Wojciech Lason

Analysis of tremor in motor learning task

Abstract Hand-eye coordination is required in many skilled tasks. Individual differences affect the performance of people at work and leisure, for example, during assembly jobs or sports. The aim of this study was to determine whether motor learning can change the physiological action of hand tremor. Tremor is a repetitive and stereotyped movement, with regular frequency and amplitude, but there are different types of tremors with pattern variation. The results were calculated by participants’ time-on and time-off the target, the average distance from the center of the target, and the frequency of oscillatory movement of a cursor (tremor). The results of this study indicate a statistically significant (p<0.05) influence of effect of task repetition on improvement of motor control and reduction of a high-amplitude tremor and an increase of a low-amplitude tremor. The assessed individuals achieved more than 50% better outcomes of a hand-eye coordination task in the final trials when compared with the initial trials. The dynamics of motor learning tend to rise, with a steady level of a 1-h interval between trials.

Prolonged Latency Saccades in Alcohol-dependent Patients

Aims The aim of this study was to assess the differences in saccadic latency (a measure of time delay experienced in eye movements) between alcohol-dependent and healthy controls. Materials and methods Participants Ninety-nine alcohol dependent patients were examined. Thirty-eight healthy controls were matched to the affected cohort according to demographic characteristics. Assessment In this study we used the Saccadometer Advanced System (Advanced Clinical Instrumentation, Cambridge, UK). The Saccadometer System allows quick and easy collection of saccadic responses within the shortest physiologically possible time (100 saccades in 5 min). The brevity of the testing routine minimizes any potential influence on the results due to fatigue in the test subjects. The eye movement measurements are automated and synchronised with stimuli presentation. This study analyzed saccadic latency and standard deviation of mean latency. Results There was higher saccadic latency and standard deviation of mean latency in alcohol-dependent individuals (224.43±56.24 msec) when compared to healthy controls (187.84±25.65 msec). A marked asymmetry of standard deviation of mean latency between right-sided and left-sided saccades was observed in the affected cohort. There was an increased standard deviation of right-sided saccades mean latency (69.96 msec) in alcohol-dependent individuals when compared to healthy controls (30.93 msec) and also an increased standard deviation of left-sided saccades mean latency (59.33 msec) when compared to healthy controls (33.09 msec). Conclusion It was found that alcohol dependence is associated with impaired (longer time delay) saccadic reaction.

The Dependence of the Saccadic Refixation Parameters Values From the Time of Substitution Treatment Opioid Addicted Subjects

Introduction The saccadic movements are associated with activation of the certain brain regions. These cerebral areas are responsible also for controlling executive functions. In the current experiment we used an objective test (i.e. saccadometry) to study the effect of a single therapeutic dose of methadone on the integrity of cortico-subcortical brain functioning in individuals with diagnosis of heroin addiction. Aims Assessment the ocular movements (saccades) in opioid addicted subjects in the dependence of the time of substitution treatment. Methods Eighty-eight patients from the substitution program were examined (mean age 39±7.7 years, mean daily dose of methadone: 71.9±(33.4) mg) The study included 55 subjects treated with methadone from one year to three years and subjects treated with methadone from three to seven years. The examination was conducted twice: before and about 1,5 hours after the administration of a therapeutic dose of methadone. Performed Latency Task (LT) with Saccadometr diagnostic system. Results The statistical analysis shows that the mean duration after the administration of methadone in the subjects treated with methadone from one year to three years was statistically significantly increased (p=0,0001) but in the subjects treated with methadone from three to seven years was no statistically significant difference (p=0,0524). No statistically significant differences were found in other parameters of the test. Conclusion The results indicate a change in the dynamics of saccade after methadone administration in subjects treated with methadone from one year to three years compared to the subjects treated with methadone from three to seven years.

Peak Velocity of Saccades in Alcohol-dependent Patients

Aims The aim of this study was to assess the differences in peak velocity of eye movements between alcohol-dependent and healthy controls. Materials and methods Participants Ninety-nine alcohol dependent patients were examined. Patients with oculomotor impairment were excluded. Thirty-eight healthy controls were matched to the affected cohort according to demographic characteristics. Assessment In this study we used the Saccadometer Advanced System (Advanced Clinical Instrumentation, Cambridge, UK). The eye movement measurements are automated and synchronized with stimuli presentation. The person conducting the experiment needs to ensure that the sensor is placed correctly and to give instructions to the test subject. The Saccadometer System does all other measurements and recordings of test data automatically. The study analyzed the peak velocity of eye movements of amplitude of 10 degrees and the deviations in peak velocity. Results There was a statistically significant higher mean peak velocity of saccadic eye movements in alcohol-dependent individuals (440.82±86.33deg/s) when compared to healthy controls (411.39±86.33deg/s). Greater asymmetry of mean peak velocity between right-sided and left-sided saccades was observed in the affected cohort when compared to the healthy test subjects. There was a higher mean right-sided peak velocity (462.73±118.54deg/s) in the alcohol dependent subjects when compared to healthy controls (414.68±73.79deg/s) and also a higher mean of left-sided peak velocity (418.82±79.83deg/s) when compared to healthy controls (405.13±49.50deg/s). Conclusion It was found that alcohol dependence is associated with differences and significant increased asymmetry of peak velocity of eye movements.

