Dissociation of face-selective cortical responses by attention

Proc Natl Acad Sci U S A. 2006 Jan 24;103(4):1065-70. doi: 10.1073/pnas.0510124103. Epub 2006 Jan 13.

Abstract

We studied attentional modulation of cortical processing of faces and houses with functional MRI and magnetoencephalography (MEG). MEG detected an early, transient face-selective response. Directing attention to houses in "double-exposure" pictures of superimposed faces and houses strongly suppressed the characteristic, face-selective functional MRI response in the fusiform gyrus. By contrast, attention had no effect on the M170, the early, face-selective response detected with MEG. Late (>190 ms) category-related MEG responses elicited by faces and houses, however, were strongly modulated by attention. These results indicate that hemodynamic and electrophysiological measures of face-selective cortical processing complement each other. The hemodynamic signals reflect primarily late responses that can be modulated by feedback connections. By contrast, the early, face-specific M170 that was not modulated by attention likely reflects a rapid, feed-forward phase of face-selective processing.

MeSH terms

  • Attention
  • Brain Mapping
  • Data Interpretation, Statistical
  • Electromagnetic Fields
  • Evoked Potentials, Visual
  • Face*
  • Facial Expression*
  • Female
  • Humans
  • Magnetic Resonance Imaging / methods*
  • Magnetoencephalography / methods*
  • Male
  • Pattern Recognition, Visual*
  • Photic Stimulation
  • Temporal Lobe / pathology
  • Time Factors
  • Visual Perception