Ternus illusion
[2] This problem of phenomenal identity that Ternus had discovered occurs due to the human visual system's natural ability to establish and then preserve the entities of objects even when the defining attributes of those objects have undergone drastic changes and no longer resemble what they once did.
Instead, apparent motion appears to arise from the visual system's processing of the physical properties of the percept.
[6] The Ternus display features a series of frames that are separated by what is known as a blank interstimulus interval (ISI).
[4] When these three frames are quickly presented in a sequential manner, individuals report perceiving two discrete types of motion from observing the Ternus display.
[9] As a response to this the higher level long-range motion process passes a signal of element movement.
A reasonable amount of the research in this area appears to be well empirically supported, such as the idea that lower level (short range processes) and higher level (long range processes) are involved in determining which illusion is perceived.
Research undertaken by Kramer and Yantis in 1997 found that perceptual grouping of the elements also appears to have important implications.
[4] Yantis found that the perceived continuity of a briefly interrupted element in perception depends on early neural mechanisms in the visual system such as visible persistence as well as on a representation of a three-dimensional surface layout.
[6] As previously mentioned, studies have alluded to the idea that high level motion mechanisms determine the final decision in which percept shows through, however recent research by He & Ooi suggests that this final decision is also influenced by accounting for numerous grouping factors such as proximity, similarity and common surface amongst the elements in the scene.
[5] Though there are many ideas relating to causative factors, even current research seems to be lacking in a conclusive explanation for why the Ternus effect occurs and has not yet discovered exactly which mechanisms are responsible.
Petersik and his team in 2006 suggested that intensive brain-imaging research on each percept is the way forward and is the most likely way to discover the answer.
