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 Muller When we perceive the figure as a whole, pints / fins as well, we tend to ‘add’ the fins to the straight line Muller Lyer illusion 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