Reduced Contrast in the Area of the Visual Field where the Own Hand is Moving: a Virtual Reality Study

T├Ánis Kristian Koppel
From an evolutionary standpoint, being able to quickly detect motion within
the visual field is very important. When an agent is moving however, a large part of motion consists of moving parts of the agent himself. The results of numerous studies suggest that the brain predicts the results of its movements and attenuates the sensory signals resulting from those movements. Using Oculus Rift virtual reality (VR) headset and a Leap Motion hand tracking device, we can study the aforementioned phenomenon.
As a part of this thesis, a program was developed that enables to test whether self generated hand movement affects the perceived contrast in the area of visual field where the hand is moving. We conducted a VR experiment where we monitored the hand positions during movements while the subjects had to perform a two-alternative forced choice task - they answered the side of the stimulus which seemed higher in contrast.
The data gathered from 11 participants in the study did not provide enough evidence to confirm that the brain attenuates the apparent contrast of objects in the area of the visual field where the own hand is moving. It was concluded that further studies with slightly modified experimental design and more participants are necessary.
Graduation Thesis language
Graduation Thesis type
Bachelor - Computer Science
Jaan Aru, Madis Vasser, Kristjan-Julius Laak
Defence year