Coordination process in counting

C ounting is an important activity because it gives rise to a whole range of arithmetic activities. Counting objects requires subjects to point at each object and to say the corresponding number‐word. Furthermore, to determine the correct cardinal of a set, the two activities of pointing and saying must be synchronized. This perfect correspondence between the two activities is achieved by a coordination process. Using Camos et al.'s (2001) paradigm, the present study tested the hypothesis that this coordination process will induce its own cognitive cost and that this cost would decrease with age. Eight‐year‐old children and adults were asked to say the numberline from 1 to 23, from 61 to 83, and from 111 to 133. They also pointed at objects in arrays that did or did not include distracters. Finally, they counted objects in arrays with or without distracters using the numberline starting at 1, then at 61, and then at 111. In children, as in adults, the simultaneous increase in the attentional demand of the pointing (due to the distracters) and the saying (for the numberline starting at 61 or 111) affected counting performance. However, it never made coordination more difficult. The coordination process in counting thus has a negligible cost. Moreover, an unexpected facilitation effect was observed. Indeed, when the attentional demand of saying was high, the simultaneous production of pointing increased the performance in saying the numberline. In other words, a verbal activity was facilitated by a concurrent motor activity. The negligible cost of coordination and the facilitation effect were both explained by an early compilation of counting as defined in ACT‐R (Anderson, 1983, 1993).