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Hypnogogic
Hypnagogia is the transitional state from wakefulness to sleep, also defined as the waning state of consciousness during the onset of sleep. Its corresponding state is '' hypnopompia'' sleep to wakefulness. Mental phenomena that may occur during this "threshold consciousness" include hallucinations, lucid dreaming, and sleep paralysis. Etymology In 1848, Alfred Maury introduced the term "hypnagogic" from the Greek words ύπνος (“hypnos”), meaning “sleep”, and αγωγός (“agōgos”), meaning “conductor” or “leader”. Later, in 1904, Frederic Myers coined the term "hypnopompic," with its word-ending originating from the Greek word "pompos," meaning "sender." Definitions The word ''hypnagogia'' is sometimes used in a restricted sense to refer to the onset of sleep, and contrasted with '' hypnopompia'', Frederic Myers's term for waking up. However, ''hypnagogia'' is also regularly employed in a more general sense that covers both falling asleep and wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wakefulness
Wakefulness is a daily recurring brain state and state of consciousness in which an individual is conscious and engages in coherent cognition, cognitive and behavioral responses to the external world. Being awake is the opposite of being asleep, in which most external inputs to the brain are excluded from neural processing. Effects upon the brain The longer the brain has been awake, the greater the synchronous firing rates of cerebral cortex neurons. After sustained periods of sleep, both the speed and synchronicity of the neurons firing are shown to decrease. Another effect of wakefulness is the reduction of glycogen held in the astrocytes, which supply energy to the neurons. Studies have shown that one of sleep's underlying functions is to replenish this glycogen energy source. Maintenance by the brain Wakefulness is produced by a complex interaction between multiple neurotransmitter systems arising in the brainstem and ascending through the midbrain, hypothalamus, thalamus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sense
A sense is a biological system used by an organism for sensation, the process of gathering information about the surroundings through the detection of Stimulus (physiology), stimuli. Although, in some cultures, five human senses were traditionally identified as such (namely Visual perception, sight, Olfaction, smell, Somatosensory system, touch, taste, and hearing), many more are now recognized. Senses used by non-human organisms are even greater in variety and number. During sensation, sense organs collect various stimuli (such as a sound or smell) for Transduction (physiology), transduction, meaning transformation into a form that can be understood by the brain. Sensation and perception are fundamental to nearly every aspect of an organism's cognition, behavior and thought. In organisms, a sensory organ consists of a group of interrelated Sensory neuron, sensory cells that respond to a specific type of physical stimulus. Via Cranial nerves, cranial and spinal nerves (nerves ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory
Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembered, it would be impossible for language, relationships, or personal identity to develop. Memory loss is usually described as forgetfulness or amnesia. Memory is often understood as an informational processing system with explicit and implicit functioning that is made up of a sensory processor, short-term (or working) memory, and long-term memory. This can be related to the neuron. The sensory processor allows information from the outside world to be sensed in the form of chemical and physical stimuli and attended to various levels of focus and intent. Working memory serves as an encoding and retrieval processor. Information in the form of stimuli is encoded in accordance with explicit or implicit functions by the working memory p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amnesia
Amnesia is a deficit in memory caused by brain damage or brain diseases,Gazzaniga, M., Ivry, R., & Mangun, G. (2009) Cognitive Neuroscience: The biology of the mind. New York: W.W. Norton & Company. but it can also be temporarily caused by the use of various sedative and hypnotic drugs. The memory can be either wholly or partially lost due to the extent of damage that is caused. There are two main types of amnesia: * Retrograde amnesia is the inability to remember information that was acquired before a particular date, usually the date of an accident or operation. In some cases, the memory loss can extend back decades, while in other cases, people may lose only a few months of memory. * Anterograde amnesia is the inability to transfer new information from the short-term store into the long-term store. People with anterograde amnesia cannot remember things for long periods of time. These two types are not mutually exclusive; both can also occur simultaneously. Case stud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetris Effect
The Tetris effect occurs when someone dedicates vast amounts of time, effort and concentration on an activity which thereby alters their thoughts, dreams, and other experiences not directly linked to said activity. The term originates from the popular video game ''Tetris''. People who have played ''Tetris'' for a prolonged amount of time can find themselves thinking about ways different shapes in the real world can fit together, such as the boxes on a supermarket shelf or the buildings on a street. They may see colored images of pieces falling into place on an invisible layout at the edges of their visual fields or when they close their eyes. They may see such colored, moving images when they are falling asleep, a form of hypnagogic imagery. For some, this creative urge to visually fit shapes together by organising and building shapes can be extremely addictive. Those experiencing the effect may feel they are unable to prevent the thoughts, images or dreams from happening.Sti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somnolence
