Susan R. Barry | |
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Nationality | American |
Occupation | Professor |
Spouse | Daniel T. Barry |
Academic background | |
Alma mater | |
Academic work | |
Discipline | Neurobiology |
Institutions | Mount Holyoke College |
Notable works |
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Website | Official website |
Susan R. Barry is a Professor Emeritus of Biological Sciences and Professor Emeritus of Neuroscience and Behavior at Mount Holyoke College and the author of three books. She was dubbed Stereo Sue by neurologist and author Oliver Sacks in a 2006 New Yorker article with that name. [1]
Barry's first book greatly expands on Sacks' article and discusses the experience of gaining stereovision through optometric vision therapy,after a lifetime of being stereoblind. It challenges the conventional wisdom that the brain is wired for perceptual skills during a critical period in early childhood and provides evidence instead for neuronal plasticity throughout life. [2] Barry's achievement of stereo vision,with the help of a developmental optometrist Theresa Ruggiero,was reported in a BBC Imagine documentary broadcast on June 28,2011. [3]
Barry expanded her discussion of sensory plasticity and recovery in her second book,Coming to Our Senses:A Boy Who Learned to See,A Girl Who Learned to Hear,and How We All Discover the World. In it she describes the experiences of Liam McCoy who was practically blind from birth but gained sight at age 15 and Zohra Damji,born profoundly deaf,who learned to hear with a cochlear implant at age 12. The book describes how they each reconstructed and reorganized their perceptual world,reshaped their identity,and rewired the neural circuits in their brain.
In her third book,Dear Oliver, Barry shares her ten-year correspondence with Oliver Sacks. Their shared passions—from classical music to cuttlefish,brain plasticity to bioluminescent plankton—sparked a friendship that buoyed both of them through life’s crests and falls. In a painful twist of fate,as Sue’s vision improved,Oliver’s declined,and his characteristic typed letters shifted to handwritten ones. Sue later recognized this to be an early sign of the cancer that ultimately ended his extraordinary life.
Barry graduated from Wesleyan University with a Bachelor of Arts in Biology in 1976. She then did her graduate work at Princeton University where she earned a Master of Arts in Biology in 1979 and a Ph.D. in Biology in 1981.
She undertook postdoctoral work at the University of Michigan and the Miami School of Medicine,and subsequently became assistant professor at the department of Physical Medicine and Rehabilitation at the University of Michigan Medical School. [4] In 1992,she joined the faculty of Mount Holyoke College where she rose to the rank of full professor before retiring at the end of 2015.
Barry has published a blog in the magazine Psychology Today ,entitled Eyes on the Brain,which explores the practical applications of the theory of neuroplasticity. [5] She is married to former astronaut Daniel T. Barry. [6]
Barry had been affected by alternating esotropia since early age,and had undergone corrective operations to her eye muscles at two,three and seven years of age. [7] At the age of forty,she became aware of difficulties in correctly perceiving objects at a distance,such as road signs and faces. The ophthalmologist whom she consulted told her that her eyesight of both eyes had only small flaws which were already corrected by her eyeglasses. [8] Years later,after a colleague drew her attention to her tendency to disregard raised hands at the back of the large classroom,she consulted an optometrist who referred her to Ruggiero. With her,Barry embarked on vision therapy to stabilize her gaze. [9] using the approach developed by Frederick W. Brock,including for example exercises to aim the two eyes at the same point in space using the Brock string.
She first saw 3D at the age of 48 sitting in the driving seat of her car after a session of vision therapy. In her own words she describes her experience as seeing the steering wheel "floating in front of the dashboard with this palpable volume of space between the steering wheel and the dashboard". [10] It took her months to accept that she truly had stereo vision (stereopsis) "because of all of the scientific dogma that indicated that this was not possible". [11] She contacted Oliver Sacks,with whom she had spoken of stereopsis at an earlier occasion. Together with ophthalmologist Bob Wasserman and vision physiologist Ralph Siegel,he came to visit her and Ruggiero in February 2005,and in 2006 he published an article on their story in The New Yorker. [1] [12]
Barry had initially found it difficult to believe in her acquisition of stereo vision for the reason that the notion of critical period was firmly set since the groundbreaking work of Torsten Wiesel and David H. Hubel with deprivation experiments in which animals did not develop the neuronal basis for stereo vision if they were prevented from performing stereo fusion for a given time period after birth. Barry contacted Hubel,who had no difficulty in believing in her vision improvements and stated that their experiments in fact had not addressed the question whether the animals might have been able to recover stereo vision later. [13]
Hubel explained to me that he had never attempted to correct the strabismus in animals in order to examine the effects of straightening the eyes on visual circuitry. It would have been difficult to realign the eyes surgically and even harder to train the animals with vision therapy. So, he couldn't be sure that the effects of strabismus on binocular circuitry were permanent. Yet to truly delineate a critical period, he and other scientists would have had to demonstrate that the effects of strabismus on cortical wiring cannot be reversed after a certain age. Indeed, Hubel had already stated these concerns in Brain and Visual Perception when he wrote, “A missing aspect of this work is knowledge of the time course of the strabismus animals, cats or monkeys, and in the monkeys the possibilities of recovery.”
