From Observed Action Identity to Social Affordances

Trends Cogn Sci. 2021 Jun;25(6):493-505. doi: 10.1016/j.tics.2021.02.012. Epub 2021 Mar 19.


Others' observed actions cause continuously changing retinal images, making it challenging to build neural representations of action identity. The monkey anterior intraparietal area (AIP) and its putative human homologue (phAIP) host neurons selective for observed manipulative actions (OMAs). The neuronal activity of both AIP and phAIP allows a stable readout of OMA identity across visual formats, but human neurons exhibit greater invariance and generalize from observed actions to action verbs. These properties stem from the convergence in AIP of superior temporal signals concerning: (i) observed body movements; and (ii) the changes in the body-object relationship. We propose that evolutionarily preserved mechanisms underlie the specification of observed-actions identity and the selection of motor responses afforded by them, thereby promoting social behavior.

Keywords: action observation; area AIP; parietal cortex; social interaction; visual invariance.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Brain Mapping
  • Movement*
  • Neurons
  • Parietal Lobe*
  • Psychomotor Performance