Presentació "Real-Life VR Integration for Mild Cognitive Impairment Rehabilit...
Ventral stream
1. What are you looking at?
Mechanisms of visual recognition.
Barbara Nordhjem
Visual Neuroscience Group
Laboratory of Experimental Ophthalmology
University Medical Center Groningen
2. Human recognition
• Gist of the scene at 7
images per second.
• Unpredictable random QuickTime™ and a
Sorenson Video 3 decompressor
sequence of images are needed to see this picture.
Potter 1971, 1975; Biederman 1972; Thorpe 1996 Movie by Jim DiCarlo
3. • Images change: object position, distance, pose, lighting
and background clutter. Yet we know where to attend and
what we are looking at.
7. Parallel increase in invariance properties (position and scale)
of neurons
Illustration from Rousselet et al., 2004
8. Pathways in the brain
• Lesions parietal lobe
(Newcombe, 1969)
• Ungerleider and Mishkin
(1982) lesions in monkeys.
Suggested regions
organized in pathways
• Goodale and Milner (1992)
distinguish between
perception and action
Figure by Mike Cohen
9. • The case of DF: visual form agnosia
• Carbon monoxide poisoning
• Lesion of lateral occipital cortex
12. Are people attending to both
constellations when they grasp?
Patient (AT) with parietal lesions was
better grasping familiar than novel
objects – interaction of memory and
action control (Jeannerod et al.,
1994).
Aglioti et al., 1995
13. Modules in the brain
Processing areas with
the ventral pathway:
Faces, Objects, Places
Figure by Mike Cohen
14. Face and form agnosia
Some patients show a specific deficit for recognizing faces, others show
deficits for recognizing all other objects.
Faces and objects are processed in separate, perhaps non-overlapping,
brain areas.
29. Summary
• Parallel increase in invariance to
position and scale of neurons from
V1 to IT
• Specialized information processing
• Dorsal and ventral pathways for
action and perception
• Keep in mind that the idea of
pathways and specialized regions
is simplified
visualneuroscience.nl
Hinweis der Redaktion
Other studies also show changes between LO and FFA for the Rubin face-vase illusion