Vertical–horizontal illusion

[4] A gradual decrease in error of vertical–horizontal illusions occur as participants age increases from eight to fourteen years.

[5] Gough and Meschieri attribute this decrease in error to the child's improved ability to detect and de-center their attention in a visual display, i.e. position their body differently to gain other perspectives.

[7] An explanation could be that those in rural areas are more accustomed to living in round houses on flat plains, or scrubland.

[8] Participants with hemispatial neglect had increased difficulty perceiving the equality of the lines on the vertical–horizontal illusion, in comparison with those in the control group.

Montalembert's study, among others, gives claim to the notion that we perceive these types of illusions utilizing the left hemisphere of our brain.

Additional research is needed to draw a significant relationship between illusion magnitude and real-world tasks.