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Blangero A.,French Institute of Health and Medical Research | Blangero A.,Institute Federatif Des Neurosciences Of Lyon Ifnl | Khan A.Z.,French Institute of Health and Medical Research | Khan A.Z.,Institute Federatif Des Neurosciences Of Lyon Ifnl | And 13 more authors.
Cortex | Year: 2010

The pre-motor theory of attention suggests that the mechanisms involved in target selection for eye movements are the same as those for spatial attention shifts. The pre-saccadic facilitation of perceptual discrimination at the location of a saccadic goal (paradigm of Deubel and Schneider, 1996) has been considered as an argument for this theory. We compared letter discrimination performance in a saccade (overt attention - pre-saccadic facilitation) and a fixation (covert attention) task in a patient with right posterior parietal damage and 4 controls.In the overt attention condition, the patient was instructed by a central cue to make a saccade to a target located at a peripheral location. During the saccade latency (in a period of time of 250. msec following the presentation of the cue), a letter was presented at the target location. Accuracy of leftward saccades was impaired compared to rightward saccades. To evaluate letter discrimination performance in this saccade task (i.e., the presence of pre-saccadic facilitation), we selected only those leftward saccades that were equivalent in accuracy (and latency) to the rightward ones. Within these selected trials, the patient was able to discriminate letters equally well in both visual fields. In contrast, he performed at chance level during the fixation task (covert attention condition) for letters presented at the same peripheral location with the same timing with respect to the cue presentation. The patient could thus discriminate the letter presented at 8° of visual eccentricity while he was preparing a saccade, whereas he was unable to perceive the letter in the fixation task.Remarkably, in the left visual field, letter discrimination was impossible even when a letter was presented as close as 2.5° of visual eccentricity in the fixation task. Altogether, these results suggest that pre-saccadic perceptual facilitation does not rely on the same processes as those of covert attention, as tested by fixation task. Instead, we propose that pre-saccadic perceptual facilitation results from a form of attention specific to action, which could correspond to a pre-saccadic remapping process. © 2009 Elsevier Srl. Source

Haesebaert F.,University of Lyon | Haesebaert F.,Center Hospitalier le Vinatier | Haesebaert F.,Institute Federatif Des Neurosciences Of Lyon Ifnl | Brunelin J.,University of Lyon | And 5 more authors.
Annales Medico-Psychologiques | Year: 2010

For the last 15. years, repetitive transcranial magnetic stimulation (rTMS) was gradually used in 2 indications in resistant schizophrenic symptoms: Negative symptoms and auditory verbal hallucinations (HAV). Although efficiency of rTMS in the treatment of negative symptoms needs further investigations, the impact of rTMS on HAV is better known and is reported in several controlled studies. This article reviews these various works and proposes attitudes to help practitioners. © 2010. Source

Brunelin J.,University of Lyon | Brunelin J.,Institute Federatif Des Neurosciences Of Lyon Ifnl | Poulet E.,University of Lyon | Poulet E.,Institute Federatif Des Neurosciences Of Lyon Ifnl | And 9 more authors.
Annales Medico-Psychologiques | Year: 2010

Purpose: The author has endeavoured to present a qualitative review of current data on the interest of repetitive Transcranial Magnetic Stimulation (rTMS) in the treatment of negative symptoms of schizophrenia, its therapeutic impact and processes that underlie it. Method: The method consisted in a review of the literature by an extensive consultation of the computerized Medline database. Results: Despite the small number of controlled studies and the small sample sizes, rTMS appears to be an effective therapeutic method in the treatment of negative symptoms of schizophrenia and also helps understanding the patho-physiologic processes that underlie them (hypofrontality, dopamine hypothesis and responsiveness of the HPA axis). Conclusion: Before any conclusion may be reached about the effectiveness of this new technology more studies are required using larger parameters for active treatment and optimal placebos (alpha-TMS at least 110 % of the motor threshold, focused on the hypo-active area). © 2010 Elsevier Masson SAS. Source

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