Object Recognition

Question 1

Describe the process of Marr’s Cognition Framework

Answer 1

1. detect the edges of the object (by using the contrast of light)
   On-off cells are responsible to detect the change of light
2. the simple cells in the V4 help us to understand the orientation of the object, and also the curvature of the object

Question 2

What does it mean by the hierarchical perception of object recognition

Answer 2

lower process: colour, contrast, orientation, movement direction,
intermediate level: surface depth, surface segmentation, object movement, shape discrimination
high-level identification = object recognition

Question 3

What are the four properties of the Inferior Temporal Cortex

Answer 3

1. It is where information is integrated (colour, depth, form)
2. larger receptive fields comparing with LGN and RGCs
3. The viewpoint does not matter (compare with V4)
4. Requires the learning and memorisation of objects

Question 4

Name the what and where streams respectively

Answer 4

ventral and dorsal

Question 5

What are the other areas that are responsible for object recognition

Answer 5

V4 (colour, curvature recognition)
Lateral Occipital Complex (LO): Object recognition
Fulsiform Face Area (FFA): Facial recognition and object recognition by experts
Parahippocampal Place Area (PPA): Recognition of places
Extrastriate Body Area (EBA): Recognition of body parts

Question 6

Explain Agnosia and the two views

Answer 6

Caused by the damage of the Inferior Temporal Cortex
The disability of recognising objects with visual cues
severity depends on the scale of the lesion

two arguments
structural mechanism: identifying the features
holistic mechanism: identifying the configurations

Although people with Agnosia have the disability to recognise objects, they can still recognise natural scenes and human-made scenes = there is another region that is for scene recognition (Paraphippocampal Place area)

Question 7

Explain face recognition and and related experiments and the disability of recognising faces

Answer 7

Desdimone found that the Inferior Temporal Cortex of monkeys are more activated when seeing faces
If the middle part of the faces are removed, excitation = decrease (shows that the recognition of the face is not just recognising the outline of the face)

Kobatake similar results, with the eyes and mouth becoming white = inhibits the reaction of the IT

Face recognition is said to be involved at the Fulsiform Face Area (FFA), which is discovered by Nancy Kanwisher. Although argued, seems to be it

Prosopagnosia = the damage to the FFA > the disability of recognising a face. However, has the ability to recognise other objects such as sound, and words