Original research
Effects of Methylphenidate on performance of a practical pistol shooting task: a quantitative electroencephalography (qEEG) study
-
* Corresponding authors: Sergio Machado secm80@yahoo.com.br - Oscar Arias-Carrión arias@exp-neuro.de
1 Panic and Respiration Laboratory, Institute of Psychiatry, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
2 Faculty of Psychology, Brazilian Institute of Medicine and Rehabilitation (IBMR), Rio de Janeiro, Brazil
3 National Institute for Translational Medicine (INCT-TM); Rio de Janeiro, Brazil
4 Brain Mapping and Sensory Motor Integration, Institute of Psychiatry of Federal University of Rio de Janeiro (IPUB/UFRJ), Brazil
5 Institute of Applied Neuroscience (INA), Rio de Janeiro, Brazil
6 Department of Neurology, Philipps University-Marburg, Baldingerstrasse D-35033 Marburg, Germany
7 Division of Epidemiology and Biostatistic, Institute of Health Community, Federal Fluminense University (UFF), Rio de Janeiro, Brazil
8 Escola de Aperfeiçoamento de Oficiais (EsAO - Ministério do Exército), Brazil
9 School of Physical Education, Laboratory of Motor Behavior, Federal University of Vale do São Francisco (UNIVASF) - Pernambuco, Brazil
10 Division of Neurosurgery of the University of São Paulo Medical School, Brazil
11 Laboratory of Psychophysiology, UMESP, Brazil
12 Department of Movement and Training Science, Institute of Sport Science, Humboldt University Berlin, Germany
13 U.S. Army Research Laboratory, Aberdeen Proving Ground, MD, USA
14 Unit of Neurology, Hospital Alvarez-Buylla, Mieres, Spain
15 Department of Pharmacology and Anesthesiology, University of Padova, Italy
16 Department of Neurology & Epilepsy Center Hessen, Philipps University-Marburg, Baldingerstrasse D-35033 Marburg, Germany
17 School of Physical Education, Bioscience Department (EEFD/UFRJ), Brazil
International Archives of Medicine 2011, 4:6 doi:10.1186/1755-7682-4-6
Published: 4 February 2011Abstract
Background
The present study examined absolute alpha power using quantitative electroencephalogram (qEEG) in bilateral temporal and parietal cortices in novice soldiers under the influence of methylphenidate (MPH) during the preparatory aiming period in a practical pistol-shooting task. We anticipated higher bi-hemispheric cortical activation in the preparatory period relative to pre-shot baseline in the methylphenidate group when compared with the control group because methylphenidate has been shown to enhance task-related cognitive functions.
Methods
Twenty healthy, novice soldiers were equally distributed in control (CG; n = 10) and MPH groups 10 mg (MG; n = 10) using a randomized, double blind design. Subjects performed a pistol-shooting task while electroencephalographic activity was acquired.
Results
We found main effects for group and practice blocks on behavioral measures, and interactions between group and phases on electroencephalographic measures for the electrodes T3, T4, P3 and P4. Regarding the behavioral measures, the MPH group demonstrated significantly poorer in shooting performance when compared with the control and, in addition, significant increases in the scores over practice blocks were found on both groups. In addition, regarding the electroencephalographic data, we observed a significant increase in alpha power over practice blocks, but alpha power was significantly lower for the MPH group when compared with the placebo group. Moreover, we observed a significant decrease in alpha power in electrodes T4 and P4 during PTM.
Conclusion
Although we found no correlation between behavioral and EEG data, our findings show that MPH did not prevent the learning of the task in healthy subjects. However, during the practice blocks (PBs) it also did not favor the performance when compared with control group performance. It seems that the CNS effects of MPH demanded an initial readjustment period of integrated operations relative to the sensorimotor system. In other words, MPH seems to provoke a period of initial instability due to a possible modulation in neural activity, which can be explained by lower levels of alpha power (i.e., higher cortical activity). However, after the end of the PB1 a new stabilization was established in neural circuits, due to repetition of the task, resulting higher cortical activity during the task. In conclusion, MPH group performance was not initially superior to that of the control group, but eventually exceeded it, albeit without achieving statistical significance.