The process of movement execution can be separated into two sections; the foreperiod and the response time. The foreperiod represents the time between the warning signal (WS) and the presentation of the imperative “go” signal, and the response time incorporates both the reaction time (RT) and the movement time (Schmidt & Lee, 2011). Transcranial magnetic stimulation (TMS) was used to probe corticospinal excitability (CE) which has been measured in a variety of RT tasks during both the foreperiod and the response time periods. The purpose of the two studies in this thesis was to measure when and at what rate changes in CE occur in both simple and complex tasks. The results of the first experiment indicated that CE levels quickly increased from baseline with the presentation of the WS. This was followed by a holding period in which CE was held constant until a decline in CE occurred prior to the presentation of the IS. This decline was followed by a rapid increase in CE as the movement was initiated and released. Importantly, even though levels of CE were decreasing relative to the start of the decline, participants were still in a heightened state as they prepared to release their movements. Furthermore, it is suggested that selective inhibitory control mechanisms were at least partly responsible for the decline prior to the IS. The results of the second experiment indicated that MEP amplitudes in a simple task were significantly larger compared to those in a complex task relative to both the IS and the onset of electromyography. These findings suggest that simple and complex tasks achieve differing levels of corticospinal excitability, and it is suggested that the complex requires the use of the cerebellum, which suppresses excitatory projections to the thalamus, and consequently to the motor cortex.

No / PURPOSE. This study examined the influence of stimulus chromaticity on simple reaction times (RTs) to determine the stage of chromatic processing that is most influential in their generation. METHODS. Simple RTs were measured in response to the cosinusoidally ramped onset of small, equiluminant, colored Gaussian spots. The chromaticity of these stimuli was varied, to modulate along a series of vectors in color space that included red-green (L-M) and blue-yellow (S-[L+M]) opponent axes. RESULTS. RTs are highly sensitive to small departures from subjective equiluminance. They are also dependent on stimulus chromaticity. The longest RTs are generated in response to equiluminant stimuli that isolate S-cone activity, whereas the shortest are generated by stimuli that modulate the L-M opponent axis. However, temporal processing differences are highly dependent on how the chromatic stimuli are scaled in relation to one another. The differences are reduced when scaling is based on detection threshold. The relationship between chromatic contrast and RT can be described by the modified Piéron equation RT = RT0 + k · C-1. CONCLUSIONS. Simple RTs generated in this study conform to the idea that they are largely determined by cone-opponency mechanisms. The use of cone contrast as a metric for scaling chromatic stimuli exaggerates differences between the temporal responsiveness of L-M and S-(L+M) opponency mechanisms.

Optimal interaction between vision and other somatosensory systems guaranties the control of human body segment stability and change in position. The lack of visual information causes changes in equilibrium, regulation of body segment position and in response to surrounding stimuli. The objective of the study: to carry out the research on the influence of the degree of visual impairment on equilibrium and simple and psychomotor reactions, and to establish the possible manifestation of compensatory reactions of vestibular and proprioception sensory systems when vision disorders are being faced. To investigate the influence of the degree of visual impairment on equilibrium and simple and psychomotor reactions, the sighted subjects, legally blind and totally blind subjects voluntarily participated in the study. A static posturography (or stabilography) method has been used for the equilibrium testing. A force plate and computerized equipment for analysis of the signals was applied for posturography. Centre of pressure coordinates have been started to be registered since the moment when the subject in bare feet stands on the force plate in the position required. Posturogram registration in every position of standing lasted 60 s. To investigate a simple reaction, we have employed an electromyoreflexometer, which consists of the equipment emitting light or sound signals, a response device and a unit for the data registration. The testing has been conducted during two parts when a... [to full text]

Optimal interaction between vision and other somatosensory systems guaranties the control of human body segment stability and change in position. The lack of visual information causes changes in equilibrium, regulation of body segment position and in response to surrounding stimuli. The objective of the study: to carry out the research on the influence of the degree of visual impairment on equilibrium and simple and psychomotor reactions, and to establish the possible manifestation of compensatory reactions of vestibular and proprioception sensory systems when vision disorders are being faced. To investigate the influence of the degree of visual impairment on equilibrium and simple and psychomotor reactions, the sighted subjects, legally blind and totally blind subjects voluntarily participated in the study. A static posturography (or stabilography) method has been used for the equilibrium testing. A force plate and computerized equipment for analysis of the signals was applied for posturography. Centre of pressure coordinates have been started to be registered since the moment when the subject in bare feet stands on the force plate in the position required. Posturogram registration in every position of standing lasted 60 s. To investigate a simple reaction, we have employed an electromyoreflexometer, which consists of the equipment emitting light or sound signals, a response device and a unit for the data registration. The testing has been conducted during two parts when a... [to full text]

This diploma thesis deals with children‘s reaction time. The theoretical part of this work describes children as vulnerable road users and discusses methods of measuring reaction time. The practical part presents some realized experiments refer to the children’s reaction time and their results evaluation.

Title: The influence of age, gender and movement activity on the reaction abilities of lower limbs. Objectives: The main objective of this dissertation was to find the reaction abilities of pubescent's (aged 10 - 15years) lower limbs on the basis of age, gender and movement activity. The further aim was to determine the pubescence period (age) when the most noticeable decrease of the visual disjunctive motor response time of lower limbs occurs. Methods: 214 boys and girls aged 10-15 years (157.8 ± 10.8 cm; 47.2 ± 10.7 kg) participated in this research. Simple, choice and disjunctive reaction time of lower limbs was measured through the Fitro Agility Check test. The results processing, including statistical procedures, was carried out using the Matlab (MathWorks, Inc.) programming environment, an IBM SPSS Statistics 22. Three-way ANOVA and Tukey post-hoc tests (α=0.05) were used to determine the individual parameters connection. Results: With increasing age, year over year, we found important differences and reaction time decreases of all types of reaction speeds. Testing brings to light the fact that the most noticeable decrease of both selection and disjunctive reaction time of lower limbs are between groups of 11 year olds (11.00-11.99) and 12 year olds (12.00-12.99). The most noticeable decrease...

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Title: The influence of age, gender and movement activity on the reaction abilities of lower limbs. Objectives: The main objective of this dissertation was to find the reaction abilities of pubescent's (aged 10 - 15years) lower limbs on the basis of age, gender and movement activity. The further aim was to determine the pubescence period (age) when the most noticeable decrease of the visual disjunctive motor response time of lower limbs occurs. Methods: 214 boys and girls aged 10-15 years (157.8 ± 10.8 cm; 47.2 ± 10.7 kg) participated in this research. Simple, choice and disjunctive reaction time of lower limbs was measured through the Fitro Agility Check test. The results processing, including statistical procedures, was carried out using the Matlab (MathWorks, Inc.) programming environment, an IBM SPSS Statistics 22. Three-way ANOVA and Tukey post-hoc tests (α=0.05) were used to determine the individual parameters connection. Results: With increasing age, year over year, we found important differences and reaction time decreases of all types of reaction speeds. Testing brings to light the fact that the most noticeable decrease of both selection and disjunctive reaction time of lower limbs are between groups of 11 year olds (11.00-11.99) and 12 year olds (12.00-12.99). The most noticeable decrease...

This thesis deals with the possibility to evaluate cognitive and emotional traits and their relations to job positions and functions. The basis is to create a set of tests which could be used during a hiring procedure while deciding among candidates. It also suggests how to classify users based on a set of tests and thereby provide support in choosing the right job. The thesis gives a brief outlook of individually tested traits, describes a proposal of a web application and its implementation, describes implementation of neural network classifier and presents obtained results.