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Hypnagogic Hallucinations
Hypnagogia is the experience of the transitional state from wakefulness to sleep: the ''hypnagogic'' state of consciousness, during the onset of sleep. Its opposite state is described as the transitional state from sleep into wakefulness. Mental phenomena that may occur during this "threshold consciousness" phase include hypnagogic hallucinations, lucid thought, exploding head syndrome, lucid dreaming, and sleep paralysis. The latter two phenomena are themselves separate sleep conditions that are sometimes experienced during the hypnagogic state. 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 waking up. Indeed, it is not always possible in practice to assign a particular episode of any given phenomenon to one or the other, given that th ... [...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 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 and basal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meditation
Meditation is a practice in which an individual uses a technique – such as mindfulness, or focusing the mind on a particular object, thought, or activity – to train attention and awareness, and achieve a mentally clear and emotionally calm and stable state. Meditation is practiced in numerous religious traditions. The earliest records of meditation ('' dhyana'') are found in the Upanishads, and meditation plays a salient role in the contemplative repertoire of Jainism, Buddhism and Hinduism. Since the 19th century, Asian meditative techniques have spread to other cultures where they have also found application in non-spiritual contexts, such as business and health. Meditation may significantly reduce stress, anxiety, depression, and pain, and enhance peace, perception, self-concept, and well-being. Research is ongoing to better understand the effects of meditation on health (psychological, neurological, and cardiovascular) and other areas. Etymology The English ''meditati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amnesia
Amnesia is a deficit in memory caused by brain damage or disease,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 caused temporarily by the use of various sedatives and hypnotic drugs. The memory can be either wholly or partially lost due to the extent of damage that was caused. There are two main types of amnesia: retrograde amnesia and anterograde amnesia. Retrograde amnesia is the inability to retrieve 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 others the person 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 occur si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetris Effect
The ''Tetris'' effect (also known as ''Tetris'' syndrome) occurs when people devote so much time and attention to an activity that it begins to pattern their thoughts, mental images, and dreams. It takes its name from the 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. Those experiencing the effect may feel they are unable to prevent the thoughts, images, or dreams from happening.Stickgold, R., interviewed 30 October 2000 by Norman Swan for '' The Health Report'' on Australia's Radio Nationaltranscript. Retrieved 15 January 2020. ... [...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, som ... [...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 or simulation of novel objects, sensations, and ideas in the mind without any immediate input of the senses. Stefan Szczelkun characterises it as the forming of experiences in one's mind, which can be re-creations of past experiences, such as vivid memories with imagined changes, or completely invented and possibly fantastic scenes. Imagination helps make knowledge applicable in solving problems and is fundamental to integrating experience and the learning process.Norman 2000 pp. 1-2 Brian Sutton-Smith 1988, p. 22 Kieran Egan 1992, pp. 50 As an approach to build theory, it is called "disciplined imagination". A basic training for imagination is listening to storytelling (narrative), in which the exactness of the chosen words is the fundamental factor to "evoke worlds". One view of imagination links it with cognition, seeing imagination as a cognitive process used in mental functioning. It is increasingly used - in the form of visual imagery - by c ... [...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, but 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. Cause Researchers noticed early on that the shape of intensity-sensitivity curves could be explained by assuming that an intrinsic source of noise in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perspective (visual)
Linear or point-projection perspective (from la, perspicere 'to see through') 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. 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 ''foreshortening'', meaning that an object's dimensions along the line of sight appear shorter than its dimensions across 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 line depending on the view used. Italian Renaissance painters and architects including Masaccio, Paolo Uccello, Piero della Francesca and ... [...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 (also know ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mental Image
A mental image is an experience that, on most occasions, significantly resembles the experience of 'perceiving' some object, event, or scene, but occurs when the relevant object, event, or scene is not actually present to the senses. There are sometimes episodes, particularly on falling asleep (hypnagogic imagery) and waking up ( hypnopompic imagery), when the mental imagery may be dynamic, phantasmagoric and involuntary in character, repeatedly presenting identifiable objects or actions, spilling over from waking events, or defying perception, presenting a kaleidoscopic field, in which no distinct object can be discerned. Mental imagery can sometimes produce the same effects as would be produced by the behavior or experience imagined. The nature of these experiences, what makes them possible, and their function (if any) have long been subjects of research and controversy in philosophy, psychology, cognitive science, and, more recently, neuroscience. As contemporary researcher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Figurative Art
Figurative art, sometimes written as figurativism, describes artwork (particularly paintings and sculptures) that is clearly derived from real object sources and so is, by definition, representational. The term is often in contrast to abstract art: Since the arrival of abstract art the term figurative has been used to refer to any form of modern art that retains strong references to the real world. Painting and sculpture can therefore be divided into the categories of figurative, representational and abstract, although, strictly speaking, abstract art is derived (or abstracted) from a figurative or other natural source. However, "abstract" is sometimes used as a synonym for non-representational art and non-objective art, i.e. art which has no derivation from figures or objects. Figurative art is not synonymous with figure painting (art that represents the human figure), although human and animal figures are frequent subjects. Formal elements The formal elements, those aesthe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
