TEMPORAL DYNAMICS OF AMYGDALA & FACE PROCESSING

Trace the precise timeline of visual information reaching different brain areas from the retina.

A:

• ~50 ms: Hits primary visual cortex (V1).

• ~170 ms: Hits the Fusiform Face Area (conscious face recognition).

• ~300 ms: Full detailed visual info reaches the amygdala via the High Road.

• ~20–30 ms: Rapid LSF threat info reaches the amygdala via the Low Road (thalamus shortcut)

Why does the amygdala exhibit a rapid response specifically to fearful faces?

A: It is not because we are afraid of the face itself, but because a fearful face signals that something dangerous is in the environment that the other person sees and we haven't noticed yet.

What did Kennedy et al. (2009) discover regarding the amygdala and social distance?

A: Individuals with normal amygdala function maintain a standard arms-length social distance from others, whereas individuals with amygdala damage significantly encroach on that boundary (standing within a foot), proving its role in regulating social distance.

What is Pareidolia, and what is its evolutionary purpose?

A: The tendency to mistakenly perceive faces where none exist (e.g., seeing a face in a cloud or electrical outlet). Evolutionarily, it's safer to have false positives than to miss seeing a real face when a threat is present.

Distinguish "Features" from "Configuration" in face processing

A:

• Features: Individual parts of a face (eyes, nose, mouth).

• Configuration: The holistic spatial relationship among those features. Tiny configuration variations determine individual identity, which remains stable despite emotional changes.

Explain the Face Inversion Effect and why it happens.

A: Turning a face upside-down impairs recognition because it disrupts configural processing, forcing the brain to rely on slow, feature-by-feature local processing instead of holistic software.

How does the Thatcher Effect (Thatcher Illusion) demonstrate holistic face processing?

A: The illusion proves that your brain processes right-side-up faces as a whole connected image, but reads upside-down faces as just a random collection of separate parts.

When an upside-down face has its eyes and mouth inverted, it looks normal because inverted faces undergo local feature processing. When turned right-side up, holistic processing kicks in, revealing a bizarre, grotesque distortion.