Sensory processing refers to the ability to register and modulate sensory information in order to enable and learn adaptive responses to the environment and facilitate engagement in daily activities, and it depends on the maturation of the nervous system. Previous studies have indicated failures in sensory processing in neurodevelopmental disorders, however, the characteristics and extent of such problems are not clear with respect to other learning difficulties due to inconsistent literature, lack of systematic approaches, and a strong emphasis on phonological processing alone. Four studies were designed to compare sensory processing profile of participants with and without learning difficulties, using Dunn’s framework (1997) of four quadrants: Registration, Seeking, Avoiding and Sensitivity. Study 1 investigated the relationship between multisensory processing and literacy skills in children. Study 2 investigated sensory profile and learning difficulties in adolescents. Study 3 investigated sensory profile and its association with reading difficulties in adults. Study 4 focused on children and comorbidity as a variable that may influence the sensory profile. Results identified clear differences in the sensory profile between groups with and without learning difficulties. Accordingly, children with learning difficulties would present a profile of high frequency of sensory-related behaviours which is widespread across the sensory dimensions, while adults would have high frequency of such behaviours in only one quadrant of the sensory profile. Regression analyses showed that Registration (a profile of high neurological threshold and passive regulation) predicts the likelihood of presenting learning difficulties at all ages. Furthermore, low scores in Seeking (lack of active behaviours) were associated with learning difficulties in children. The findings suggest an atypical frequency of sensory-related behaviours associated with a range of learning difficulties. Future research should assess the sensory abilities across the ages, including performance in cross-modal tasks, and the use of neuroimaging techniques to obtain more insights of brain functioning
