Experience-dependent coding of facial expression in superior temporal sulcus

• DOI: 10.1073/pnas.0702548104
• Publication Date: 2007-08-08T01:55:24Z
• Authors: Nicholas Furl; Nicola J. van Rij...; Alessandro Treves; Karl J. Friston; Raymond J. Dolan
• Keywords: Superior temporal sulcus; Magnetoencephalography; Neural adaptation; Neural coding

Sensory information from the external world is inherently ambiguous, necessitating prior experience as a constraint on perception. Prolonged (adaptation) induces perception of ambiguous morph faces category different adapted category, suggesting sensitivity in underlying neural codes to differences between input and recent experience. Using magnetoencephalography, we investigated dynamics such experience-dependent visual coding by focusing timing responses morphs after facial expression adaptation. We show that evoked fields arising superior temporal sulcus (STS) reflect degree which deviate. Furthermore, adaptation effects within STS predict magnitude behavioral aftereffects. These findings expressions relative rather than absolutely may bias expressions. One potential mechanism for late both appeals hierarchical models ascribe central role backward connections mediating predictive codes.