Susan R. Barry: Fixing my Gaze, 2009. [13]
Hubel further suggested that newborns may be already equipped with binocular depth neurons.
In her book Fixing my Gaze, Barry points out that Wiesel and Hubel's results were mistakenly extrapolated, not by Wiesel and Hubel themselves, but by the majority of scientists and physicians, who mistakenly assumed that the critical period for developing amblyopia (a "lazy eye") also applied to the recovery from amblyopia. She concludes:
After the article on "Stereo Sue" was published, Barry found and took up contact with a number of people who shared with her their own stories of lacking and acquiring stereo vision. She reports on their experiences at regaining 3D vision in her book Fixing my Gaze.
Apart from the cases recounted by Barry, further cases have been pointed out recently in which a formerly stereoblind adult has acquired the ability for stereopsis.[ citation needed ]
This happened also to neuroscientist Bruce Bridgeman, professor of psychology and psychobiology at University of California Santa Cruz, who had grown up nearly stereoblind and acquired stereo vision spontaneously in 2012 at the age of 67, when watching the 3D movie Hugo with polarizing 3D glasses. The scene suddenly appeared to him in depth, and the ability to see the world in stereo stayed with him also after leaving the cinema. [15] [16]
The Princeton Review lists Barry among the 300 outstanding college teachers in the U.S., her paper on the work of Frederick W. Brock was selected as the best published paper in the Journal of Behavioral Optometry in 2011, and in 2013 she received the Meribeth E. Cameron Faculty Award for Scholarship. [4]
Esotropia is a form of strabismus in which one or both eyes turns inward. The condition can be constantly present, or occur intermittently, and can give the affected individual a "cross-eyed" appearance. It is the opposite of exotropia and usually involves more severe axis deviation than esophoria. Esotropia is sometimes erroneously called "lazy eye", which describes the condition of amblyopia; a reduction in vision of one or both eyes that is not the result of any pathology of the eye and cannot be resolved by the use of corrective lenses. Amblyopia can, however, arise as a result of esotropia occurring in childhood: In order to relieve symptoms of diplopia or double vision, the child's brain will ignore or "suppress" the image from the esotropic eye, which when allowed to continue untreated will lead to the development of amblyopia. Treatment options for esotropia include glasses to correct refractive errors, the use of prisms, orthoptic exercises, or eye muscle surgery. The term is from Greek eso meaning "inward" and trope meaning "a turning".
In biology, binocular vision is a type of vision in which an animal has two eyes capable of facing the same direction to perceive a single three-dimensional image of its surroundings. Binocular vision does not typically refer to vision where an animal has eyes on opposite sides of its head and shares no field of view between them, like in some animals.
Orthoptics is a profession allied to the eye care profession. Orthoptists are the experts in diagnosing and treating defects in eye movements and problems with how the eyes work together, called binocular vision. These can be caused by issues with the muscles around the eyes or defects in the nerves enabling the brain to communicate with the eyes. Orthoptists are responsible for the diagnosis and non-surgical management of strabismus (cross-eyed), amblyopia and eye movement disorders. The word orthoptics comes from the Greek words ὀρθός orthos, "straight" and ὀπτικός optikοs, "relating to sight" and much of the practice of orthoptists concerns disorders of binocular vision and defects of eye movement. Orthoptists are trained professionals who specialize in orthoptic treatment, such as eye patches, eye exercises, prisms or glasses. They commonly work with paediatric patients and also adult patients with neurological conditions such as stroke, brain tumours or multiple sclerosis. With specific training, in some countries orthoptists may be involved in monitoring of some forms of eye disease, such as glaucoma, cataract screening and diabetic retinopathy.
Strabismus is a vision disorder in which the eyes do not properly align with each other when looking at an object. The eye that is pointed at an object can alternate. The condition may be present occasionally or constantly. If present during a large part of childhood, it may result in amblyopia, or lazy eyes, and loss of depth perception. If onset is during adulthood, it is more likely to result in double vision.
Amblyopia, also called lazy eye, is a disorder of sight in which the brain fails to fully process input from one eye and over time favors the other eye. It results in decreased vision in an eye that typically appears normal in other aspects. Amblyopia is the most common cause of decreased vision in a single eye among children and younger adults.
