The life of the cortical column: opening the domain of functional architecture of the cortex

The concept of the cortical column refers to vertical cell bands with similar response properties, which were initially observed by Vernon Mountcastle’s mapping of single cell recordings in the cat somatic cortex. It has subsequently guided over 50 years of neuroscientific research, in which fundamental questions about the modularity of the cortex and basic principles of sensory information processing were empirically investigated. Nevertheless, the status of the column remains controversial today, as skeptical commentators proclaim that the vertical cell bands are a functionally insignificant by-product of ontogenetic development. This paper inquires how the column came to be viewed as an elementary unit of the cortex from Mountcastle’s discovery in 1955 until David Hubel and Torsten Wiesel’s reception of the Nobel Prize in 1981. I first argue that Mountcastle’s vertical electrode recordings served as criteria for applying the column concept to electrophysiological data. In contrast to previous authors, I claim that this move from electrophysiological data to the phenomenon of columnar responses was concept-laden, but not theory-laden. In the second part of the paper, I argue that Mountcastle’s criteria provided Hubel Wiesel with a conceptual outlook, i.e. it allowed them to anticipate columnar patterns in the cat and macaque visual cortex. I argue that in the late 1970s, this outlook only briefly took a form that one could call a ‘theory’ of the cerebral cortex, before new experimental techniques started to diversify column research. I end by showing how this account of early column research fits into a larger project that follows the conceptual development of the column into the present

Color coding in the cortex: a modified approach to bottom-up visual attention

Itti and Koch’s (Vision Research 40:1489–1506,2000) saliency-based visual attention model is a broadlyaccepted model that describes how attention processes aredeployed in the visual cortex in a pure bottom-up strategy.This work complements their model by modifying the colorfeature calculation. Evidence suggests that S-cone responsesare elicited in the same spatial distribution and have the samesign as responses to M-cone stimuli; these cells are tenta-tively referred to as red-cyan. For other cells, the S-coneinput seems to be aligned with the L-cone input; these cellsmight be green-magenta cells. To model red-cyan and green-magenta double-opponent cells, we implement a center-sur-round difference approach of the aforementioned model. Theresulting color maps elicited enhanced responses to colorsalient stimuli when compared to the classic ones at highstatistical significance levels. We also show that the modi-fied model improves the prediction of locations attended byhuman viewer