Image Reversal in Space (Iris) experiment is an educational experiment developed by students at the International Space University. This experiment will study the effects of microgravity on the way people perceive two-dimensional and three-dimensional objects. The experiment and its software was designed by a multidisciplinary group of students, giving them valuable experience as they prepare to launch their own careers in space.Principal Investigator(s)
Canadian Space Agency (CSA)Sponsoring Organization
Information PendingResearch Benefits
Information PendingISS Expedition Duration
March 2009 - October 2009Expeditions Assigned
19/20Previous ISS Missions
ISS Expedition 19/20 was the first performance of Iris on the ISS.
There are many situations, known as illusions, which clearly demonstrate that our visual perception is less than entirely accurate. For example, when looking at a picture or a television screen, the brain assumes that we are seeing objects and spaces that have depth. As a result, we are accepting a set of signals or cues that create an illusion of three-dimensional space. The vast majority of human beings experience the same illusion, suggesting that its origin lies in the physiological mechanisms of perception.
A clear demonstration of the interpretive nature of visual perception comes from ambiguous figures (optical illusions), i.e., single images that can give rise to two or more distinct perceptions. These are two-dimensional images that are perceived as three-dimensional objects. Due to gravity constraints, some configurations are more often present than others. The Image Reversal in Space (Iris) experiment will investigate whether the perception of three-dimensional ambiguous figures is affected when the observer is in a reduced gravity environment.
In order to conduct the Iris experiment, a series of 20 to 25 obscured figures will be displayed on one of the International Space Station laptops using an interactive presentation. Some figures will be three-dimensional while others will be two-dimensional. For each figure, the astronaut-subject will be asked to identify which form they see first, and then to indicate when they recognize the second form. The time delay between the occurrence of the first and the second form will then be calculated.
Tests will be performed with Canadian Astronaut Dr. Bob Thirsk before and during the flight. The same tests will also be conducted on a population of subjects on Earth. The students hypothesized that there will be a significant difference in three-dimensional figures when observed both on Earth and in space, but not for two-dimensional figures.
The Iris payload supports the objective to explore and support decisions related to human exploration as well as promoting international participation in exploration. It also supports ISS activities in terms of supporting space exploration goals with an emphasis on understanding how the space environment affects astronauts? health, capabilities and developing countermeasures.Earth Applications
As an educational payload, Iris provides an opportunity for students to better understand the process required in order to develop science destined for space implementation, as well as increasing their understanding of the space environment and its effects on the human physiological systems through the associated International Space University workshops.
Operations for Iris will be performed with a crewmember before and during the flight. The same tests will also be conducted on a population of subjects on Earth.Operational Protocols
Subjects will be tested during free-floating while viewing 5 ambiguous, perspective-reversible figures through a lightweight headset and a finger trackball connected to a laptop. For each figure, the subjects must identify which percept they see first, and then indicate when the percept changes. Ground-based tests will be performed in 1g before and after the mission.