By: Georgina Ferry | Horace Barlow obituary | Neuroscience | The Guardian
The lightning flick of the tongue that secures a frog its next meal depends on a rapid response to a small black object moving through its field of view. During the 1950s the British neuroscientist Horace Barlow established that neurons in the frog’s retina were tuned to produce just such a response, not only detecting but also predicting the future position of a passing fly. This discovery raised the curtain on decades of research by Barlow and others, establishing that individual neurons of the billions that make up the visual system contribute to the efficient processing of movement, colour, position and orientation of objects in the visual world.
Barlow, who has died aged 98, combined three approaches to the question of how the brain enables us to see. He looked at how people perceive, for example measuring the smallest and faintest spot of light they could reliably detect; he studied the responses of single neurons in the retina and brain to different visual stimuli; and he developed theories to account for the relationship between what neurons are doing and the corresponding visual experience.