Alliesthesia in visual and auditory sensations from environmental signals.

'Alliesthesia' describes the fact that sensory stimuli can arouse pleasant or unpleasant sensations according to the internal state of a person. In the present work, the hedonicity aroused by stimuli from the environment in visual and auditory sensations was evaluated in 5 situations: 1) daytime without sensory stimulations (no video-tape); 2) daytime with poor sensory stimulations (uninteresting video-tape film); 3) daytime with rich sensory stimulations (interesting chosen movie on video-tape); 4) night-time without sensory stimulations (no video-tape); 5) night-time with poor sensory stimulations (uninteresting video-tape). During the day, hedonic ratings decreased with time in the no- and uninteresting video-tape film conditions (p<0.01), but increased with the chosen movie (p<0.05). During the night, hedonic ratings decreased similarly to daytime ratings with the uninteresting video-tape film (p<0.01) but rose in the no-video-tape environment (p<0.01). The time course of motivation to leave the environment mirrored that of hedonic ratings. Changes in hedonic ratings as well as motivation to leave the environment correlated with the state of tiredness in the day-no-video and night-no-video situations (r=0.541 and r=-0.593; p<0.01). Thus, alliesthesia occurred in visual and auditory sensations that originated from the environment, and motivated behavior that was not consummatory. Such results suggest that alliesthesia is a general property of all sensations, and emphasizes the fundamental role of pleasure in motivation for all behaviors.