Working Memory Accuracy Micro-controlled through a Tablet Pen

Abstract

In this study, visual working memory was assessed using nonverbal “accuracy,” in contrast to typical memory research, which is usually based on “right/wrong” answers. We analyzed the relationship between dynamic control of pen-use and pointing accuracy using a tablet liquid crystal device (LCD). Healthy participants held a pen equipped with a triaxial accelerometer in each hand. Using the dominant hand, they targeted a point at the center of a “diamond” formed by the intersection of two 4×1 cm rectangles tilted 45° to the left and right, respectively. The rectangles were quasi-randomly displayed at various locations on the LCD with time lags. The working memory accuracy was defined as the standard deviation of the distance between the absolute and surmised centers. The evident result indicated that the pen-dynamics (4-100 Hz) of the dominant hand started to increase for action readiness then decayed for the last 3 s during a 4-s interval (waiting period). Furthermore, the ability to sustain power for 100-200 Hz correlated with decrease of pointing deviation (i.e., increased working memory accuracy). We also discuss the relationship between our results and other memory theories, including those derived from rodent studies.