David Hunter Hubel was an American Canadian neurophysiologist noted for his studies of the structure and function of the visual cortex. He was co-recipient with Torsten Wiesel of the 1981 Nobel Prize in Physiology or Medicine, for their discoveries concerning information processing in the visual system. For much of his career, Hubel worked as the Professor of Neurobiology at Johns Hopkins University and Harvard Medical School. In 1978, Hubel and Wiesel were awarded the Louisa Gross Horwitz Prize from Columbia University. In 1983, Hubel received the Golden Plate Award of the American Academy of Achievement.
Pediatric ophthalmology is a sub-speciality of ophthalmology concerned with eye diseases, visual development, and vision care in children.
Random-dot stereogram (RDS) is stereo pair of images of random dots which, when viewed with the aid of a stereoscope, or with the eyes focused on a point in front of or behind the images, produces a sensation of depth, with objects appearing to be in front of or behind the display level.
Stereopsis is the component of depth perception retrieved through binocular vision. Stereopsis is not the only contributor to depth perception, but it is a major one. Binocular vision happens because each eye receives a different image because they are in slightly different positions in one's head. These positional differences are referred to as "horizontal disparities" or, more generally, "binocular disparities". Disparities are processed in the visual cortex of the brain to yield depth perception. While binocular disparities are naturally present when viewing a real three-dimensional scene with two eyes, they can also be simulated by artificially presenting two different images separately to each eye using a method called stereoscopy. The perception of depth in such cases is also referred to as "stereoscopic depth".
Vision therapy (VT), or behavioral optometry, is an umbrella term for alternative medicine treatments using eye exercises, based around the pseudoscientific claim that vision problems are the true underlying cause of learning difficulties, particularly in children. Vision therapy has not been shown to be effective using scientific studies, except for helping with convergence insufficiency. Most claims—for example that the therapy can address neurological, educational, and spatial difficulties—lack supporting evidence. Neither the American Academy of Pediatrics nor the American Academy of Ophthalmology support the use of vision therapy.
Exotropia is a form of strabismus where the eyes are deviated outward. It is the opposite of esotropia and usually involves more severe axis deviation than exophoria. People with exotropia often experience crossed diplopia. Intermittent exotropia is a fairly common condition. "Sensory exotropia" occurs in the presence of poor vision in one eye. Infantile exotropia is seen during the first year of life, and is less common than "essential exotropia" which usually becomes apparent several years later.
The Optometric Extension Program Foundation (OEPF) is an international, non-profit organization dedicated to the advancement of the discipline of optometry, with recent emphasis on behavioral optometry and vision therapy.
Suppression of an eye is a subconscious adaptation by a person's brain to eliminate the symptoms of disorders of binocular vision such as strabismus, convergence insufficiency and aniseikonia. The brain can eliminate double vision by ignoring all or part of the image of one of the eyes. The area of a person's visual field that is suppressed is called the suppression scotoma. Suppression can lead to amblyopia.
Stereoblindness is the inability to see in 3D using stereopsis, or stereo vision, resulting in an inability to perceive stereoscopic depth by combining and comparing images from the two eyes.
A vision disorder is an impairment of the sense of vision.
The Mind's Eye is a 2010 book by neurologist Oliver Sacks. The book contains case studies of people whose ability to navigate the world visually and communicate with others have been compromised, including the author's own experience with cancer of the eye and his lifelong inability to recognise faces.
Monocular deprivation is an experimental technique used by neuroscientists to study central nervous system plasticity. Generally, one of an animal's eyes is sutured shut during a period of high cortical plasticity. This manipulation serves as an animal model for amblyopia, a permanent deficit in visual sensation not due to abnormalities in the eye.
Stereopsis recovery, also recovery from stereoblindness, is the phenomenon of a stereoblind person gaining partial or full ability of stereo vision (stereopsis).
Frederick W. Brock (1899–1972), born in Switzerland, was an optometrist, a major contributor to vision therapy, and the inventor of various vision therapy devices including the Brock string. Brock's approach to treating eye disorders was crucial in paving the way to overcoming an erroneous but long-standing medical consensus that stereopsis could not be acquired in adulthood but only during a critical period early in life: neuroscientist Susan R. Barry, the first person to have received widespread media attention for having acquired stereo vision in adulthood, attributes him a central role in her recovery of stereopsis, a discovery which in turn influenced the prevalent scientific conceptions with regard to the neuroplasticity of the visual system.
Binocular neurons are neurons in the visual system that assist in the creation of stereopsis from binocular disparity. They have been found in the primary visual cortex where the initial stage of binocular convergence begins. Binocular neurons receive inputs from both the right and left eyes and integrate the signals together to create a perception of depth.