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Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
 
 
 
 
 

Attention shifts and anticipatory mechanisms in hyperactive children: an ERP study using the Posner paradigm.

BACKGROUND: The aim of this study was to assess attentional, decisional, and motor processing stages during the performance of an attention shifting paradigm, both in normal children and children with attention-deficit/hyperactivity disorder (ADHD). METHODS: We recorded event-related potentials (ERPs) and performance measures during a variant of the Posner paradigm in 13 control subjects and 24 ADHD children. Subjects responded with a spatially concordant motor response to left or right visual targets, which could be either preceded by a spatial cue ("valid" = same side; "invalid" = opposite side) or presented uncued. RESULTS: Patients made significantly more errors than control subjects, with predominance of the anticipatory type. As compared to control subjects, ADHD children had faster reaction times, as well as a shortened interval between the N2 and P3 ERPs and the motor response. Patients also showed a decreased attentional priming effect on early sensory responses (P1). Finally, the slow negativity (contingent negative variation/readiness potential) that preceded the target in the "no cue" condition was absent in ADHD patients. CONCLUSIONS: The combined analysis of electrophysiological and behavioral data suggest a characteristic mode of response of ADHD in attention shifting tasks, characterized by "motor impulsivity" with release of motor responses before stimulus processing is adequately completed, as well as a lack of strategic planning/anticipatory mechanisms in the absence of warning stimulus. These deficits may be partly attributed to dysmaturation of executive frontal functions. In addition, a minor deficit in early attentional priming was also observed in ERPs, with no apparent behavioral counterparts.[1]

References

  1. Attention shifts and anticipatory mechanisms in hyperactive children: an ERP study using the Posner paradigm. Perchet, C., Revol, O., Fourneret, P., Mauguière, F., Garcia-Larrea, L. Biol. Psychiatry (2001) [Pubmed]
 
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