Selection reaction time is usually measured. Research

Reaction time (reaction time )

The measurement of reaction time (RT) is probably the most revered subject in empirical psychology. It originated in the field of astronomy, in 1823, with the measurement of individual differences in the rate of perception of a star crossing a telescope's risk line. These measurements were called personal equation and used to correct astronomical measurements of time, taking into account the difference between observers. The term "VR" was introduced in 1873 by the Austrian physiologist Sigmund Exner.

In psychology, the study of VR has a double history. Both of its branches date back to the second half of the 19th century, and Cronbach called them experimental. psychology and differential psychology, two "disciplines of scientific psychology". These branches originated in the laboratories of W. Wundt, the founder of experiments. psychology, and F. Galton, the creator of psychometry and differential psychology. In the experiment VR psychology was of interest mainly as a way to analyze the mental. processes and the discovery of general laws governing the mechanisms of perception and thinking. In differential psychology, VR has been of interest as a way of measuring individual differences in intelligence, especially in general intelligence, stemming from Galton's suggestion that a biologist. the basis of individual differences in ability is the speed of mental operations (together with sensory absolute and differential sensitivity). These two branches of research VR were considered more or less separately in acc. literature throughout the history of psychology. However, the last decade has been evidence of a significant "cross-pollination" of these two areas, since researchers and in the experiment. cogn. psychol., and in differential psychology adopted the methodology of mental chronometry, or measuring the processing time of information. in the NS.

Research VR cannot be explained without resorting to special terminology to describe the essential features of paradigms and VR measurement methodology. In a typical VR experiment, the observer (N) is brought into a state of attentive expectation by a preparatory stimulus (PS), which usually belongs to a different sensory modality than the subsequent response stimulus (SR), to which N responds to c.-l . an open (physical) reaction (P), such as pressing or releasing a telegraph key or button, usually with the index finger. The time elapsed between the end of the PS and the beginning of the SR is the preparatory interval (PI). It is usually between 1 and 4 s, varying randomly so that H cannot learn to anticipate the exact moment when SR begins. The interval (usually measured in ms) between the presentation of SR and the appearance of P is VR, tzh called. response time (RT). In some VR paradigms, the H response is actually a double response with two different actions: a) releasing a button, and then b) pressing another button, causing the SR to stop. In this case, the interval between the start of the CP and the button release response is VR, and the interval between the release response and the response of pressing another button is the movement time (TD), also measured in ms. (RT is usually much shorter than RT.) The device for measuring RT and RT is usually extremely simple, but the accuracy and reliability of the timing mechanisms is critical. Older mechanical chronoscopes were quite accurate, but they needed frequent calibration. Nowadays, microcomputers with electronic timers provide greater accuracy and stability of VR measurements; the variability in H from test to test far exceeds any measurement error attributed to the VR device itself. Accurate measurement of VR has proven to be useful in psychophysics for scaling the strength and discrimination of sensations in units of VR, as well as for obtaining an objective scale of relations with internationally standardized ones. unit level.

On the basis of this simple VR paradigm, other, more complex VR paradigms are developed that aim to distinguish between sensorimotor and cognitive aspects of performance. Fundamental improvements were made in 1862 by the Dutch physiologist Frans K. Donders, whose variants of the VR paradigm made it possible to measure the speed of specific mental. processes in contrast to the sensorimotor components of VR. Therefore, it is rightly called. creator of mental chronometry. Donders identified three paradigms, which are called. A-, B- and C - reactions: A - simple reaction time (VPR) (i.e. one P per one SR); B is the choice reaction time (CRT), t, denoted as the disjunctive reaction time (i.e., two (or more) different SRs and two (or more) different P, requiring H to distinguish between different SRs and choose the corresponding P from a series alternatives (e.g., different buttons)) and C - discrimination reaction time (VRP) (i.e., two (or more) SRs, to-rye must distinguish H, are presented in a random sequence, but only one P is allowed for a single one of SR (designated by the experimenter), while H should inhibit the response to other SRs.

