On the basis of such specificity, it has been suggested that VPL occurs in V1, which was once thought to become hard-wired early in the human development process (i.e., so rigid that very little change occurred after an early critical period in life). It has been shown that this high specificity of a feature in VPL is in accord with neurophysiological findings that neurons in V1 tend to possess smaller receptive fields than those in higher areas