- 1540–50; < MLatin receptīvus.
- 1. having the quality of receiving, taking in, or admitting.
- 2. able or quick to receive knowledge, ideas, etc.: a receptive mind.
- 3. willing or inclined to receive suggestions, offers, etc., with favor: a receptive listener.
- 4. of or pertaining to reception or receptors: a receptive end organ.
- 5. (in language learning) of or pertaining to the language skills of listening and reading (opposed to productive ).
Thought processes on the edge of sleep tend to differ radically from those of ordinary wakefulness. Hypnagogia may involve a “loosening of ego boundaries ... openness, sensitivity, internalization-subjectification of the physical and mental environment (empathy) and diffuse-absorbed attention,” Hypnagogic cognition, in comparison with that of normal, alert wakefulness, is characterised by heightened suggestibility, illogic and a fluid association of ideas. Subjects are more receptive in the hypnagogic state to suggestion from an experimenter than at other times, and readily incorporate external stimuli into hypnagogic trains of thought and subsequent dreams. This receptivity has a physiological parallel; EEG readings show elevated responsiveness to sound around the onset of sleep.
Herbert Silberer described a process he called autosymbolism, whereby hypnagogic hallucinations seem to represent, without repression or censorship, whatever one is thinking at the time, turning abstract ideas into a concrete image, which may be perceived as an apt and succinct representation thereof.
This process can even lead to genuine insight into a problem, a well known example being the story of August Kekulé’s discovery of the structure of benzene. Similarly, the teenaged Karl Gauss obtained an insight during a hypnagogic reverie into how to construct a 17-sided polygon. Many other artists, writers, scientists and inventors – including Beethoven, Richard Wagner, Walter Scott, Thomas Edison and Isaac Newton – have credited hypnagogia and related states with enhancing their creativity. According to himself, Keith Richards wrote the Rolling Stones' biggest hit "(I Can't Get No) Satisfaction" while sleeping. He has stated that he went to bed with a tape recorder on the bedside table, and when he woke up the tape was full with mumbling and half-singing, mixed with some snoring.
A widely cited instance of what could well be this phenomenon is the story of the composition of the Devil's Trill violin sonata by Giuseppe Tartini. Tartini dreamt that the devil appeared at the end of his bed and played the violin with otherwordly mastery. Tartini woke and immediately began writing the virtuoso music down, though managed only to transcribe what he painfully felt to be a massively inferior version of what he had heard in his sleep; incidentally, such loss of memory of the dreamt events is a common circumstance of dreams.