Typical procedure, on any of these paradigms, is a series of practical. samples to provide an understanding of the H requirements of the task, followed by a large series of test samples to ensure a sufficiently stable and reliable measurement of VR. Since there is a physiologist. the limit of the maximum reaction rate (about 180 ms for visual and 140 ms for auditory stimuli), the distribution of VR of any H is noticeably skewed to the right. Therefore, the preferred measure of the central tendency of the distribution of VR obtained on the basis of P samples of any H, is the median, since it is less sensitive to distribution skewness than the average. A logarithmic transformation of RT values ​​is often used because the logarithm of RT values ​​has an approximately normal (Gaussian) distribution. Values ​​of BP, to-rye less than the best estimates of the physiologist. RT limits for a given sensory modality are usually discarded as anticipatory errors. Dr. the measured characteristic of HR data is the intra-individual variability in HR, measured as standard deviation ( SD) VR values ​​of a specific H obtained in P samples (denoted SD BP). This characteristic has interesting properties - both experimental and organismal, which are different from the properties of VR per se. More complex paradigms than VPR, such as the reactions of choice and discrimination identified by Donders, obviously allow for the possibility of erroneous reactions and, therefore, the possibility of adopting H compromise strategies in relation to the speed-accuracy relationship, in which the accuracy of the response is sacrificed to pure speed. Errors can be significantly minimized by means of instructions for H, which emphasize both accuracy and speed of response.

In theory and research. First of all, VR takes into account the fact that VLOOKUP and increasingly complex VR paradigms include two sources of time, which can be called peripheral and central. Duncan Lewis, leading researcher in math. decision-making models, explains it as follows.

Probably the first thing the simple reaction time data suggests is that the measured RT is at least the sum of two completely different time components. One of them is related to the decision processes performed by the central nervous system and aimed at making a decision at the time when a certain signal is presented. Dr. the component concerns the time it takes to convert and transmit a signal to the brain, and the time it takes for the commands sent by the brain to activate the muscles that provide the reactions.

Main the assumption of mental chronometry is that the processing of information. occurs in real time, passing through a certain sequence of stages, and the measured total time from setting to solving a mental problem can be. analyzed from t. sp. the time required for each stage of processing. Essentially, this is a consequence of the subtraction method proposed by Donders. However, the assumption of a consistent, with clearly defined stages, the processing of information. it turned out several. simplified, since in many cases, there is parallel processing and interaction between the base processes, when additional processes are called by the increased complexity of the task. Therefore, to determine whether the stages of processing inform. separated in time, partially overlapping or interacting in solving any given problem, were developed. statistical methods based on analysis of variance, like Saul Sternberg's method of additive factors.

To the main experimental Variables influencing RT include the nature of the PS and the length of the PI, the sensory modality of the SR, the intensity and duration of the SR, the nature of the response, the degree of compatibility between the stimulus and the response (for example, the spatial proximity of the SR to the response button), the amount of pre-training in the task and the effect of the experimenter's instruction on the level of drive or motivation H to establish the ratio of speed and accuracy of reactions. Among the organismal factors that affect VR are the subject's age, concentration on the task, finger tremor, anoxia (eg, at high altitudes), stimulants and depressants (caffeine, tobacco, alcohol), physical. shape, diurnal fluctuations in body temperature (higher temperatures suggest faster responses), and physiology. state of H at a specific time of day (eg, a recent meal slows down BP). In general, factors that increase VR increase SD BP. These organismal variables seem to have a greater influence on the central, or cognitive, component of VR than on its peripheral component, as follows from a comparative analysis of their effects on CM and RT.

One of the most enduring and theoretically attractive phenomena in the field of VR, which has been studied extensively by experimental psychologists, is the linear relationship between VR and the logarithm of a number ( n) choices, or alternative reactions, in the RTW problem. Although this phenomenon was discovered in 1934 by the German psychologist G. Blank, the established dependence itself was called. "Hick's law" thanks to a paper published by W. E. Hick containing fruitful ideas. In particular, Hick argued that the slope (or slope) of the straight line VR as a function of the binary logarithm P reflects the speed of information processing, measured as the amount of information processed per unit of time (for example, 40 ms per bit of information). The inverse slope value (x 1000) expresses the information processing speed, estimated by the number of bits / s. One bit (for a binary sign) as a unit of information, used in the theory of information, corresponds to the amount of information, which reduces the uncertainty by half; the number of bits in CRT problems is equal to the binary logarithm P. Hick et al. authors have proposed neurological and mat. models of linear dependence of VR on the amount of processed information.

