The document summarizes the two main visual pathways in the brain - the dorsal and ventral pathways. The dorsal pathway projects from the occipital lobe to the parietal lobe and is involved in spatial processing and visually guided actions. The ventral pathway projects from the occipital lobe to the temporal lobe and is responsible for object recognition and memory formation. It clusters visual information into categories like faces, bodies, and objects. Major output pathways from the ventral pathway include connections to the amygdala, medial temporal lobe, orbitofrontal cortex, and ventrolateral prefrontal cortex.

1. The visual pathway
Domina Petric, MD

2. Introduction
Cortical visual processing is
commonly thought to proceed
along two distinct pathways:
• dorsal pathway projecting
into parietal cortex
• ventral pathway projecting
into temporal cortex

3. Dorsal visual pathway
The dorsal pathway is an occipitoparietal
network that lies between early visual cortex
and specialized cortical structures involved in:
• visually-guided action
• somatosensation
• spatial audition
• navigation
• spatial working memory

4. Dorsal visual pathway
The dorsal pathway
specializes in capturing
arbitrary and dynamic
spatiotemporal
relationships between
multiple items.

5. Ventral visual pathway
• It is an occipitotemporal network that bridges
the early visual cortex and specialized
cortical and subcortical structures involved
in various forms of memory and learning,
specifically habit formation, emotion, long-
term and short-term memory, reward, and
value.
• These structures are involved in forming
specific representations or associations
involving stable aspects of visual
information.

6. Ventral visual pathway
Processing of object quality:
• inclusive term meant to capture the wide
variety of stable visual information that can
be processed as the basis of these
associations
• processing of the features or perceptual
dimensions (e.g. shape, color, size,
brightness) that are available in the
information passed to striate cortex from the
retina

7. Clustering
One of the most consistent findings regarding the
intrinsic function of the occipitotemporal network is
the presence of functional clustering in cortex with
selectivity for particular object categories:
• body parts
• faces
• scenes
• objects
• tools
• written words
• color

8. Major subcortical and cortical output pathways
from the occipitotemporal network are:
• cortico-subcortical output pathways
• occipitotemporo-neostriatal pathway
• occipitotemporo-ventral striatum pathway
• occipitotempo-amygdaloid pathway
• cortico-cortical output pathways
• occipitotemporo-medial temporal pathway
• occipitotemporo-orbitofrontal pathway
• occipitotemporo-ventrolateral prefrontal
pathway

9. http://www.keywordsuggests.com

10. Literature:
• Kravitz DJ, Saleem KS, Baker CI,
Ungerleider LG, Mishkin M. The ventral
visual pathway: An expanded neural
framework for the processing of object
quality. Trends in cognitive sciences.
2013;17(1):26-49.
doi:10.1016/j.tics.2012.10.011.
• http://www.keywordsuggests.com