BackgroundCerebral activation during planning of reaching movements occurs both in the superior parietal lobule (SPL) and premotor cortex (PM), and their activation seems to take place in parallel.MethodologyThe activation of the SPL and PM has been investigated using transcranial magnetic stimulation (TMS) during planning of reaching movements under visual guidance.Principal FindingsA facilitory effect was found when TMS was delivered on the parietal cortex at about half of the time from sight of the target to hand movement, independently of target location in space. Furthermore, at the same stimulation time, a similar facilitory effect was found in PM, which is probably related to movement preparation.ConclusionsThis data contributes to the understanding of cortical dynamics in the parieto-frontal network, and suggests that it is possible to interfere with the planning of reaching movements at different cortical points within a particular time window. Since similar effects may be produced at similar times on both the SPL and PM, parallel processing of visuomotor information is likely to take place in these regions.

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This study aimed to investigate the extent to which gesture performance depends on input modality and whether gestural development patterns differ in children with and without developmental coordination disorder (DCD). Therefore, development of limb gesture was studied in 140 children ‐105 control children (94 males, 11 females) and in 35 children with DCD (29 males, six females) divided into three age bands: 5 to 6 years, 7 to 8 years, and 9 to 10 years. Transitive gestural skills were investigated through four input modalities: Imitation, Visual plus Tactile, Visual, and Verbal. Results indicate that limb gestural skills in normally developing children follow a progressive maturation pattern: Imitation, Visual plus Tactile, and visual routes appear to mature before the verbal route and appear to be available earlier to enable the child to perform a correct gesture. The performance of children with DCD throughout the four modalities suggested a general maturational delay. When gestures were required through the Verbal modality, there was a specific deficit in using sensory‐motor information and in integrating it into a motor representation. In the Verbal modality, children with DCD performed consistently worse than their control peers and the difference in performance tended to increase rather than improve with age.

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In Experiment 1, four groups of 16 subjeets performed ordered recall of six-syllable lists in both suffix and nonsuffix conditions. Sequential presentation of the lists varied for eaeh group. In the auditory presentation, the syllables were delivered from one location only and were read aloud by the subjects. For the visual, spatially nondistributed presentation, the syllables appeared in one loeation only and were read silently. For visual, spatially distributed presentations, the syllables were spread out either vertically or horizontally and were read silently. Very robust receney and auffix effects were found in the auditory presentation, as well as in visual, spatially distributed presentations. In Experiment 2, 16 subjeets performed ordered reeall of visually presented lists with the items spread out vertieally and eonflicting spatial and temporal orders. A reliable receney effect was found for the final block oftrials. In Experiment 3,16 subjeets performed ordered recall in the same eonditions as in Experiment 2, exeept that they were instructed to reeall the temporal order in whieh the spatial positions would be filled in. A bow-shaped eurve and a strong reeency effeet were obtained.In the immediate ordered reeall of a list of items presented one at a time, recall of the last one or two items is better following auditory presentation than following visual presentation. This larger recency effect for auditory presentation than for visual presentation, known as the modality effect, is reduced or abolished when an extra item, a suffix, follows the end of the list (the suffix effect). Until relatively recently, these effects were believed to be well explained by Crowder and Morton's (1969) model of sensory memory (precategorical acoustic storage, or PAS). According to the PAS model, auditory information persists longer in an auditory sensory store than does visual information in a visual sensory store. The sensory, or eehoic, traee of a heard list would therefore provide an additional souree of information for recall of the last item(s). In contrast, the sensory, or iconic, trace of a seen list, being of much shorter duration, cannot provide extra information. When a suffix is added, it interferes with information about the last item(s) within the aeoustic storage and thereby subtraets the additional source of information.In recent years, results that are not consistent with the PAS model have been accumulating. Modality and suffix effects have been found in many conditions in which no auditory information is available. A modality effect is ob-