Abstract
The purpose of this study was to quantify the cognitive demands associated with tactile information processing while the cutaneous system was perturbed by concurrent task-irrelevant stimulation. In a between-participants experimental study, 24 healthy volunteers, naïve to Morse Code interpretation participated. 12 of whom received task-irrelevant stimulation while the other 12 were not perturbed during vibrotactile letter acquisition, followed by immediate and 24-hour delayed retention and transfer tests. During acquisition vibration patterns representing 8 Morse Code letters were individually and randomly delivered to the palmar surface of the distal aspect of the right 5th digit.. Participants responded with the letter they believed was communicated, and augmented accuracy feedback was displayed. Retention trial conditions were identical to acquisition with exception of the removal of augmented feedback. Transfer required participants to motorically reproduce the temporal components of Morse Code patterns via sequences of key presses/releases. Response accuracy and total response time (TRT) were recorded and analysed. The results indicated that while accuracy increased, and TRT decreased across acquisition trials, participants with a perturbed cutaneous system were significantly less accurate at letter identification than participants without perturbation. All participants demonstrated decay in the accuracy of information in the retention tests. Transfer to a novel task was actually facilitated by the presence of task-irrelevant nerve perturbation. The findings are discussed relative to current models of tactile attention and information processing.
