Modern MRI rediscovers VOF, Major brain pathway forgotten for a century

Major brain pathway rediscovered after century-old confusion, controversy | (e) Science News

A couple of years ago a scientist looking at dozens of MRI scans of human brains noticed something surprising. A large, fiber pathway that seemed to be part of the network of connections that process visual information showed up on the scans, but the researcher couldn't find it mentioned in any of the modern-day anatomy textbooks he had. "It was this massive bundle of fibers, visible in every brain I examined," said Jason Yeatman, a research scientist at the University of Washington's Institute for Learning & Brain Sciences. "It seemed unlikely that I was the first to have noticed this structure; however, as far as I could tell, it was absent from the literature and from all major neuroanatomy textbooks."
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In the paper, published Nov. 17 by the Proceedings of the National Academy of Sciences, the team describes the history and controversy of the elusive brain pathway, explains how modern MRI techniques rediscovered it, and gives analytical tools researchers can use to identify the brain structure -- now known as the vertical occipital fasciculus.

The vertical occipital fasciculus: A century of controversy resolved by in vivo measurements

The vertical occipital fasciculus (VOF) is a major white-matter fascicle connecting dorsal and ventral visual cortex. Few vision scientists or cognitive neuroscientists are aware of the VOF's existence. The scarcity of papers on this important pathway stems from the contentious history surrounding its discovery by Wernicke in 1881. We review the conflict surrounding the classic, postmortem, VOF measurements, and we introduce modern, in vivo methods to precisely characterize the VOF's cortical terminations and unique tissue properties. The new VOF measurements provide insight into the communication between ventral stream regions involved in form perception and dorsal stream regions involved in eye movements and attention.

A camera lucida drawing made by E.J Curran depicts a
postmortem dissection of the vertical occipital fasciculus.
Curran described the VOF as “striking in its appearance, size,
and complete isolation from the longitudinal fibers under it.”
Jason Yeatman

 Major brain pathway rediscovered after century-old confusion, controversy | UW Today

“We believe that signals carried by the VOF play a role in many perceptual processes, from recognizing a friend’s face to rapidly reading a page of text,” said Yeatman, who is now studying brain mechanisms involved in learning to read.
In the paper, the researchers also provide an algorithm that others can use on their own data to find the pathway and measure its properties.
“To support reproducible research, our lab makes a strong effort to share software and data,” said Brian Wandell, senior author of the paper and a psychology professor at Stanford. “We believe this is a powerful way to ensure that our findings can be both checked and used in labs around the world.”

VOF deficit may have a relation to visual agnosia, as described by Oliver Sacks in  "the man who mistook his wife for a hat"