Working memory development in different modalities in children and young adults.

Research on working memory (WM) development is concentrated largely on the verbal and visuospatial domains, whereas the tactile modality has received much less attention. The current study aimed to compare the development of storage and manipulation in the tactile sense with other modalities in children and young adults. A total of 96 typically developed individuals were divided into three equally numbered age groups in the ranges of 7 and 8, 11 and 12, and 20 to 29 years. They were asked to perform a battery of span tasks, including forward and backward stages, in the verbal, visual, visuospatial, and tactile modalities. Results showed improvement of WM performance across age in all modalities. In addition, in the forward stage, the Tactual Span was shorter than all other tasks and the Visuospatial Span was shorter than the Visual-Digit Span. In the backward stage, the Digit Span and Tactual Span had lower scores than the Visuospatial Span. Finally, interaction effects for the forward and backward stages were also significant, mainly indicating greater improvement in both storage and manipulation of the tactile sense compared with the other senses. It can be concluded that the tactile modality shows a course of WM development similar to the other modalities, in all of which the storage and manipulation components are affected differently. In addition, tactile WM improves more during growth than other modalities. Therefore, professionals in the field of education and neuropsychology are encouraged to use tactile tasks to assess and treat WM, particularly in response to the increased use of digital technology during recent years.