Visual Information Processing II: Perception

What happens after VI (striate cortex – where Hubel and Wiesel isolated cells sensitive to lines oriented at certain angles moving in certain directions)?

There are 2 main pathways (Ungerlieder and Mishkin):

1) The Dorsal Stream (upper pathway – parietal lobes)

"WHERE?" or, more recently visually guided movement (Milner and Goodale)

2) The Ventral Stream (lower pathway - ventral part of temporal lobes)

"WHAT?" Cells here are sensitive to forms and features. Some are particularly sensitive to faces.

In monkeys, these cells only fire for regular (non-distorted) faces.

fMRI (functional magnetic resonance imaging) work (Leslie Ungerlieder) has corroborated the activity of the ventral temporal lobes during face recognition. Frontal lobes are also important for remembering faces.