Neuropsychological assessment tools for individuals with blindness are relatively scarce. In the current study, we assessed the validity of the Tactual Span, a task aimed at evaluating tactile working memory. During the task, the fingers of both hands are touched in specific sequences of ascending difficulty, which participants are asked to repeat in exact and reverse order. Twelve participants with congenital blindness and 13 with acquired blindness were examined alongside 18 sighted controls, matched to the experimental group with respect to age and education. Participants performed the Tactual Span and three additional tasks assessing working memory in the auditory modality, as well as a Semantic Fluency test. Results showed that the Tactual Span was significantly correlated with most of the other working memory measures, in all groups, but not with the Semantic Fluency test. In addition, the congenital and acquired blindness groups performed similarly to one another and better than sighted controls on most working memory tasks, but not on the Semantic Fluency test. Findings suggest that the Tactual Span is a feasible task for measuring tactile working memory in individuals with congenital and acquired blindness. Therefore, it can expand the cognitive assessment toolbox of professionals working with blind individuals and increase the strength of conclusions drawn from cognitive assessments in educational and vocational settings.
Neuronal Correlates of Tactile Working Memory in Prefrontal and Vibrissal Somatosensory Cortex
