The effects of training on tactile enumeration.

Subitizing is a fast and accurate process of enumerating small quantities. Whether subitizing carried out in the tactile modality is under debate. We previously found a moderately increasing RT slope from one to four stimuli and a large decrease in RT for five stimuli when using one hand. Yet, a high error rate was observed, making it difficult to determine if the RT pattern found was indeed subitizing. To increase accuracy, we carried out training of the tactile enumeration task using one hand for 6 days. We compared performance in the trained and additional non-trained tasks between two groups-the 6-day training group (6DT) and the non-trained controls (C)-after three periods (1 week, 1 and 6 months after the training of the 6DT group ended). Results showed an increase in accuracy rates for both groups but a decrease in RT for the 6DT group only for the trained task. This RT improvement was present even after 6 months. Importantly, the RT slope of one-hand enumeration did not change after training, showing a moderately increased slope up to four stimuli and a decrease for five stimuli. Our study shows the training long-term effect on tactile enumeration and emphasizes the embodiment of finger counting on enumeration. Two possible enumeration processes are discussed-accelerated counting and subitizing-both based on spatial cues and pattern recognition of familiarized finger-counting patterns.