After disappearing from scientific and medical textbooks for decades, a major pathway in the human brain has been rediscovered by a team of neursoscientists, and they say that the tract of white matter could play an important role in how we process visual information, and how children’s reading skills develop. “The vertical occipital fasciculus (VOF) is a large flat bundle of nerve fibres that forms long-range connections between sub-regions of the visual system at the back of the brain,” reports the Guardian. “It was originally discovered by the German neurologist Carl Wernicke, who had by then published his classic studies of stroke patients with language deficits, and was studying neuroanatomy in Theodor Maynert’s laboratory at the University of Vienna. Wernicke saw the VOF in slices of monkey brain, and included it in his 1881 brain atlas, naming it the senkrechte occipitalbündel, or ‘vertical occipital bundle’.” However, Maynert refused to accept Wernicke’s discovery. “He had already described the brain’s white matter tracts, and had arrived at the general principle that they are oriented horizontally, running mostly from front to back within each hemisphere. But the pathway Wernicke had described ran vertically.”
Although the VOF appeared in Gray’s Anatomy in 1918, it eventually fell into obscurity. “This may have been due to early confusion over the nomenclature; to Maynert, who remained influential but refused to acknowledge Wernicke’s discovery up until his death in 1892; and to changes in neuroanatomical methods, which gradually moved from brain dissections that exposed the white matter tracts in large part, to brain tissue slices, which did not.” It was rediscovered by Stanford University’s Jason Yeatman and his colleagues. “I stumbled upon it while studying the visual word form area,” says Yeatman. “In every subject, I found this large, vertically-oriented fibre bundle terminating in that region of the brain.” He was unable to find any reference to in medical literature, but “eventually someone remembered seeing it in an old medical textbook. With this tip, we found it in a number of atlases from the late 1800s and early 1900s, and this started the detective mission to track down how it disappeared from the modern literature.” Yeatman performed DTI scans on more than seventy participants, and “using a new open source algorithm they identified the VOF in all them, and mapped it as accurately as possible.” Yeatman feels “the VOF likely plays an important role in perceptual processes such as reading and recognizing faces.” In the digital age, we can rest assured the VOF won’t be lost again.
