Gestaltzerfall (German for "shape decomposition" or Gestalt decomposition[1]) is a type of visual agnosia and is a psychological phenomenon where delays in recognition are observed when a complex shape is stared at for a while as the shape seems to decompose into its constituting parts.
With regards to kanji, a study has shown that delays are most significant when the characters are of the same size.
When characters to recognize are of different sizes, delays are observed only when they are of different patterns.
[2] Gestaltzerfall has also been described as a phenomenon where the output signals from the brain go beyond their expected range.
[4] Gestaltzerfall has also been applied in the case of spoken text where the speaker experiences a slip of the tongue during repeated poetry lectures.