and temperature drop.
5. Stage IV NREM: Dominated by slow delta waves, this is deep sleep—difficult to wake from and highly restorative.

After these stages, we move into REM sleep, often called paradoxical sleep because the brain becomes as active as if awake, while the body remains paralyzed. Most vivid dreams occur here. Interestingly, REM sleep consumes energy on par with wakefulness, challenging the common belief that sleep’s purpose is simply to conserve energy.

The transitions in and out of sleep—hypnagogic (falling asleep) and hypnopompic (waking up)—are notorious for strange experiences like vivid imagery, sounds, or even sensations of presence. Such phenomena likely arise from increased activity in the temporal lobes, areas linked to perception and memory. It’s no coincidence that many so-called “paranormal” experiences occur during these liminal states.

Consciousness, the Psyche, and the Inner Journey
Beyond scientific explanations, consciousness also extends into the moral and spiritual dimensions of human life. The early Christian hermits—known as the Desert Fathers and Mothers—were pioneers in exploring the interior world. Living in solitude and simplicity, they sought purity of heart and deep self-knowledge. In the harsh landscapes of the Middle East, they confronted not external dangers, but the restless movements of their own minds.

They recognized the importance of becoming aware of one’s thoughts, especially the negative ones—fear, anger, pride—that often undermine inner peace. These early seekers viewed self-awareness as the foundation for transformation. But their notion of self-awareness was not mere introspection.

Introspection means looking within and analyzing one’s feelings. Self-awareness, however, goes further—it means understanding how our inner state affects our actions, relationships, and even the world around us. It calls us to see how our emotions and attitudes shape both perception and behavior.

In this view, there’s no strict boundary between the private and public self. An angry or resentful interior life doesn’t remain hidden—it radiates outward, shaping interactions and environments. The inner world, then, is not isolated from moral consequence. Simply feeling anger can be harmful, not only to oneself but to others who absorb its energy.

Living with Conscious Awareness
To live consciously is more than to stay awake—it means being in touch with both the physiological rhythms of the brain and the deeper movements of the psyche. Consciousness is a bridge between matter and meaning, neurons and nuance.

Perhaps the ultimate challenge lies in harmonizing these two layers: understanding the science of how we awaken and sleep, while also cultivating the art of self-awareness that awakens the heart.

Source : Psychology for Busy People: Everything You Really Should Know by Joel Levy

Goodreads : https://www.goodreads.com/book/show/45189458-psychology-for-busy-people

Read the Previous Article in the Series :

Understanding Psychology: The Science of Mind and Behavior