Show Reference: "Subcortical Face Processing"

Subcortical Face Processing Nature Reviews Neuroscience, Vol. 6, No. 10. (01 October 2005), pp. 766-774, doi:10.1038/nrn1766 by Mark H. Johnson
@article{johnson-2005,
abstract = {Recent functional imaging, neuropsychological and electrophysiological studies on adults have provided evidence for a fast, low-spatial-frequency, subcortical face-detection pathway that modulates the responses of certain cortical areas to faces and other social stimuli. These findings shed light on an older literature on the face-detection abilities of newborn infants, and the hypothesis that these newborn looking preferences are generated by a subcortical route. Converging lines of evidence indicate that the subcortical face route provides a developmental foundation for what later becomes the adult cortical 'social brain' network, and that disturbances to this pathway might contribute to certain developmental disorders.},
author = {Johnson, Mark H.},
day = {01},
doi = {10.1038/nrn1766},
issn = {1471-003X},
journal = {Nature Reviews Neuroscience},
keywords = {face-detection, sc, visual-processing},
month = oct,
number = {10},
pages = {766--774},
pmid = {16276354},
posted-at = {2013-08-23 06:45:07},
priority = {2},
publisher = {Nature Publishing Group},
title = {Subcortical Face Processing},
url = {http://dx.doi.org/10.1038/nrn1766},
volume = {6},
year = {2005}
}


According to Johnson and Morton, there are two visual pathways for face detection: the primary cortical pathway and one through SC and pulvinar.

The cortical pathway is called CONLEARN and is theorized to be plastic, whereas the sub-cortical pathway is called CONSPEC and is thought to be fixed and genetically predisposed to detect conspecific faces.

Newborn children prefer to look at faces and face-like visual stimuli.

Visual cortex is not fully developed at birth in primates.

The fact that visual cortex is not fully developed at birth, but newborn children prefer face-like visual stimuli to other visual stimuli could be explained by the presence of a subcortical face-detector.

The fact that visual cortex is not fully developed at birth, but newborn children prefer face-like visual stimuli to other visual stimuli could be explained by the presence of a subcortical face-detector.

Looking behavior in newborns may be dominated by non-cortical processes.

Different parts of the visual field feed into the cortical and subcortical visual pathways more or less strongly in humans.

The nasal part of the visual field feeds more into the cortical pathway while the peripheral part feeds more into the sub-cortical pathway.

In one experiment, newborns reacted to faces only if they were (exclusively) visible in their peripheral visual field, supporting the theory that the sub-cortical pathway of visual processing plays a major role in orienting towards faces in newborns.

It makes sense that sub-cortical visual processing uses peripheral information more than cortical processing:

• sub-cortical processing is concerned with latent monitoring of the environment for potential dangers (or conspecifiics)
• sub-cortical processing is concerned with watching the environment and guiding attention in cortical processing.

SC has been implicated as part of a subcortical visual pathway which may drive face detection and orienting towards faces in newborns.

The subcortical visual pathway which may drive face detection and orienting towards faces in newborns hypothesized by Johnson also includes amygdala and pulvinar.

According to the hypothesis expressed by Johnson, amygdala, pulvinar, and SC together form a sub-cortical pathway which detects faces, initiates orienting movements towards faces, and activates cortical regions.

This implies that this pathway may be important for the development of the `social brain', as Johnson puts it.