Processing data in congenital blindness: behavior and anatomy

The visual system takes more space in the human brain than any other sensation. A visually deprived brain seems to undergo changes in the cortical areas originally taking part in vision and visualisation. Studies have shown that the blind outperform sighted in many sensory modalities. This has been attributed to crossmodal plasticity due to recruitment of the visual cortex early in life. The aim of this study is to explore how congenitally blind perform in a haptic discrimination task and a following short-term tactile memory task when compared to sighted controls. The experiment consisted of both groups touching different textures of surfaces and rate their qualitative characteristics in a quantitative rating scale. Ten minutes following haptic discrimination, the participants performed a tactile short-term memory test. Surprisingly, our results do not show any significant difference between the scores of the congenitally blind and the sighted controls in the short-term tactile memory task (Sig. = 0.217) and their haptic discrimination scores were not significantly different in any of the five qualitative factors. These findings indicate that congenital blindness does not induce a different haptic discrimination or better short-term tactile memory. Another study was carried out in brain sections of WT and Cone-Rod Homeobox - / - mice in order to compare S1 (primary somatosensory cortex) and V1 (primary visual cortex) areas using the histological Nissl technique. There were differences in the thickness of the layers and nuclei in S1, but in V1 there was a homogeneity in both areas of the two groups