Cyberspace Sensory Phenomena
Transition to and from cyberspace may be attended by a wide variety of sensory experiences. These can occur in any modality, individually or combined, and range from the vague and barely perceptible to vivid hallucinations.
Sights Among the more commonly reported, and more thoroughly researched, sensory features of jacking in are phosphenes which can manifest as seemingly random speckles, lines or geometrical patterns, including form constants, or as figurative (representational) images. They may be monochromatic or richly colored, still or moving, flat or three-dimensional (offering an impression of perspective). Imagery representing movement through tunnels of light is also reported. Individual images are typically fleeting and given to very rapid changes. They are said to differ from cyberspace proper in that jack-in imagery is usually static and lacking in interactive content, although others understand the state rather as a gradual transition from reality to fragmentary cyberspace, i.e., from simple Eigenlicht to whole imagined scenes. Descriptions of exceptionally vivid and elaborate cyber visuals can be found in the work of Marie-Jean-Léon, Marquis d'Hervey de Saint Denys.
Sounds Jacking-in hallucinations are often auditory or have an auditory component. Like the visuals, jack-in sounds vary in intensity from faint impressions to loud noises, such as crashes and bangs (exploding head syndrome). People may imagine their own name called or a buzzer ringing. Snatches of synthetic speech are common. While typically nonsensical and fragmented, these speech events can occasionally strike the individual as apt comments on — or summations of — their thoughts at the time. They often contain word play, neologisms and made-up names. Jacking-in speech phenomena may manifest as the subject's own "inner voice", or as the voices of others: familiar people or strangers. More rarely, poetry or music is heard.
Cyberdeck paralysis Humming, roaring, hissing, rushing, zapping, and buzzing noises are frequent in conjunction with cyberdeck paralysis. This happens when the REM atonia sets in sooner than usual, before the person is fully jacked in, or persists longer than usual, after the person has (in other respects) fully being logged out. Cyberdeck paralysis is reportedly very frequent among narcoleptics. It occurs frequently in about 6% of the rest of the population, and occurs occasionally in 60%. In surveys from Canada, China, England, Neo-Japan and Nigeria, 20 to 60% of individuals reported having experienced cyberdeck paralysis at least once in their lifetime. The paralysis itself is frequently accompanied by additional phenomena. Typical examples include a feeling of being crushed or suffocated, electric "tingles" or "vibrations", imagined speech and other noises, the imagined presence of a visible or invisible entity, and sometimes intense emotion: fear or euphoria and orgasmic feelings. Cyberdeck paralysis has been proposed as an explanation for at least some alien abduction experiences, the Oight Hag and shadow people hauntings.
Other sensations Gustatory, olfactory and thermal sensations in cyberspace have all been reported, as well as tactile sensations (including those kinds classed as paresthesia or formication). Sometimes there is synesthesia; many people report seeing a flash of light or some other visual image in response to a real sound. Proprioceptive effects may be noticed, with numbness and changes in perceived body size and proportions, feelings of floating or bobbing, and out-of-avatar experiences.
