Visual illusions

and what happens in the brain

Bistable global-local illusion ©Natalia Zaretskaya

Bistable figures

With bistable stimuli (also known as bistable figures), the same image can be perceived in two different ways. An example of this is this global-local motion stimulus.

When looking at the red dot for a longer time, the perception starts to switch between the local motion of the dots and the global motion of two illusory squares. The stimulus was used in some of our studies to investigate the neural basis of shape perception.

Illusory surface

Why do we perceive an illusory surface in this picture? What happens in the brain when we perceive such a surface? Our research shows that many areas of the brain contribute to the perception of illusory surfaces, not only the areas of the posterior parietal cortex, but also thalamic nuclei.

Kanizsa square ©Ana Arsenovic

Links to selected publications

Resting-state neural correlates of visual Gestalt experience

Wilding et al, 2023
Dissociation between attention-dependent and spatially specific illusory shape responses within the topographic areas of the posterior parietal cortex.

Arsenovic et al, 2022
Increased insula activity precedes the formation of subjective illusory Gestalt

Wilding et al., 2022
Parietal Cortex Mediates Conscious Perception of Illusory Gestalt

Zaretskaya et al, 2013