Scientists have developed ‘4D goggles’ that allow wearers to be physically ‘touched’ by a movie when they see a looming object on the screen, such as an approaching spacecraft. Neuroscientists at University of California – San Diego in the US mapped brain areas that integrate the sight and touch of a looming object and aid in their understanding of the perceptual and neural mechanisms of multisensory integration.
The device can be synchronised with entertainment content, such as movies, music, games and virtual reality, to deliver immersive multisensory effects near the face and enhance the sense of presence. “We perceive and interact with the world around us through multiple senses in daily life,” said Ruey-Song Huang, neuroscientist at UC San Diego.
“Though an approaching object may generate visual, auditory, and tactile signals in an observer, these must be picked apart from the rest of world,” said Huang, first author of the paper published in the journal Human Brain Mapping. “To detect and avoid impending threats, it is essential to integrate and analyse multisensory looming signals across space and time and to determine whether they originate from the same sources,” Huang said.
In experiments, subjects assessed the subjective synchrony between a looming ball (simulated in virtual reality) and an air puff delivered to the same side of the face. When the onset of ball movement and the onset of an air puff were nearly simultaneous (with a delay of 100 milliseconds), the air puff was perceived as completely out of sync with the looming ball.
With a delay between 800 to 1,000 milliseconds, the two stimuli were perceived as one (in sync), as if an object had passed near the face generating a little wind. In experiments using functional Magnetic Resonance Imaging, or fMRI, the scientists delivered tactile-only, visual-only, tactile-visual out-of-sync, and tactile-visual in-sync stimuli to either side of the subject’s face in randomised events.
More than a dozen of brain areas were found to respond more strongly to lateralised multisensory stimuli than to lateralised unisensory stimuli, and the response was further enhanced when the multisensory stimuli are in perceptual sync.