Somnolence (alternatively sleepiness or drowsiness) is a state of strong desire for sleep, or sleeping for unusually long periods (compare hypersomnia). It has distinct meanings and causes. It can refer to the usual state preceding falling asleep, the condition of being in a drowsy state due to circadian rhythm disorders, or a symptom of other health problems. It can be accompanied by lethargy, weakness and lack of mental agility. Somnolence is often viewed as a symptom rather than a disorder by itself. However, the concept of somnolence recurring at certain times for certain reasons constitutes various disorders, such as excessive daytime sleepiness, shift work sleep disorder, and others; and there are medical codes for somnolence as viewed as a disorder. Sleepiness can be dangerous when performing tasks that require constant concentration, such as driving a vehicle. When a person is sufficiently fatigued, microsleeps may be experienced. In individuals deprived of sleep, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marie-Jean-Léon, Marquis D'Hervey De Saint Denys
Marie-Jean-Léon Lecoq, Baron d'Hervey de Juchereau, Marquis d'Hervey de Saint-Denys (; 6 May 1822 – 2 November 1892) son of Pierre Marin Alexandre Le Coq or Lecoq, Baron d'Hervey (1780-1858), and Marie Louise Josephine Mélanie Juchereau de Saint-Denys (1789-1844) was born on 6 May 1822. D'Hervey was a French sinologist also known for his research on dreams. Contributions to Sinology Hervey de Saint Denys made an intense study of Chinese, and in 1851 D'Hervey published his ''Recherches sur l'agriculture et l'horticulture des Chinois'' (Transl: ''Research on the agriculture and horticulture of the Chinese''), in which he dealt with the plants and animals that potentially might be able to be acclimatized to and introduced in Western countries. He translated as well Chinese texts as some Chinese stories, not of classical interest, but valuable for the light they throw on Chinese culture and customs. He was a man of letters too. E.g. he translated some Spanish-language w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Imagination
Imagination is the production of sensations, feelings and thoughts informing oneself. These experiences can be re-creations of past experiences, such as vivid memories with imagined changes, or completely invented and possibly fantastic scenes. Imagination helps apply knowledge to solve problems and is fundamental to integrating experience and the learning process. Imagination is the process of developing theories and ideas based on the functioning of the mind through a creative division. Drawing from actual perceptions, imagination employs intricate conditional processes that engage both semantic and episodic memory to generate new or refined ideas. This part of the mind helps develop better and easier ways to accomplish tasks, whether old or new. A way to train imagination is by listening to and practicing storytelling (narrative), wherein imagination is expressed through stories and writings such as fairy tales, fantasies, and science fiction. When children develop their i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eigengrau
Eigengrau ( German for "intrinsic gray"; ), also called Eigenlicht ( Dutch and German for "intrinsic light"), dark light, or brain gray, is the uniform dark gray background color that many people report seeing in the absence of light. The term ''Eigenlicht'' dates back to the nineteenth century, and has rarely been used in recent scientific publications. Common scientific terms for the phenomenon include "visual noise" or "background adaptation". These terms arise due to the perception of an ever-changing field of tiny black and white dots seen in the phenomenon. Eigengrau is perceived as lighter than a black object in normal lighting conditions, because contrast is more important to the visual system than absolute brightness. For example, the night sky looks darker than Eigengrau because of the contrast provided by the stars. Contrast threshold data, collected by Blackwell and plotted by Crumey, shows Eigengrau occurring at adaptation luminances below approximately 10� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perspective (visual)
Linear or point-projection perspective () is one of two types of graphical projection perspective in the graphic arts; the other is parallel projection. Linear perspective is an approximate representation, generally on a flat surface, of an image as it is seen by the eye. Perspective drawing is useful for representing a three-dimensional scene in a two-dimensional medium, like paper. It is based on the optical fact that for a person an object looks N times (linearly) smaller if it has been moved N times further from the eye than the original distance was. The most characteristic features of linear perspective are that objects appear smaller as their distance from the observer increases, and that they are subject to , meaning that an object's dimensions parallel to the line of sight appear shorter than its dimensions perpendicular to the line of sight. All objects will recede to points in the distance, usually along the horizon line, but also above and below the horizon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monochromatic
A monochrome or monochromatic image, object or palette is composed of one color (or values of one color). Images using only shades of grey are called grayscale (typically digital) or black-and-white (typically analog). In physics, monochromatic light refers to electromagnetic radiation that contains a narrow band of wavelengths, which is a distinct concept. Application Of an image, the term monochrome is usually taken to mean the same as black and white or, more likely, grayscale, but may also be used to refer to other combinations containing only tones of a single color, such as green-and-white or green-and-red. It may also refer to sepia displaying tones from light tan to dark brown or cyanotype ("blueprint") images, and early photographic methods such as daguerreotypes, ambrotypes, and tintypes, each of which may be used to produce a monochromatic image. In computing, monochrome has two meanings: * it may mean having only one color which is either on or off (a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