What could be called the Galtonian branch of the application of VR can be seen in the example of research. individual differences, especially in mental abilities, although VR has been used in psychopathological studies. (schizophrenics, for example, have an unusually slow reaction time and variability in reaction time compared to mentally normal people of the same age and IQ). Galton was the first to suggest in 1862 that the biologist. the basis of individual differences in general mental ability (later called the factor g, i.e., a common factor singled out in any set of heterogeneous mental tests) m. b. measured by VR score. Galton measured the reaction time of thousands of people when they performed a variety of sensorimotor tasks in visual, auditory, and other modalities. Nevertheless, his measurements of VR were basic. on too few samples in order to have sufficient reliability, and did not allow us to detect significant correlations with k.-l. external criteria of mental ability, such as educational and professional levels (tests IQ did not exist at the time). Dr. attempts to confirm Galton's hypothesis, undertaken at the beginning of the century, brought disappointment, and therefore interest in the use of VR measurements in works on differential psychology was lost, but, as the development of events showed, prematurely.

Research VR was methodologically naive at the time, and the arguments for concluding that there is no connection between VR and intelligence were equally naive. These early research contained such a number of flaws, which primarily include an extremely high measurement error, a limited range of ability in the surveyed samples, inadequate and unreliable measures of the criterion of intelligence, and the lack of sufficiently powerful methods of statistical analysis and inference, which was practically impossible to obtain. l. scientifically significant results. Premature rejection of VR as a research tool. mental abilities of people, was ist. a precedent for what statisticians call a Type II error—accepting the null hypothesis when it is wrong.

Half a century later, thanks to the creation of the theory of inform., the development of experimental. cogn. psychol. and formulating on their basis the concept of individual differences in intelligence as a reflection of the speed or effectiveness of elementary inform. processes, Galton's hypothesis was brought back to life and re-tested. Its time came around 1970. Microcomputers with precise timing mechanisms, sophisticated measurement theory, and improved statistical methods for multivariate analysis offered advantages that Galton and his immediate successors lacked. Since the 1970s there is an increasing pace of publications devoted to research. links between VR and intelligence, especially the g factor. Most of these publications appeared in two psychol. magazines: "Intellect" ( Intelligence) and "Personality and Individual Differences" ( Personality and individual Differences). Some theories and empirical research. summarized in books edited by Eysenck and Vernon.

Unlike Galton and his early followers, modern. researchers use a wide variety of tasks, called. elementary cognitive tasks (ECT), in which VR (and often SD VR, VD, and SD PD) are dependent variables. These EKZs vary in the number or complexity of their cognitive requirements and are intended to reflect the temporal components required to realize hypothetical information. processes, such as stimulus perception, discrimination, selection, visual scanning of many elements in search of a given "target" element, scanning information held in short-term memory (eg, S. Sternberg's paradigm), search and retrieval of information. from long-term memory (eg, Posner's paradigm), categorization of words and objects, and semantic verification of short declarative statements. Although it is not possible to describe the study here. each of these ECZs in detail, the VR data obtained in each of them showed significant correlations with psychometric intelligence, or IQ. Some of the main. results in this area are reproduced with sufficient consistency to allow a number of empirical generalizations to be made:

