Alpha wave

Alpha waves are neural oscillations in the frequency range of 7.5–12.5 Hz arising from synchronous and coherent (in phase or constructive) electrical activity of thalamic pacemaker cells in humans. They are also called Berger's wave in memory of the founder of EEG.

Alpha waves are one type of brain waves detected either by electroencephalography (EEG) or magnetoencephalography (MEG) and predominantly originate from the occipital lobe during wakeful relaxation with closed eyes. Alpha waves are reduced with open eyes, drowsiness and sleep. Historically, they were thought to represent the activity of the visual cortex in an idle state. More recent papers have argued that they inhibit areas of the cortex not in use, or alternatively that they play an active role in network coordination and communication. Occipital alpha waves during periods of eyes closed are the strongest EEG brain signals.

Alpha waves can be quantified using Quantitative electroencephalography (qEEG) using freely available toolboxes, such as, EEGLAB or the Neurophysiological Biomarker Toolbox.

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."

Alpha Waves

Alpha Waves is an early 3D game that combines labyrinthine exploration with platform gameplay. By most definitions of the genre it could be considered to be the first 3D platform game, released in 1990, 6 years before Super Mario 64. Alpha Waves was released one year before Hovertank 3D, which is sometimes incorrectly credited as being the first 3D game on the PC. It provided the first truly immersive 3D experience, combining for the first time full-screen, six-axis, flat-shaded 3D with 3D object interaction (like bouncing on a platform). Alpha Waves was an abstract game with a moody, artistic presentation, curiously named for its supposed ability to stimulate the different emotional centers of the brain with its use of color and music.

It was developed initially for the Atari ST by Christophe de Dinechin, and later ported to the Amiga and DOS. The DOS port was done by Frédérick Raynal, a notable game designer who would go on to develop Alone in the Dark (often abbreviated AitD), and Little Big Adventure. He has said that his work on Alpha Waves was a major inspiration for the 3D engine for Alone in the Dark. The PC version was also localized in North America by Data East, and retitled Continuum. Infogrames may have also published their own version in the US under the original title, and it was also released as a part of no less than two Infogrames compilations, on which it retained its original name.

Classical music

Classical music is art music produced or rooted in the traditions of Western music, including both liturgical (religious) and secular music. While a similar term is also used to refer to the period from 1750-1820 (the Classical period), this article is about the broad span of time from roughly the 11th century to the present day, which includes the Classical period and various other periods. The central norms of this tradition became codified between 1550 and 1900, which is known as the common practice period. The major time divisions of classical music are as follows: the early music period, which includes the Medieval (500–1400) and the Renaissance (1400–1600) eras; the Common practice period, which includes the Baroque (1600–1750), Classical (1750–1820), and Romantic eras (1804–1910); and the 20th century (1901–2000) which includes the modern (1890–1930) that overlaps from the late 19th-century, the high modern (mid 20th-century), and contemporary or postmodern (1975–2015) eras.

Alpha

Alpha (uppercase Α, lowercase α; Greek: Άλφα Álpha) is the first letter of the Greek alphabet. In the system of Greek numerals it has a value of 1. It was derived from the Phoenician letter aleph . Letters that arose from alpha include the Latin A and the Cyrillic letter А.

In English, the noun "alpha" is used as a synonym for "beginning", or "first" (in a series), reflecting its Greek roots.

Uses

Greek

In Ancient Greek, alpha was pronounced [a] and could be either phonemically long ([a:]) or short ([a]). Where there is ambiguity, long and short alpha are sometimes written with a macron and breve today: Ᾱᾱ, Ᾰᾰ.

In Modern Greek, vowel length has been lost, and all instances of alpha simply represent [a].

In the polytonic orthography of Greek, alpha, like other vowel letters, can occur with several diacritic marks: any of three accent symbols (ά, ὰ, ᾶ), and either of two breathing marks (ἁ, ἀ), as well as combinations of these. It can also combine with the iota subscript (ᾳ).