Depression affects vision

 

Which of the two dots in the picture above is darker?

Researchers in psychiatry and psychology at the University of Helsinki studied the effects of depression on visual perception.

Studies have confirmed that the processing of visual information by patients with depression has changed, and this phenomenon is likely to be related to the processing of information by the cerebral cortex.

The research was published in the Journal of Psychiatry and Neuroscience.

The study was published in the Journal of Psychiatry and Neuroscience (latest impact factor: 4.382) on March 11, 2021

In the study, two visual tests were used to compare the processing of visual information between patients with depression and patients in the control group. In the perception test, the subjects compared the brightness and contrast of simple patterns.

Viljami Salmela, a researcher at the Finnish Academy of Sciences, said: "It is surprising that patients with depression have a different perception of the contrast of the displayed image from those with non-depression."

Compared with patients who have not been diagnosed with depression, patients with depression believe that the visual illusion presented in the pattern is weaker, and therefore, the contrast is stronger.

The brightness of picture A and picture B are exactly the same, but because of the different background, their perception is different. The perception of this illusion is similar between patients and healthy controls. The comparison between Figure C and Figure D is exactly the same, but it feels different. Compared with the control group, depressed patients have a weaker perception of this illusion

Salmela explained: "In non-depressive patients, this contrast is suppressed by about 20%, while in depressed patients, the corresponding figure is about 5%."

Identifying the changes in brain function behind mental disorders is important to increase understanding of the pathogenesis of these disorders and how to develop effective treatments.

This is why researchers believe that it is necessary to further study the changes in the brain's visual information processing caused by depression.

Salmela said: "It would be beneficial to evaluate and further develop the usability of perception testing, which is both a research method and a potential method for identifying patient information processing disorders."

For example, sensory testing can be used as an additional tool to evaluate the effects of various therapies in the progress of treatment.

Salmela pointed out: "However, depression cannot be determined by testing visual perception, because the observed differences are small, especially when the groups are compared."

What's in this picture?

references：

Source：University of Helsinki

Depression affects visual perception

Reference：

Salmela V, Socada L, Söderholm J, Heikkilä R, Lahti J, Ekelund J, Isometsä E. Reduced visual contrast suppression during major depressive episodes. J Psychiatry Neurosci. 2021 Mar 11;46(2):E222-E231. doi: 10.1503/jpn.200091. PMID: 33703869.