Fusiform Face Area Notes

Fusiform Face Area (FFA)

  • Located in the fusiform gyrus in the extrastriate cortex.
  • Specialized for face perception.
  • fMRI studies showed higher activation when viewing faces compared to objects.

Methods

  • fMRI was used to measure brain activity while subjects viewed faces and objects.
  • Regions of interest (ROIs) were defined based on face-selective activation.
  • Multiple stimulus comparisons were conducted within the same ROIs.

Key Findings

  • FFA responds more strongly to faces than to various control stimuli.
  • FFA is not solely driven by low-level visual features.
  • FFA is not simply involved in subordinate-level classification or general processing of animate objects.
  • The study suggests that face recognition may involve distinct neural mechanisms compared to object recognition.

Specificity Tests

  • Intact vs. Scrambled Faces: FFA responds more to intact faces, ruling out low-level feature extraction.
  • Faces vs. Houses: FFA responds more to faces than houses, suggesting face-specific processing.
  • Three-Quarter-View Faces vs. Hands: FFA responds more to faces, indicating it's not just animate objects or body parts.
  • 1-Back Matching Task: FFA activation during face matching is higher than during hand matching, controlling for attention and subordinate-level classification.

Alternative Interpretations Rejected

  • Visual Attention: Ruled out as the primary driver of FFA activity.
  • Subordinate-Level Classification: FFA activity is specific to faces, not general object recognition.
  • General Animate Object Processing: Hands were used as a control to rule out general animate object processing.

Location and Consistency

  • The right fusiform gyrus showed consistent face activation across subjects.
  • активация была очень последовательной в разных сеансах тестирования у одного и того же субъекта.

Relation to Other Brain Areas

  • Middle temporal gyrus/superior temporal sulcus (MT gyrus/STS) may also be involved in face processing.
  • The FFA might be the human homolog of the macaque inferotemporal region.

Implications

  • The existence of FFA supports the idea of specialized cortical machinery for face perception.
  • Suggests that face recognition may involve qualitatively different computations than object recognition.