Perceptual Illusion

The visual illusion we created revolves around visual pareidolia, which is our tendency to see faces out of random objects. This illusion in general occurs because our brain is just wired that way (more specifically, there is a portion of the brain called the fusiform face area that appears to specialize in face recognition). In the video, this illusion occurs because the light is initially pointing to only one light, which draws your attention away from the rest of the "face," but as the light spreads out, it brings your attention to the entire "face," and you can see it due to visual pareidolia.

The auditory illusion we chose, the Shepard-Risset tone, is created by a superposition of pitches separated by specific intervals that consistently decrease or increase, which result in a sound that seems to constantly increase or decrease without actually moving to a different octave. The overlapping notes heard at a single moment are all an octave apart, creating an ambiguous tone, and each scale fades in and out so we can't hear the beginning and end of the scale. Each scale, though, is increasing/decreasing, thus the ambiguous sound we hear seems to be increasing/decreasing without end.