Related Experiment Video
Updated: Mar 29, 2026

Central and Divided Visual Field Presentation of Emotional Images to Measure Hemispheric Differences in Motivated Attention
Published on: November 16, 2017
Modular Representation of Luminance Polarity in the Superficial Layers of Primary Visual Cortex
Gordon B Smith1, David E Whitney1, David Fitzpatrick1
1Department of Functional Architecture and Development of Cerebral Cortex, Max Planck Florida Institute for Neuroscience, Jupiter, FL 33458, USA.
Abstract:
The spatial arrangement of luminance increments (ON) and decrements (OFF) falling on the retina provides a wealth of information used by central visual pathways to construct coherent representations of visual scenes. But how the polarity of luminance change is represented in the activity of cortical circuits remains unclear. Using wide-field epifluorescence and two-photon imaging we demonstrate a robust modular representation of luminance polarity (ON or OFF) in the superficial layers of ferret primary visual cortex. Polarity-specific domains are found with both uniform changes in luminance and single light/dark edges, and include neurons selective for orientation and direction of motion. The integration of orientation and polarity preference is evident in the selectivity and discrimination capabilities of most layer 2/3 neurons. We conclude that polarity selectivity is an integral feature of layer 2/3 neurons, ensuring that the distinction between light and dark stimuli is available for further processing in downstream extrastriate areas.
Related Concept Videos
Vision
Photoreceptors and Visual Pathways
Anatomy of the Eyeball
Visual System
Once through the pupil, the light passes through the lens, a...
The Retina
Motor and Sensory Areas of the Cortex
Motor Areas
The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex....

