Theta rhythm

The theta rhythm is an oscillatory pattern in electroencephalography (EEG) signals recorded either from inside the brain or from electrodes glued to the scalp. Two types of theta rhythm have been described. The "hippocampal theta rhythm" is a strong oscillation that can be observed in the hippocampus and other brain structures in numerous species of mammals including rodents, rabbits, dogs, cats, bats, and marsupials. "Cortical theta rhythms" are low-frequency components of scalp EEG, usually recorded from humans. Theta rhythms can be quantified using Quantitative electroencephalography (qEEG) using freely available toolboxes, such as, EEGLAB or the Neurophysiological Biomarker Toolbox (NBT).

In rats, the most frequently studied species, theta rhythmicity is easily observed in the hippocampus, but can also be detected in numerous other cortical and subcortical brain structures. Hippocampal theta, with a frequency range of 6–10 Hz, appears when a rat is engaged in active motor behavior such as walking or exploratory sniffing, and also during REM sleep. Theta waves with a lower frequency range, usually around 6–7 Hz, are sometimes observed when a rat is motionless but alert. When a rat is eating, grooming, or sleeping, the hippocampal EEG usually shows a non-rhythmic pattern known as Large irregular activity or LIA. The hippocampal theta rhythm depends critically on projections from the medial septal area, which in turn receives input from the hypothalamus and several brainstem areas. Hippocampal theta rhythms in other species differ in some respects from those in rats. In cats and rabbits, the frequency range is lower (around 4–6 Hz), and theta is less strongly associated with movement than in rats. In bats, theta appears in short bursts associated with echolocation. In humans and other primates, hippocampal theta is difficult to observe at all.

Music

Music is an art form and cultural activity whose medium is sound and silence. The common elements of music are pitch (which governs melody and harmony), rhythm (and its associated concepts tempo, meter, and articulation), dynamics (loudness and softness), and the sonic qualities of timbre and texture (which are sometimes termed the "color" of a musical sound). Different styles or types of music may emphasize, de-emphasize or omit some of these elements. Music is performed with a vast range of instruments and with vocal techniques ranging from singing to rapping, and there are solely instrumental pieces, solely vocal pieces and pieces that combine singing and instruments. The word derives from Greek μουσική (mousike; "art of the Muses"). In its most general form, the activities describing music as an art form include the production of works of music (songs, tunes, symphonies, and so on), the criticism of music, the study of the history of music, and the aesthetic examination of music. Ancient Greek and Indian philosophers defined music as tones ordered horizontally as melodies and vertically as harmonies. Common sayings such as "the harmony of the spheres" and "it is music to my ears" point to the notion that music is often ordered and pleasant to listen to. However, 20th-century composer John Cage thought that any sound can be music, saying, for example, "There is no noise, only sound."

Theta

Theta (uppercase Θ or ϴ, lowercase θ (which resembles digit 0 with horizontal line) or ϑ; Ancient Greek: θῆτα, thē̂ta, [tʰɛ̂ːta]; Modern: θήτα, thī́ta, [ˈθita]; UK /ˈθiːtə/, US /ˈθeɪtə/) is the eighth letter of the Greek alphabet, derived from the Phoenician letter Teth . In the system of Greek numerals it has a value of 9.

Greek

In Ancient Greek, θ represented the aspirated voiceless dental plosive /t̪ʰ/, but in Modern Greek it represents the voiceless dental fricative /θ/.

Forms

In its archaic form, θ was written as a cross within a circle (as in the Etruscan or ), and later, as a line or point within a circle ( or ).

The form ϑ was retained by Unicode as U+03D1 ϑ "GREEK THETA SYMBOL" ("=script theta"), separate from U+03B8 θ "GREEK SMALL LETTER THETA". For the purpose of writing Greek text, the two can be font variants of a single character, but θ and ϑ are also used as distinct symbols in technical and mathematical contexts.

Latin

In the Latin script used for the Gaulish language, theta developed into the tau gallicum, conventionally transliterated as Ð, although the bar extends across the centre of the letter. The phonetic value of the tau gallicum is thought to have been [t͡s].

Deep Sleep

Deep Sleep is a 2012 point-and-click adventure game by Scriptwelder. It is a free browser game in which players attempt to navigate a dream world inhabited by shadow people. It was designed for and won first place in the 2012 Jay Is Games Casual Gameplay Design Competition.

Game Plot

Interested in lucid dreams, a researcher constructs a world in his mind to explore. However, the world in his dream quickly turns nightmarish, and the researcher becomes trapped. He needs to wake up, which is explained when the player finds a telephone saying he "must wake up". Shadowy figures haunt this world and attempt to restrict the player from guiding the researcher to freedom. At the beginning of the game, the player appears to be in a bedroom. To escape, the player must first find a key, then go into the next room and use the key on a locker. A cube with a keyhole in it appears, and the walls of the room melt down. The player will then have to explore his or her surroundings, and use acquired items to escape. The main obstacle in the game are locked doors, and cannot be opened unless certain items are acquired. After a long period of time, the player finally escapes the building he is in, but still has not woken up yet. Near the end of the game, shadowy figures start to appear and will advance towards the player. The player will then have to escape, as it is impossible to kill them. Running away, the player reaches a lighthouse with a Shadow Figure inside. The player then turns the light so it directly faces the Shadow Figure, and it vanishes. The game then ends, as the player "wakes up". However, the character is curious about the Shadow Figures he encountered and declares that he wants to visit them again.

Meditation

Meditation is a practice where an individual trains the mind or induces a mode of consciousness, either to realize some benefit or for the mind to simply acknowledge its content without becoming identified with that content, or as an end in itself.

The term meditation refers to a broad variety of practices that includes techniques designed to promote relaxation, build internal energy or life force (qi, ki, prana, etc.) and develop compassion, love, patience, generosity and forgiveness. A particularly ambitious form of meditation aims at effortlessly sustained single-pointed concentration meant to enable its practitioner to enjoy an indestructible sense of well-being while engaging in any life activity.

The word meditation carries different meanings in different contexts. Meditation has been practiced since antiquity as a component of numerous religious traditions and beliefs. Meditation often involves an internal effort to self-regulate the mind in some way. Meditation is often used to clear the mind and ease many health concerns, such as high blood pressure,depression, and anxiety. It may be done sitting, or in an active way—for instance, Buddhist monks involve awareness in their day-to-day activities as a form of mind-training. Prayer beads or other ritual objects are commonly used during meditation in order to keep track of or remind the practitioner about some aspect of that training.