Sofia Guzzoni

An illusion refers to something that produces a misleading representation of reality and describes something that is perceived differently than the actual physical stimulus. Illusions are typically perceived as real experiences, which means that our brains cannot distinguish between what is real and what is an illusion, and they work remarkably well due to limitations in our visual system. Visual illusions can be used to study neurodevelopmental disorders by revealing the differences in perceptual processing between individuals with and without mental disorders. They can therefore be used to study certain neurodevelopmental disorders effectively, especially those presenting visual deficits, such as schizophrenia. 

According to recent research, patients with schizophrenia were found to have reduced susceptibility to visual illusions that involved a perceptual phenomenon known as lateral inhibition, which is when neuron’s activity is reduced by neighboring neurons. This allows the individual to clearly distinguish between objects and enhances the contrast and sharpness of an image. For example, if there is a pattern of squares with varying intensities of brightness, it has been found that the brightest square in the pattern seems to reduce the luminosity or brightness of the other squares. 

By using illusions that rely on lateral inhibition (such as the Hermann Grid illusion and simultaneous contrast illusion), researchers can gain insight on how lateral inhibition is impaired in these patients. By understanding how the brain of individuals with mental disorders processes these illusions, researchers can develop new targeted interventions and therapies that address these deficits in the brain. For example, cognitive remediation treatment can be used to target impaired lateral inhibition in patients. This research has the potential to significantly improve the lives of individuals with mental health disorders, and further our understanding of the brain.