Related Experiment Video
Updated: May 28, 2026

09:23
High-Definition Transcranial Direct Current Stimulation During Sleep
Published on: December 5, 2025
The “dreamy state” in the work of John Hughlings Jackson
Journal of the History of the Neurosciences
|October 19, 2011
Abstract
No abstract available in PubMed .
Related Concept Videos
Dreaming
Sigmund Freud revolutionized our understanding of dreams by proposing that they are a window into the unconscious mind. According to Freud, dreams are not mere stories our minds create while we sleep but are profoundly meaningful narratives about our hidden desires and fears. He introduced two key concepts: manifest content and latent content. The manifest content is the actual content and imagery of the dream — what we remember when we wake up. The latent content, however, represents the...
Lucid Dreaming
Lucid dreaming is a unique state of consciousness where an individual realizes they are dreaming while still in the dream. This awareness allows them to manipulate their dream environment consciously. Researchers like Stephen LaBerge have significantly contributed to the understanding of lucid dreams, highlighting that during these dreams, certain areas of the brain, such as the prefrontal cortex, that involve self-awareness and thought evaluation show increased activity.
Studies have shown...
Studies have shown...
Altered States of Awareness
Altered states of consciousness represent significant deviations from one's normal mental state. These deviations can range from subtle changes in awareness to profound transformations in perception, thought processes, and sensory experiences. Altered states of consciousness can be triggered by various factors, including drug use, meditation, hypnosis, illness, or even intense fatigue.
The ingestion of substances like stimulants or hallucinogens leads to chemical alterations in the brain that...
The ingestion of substances like stimulants or hallucinogens leads to chemical alterations in the brain that...
Sleep-Wake Cycles
Sleep is an essential physiological process vital to maintaining overall well-being. The reticular activating system (RAS), a network of neurons in the brainstem, regulates wakefulness and sleep. While it may seem passive, sleep consists of distinct cycles, each with its unique characteristics and functions. Two key sleep phases are non-rapid eye movement (NREM) and rapid eye movement (REM).
NREM Sleep
NREM sleep comprises four progressive stages that seamlessly merge:
NREM Sleep
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High-Level and Low-Level Awareness
Controlled processes in human consciousness represent high-alert mental states where individuals deliberately focus their attention on achieving specific goals. Controlled processes can be seen in situations like mastering new technology, where a person might become so absorbed that they ignore surrounding distractions. Such processes involve selective attention, requiring one to concentrate on particular elements of experience while disregarding others. These are governed by executive...
Sleepwalking and Sleep Talking
Somnambulism, commonly known as sleepwalking, involves individuals engaging in activities ranging from simple walking to more complex behaviors such as driving. Sleepwalking typically occurs during the slow-wave sleep stages 3 and 4 early in the night when the person is not dreaming, contradicting the myth that sleepwalkers are acting out their dreams.
Factors that increase the likelihood of sleepwalking include sleep deprivation and alcohol consumption. Contrary to common beliefs, it is safe...
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