Camille-Aimé Possamaï

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The present study was aimed at deciphering whether the delay in choice reaction time (RT) and the silent period (SP) caused by transcranial magnetic stimulation (TMS) of the motor cortex in the ongoing electromyogram are due to the same physiological mechanism. To this end, the effect of TMS was studied in 6 healthy volunteers performing a between-hand(More)
Manual responses to lateralized stimuli are faster for spatially congruent stimulus-response associations than for incongruent associations, even if the stimulus location is irrelevant. This effect, however, decreases as reaction time increases. Recent data suggest that such a decrease reflects online, within-trial executive control. The present study was(More)
Rationale. Dopamine is involved in a variety of motor and non-motor information-processing operations. One way to determine its contribution to human information processing is to study reaction time (RT) performance after oral absorption of its precursor, levodopa, which increases its concentration in the nervous system. Objective. The purpose of the(More)
Abstract Rationale. Recently, we have shown that oral absorption of levodopa shortens reaction time (RT), measured as the interval between the response signal and the onset of voluntary electromyographic (EMG) activity. The motor time (MT) interval that elapses from the EMG activity to the mechanical response was not analysed. Objective. The purpose of the(More)
In between-hand choice reaction time tasks, the motor cortex involved in the required response is activated while the motor cortex involved in the non-required response is inhibited. Such an inhibition could be implemented actively between the responses defined as possible alternatives by the task instructions or, alternatively, could passively result from(More)
In a common version of the Simon task, the subjects respond by a left- or a right-hand key press to the color of a stimulus (S) presented to the left or right of a fixation point. Albeit S location is irrelevant, the incorrect response is more often activated when the required response is contralateral to the S (incongruent) than when it is ipsilateral to(More)
We present evidence that advance information reducing the number of stimulus-response alternatives in a choice reaction time (RT) task can shorten the very latest motoric stages of RT. Effects of such advance information on late stages of RT have been demonstrated recently by Osman, Moore, and Ulrich (Acta Psychol. 90 (1995) 111), Leuthold, Sommer, and(More)
Abstract Rationale. Nitrous oxide (N2O) inhalation, at subanaesthetic concentrations, impairs choice reaction time (RT). However, the functional locus of this effect remains to be ascertained. In the present study, this issue was investigated by applying the additive factor logic to the RTs of rats performing a visuo-motor task. Method. The task consisted(More)
In the field of sensorimotor activities, progresses achieved over the last fifty years have been largely driven by the Reaction Time (RT) paradigm. Information processing models are set in the context of a global breakdown of sensorimotor activities in multiple concatenated stages, each aggregated in many fundamental operations that are functionally linked.(More)
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