Chapter 14, Figure
6
NMDS representation
of the dataset from Fig.1. Green lines indicate unidirectional, red lines reciprocal
connections between the areas. For details of the analysis see main text. Starting
with V1, the diagram shows the separation of the primate visual system into
two main streams that are more connected internally than between each other.
The "ventral stream" of mainly temporal areas is situated towards the left,
the "dorsal stream" of occipital and occipito-parietal areas towards the right
side The arrangement hints that the streams might reconverge in prefrontal (e.g.
A46) and polymodal (STP) cortical regions of the diagram. Also apparent is the
intermediate position held by area V4, based on its interconnections with both
the 'peripheral' dorsal stream and the ventral stream. Additionally, the bottom
to top arrangement of visual areas in this diagram broadly agrees with the arrangement
from 'peripheral' to more 'internal' areas in the brain. The stress value for
the shown diagram is 0.31, and the variance of the high-dimensional topology
explained by the low-dimensional configuration (as represented by the configuration's
squared correlation in distances) is 0.48, indicating a moderate fit.
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