assessment of the effect of short-term exposure with vibration in different acceleration and frequencies of 3-7hz on cognitive abilities attention

background: deficiency of attention and concentration is one of great reasons of traffic incidents and it covers between 20 to 50 percent of events due to careless and mindedness. studies show that attention and concentration are considered as one of important cognitive components in safe driving. vibration is an important physical effect in all vehicles. till now has not been any organized study to inspect influence vibration on cognitive function especially on attention and concentration. this study has been carried out with the aim of investigating to vibration effects on attention and concentration of using neuropsychological tests. methods: in this research 25 male students did the on 4 phases: low vibration (0.53m/s 2 ), medium vibration (0.81m/s 2 ), high vibration (1.12m/s 2 ) and non-contact with vibration (control status) according to iso2631-1 and with fixed frequency between 3 to 7hz, and the selective attention & of divided attention tests are conducted to sit on the vibration simulator. statistical analysis was performed using software spss ver. 19. finding: the results showed that vibration effect on the reaction time selective attention of the subjects was not significant. vibration significantly reduce the number of correct answers selective attention and reaction time divided attention.   conclusion: in this study it was found that the vibration disrupts the ability to sustain attention to the subjects. it also increases the accuracy and speed of information processing systems on studied persons. it appears that the long-term vibration can cause drowsiness during driving.