Interresponse Interval Variability Research Articles

The effect of perceptual-motor continuity compatibility on the temporal control of continuous and discontinuous self-paced rhythmic movements.

One of the questions yet to be fully understood is to what extent the properties of the sensory and the movement information interact to facilitate sensorimotor integration. In this study, we examined the relative contribution of the continuity compatibility between motor goals and their sensory outcomes in timing variability. The variability of inter-response intervals was measured in a synchronization-continuation paradigm. Participants performed two repetitive movement tasks whereby they drew circles either using continuous or discontinuous self-paced movements while receiving discrete or continuous auditory feedback. The results demonstrated that the effect of perceptual-motor continuity compatibility may be limited in self-paced auditory-motor synchronization as timing variability was not significantly influenced by the continuity of the feedback or the continuity compatibility between feedback and the movement produced. In addition, results suggested that the presence of salient perceptual events marking the completion of the time intervals elicited a common timing process in both continuous and discontinuous circle drawing, regardless of the continuity of the auditory feedback. These findings open a new line of investigation into the role of the discriminability and reliability of the event-based information in determining the nature of the timing mechanisms engaged in continuous and discontinuous self-paced rhythmic movements.

Diminished Motor Timing Control in Children Referred for Diagnosis of Learning Problems

Disabled readers exhibit motor timing control (MTC) deficits in bimanual coordination relative to average readers. This article evaluates to what extent poor MTC is specific to reading or if it is related to learning problems in general. Children (7 to 11 years of age) referred for learning impairment (LI; n = 100) and same-age children nonlearning impaired (NLI; n = 243) performed a paced finger-tapping task. Greater variability of interresponse intervals was associated with poorer reading, spelling, and arithmetic achievement. The LI group performed more poorly than the NLI group, a difference that persisted even after adjusting for reading skill. Poor MTC is associated with poor reading but may also be a characteristic of children referred for learning problems, possibly signaling increased vulnerability of underlying neural integrative processes relevant to the child's adaptation to academic demands, including reading.

The development of interlimb coordination during bimanual finger tapping

Normal subjects aged 7-25 years were asked to tap the index fingers of both hands: a) in four different patterns of interlimb coordination; b) at two different response frequencies; and c) both before and after the entraining metronome was turned off. The outcome variables of primary interest were the within-subject variability of interresponse intervals (IRI) as an index of timing precision; and deviations from prescribed response frequency, as an index of temporal tracking accuracy. Stability of timing precision and accuracy of temporal tracking increased significantly from 7 to 9 and from 9 to 11 years, with only minor advances thereafter. There were significant right-left performance asymmetries in all bimanual tasks; variability of IRI and deviations from prescribed rate were greater at the faster of the two response frequencies tested; and stability of IRI and accuracy of temporal tracking were greater with than without the metronome. Stability of IRI and accuracy of temporal tracking were strongly correlated in some bimanual tasks. The findings are discussed in terms of the two major theoretical perspectives on human brain-behavior relationships that have specifically addressed the issue of bimanual coordination.