1. VR, VD, SD VR and SD VDs decrease from infancy to adulthood and rise during late adulthood and old age. Age differences are more strongly associated with the central, or cognitive, components of these variables than with the peripheral, or sensorimotor, components.
2. Negative correlations between VR and IQ for each individual ECZ fluctuate between -0.1 and -0.5, averaging -0.35. This correlation is not a function of test passing speed. IQ, and what is surprising in these correlations is precisely the fact that VR was measured during the performance of the EPC, which actually have no intellectual content and do not require specific knowledge and skills necessary to perform tests IQ. In addition to sensorimotor components, VR and SD VRs are probably content-free measures of the speed and effectiveness of information. processes.
3. VR is more strongly correlated (negatively) with g-factor than with other factors (independent of g), which are part of the variance of psychometric tests, such as verbal, spatial, numerical, mnemonic and speed clerical factors plus specific factors.
4. The variability of correlations between VR and psychometric abilities is associated with loads on the factor g specific psychometric tests, differences in range limits IQ in samples and the degree of complexity of the EPC used to measure VR, which probably depends on the number of different inform. processes required by a particular task, and the amount of information that needs to be processed to achieve the correct response.
5. There is an inverted U-shaped relationship between the magnitude of the VR-correlation IQ and the complexity of the task. VR problems of medium complexity show the highest correlation with IQ; further increase in the complexity of the task causes individual differences in cognitive strategies, which are often not associated with g.
6. VR is more strongly correlated with IQ than WD. The sensorimotor, or peripheral, component of VR, which makes up a relatively large part of the dispersion in VFR than in VRV and other more complex forms of VR, is not associated with IQ. Hence, provided that the RT measures are sufficiently reliable, removing the peripheral components from the RT and the RT by subtracting the RT increases the correlation of these measures with IQ.
7. SD VR (i.e. intra-individual VR variability) shows a higher negative correlation with IQ than VR itself. In addition to a large proportion of the variance common to VR and SD VR (to-paradise negatively correlates with IQ), VR and SD BP contain also unique components that are negatively correlated with IQ. Theoret speaks. the assumption that SD VR reflects errors, or "noise", when transmitting information. in the NS.
8. Although the correlations of VR and SD BP, main on the performance of one EPC, in general, are small (in most cases from -0.2 to -0.4), when a number of EPCs are used that require different cognitive processes for their solution, their multiple correlation ( R) with IQ(and especially with factor g) rises to 0.70 (adjusted for compression); magnitude R depends on the number of different ECs included in the analysis. That the adjusted multiple correlation coefficient ( R), main on a set of different EKZs, is significantly greater than the zero-order correlation coefficient ( r) calculated from the execution data of any one EKZ, suggests that IQ(or psychometric g) reflects a number of different information. processes, to some extent not correlated with each other. People who differ in IQ, tzh differ, on average, in the speed or efficiency of those brain processes that mediate the implementation of a given EPC.

Edwin G. Boring stated in 1926 that "if intelligence (as measured by tests) is eventually established with any kind of VR, this will have important consequences, both in practice and in theory." Today there is no “if” in this: the connection of intelligence with VR is firmly established. However, Boring's prediction still remains to be realized and realized.

see also Anticipation method, Ergopsychometry, Physiological psychology, Sensorimotor processes

The first studies of human voluntary reaction time were carried out at the beginning of the 19th century. astronomers.

The need for them arose after it was discovered that observers who record the moment a star passes through the meridian give different readings. An analysis of these data accumulated over several years showed that the observers' errors are not random, but characterize the individual reaction rate of each observer.

The famous astronomer F. Bessel, who discovered this phenomenon, was the first to conduct a chronometric experiment (1823), in which he measured the time of a person's reaction to a sudden stimulus. From that moment on, the human reaction time became the object of study by many astronomers (Arago, 1842; Hirsch, 1861; Wolf, 1865, etc.).

These studies have attracted the attention of physiologists and psychologists. The German physiologist G. Helmholtz, being interested in the problem of the rate of transmission of excitation along the centripetal nerves in humans, used the method of measuring the reaction time. He used an electrocutaneous stimulus applied to different parts of the body, more or less distant from the brain. Having calculated the average difference in reaction time in response to stimulation of these parts of the body, Helmholtz tried to determine the rate of transmission of excitation along the afferent pathways, which, according to his calculations, is approximately 60 msec.

Further studies showed, however, that this figure is not constant, since the speed of excitation conduction in different nerves is not the same, since it depends on many factors.

The works of G. Helmholtz and his followers had a great influence on the development of the chronometric experiment. Based on the research of Helmholtz, F. Donders and Z. Exner tried to approach the physiological analysis of mental processes proper with the help of a chronometric experiment. 3. Exner (1873) concentrated his attention on the simplest form of reactions carried out in response to visual, auditory, and electrocutaneous signals. F. Donders (1865-1868) took up the measurement of more complex mental acts, including the processes of distinguishing and choosing a response between two or five different stimuli.

3. Exner coined the term "reaction time", defining it as the time required to "consciously respond to a certain sensory impression."

