Face-identity change activation outside the face system: "release from adaptation" may not always indicate neuronal selectivity

Cereb Cortex. 2010 Sep;20(9):2027-42. doi: 10.1093/cercor/bhp272. Epub 2010 Jan 5.

Abstract

Face recognition is a complex cognitive process that requires distinguishable neuronal representations of individual faces. Previous functional magnetic resonance imaging (fMRI) studies using the "fMRI-adaptation" technique have suggested the existence of face-identity representations in face-selective regions, including the fusiform face area (FFA). Here, we present face-identity adaptation findings that are not well explained in terms of face-identity representations. We performed blood-oxygen level-dependent (BOLD) fMRI measurements, while participants viewed familiar faces that were shown repeatedly throughout the experiment. We found decreased activation for repeated faces in face-selective regions, as expected based on previous studies. However, we found similar effects in regions that are not face-selective, including the parahippocampal place area (PPA) and early visual cortex (EVC). These effects were present for exact-image (same view and lighting) as well as different-image (different view and/or lighting) repetition, but more widespread for exact-image repetition. Given the known functional properties of PPA and EVC, it appears unlikely that they contain domain-specific face-identity representations. Alternative interpretations include general attentional effects and carryover of activation from connected regions. These results remind us that fMRI stimulus-change effects can have a range of causes and do not provide conclusive evidence for a neuronal representation of the changed stimulus property.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Adaptation, Physiological*
  • Adult
  • Cerebral Cortex / anatomy & histology*
  • Cerebral Cortex / cytology
  • Cerebral Cortex / physiology*
  • Face / physiology*
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Neurons / cytology
  • Neurons / physiology*
  • Oxygen / blood
  • Pattern Recognition, Visual / physiology*
  • Photic Stimulation / methods
  • Recognition, Psychology / physiology*

Substances

  • Oxygen