Our brains devote substantial resources to creating a singular, coherent view from the two images in our eyes. Both anatomical and functional studies have established that the underlying fusion of monocular signals into a combined binocular response starts within the first synapses downstream from our eyes. Long-standing consensus held that the two eyes' signals remain largely segregated until they are combined by neurons in the upper layers of the primary visual cortex. However, new experimental data challenge this classic model, suggesting that there are pronounced earlier interactions between the two eyes' streams of activation. In this article, we review the literature and detail how these findings can be functionally interpreted in context with previously established psychophysical models of binocular vision.
Keywords: LGN; V1; binocular combination; binocular fusion; binocular vision.