Horace Basil Barlow FRS (8 December 1921 – 5 July 2020) was a British vision scientist.

Early life

Barlow was the son of the civil servant Sir

Alan Barlow Sir James Alan Noel Barlow, 2nd Baronet (25 December 1881 – 28 February 1968) was a British civil servant and collector of Islamic and Chinese art. He was Principal Private Secretary to Ramsay MacDonald, 1933–1934, and later Under-secreta ...

and his wife Lady Nora (granddaughter of the naturalist Charles Darwin). Barlow was the great-grandson of

Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English Natural history#Before 1900, naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all speci ...

and thus part of the

Darwin — Wedgwood family Darwin may refer to: Common meanings * Charles Darwin (1809–1882), English naturalist and writer, best known as the originator of the theory of biological evolution by natural selection * Darwin, Northern Territory, a capital city in Australia, ...

. He was educated at

Winchester College Winchester College is an English Public school (United Kingdom), public school (a long-established fee-charging boarding school for pupils aged 13–18) with some provision for day school, day attendees, in Winchester, Hampshire, England. It wa ...

where he met and befriended

Freeman Dyson Freeman John Dyson (15 December 1923 – 28 February 2020) was a British-American theoretical physics, theoretical physicist and mathematician known for his works in quantum field theory, astrophysics, random matrix, random matrices, math ...

. Barlow read natural sciences at

Trinity College, Cambridge Trinity College is a Colleges of the University of Cambridge, constituent college of the University of Cambridge. Founded in 1546 by King Henry VIII, Trinity is one of the largest Cambridge colleges, with the largest financial endowment of any ...

and earned an M.D. at

Harvard University Harvard University is a Private university, private Ivy League research university in Cambridge, Massachusetts, United States. Founded in 1636 and named for its first benefactor, the History of the Puritans in North America, Puritan clergyma ...

in 1946.

Research

In 1953, Barlow discovered that the

frog A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...

brain has

neurons A neuron (American English), neurone (British English), or nerve cell, is an membrane potential#Cell excitability, excitable cell (biology), cell that fires electric signals called action potentials across a neural network (biology), neural net ...

which fire in response to specific visual stimuli. This was a precursor to the work of Hubel and Wiesel on

visual receptive fields The visual system is the physiological basis of visual perception (the ability to detect and process light). The system detects, transduces and interprets information concerning light within the visible range to construct an image and build ...

in the visual cortex. He conducted a long study of visual inhibition, the process whereby a neuron firing in response to one group of retinal cells can inhibit the firing of another neuron; this allows perception of relative contrast. In 1961, Barlow wrote a seminal article where he asked what the computational aims of the visual system are. He concluded that one of the main aims of visual processing is the reduction of redundancy, which has been extended to the

efficient coding hypothesis The efficient coding hypothesis was proposed by Horace Barlow in 1961 as a theoretical model of sensory neuroscience in the brain. Within the brain, neurons communicate with one another by sending electrical impulses referred to as action potential ...

. While the brightnesses of neighbouring points in images are usually very similar, the

retina The retina (; or retinas) is the innermost, photosensitivity, light-sensitive layer of tissue (biology), tissue of the eye of most vertebrates and some Mollusca, molluscs. The optics of the eye create a focus (optics), focused two-dimensional ...

reduces this redundancy. His work thus was central to the field of statistics of natural scenes that relates the statistics of images of real world scenes to the properties of the nervous system. Barlow also worked in the field of

factorial code {{Short description, Data representation for machine learning Most real world data sets consist of data vectors whose individual components are not statistically independent. In other words, knowing the value of an element will provide information a ...

s. The goal was to encode images with

statistically Statistics (from German: ', "description of a state, a country") is the discipline that concerns the collection, organization, analysis, interpretation, and presentation of data. In applying statistics to a scientific, industrial, or social ...

redundant components or pixels such that the code components are

statistically independent Independence is a fundamental notion in probability theory, as in statistics and the theory of stochastic processes. Two event (probability theory), events are independent, statistically independent, or stochastically independent if, informally s ...

. Such codes are hard to find but highly useful for purposes such as image classification.

Awards and distinctions

Barlow was a fellow of

Trinity College Trinity College may refer to: Australia * Trinity Anglican College, an Anglican coeducational primary and secondary school in , New South Wales * Trinity Catholic College, Auburn, a coeducational school in the inner-western suburbs of Sydney, New ...

University of Cambridge The University of Cambridge is a Public university, public collegiate university, collegiate research university in Cambridge, England. Founded in 1209, the University of Cambridge is the List of oldest universities in continuous operation, wo ...

. He was elected a

Fellow of the Royal Society Fellowship of the Royal Society (FRS, ForMemRS and HonFRS) is an award granted by the Fellows of the Royal Society of London to individuals who have made a "substantial contribution to the improvement of natural science, natural knowledge, incl ...

in 1969 and was awarded their

Royal Medal The Royal Medal, also known as The Queen's Medal and The King's Medal (depending on the gender of the monarch at the time of the award), is a silver-gilt medal, of which three are awarded each year by the Royal Society. Two are given for "the mo ...

in 1993. He received the 1993 Australia Prize (along with

Peter Bishop Peter Bishop is a fictional character of the Fox television series ''Fringe''. He is portrayed by Joshua Jackson. Fictional character biography Peter Bishop was born on September 18, 1978, in the alternate universe, to parents Walter Bishop, al ...

and

Vernon Mountcastle Vernon Benjamin Mountcastle (July 15, 1918 – January 11, 2015) was an American neurophysiologist and Professor Emeritus of Neuroscience at Johns Hopkins University. He discovered and characterized the columnar organization of the cerebral co ...

) for his research into the mechanisms of visual perception, and the 2009 Swartz Prize for Theoretical and Computational Neuroscience from the

Society for Neuroscience The Society for Neuroscience (SfN) is a professional society, headquartered in Washington, D.C., for basic scientists and physicians around the world whose research is focused on the study of the brain and nervous system. It is especially well k ...

. He was awarded the first Ken Nakayama Prize from the Vision Sciences Society in 2016.

Personal life

Barlow was married twice and fathered seven children. In 1954, he married Ruthala Salaman, daughter of M.H. Salaman. They had four daughters: Rebecca, Natasha, Naomi and Emily. They were divorced in 1970. In 1980, he married Miranda, daughter of John Weston-Smith. They had one son, Oscar, and two daughters, Ida and Pepita. Barlow died on 5 July 2020, at the age of 98.

Selected publications

*H. B. Barlow. Possible principles underlying the transformation of sensory messages. Sensory Communication, pp. 217–234, 1961 *H. B. Barlow. Single units and sensation: A neuron doctrine for perceptual psychology? Perception 1(4) 371 – 394, 1972 *H. B. Barlow, T. P. Kaushal, and G. J. Mitchison. Finding minimum entropy codes. Neural Computation, 1:412-423, 1989.

References

External links

''Horace Barlow (1921–2020).''
Current Biology, Vol. 30, 16, p. PR907-R910, August 17, 2020.
List and full text of Horace Barlow publications
* Australia Prizebr>Biography of Barlow

Horace Barlow in Neurotree

Interviewed by Alan Macfarlane 5 March 2012 (video)
{{DEFAULTSORT:Barlow, Horace Basil 1921 births 2020 deaths Australian neuroscientists Australian people of English descent Australia Prize recipients Darwin–Wedgwood family Fellows of the Royal Society Fellows of Trinity College, Cambridge Harvard Medical School alumni Royal Medal winners Vision scientists People educated at Winchester College Younger sons of baronets 20th-century British medical doctors British expatriates in the United States