Journal Club (FFA)

Discussions on the fusiform face area.

What motivated the study?

Researchers already knew that the fusiform face area (FFA) in the human brain responds strongly and selectively to faces. Some theorists argued this face response was automatic (triggered any time a face appears). However, it was not known whether attention influences this specialized brain activity. The study was motivated by the question: Does covert visual attention modulate activity in the FFA, or is face processing mandatory and automatic?

What was the main hypothesis?

The authors hypothesized that FFA activity depends on covert visual attention. Specifically, they predicted that the FFA response to faces would be weaker when faces were outside the focus of attention compared to when faces were attended.

Why does it matter?

This question addresses a key debate in cognitive neuroscience:

• Are face modules in the brain fully automatic and mandatory?

• Or do even highly specialized systems (like the FFA) depend on voluntary attention?

  The answer informs how we understand modularity, attention, and the brain’s handling of biologically significant stimuli.

How was the main hypothesis evaluated?

The researchers used fMRI to measure activity in each subject’s FFA.

1. First, they localized the FFA in each subject by comparing brain responses to passive viewing of faces vs. objects.

2. Then, they tested attention effects using a task: participants viewed displays with two faces and two houses, and were instructed to match either the faces or the houses while maintaining central fixation.

Who was studied? What was measured?

• Participants: 11 volunteers (4 women, 7 men, ages 17–38); 10 usable data sets after motion exclusions.

• Measurements: Percent signal change (PSC) in the FFA, measured via fMRI, while participants performed different matching tasks.

How was the main outcome evaluated?

• Key comparison: FFA activity during face-matching vs. house-matching tasks.

• Analyses were restricted to individually defined ROIs (FFAs) localized in each subject.

• Outcome was evaluated with paired t-tests comparing PSC between conditions.

What did the researchers find?

• FFA localized: Responded more strongly to faces than objects.

• Attention effects: FFA activity was significantly stronger during face-matching than house-matching, even though the visual displays were identical.

• Both right and left FFAs showed this effect.

• This demonstrates that face-specific activity is modulated by covert attention, not purely stimulus-driven.

Do they support (or refute) the hypothesis?

Yes. The findings support the hypothesis: the FFA’s response to faces is not mandatory, but depends on where attention is directed.

Why do the results matter?

They challenge the strong modularity view that face processing in the FFA is completely automatic. Instead, the results show that attention plays a crucial role in shaping face-specific neural responses, placing face perception within the broader framework of attentional modulation seen across other sensory domains.

What are the limitations of the study?

• Attention effects could partly reflect spatial gating (faces vs. houses were in different spatial positions).

• Stimuli differed between localization (grayscale foveal faces) and attention tasks (two-tone peripheral faces), so comparisons across parts may be confounded.

• Sample size was relatively small (n = 10 analyzed).

What should be done next?

• Test attentional modulation using faces and houses presented at the same location, ruling out spatial gating effects (the authors mention preliminary work in this direction).

• Examine whether attention modulates face processing in other conditions, like rapid serial visual presentation or more naturalistic viewing.

• Extend the work to other categories of biologically significant stimuli (e.g., bodies, expressions).

• Use larger samples and higher-resolution imaging for robustness.