Electrophysiological priming effects demonstrate independence and overlap of visual regularity representations in the extrastriate cortex

PLoS One. 2021 Jul 9;16(7):e0254361. doi: 10.1371/journal.pone.0254361. eCollection 2021.

Abstract

An Event Related Potential (ERP) component called the Sustained Posterior Negativity (SPN) is generated by regular visual patterns (e.g. vertical reflectional symmetry, horizontal reflectional symmetry or rotational symmetry). Behavioural studies suggest symmetry becomes increasingly salient when the exemplars update rapidly. In line with this, Experiment 1 (N = 48) found that SPN amplitude increased when three different reflectional symmetry patterns were presented sequentially. We call this effect 'SPN priming'. We then exploited SPN priming to investigate independence of different symmetry representations. SPN priming did not survive changes in retinal location (Experiment 2, N = 48) or non-orthogonal changes in axis orientation (Experiment 3, N = 48). However, SPN priming transferred between vertical and horizontal axis orientations (Experiment 4, N = 48) and between reflectional and rotational symmetry (Experiment 5, N = 48). SPN priming is interesting in itself, and a useful new method for identifying functional boundaries of the symmetry response. We conclude that visual regularities at different retinal locations are coded independently. However, there is some overlap between different regularities presented at the same retinal location.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Electroencephalography
  • Evoked Potentials / physiology*
  • Humans
  • Male
  • Middle Aged
  • Motor Activity / physiology
  • Pattern Recognition, Visual / physiology*
  • Visual Cortex / physiology*
  • Young Adult

Grants and funding

This project was part funded by an ESRC grant award to Marco Bertamini (ES/K000187/1) and part funded by an ESRC grant awarded to Alexis Makin (ES/S014691/1).