Abstract
In cognition and everyday life, common factors are frequently encountered. For example, grades in physics correlate well with grades in mathematics. What about vision? We will first show that performance levels in 19 versions of the Ebbinghaus illusion correlated very strongly. For example, observers adjusted the centre disk in the classic Ebbinghaus illusion or a centre square surrounded by other squares. Performance strongly correlated for this and all other versions, including static and dynamic ones (n=87). Hence, there is a factor for the Ebbinghaus illusion. Next, we correlated the illusion susceptibility for the classic Ponzo and Müller-Lyer illusions (line drawings) and corresponding real world versions (pictures). In 86 new observers, we found almost no significant correlations. In the third experiment with 113 new observers, we tested six classic illusions, including the Ebbinghaus, the Müller-Lyer and the Ponzo illusion, and found, again, mainly Null results, except for a moderate link between the Ebbinghaus and Ponzo illusion. Hence, there seems to be no general factor for illusion strength, but sporadic associations. In the fourth experiment with 15 new observers, we tested seven similar illusions and four personality traits, including cognitive disorganization and mental imagery. Again, illusions were only weakly correlated but we found a significant and reliable association between the Ponzo illusion and both cognitive disorganization and mental imagery. We found similar results with other visual paradigms than illusions. We propose that the visual space comprises extremely small factors (Ebbinghaus factor), which may be linked to other visual factors- in a way we are far from understanding at the moment. To understand the mechanisms common to vision, we need to use batteries of tests and publish Null results, things that are not very common in our field.
Meeting abstract presented at VSS 2017