Nostalgia has been found to have important psychological functions, such as to improve mood, increase social connectedness, enhance positive self-regard, and provide existential meaning. The modern view is that nostalgia is an independent, and even positive, emotion that many people experience often. Consistent with its Greek word roots meaning 'homecoming' and 'pain,' nostalgia was for centuries considered a potentially debilitating and sometimes fatal medical condition expressing extreme homesickness. Nostalgia's definition has changed greatly over time. Cultural phenomena such as music, movies, television shows, and video games, as well as natural phenomena such as weather and environment can also be strong triggers of nostalgia. These recollections of one's past are usually important events, people one cares about, and places where one has spent time.

Emotion is a strong evoker of nostalgia due to the processing of these stimuli first passing through the amygdala, the emotional seat of the brain. The scientific literature on nostalgia usually refers to nostalgia regarding one's personal life and has mainly studied the effects of nostalgia as induced during these studies. When applied to one's beliefs about a society or institution, this is called declinism, which has been described as 'a trick of the mind' and as 'an emotional strategy, something comforting to snuggle up to when the present day seems intolerably bleak.' There is a predisposition, caused by cognitive biases such as rosy retrospection, for people to view the past more favourably and future more negatively. Nostalgia is associated with a yearning for the past, its personalities, possibilities, and events, especially the ' good ol' days' or a 'warm childhood'. Described as a medical condition-a form of melancholy-in the Early Modern period, it became an important trope in Romanticism. The word nostalgia is a learned formation of a Greek compound, consisting of νόστος ( nóstos), meaning 'homecoming', a Homeric word, and ἄλγος ( álgos), meaning 'sorrow' or 'despair', and was coined by a 17th-century medical student to describe the anxieties displayed by Swiss mercenaries fighting away from home. Nostalgia is a sentimentality for the past, typically for a period or place with happy personal associations.

Nostalgia significado