The remapping of cortical topography following retinal lesions opens the possibility that experience can affect the functional properties of neurons in early sensory areas and that it can do so throughout life. Thus one must make the distinction between properties and connections that Histone Methyltransferase inhibitor are mutable only during the critical period early in postnatal life (such as ocular dominance and thalamocortical connections) and other aspects of cortical function and other cortical circuits that can undergo change into adulthood (such as cortical topography and horizontal connections). The nature of the experience dependent changes suggests that

preexisting circuits that are used for the normal integrative properties of visual cortex can become

modified to promote adaptive functional changes for recovery after CNS lesions. Strengthening the association field, which is used for contour integration in normal visual processing, enables perceptual fill-in across retinal lesions. The findings on plasticity of primary visual cortex following retinal lesions raise the possibility that normal visual experience can induce plastic changes there as well, perhaps by recruiting the same cortical circuits. The phenomenon of topographic remapping following retinal lesions has provided a tractable model for the study of the circuitry underlying cortical plasticity, including both excitatory much horizontal connections and inhibitory connections,

and has revealed the rapidity with which changes in these connections GSK1210151A in vitro can be induced. These results provide motivation for determining whether similar mechanisms are involved in normal visual experience. We now turn to consider a prominent feature of experience dependent change in the visual system, perceptual learning. Here, we propose that the same mechanisms involved in recovery after CNS lesions are involved in the functional and structure changes associated with learning. Performance on various visual discrimination or detection tasks can be substantially improved with repetitive practice, as is seen in a decrease of threshold for discrimination of the trained stimulus attributes such as orientation, or an increase in efficiency for detection of familiar shapes embedded in distracters (for review see Sagi, 2011). Helmholtz described perceptual learning as “the judgment of the senses may be modified by experience and by training derived under various circumstances, and may be adapted to the new conditions. Thus, persons may learn in some measure to utilize details of the sensation which otherwise would escape notice and not contribute to obtaining any idea of the object” (Helmholtz, 1866).