Abstract The lateral geniculate nucleus (LGN), located in the thalamus, serves as the brain’s primary relay for visual information from the retina to the cortex 1,2. It is organized into three main cellular subsystems: magnocellular (M), parvocellular (P), and koniocellular (K) layers, each processing different visual features 3. Magnocellular neurons (M cells) are large, fast-conducting cells specialized for detecting motion, luminance contrast, and low spatial frequency information— critical for tracking moving objects 4. Parvocellular neurons (P cells) are smaller, slower conducting, and tuned to fine detail, high spatial frequency, and red-green color discrimination— key for object recognition and reading 3. Koniocellular neurons (K cells) are small, diverse relay cells located between the M and P layers. They process multiple visual modalities, including short-wavelength (“blue”) color information, spatial and motion cues, and possibly brain-state modulating rhythms 5, 6. K cells have unique projections to both primary visual cortex (V1) and extrastriate visual areas, including MT/V5, making them a prime candidate for alternative visual processing routes 7.
Staes et al. (2026) studied this question.