mohammadreza doostan

 

Preparation is the time following the receipt ofa warning signal during which the motor system is activated prior to action and prepares the individual for performance. We investigate the impact of the effect of various foreperiods (0/5, 1/5, 2/5 and 3/5 seconds) also the handedness ofthe athletes upon the time of simple and choice auditory reaction time.

The current research followed a semi-empirical methodology andwas carried out using a self-made software. The statistical population was comprised of the female students of Shahid Chamran University, of which 40 was selected through purposive sampling and classified intwo groups of right-handed and left-handed. Each individual was randomly tested for simple and selective reaction with randomly chosen pre-periods.

The findings demonstrated that short (0/5 seconds) and long (3/5 seconds) foreperiods will result in the increase of reaction time, and that left-handed individuals are associated with shorter reaction times compared to their right-handed counterparts.

In left-handed, the dominance ofthe right hemisphere which contains higher numbers of neurons might have lower reaction times compared to the right-handed individuals. Additionally, we recommend that pre-periods with too short or too long durations be avoided when preparing the individuals fordifferent motor skills.

Aim: The aim of this study was to investigate the behavioral and neurological of learning and transfer of asymmetric bimanual task.
The study is quasi-experimental. Instruments used in this study included quad-channel EEG, pen Mouse, laptop, special gloves and metronome. The participations of the research were eight grade, right-handed students (mean age, 14/2 ± 0/13) formed (N=10). They has normal vision and no physical problem or there was no movement. After pre-test participants for three days of training and then post-test were performed. Tests were performed in conditions difficult task with the dominant hand and the conditions were difficult task with non-dominant hand. Asymmetric training can mean the difference was the speed and the effect of gravity on two hands.
Findings: The results showed that training of bimanual coordination pattern that movement difference between two hands is both the speed and the effect of gravity, the transfer does not occur to vice versa. EEG results showed it seems that in difficult bimanual coordination task, prior training that task to do more difficult, brain activity of cortical areas is higher. Furthermore, brain activity in motor and frontal regions in the left hemisphere was higher than right hemisphere.
Combining two or more features that together in asymmetric bimanual task to make a stronger coupling that levels of control take up a higher level.

Aim: Techniques that directly examine and regulate the activity of the cortex can helps to improving working memory and response time. The aim of this study was to investigate the effect of cerebral magnetic stimulation on working memory and reaction time in athlete girls.
This study was semi-experimental method which was carried out using two groups with pre-test- and post-test design. A sample of 30 female athletes from the city of Shadegan were selected by sampling method and participated in the research process. First, a pre-test was taken. All respondents tested the reaction time and also a working memory test was taken. Subjects were randomly divided into two groups: transcranial Direct Current Stimulation and sham group. Acquisition stage was held in 2 days and a one rest day in between.
The results showed that brain of transcranial Direct Current Stimulation improved the progressive working memory, postoperative, mental control, logical memory, and retrieval. It also reduces the simple reaction time and selective.
In a general conclusion, direct brain stimulation in the prefrontal cortex in female students is one of the ways that can improve working memory and reduce the reaction time in athlete girls.

bimanual coordination tasks routine and dominant. So, the aim of this study was investigating the effect of handedness and bimanual coordination task difficulty on the brainwave of cortical areas.
Material:the present study is of semi-experimental type. 20 woman (10 left and 10 right-handed) with a mean age of 42þþ/8 years That were selected by Purposive sampling. Each of the participants did a five-difficulty level of bimanual coordination tasks.
according to the results of analysis of variance and independent t-test in c3 between right and left hand group there was a significant difference in gamma wave. And in level 5&4 of bimanual coordination task difficulty between tow group in delta waves there was a significant difference too.
There was a high activity in the motor cortex, supplementary motor area (C3 & C4) during bimanual coordination task. This activity of wave increasing with enhancement tasks difficulty. This finding shown the important role of Supplementary motor area in bimanual coordination.

The aim of this study was the evaluation of the effect of changes in different characteristics in movements of two hands on transfer of asymmetrical bimanual movement to its converse pattern, and effector-independent hypothesis from motor memory was investigated.
The instrument used in this study included pen Mouse, laptop, special glove and metronome. The subjects of the research were right-handed male students. Thirty right-handed subjects participated in the experiment, that practiced asymetrical bimanual coordination task In three groups. The movement patterns of two hands were different from each other in motor features (Group 1:The effect of gravity, Group 2:velocity pattern, 3:amplitude of movement). Each of the test groups after the practice run for four days and then tests were performed.
The results showed that when asymmetries in two hands that perform the bimanual movement is the effect of gravity on hands, transfer to vice versa pattern is positive. However, when the difference is in velocity pattern there is a positive transition and the transition is zero, and when the two hands movement patterns are different in amplitude of movement, transfer was negative.
The research shows that in terms of the differences in the pattern of asymmetric of two hands is controlled in what level of the hierarchy of nervous system, it is possible that bimanual movement transfer to reverse pattern or not. It can be concluded that the effector-independent hypothesis from motor memory in bimanual movement coordination depends on difference between the two hands special features,Soneed for revision.

Preparation capacity in the course of time does not mean low confidence about important events that will occur in the future. The aim of this study was to evaluate the effect of long preparation and handedness on the neuropsychological performance (ie, reaction time).
The method of this study was semi-experimental which was performed by a self-made software. The participants were 40 of Shahid Chamran University female students who were chosen for sampling and were included in two groups of left and right handedness. Edinburgh Handedness Inventory was administered to them. Repeated measure analysis of variance and Bonferroni post hoc test intergroup for data analysis were used.
Findings: The findings demonstrated that very short (0/5 seconds) and very long (3/5 seconds) foreperiods would result in the increase of the reaction time, and that left-handed individuals were associated with shorter reaction times compared to their right-handed counterparts.
Sustainable pattern of right and left hands to control the movement and the deployment strategies are different. Apparently, the cause of these differences is that different motor components specifically processed in two cerebral hemispheres. Moreover, it is better to prepare people for performing different skills from while avoiding too short and too long foreperiodes.