Abstract

CAVALCANTI, Alessandra Magalhães  and  SANTOS, Natanael Antonio dos. The effects of depression on contrast visual perception in humans: preliminary results. Rev. bras.ter. cogn. [online]. 2005, vol.1, n.1, pp. 21-28. ISSN 1808-5687.

The objective of this study was the characterization of alterations in visual perceptions of form in patients with major depression disorder, using the contrast sensitivity function (CSF). Six volunteers between the ages of 20-26 years participated in the experiments, three without depression and three with major depression, all of them without visual illness. The CSF was estimated with a radial frequency of 0.2, 1 and 4 cpd and forced-choice psychophysical method. The results showed maximum contrast sensibility to radial frequency occurring in 0.25 cpd for both groups. Therefore, participants with depression disorder needed around 1.7 more contrast to detect the radial frequency of 0.2 and 1 cpd and around 3.4 more contrast to detect the radial frequency of 4 cpd, when compared with participants without the disorder. The results showed alterations in the sensibility to contrast associated with major depression.

Keywords : Form visual perception; Contrast sensitivity; Depression; Radial frequency.