Reading focus
Syllabus: How Can We Study Conscious Experience?
Trace the argument from face-selective recording to stimulation and the reported change in appearance.
Why you’re reading it. Add intervention evidence to the earlier correlational comparisons without treating any perturbation as a complete mechanism.
A question to consider. Which result distinguishes a causal contribution from a correlate, and which further comparison would be needed to establish that the stimulated site is necessary?
Why this reading
Changing neural activity can strengthen an argument that a region contributes to perception. Parvizi and colleagues combine functional localization, intracranial recording, and electrical stimulation in one patient who reports distortions of faces. The case reveals both the value and the limits of an intervention.
Before you read
The fusiform gyrus lies on the underside of the temporal lobe. A face-selective response is stronger for faces than comparison categories; it does not imply exclusive processing of faces. Electrodes were implanted for epilepsy care. fMRI and electrical recordings helped locate the sites subsequently stimulated.
Read for
- Compare stimulation of the selected sites with sham and nearby-site controls. What does each comparison address?
- Distinguish changes in the appearance of real faces from performance on photograph tasks. The conditions differ in more than whether recognition or perception is measured.
Consider afterwards
- What supports a causal contribution to the reported distortion, and what would be needed to establish necessity?
- How would effects spreading through connected regions change the interpretation?
Editorial context
This single case supports a contribution of the stimulated network to face experience under the tested conditions. It does not locate all consciousness in one region or establish that a small isolated site is sufficient. Stimulation can affect connected tissue, and clinical electrode placement restricts sampling. A 2013 correction fixes the fourth author's surname to Witthoft; that spelling is used here.