GCSE Psychology
The Gestalt theory of illusions
Learning objectives
• To learn abut the Gestalt theory of illusions
• To identify the strengths and weaknesses of this theory
• To learn about Gregory’s perspective theory of illusions
• To learn how to evaluate Gregory’s theory.
Illusions recap
Ponzo illusion
Muller Lyer illusion
Hering illusions
What type of illusions are these?
DISTORTIONS
What about these?
Kanizsa Triangle
FICTIONS
And these?
Rubin’s Vase
Leeepers Lady
AMBIGUOUS FIGURES
Gestalt theory of illusions
• Gestalt theory could explain these illusions by....
DISTORTIONS
Can only
explain the
distortion
MullerPonzo illusion
Lyer!!
Muller Lyer illusion
When we perceive
the figure as a
whole, pints / fins as
well, we tend to
‘add’ the fins to the
straight line
perceiving
it as a
Hering illusions
whole rather than its
separate parts. So
we are stretching the
line out.
What about these?
Kanizas triangle – according to the
law of closure, we should make
out a whole even though there
are parts missing....we should
make out a 6 pointed star but we
don’t – we see 2 triangles.
Kanizsa Triangle
Explains fictions well
~ closure law but for
some there is a
problem...
FICTIONS
Seems to use
different
explanations at
different times
AMBIGUOUS FIGURES
Tells us about
ambiguous figs well ~
using figure-ground
law
Perception has to be organised
differently to see the different images
due to the whole being made up of
the same parts meaning they can
not be seen at the same time
Task...
• Consider the strengths and weaknesses of Gestalt theory.
Gestalt theory of illusions
• You should now produce a booklet or poster to explain the Gestalt
theory of illusions.
• Use the internet to help you also but stick to the following points:
• Explaining fictions, which do we recognise first?,
• explaining distortions
• explaining ambiguous