EPA-1229 – Comparison of the saccadic refixation parameters in patients treated with methadone and individuals from the control group

Introduction Administration of psychoactive drugs increases dopaminergic receptor stimulation, improves mood and stimulates motor activity. Structural and functional changes can be observed in particular structures of the central nervous system (CNS). Aims/Objectives This study aims to assess the saccadic refixation parameters in opioid addicted subjects treated with methadone compared to control group. Methods Eighty-six patients from the substitution program were examined. The study included 36 subject of the control group. The trial was conducted twice: before and about 1.5 hours after the administration of therapeutic dose of methadone. Performed Latency Test(LT) with Saccadometr diagnostic system. Results The statistical analysis showed that the mean duration before and after the administration of methadone was a statistically significant increases (p=0,0001) in the subjects from substitution program compared of the control group but after administration of methadone the value greatly increased in experimental group (before 52 ms , after 56 ms ). It was observed that the mean amplitude after the administration of methadone increased statistically significantly in experimental group compared of the control group (p=0,02). Mean peak velocity of latency after the administration of a therapeutic dose of methadone was statistically significant decreased in experimental group compared of the control group (p=0,0004). Conclusion The results indicate a change in the dynamics of saccade after methadone administration. The observed changes in values for eye movements may be due to the inhibitory effect of methadone on CNS.

1903 – Effect of a single dose of methadone on saccadic refixations in opioid addicted subjects with hiv (+) and hiv (-)

Introduction Eye movements are closely related to cognitive and emotional functions. Information of saccadic dynamics during certain tasks may indicate disorders of mental functions that can help to explain the neurobiology of sensory-motor systems and be useful in neuropsychiatric diagnosis. Aims/objectives This study aims to assess the impact of a therapeutic dose of methadone on eye movements (saccades) in opioid addicted subjects with HIV(+) and HIV(-). Methods Sixty patients (29 patients with HIV(-) and 31 of HIV(+)) from the substitution program were examined. The examination was conducted twice: before and 1,5 hours after the administration of a therapeutic dose of methadone. Performed Latency Test (LT) with saccadometr diagnostic system. Results Mean duration of latency measured by LT Test after the administration of a therapeutic dose of methadone increases significantly in HIV(-) subjects but the mean peak velocity decrease in the study group. Mean peak velocity latency in HIV(+) subjects is not statistically significant. Mean duration and amplitude of latency after the administration of a therapeutic dose of methadone is a statistically significant in opioid addicted subjects with HIV(+). It was found that the mean peak velocity before the administration of a therapeutic dose of methadone was statistically significantly different in HIV(-) subjects as compared to HIV(+) ones. Conclusion The increase of saccadic refixation parameters values in opioid-addicted subjects after the administration of a therapeutic dose of methadone was observed.

Computer-based system to capture, collect, process and analyze data in psychomotor tests

Abstract The article explains the principles and goals in creating a computer-based system for the measurement of psychomotor functioning, its functionality, and user interface. To illustrate the capabilities of the system, the results of analysis of the selected psychomotor tests performed in different groups of patients are presented. The usefulness of the presented tool in the quantitative study of psychomotor functioning is assessed.

P-53 - The effect of administration of a single methadone dose on psychomotor performance in patients addicted to opioids during substitution therapy

Objective The aim of the study is to assess graphomotor and psychomotor skills of people treated with substitution therapy in opiate addiction. Methods 36 patients were examined twice, immediately before and about 1.5h after oral administration of therapeutic dose of methadone. The original test implemented on a tablet was used. A task in the first part was to map, as accurately as possible, geometric shapes printed on the sheet of paper by drawing on contour, and in the second part to sign up on the sheet. The patients used dominant hand. The software used allows to make analysis of the motions parameters: time, force levels, speed and acceleration of the plot, amplitude and frequency of hand tremors. Results The amplitude of tremors in the spectrum of variations in 13 of the 16 components analyzed in the drawing task and all the components in the spectrum of the instantaneous velocity tremors were reduced. In the signature task a significant reduction in the average amplitude of tremors for medium and higher spectral components (from the 4 th up) and a reduction in the amplitude of tremors in the spectrum of instantaneous velocity for most precisely analyzed components was observed. Conclusion A single dose of methadone in opioid-addicted individuals reduces dominant hand tremors, particularly in the 1 st spectrum component frequency for the drawing test. This indicates improvement in graphomotor and psychomotor function.