Mechanisms of feature selectivity and invariance in primary visual cortex

Ali Almasi, Hamish Meffin, Shaun L. Cloherty, Yan Wong, Molis Yunzab, Michael R. Ibbotson

Research output: Contribution to journalArticleResearchpeer-review

12 Citations (Scopus)


Visual object identification requires both selectivity for specific visual features that are important to the object's identity and invariance to feature manipulations. For example, a hand can be shifted in position, rotated, or contracted but still be recognized as a hand. How are the competing requirements of selectivity and invariance built into the early stages of visual processing? Typically, cells in the primary visual cortex are classified as either simple or complex. They both show selectivity for edge-orientation but complex cells develop invariance to edge position within the receptive field (spatial phase). Using a data-driven model that extracts the spatial structures and nonlinearities associated with neuronal computation, we quantitatively describe the balance between selectivity and invariance in complex cells. Phase invariance is frequently partial, while invariance to orientation and spatial frequency are more extensive than expected. The invariance arises due to two independent factors: (1) the structure and number of filters and (2) the form of nonlinearities that act upon the filter outputs. Both vary more than previously considered, so primary visual cortex forms an elaborate set of generic feature sensitivities, providing the foundation for more sophisticated object processing.

Original languageEnglish
Pages (from-to)5067-5087
Number of pages21
JournalCerebral Cortex
Issue number9
Publication statusPublished - Sept 2020


  • complex cell
  • maximum likelihood
  • object recognition
  • single neuron computation
  • visual cortex

Cite this