The span paradigm is commonly used to assess working memory (WM), predominantly through the visual and auditory routes and less often through the tactile modality. The current study aimed to validate the "Tactual Span", a new task developed to evaluate WM in the tactile modality. Participants were 140 healthy young adults, who performed the Tactual Span alongside span tasks in three additional modalities (auditory, visual, and visuospatial), as well as a selective attention task and a semantic verbal fluency task. The Tactual Span and other span tasks were found to correlate, while correlations with the selective attention and semantic fluency tasks were largely nonsignificant, indicating good construct validity. Cronbach's alpha for both stages as well as skewness and kurtosis were also adequate. An exploratory factor analysis for the forward stage showed that the Tactual Span and Visuospatial Span were loaded on one factor, whereas the Auditory and Visual Spans were loaded on another factor. In the backward stage, all span tasks were loaded on a single factor. The findings provide an initial indication that the Tactual Span task is a feasible and valid tool for assessing WM in the tactile modality.
Keywords: neuropsychological assessment; span task; tactile modality; validation; working memory.