Is semantic memory shaped by visual experience?

Humans are unique and different from other species; in that they can adjust their behaviour to different types of experiences. A crucial example comes from research on sensory deprivation. In this review we will learn more about how the lack of vision might impact the semantic memory system and how the blinded neural networks deputed to semantic knowledge compensates for the lack of visual input. We will discuss this issue by starting to ask ourselves to what extent is vision really necessary for the human brain to develop and function. We will answer this question by investigating the sensorimotor and linguistic contribution to semantic representations in visually deprived individuals. Empirical philosophers such as Locke claimed that the blind could never grasp the meaning of concepts reflecting visual experience, emphasising the role of first-person sensory experience in learning the meaning of words. Yet, according to recent research, blind individuals could acquire the knowledge of visual verbs similar to sighted, even though they have never experienced seeing them. In fact, when deriving inferences from visual verbs, both blind and sighted individuals activate the same brain areas. Despite the superior abilities in language processes, blind can conceptualise visual verbs to a limited extent compared to sighted, which proves that language is an important but not enough source for semantic representation. In addition to this, blind individuals tend to acquire comparable and even superior numerical abilities of sighted individuals. The left anterior temporal lobe ATL is an important region for storage and retrieval of semantic and conceptual information early visual deprivation can partially alter the neuronal grounds of conceptual retrieval , showing that the posterior occipital regions , that is responsible for fine-grain visual details of objects activated only in sighted. What we can infer from this review is that the brain plasticity rearranges the semantic system of blind and allows a semantic computation to breakthrough in to the visual cortex.