Coordinating Actions

The motor system composes complex actions by combining simpler submovements. This presumably involves sharing information about the progress of one submovement with the centres controlling another submovement, to ensure that the second happens in an appropriate relation to the first. This process is called coordination. In this paper Idiscuss evidence that coordinating actions indeed involves an active process of sharing information about the current state of movements. Coordination appears to be qualitatively different from the process of reacting to external stimuli. This may reflect the importance of predictive representations in coordination. Finally, the processes underlying coordination appear to be organized in a response-specific fashion, as a number of relatively independent circuits. The development and tuning of these circuits may, in part, be what makes an action "skilled".     

Examining children's ability to delay reward: Is the delay discounting task a suitable measure?

Discounting the value of delayed rewards has primarily been measured in children with the delay of gratification task and in adolescents and adults with the delay discounting task. In the present study, we assessed the suitability of the delay discounting task as a measure of temporal discounting in children. A sample of 7- to 9-year-olds (N = 98) completed a delay discounting task, a delay of gratification task, a sensation seeking measure, and IQ measures. In addition, teacher-based assessments of attention-deficit/hyperactivity disorder traits were measured. The results indicated that the majority of children produced meaningful data on the discounting task and discounted rewards hyperbolically. Children with an elevated risk of attention-deficit/hyperactivity disorder showed a trend towards discounting future rewards on the delay discounting task more steeply than did those at low risk. However, delay discounting was unrelated to either delay of gratification or sensation seeking. We interpret these results as providing some support for the use of delay discounting as a measure of intertemporal choice in children, although the results also suggest that delay discounting and delay of gratification tasks may tap different processes in this population.