An Electroencephalography Investigation on Sustained Posterior Negativity Using Realistic, Uncontrolled Images

Symmetry is one of the most essential cues in vision, because at its essence, symmetry is a concept closely related to structure and regularity. (Bertamini et al., 2018). Recently neural basis of symmetry perception has been explored in humans using electroencephalography (EEG). A well-established marker of symmetry perception is the Sustained Posterior Negativity (SPN), an event-related potential (ERP) component characterized by a sustained negative deflection over posterior electrodes in response to visual symmetry (Bertamini et al., 2019). Previous research has primarily used low-level visual stimuli, such as dot patterns or line drawings arranged symmetrically or asymmetrically, to measure the SPN. In contrast, the present study examined SPN responses to realistic, uncontrolled images to assess whether the neural signature of symmetry perception extends to more naturalistic visual input.