An anti-Hebbian model for binocular visual plasticity and its attentional modulation.

Monocular deprivation during the critical period impairs the cortical structure and visual function of the deprived eye. Conversely, transient occlusion of one eye in adults enhances the predominance of that eye. This counter-intuitive effect of short-term monocular deprivation is a form of homeostatic plasticity. However, whether this sensory plasticity requires attention, and the underlying neural mechanisms remain unclear. Here, through a psychophysical experiment, we demonstrate that the deprivation effect is dramatically attenuated in the absence of attention. We develop a neural computational model incorporating the Hebbian learning rule in interocular inhibitory synapses (i.e., anti-Hebbian learning) to explain the deprivation effect. Our model predicts both the boosting of the deprived eye and its dependence on attention. Moreover, it accounts for other forms of binocular plasticity, including plasticity observed in prolonged binocular rivalry. We suggest that short-term binocular plasticity arises from the plasticity in inhibitory connections between the two monocular pathways.