Horace Barlow was a British neuroscientist who specialized in research on vision.

He wrote two seminal articles on the neuroscience of vision.

The first was just a couple of years before the pioneering work on the frog's eye by David Hubel, Torsten Wiesel, Jerome Lettvin, Warren McCulloch, Walter Pitts, and Humberto Maturana, Barlow identified neurons in the frog's brain that fire in response to particular visual stimuli.

A Vision of the Brain, pp.118-119

Barlow's second seminal article was Single Units and Sensation: A Neuron Doctrine for Perceptual Psychology? in 1972. In it, Barlow began with five dogmas

1. To understand nervous function one needs to look at interactions at a cellular level, rather than either a more macroscopic or microscopic level, because behaviour depends upon the organized pattern of these intercellular interactions.

2. The sensory system is organized to achieve as complete a representation of the sensory stimulus as possible with the minimum number of active neurons.

3. Trigger features of sensory neurons are matched to redundant patterns of stimulation by experience as well as by developmental processes.

4. Perception corresponds to the activity of a small selection from the very numerous high-level neurons, each of which corresponds to a pattern of external events of the order of complexity of the events symbolized by a word.

5. High impulse frequency in such neurons corresponds to high certainty that the trigger feature is present.

The development of the concepts leading up to these speculative dogmas, their experimental basis, and some of their limitations are discussed.

Single Units and Sensation, p.371

In David Marr's "Epilogue" to his Vision book, Marr wrote an imagined conversation between himself, his colleague Tomaso Poggio, and Francis Crick. He began with the work of Horace Barlow.

CONVERSATION

Can we begin with the levels-of-explanation idea, since you attribute so much importance to it? How is it related to ideas about feature detectors and in particular to Horace Barlow’s first dogma (1972, p. 380), which states, “A description of the activity of a single nerve cell which is transmitted to and influences other nerve cells, and of a nerve cell’s response to such influences from other cells, is a complete enough description for functional understanding of the nervous system ”?

Here, of course, I must disagree with Barlow’s formulation, although I do agree with one of the thoughts behind this dogma, namely, that there is nothing else looking at what the cells are doing — they are the ultimate correlates of perception. However, the dogma fails to take level one analysis—the level of the computational theory—into account.

Vision, p.336

We must review Barlow carefully.

5 Current concept of the single neuron
The cumulative effect of all the changes I have tried to outline above has been to make us realise that each single neuron can perform a much more complex and subtle task than had previously been thought. Neurons do not loosely and unreliably map the luminous intensities of the visual image onto our sensorium, but instead they detect pattern elements, discriminate the depth of objects, ignore irrelevant causes of variation, and are arranged in an intriguing hierarchy. Furthermore, there is evidence that they give prominence to what is informationally important, can respond with great reliability, and can have their pattern selectivity permanently modified by early visual experience.

This amounts to a revolution in our outlook. It is now quite inappropriate to regard unit activity as a noisy indication of more basic and reliable processes involved in mental operations; instead, we must regard single neurons as the prime movers of these mechanisms. Thinking is brought about by neurons, and we should not use phrases like 'unit activity reflects, reveals, or monitors thought processes', because the activities of neurons, quite simply, are thought processes. This revolution stemmed from physiological work and makes us realize that the activity of each single neuron may play a significant role in perception. I think that more clearly stated hypotheses are now needed about these roles in order to allow our psychological knowledge and intuitions about our perceptions to help us plan future experiments...

5 6.1 First dogma A description of that activity of a single nerve cell which is transmitted to and influences other nerve cells, and of a nerve cell's response to such influences from other cells, is a complete enough description for functional understanding of the nervous system. There is nothing else 'looking at' or controlling this activity, which must therefore provide a basis for understanding how the brain controls behaviour.

Normal | Teacher | Scholar