He owns a systematic study of the time of a simple reaction and its dependence on a number of factors (the individual characteristics of the subject, the modality of the stimulus, various kinds of external conditions of the experiment, the action of pharmacological and alcoholic drugs). 3. Exner was the first to describe the state of expectation, readiness that occurs in the interstimulus interval. He also showed that the introduction of an external stimulus lengthens the time of a simple reaction. Further, relying on the studies of G. Helmholtz, 3. Exner, having divided the whole process - from the beginning of the action of the stimulus to the end of the response - into seven stages, he tried to estimate, firstly, "the time of the sense organ" and, secondly, " time of transformation of centripetal excitation into centrifugal. The results obtained by him were an important contribution to the psychophysiological studies of human voluntary reactions.

The name of F. Donders is associated primarily with the classification of voluntary reactions of a person and an attempt to measure the time of the actual mental link of these reactions. To solve the latter problem, he built an experiment in which, in one case, two different reactions to two different signals were carried out, while each time the subject knew which signal would appear and what response he should produce. F. Donders designated this type of reaction as A-reaction. (Later, W. Wundt called it a "simple" reaction. This name has survived to this day.) In another case, both signals followed in a random order. The reaction time has increased by 66 ms. Donders assumed that this additional time was spent on the presentation and selection of the desired reaction. This type of reaction, in which one or more signals were distinguished and, accordingly, one of two or more answers was selected, Donders called the B-reaction. It should be emphasized that in this experiment, Donders really measured the time of a complex mental process that ensures the discrimination of signals and an adequate choice of response. Further, he tried to separate the act of distinguishing a signal from the choice of a response in order to determine the time of each of them separately. Donders built an experiment in which the subject was presented with two or more signals, and it was necessary to respond to only one. The reaction time turned out to be longer than the A-reaction time and less than the B-reaction time. F. Donders designated this type of reaction as a C-reaction, suggesting that only sensory discrimination takes place here, and there is no choice of response. However, as Wundt rightly noted, one of the largest researchers of reaction time after Exner and Donders, in this situation there is also an element of choice, since the subject must make a choice between movement and rest.

An analysis of these reactions in terms of the physiology of higher nervous activity convincingly shows that both of these types of reactions are differentiation, while in one of them several positive stimuli are differentiated (B-reaction), and in the other - one positive and several negative, inhibitory - ( C-reaction).

In the school of W. Wundt, the chronometric experiment received its further methodological development, although the interpretation of the chronometric data was extremely subjective.

A simple reaction was subjected to a systematic study. It was shown how the time of a simple reaction depends on the modality of the signals, the nature of the reactions, and the intensity of the signal.

The classical chronometric technique is widely used in modern psychology, in solving both general theoretical and applied problems of psychology.

The measurement of VR depending on the degree of complexity of the situation shows that the main part of VR falls on the share of the mental link itself and makes it possible to consider it as a parameter characterizing the duration of the information processing process.

According to the degree of complexity, arbitrary reactions of a person can be divided into the following 3 classes: 1: 1) simple reaction, 2) discrimination reaction, 3) choice reaction.

simple reaction in psychology, they call a reaction that is carried out under the conditions of presenting one previously known signal and receiving one definite answer. For example, in response to sound, light, tactile, etc. signals, a person must perform a certain action as quickly as possible - press a key or pronounce a certain syllable. Studies show that at suprathreshold stimulus intensity, the time of a simple reaction is determined mainly by the physical nature of the stimulus and the characteristics of the perceiving receptor. The highest speed of a simple reaction was obtained using sound and tactile signals (105-180 ms). The speed of reaction to the visual signal was significantly lower (150-225 msec).

This is explained by the fact that the time of reception of sound and tactile stimuli is much shorter than the time of reception of a visual stimulus, since in the latter case a significant portion of the time is taken by the photochemical process that converts light energy into a nerve impulse. The VR for an olfactory signal is 200-300 ms (the shortest for a salty taste, and the longest for a bitter taste), for painful stimuli - 400-1000 ms.

Discrimination reaction denote a reaction that is produced under conditions when a person must respond only to one of two or more signals (letters, sounds, syllables), and a response action must be performed only on one of them.

Choice reaction also occurs when two or more signals are presented, but on the condition that you need to respond to each of them with your own specific action. Compared to the simple reaction time, the reaction time of discrimination and the reaction time of choice are markedly longer. So, for example, according to Donders data (see Table 1), the discrimination reaction time (C) is longer than the simple reaction time (A) by 36 ms, and the choice reaction time (B) is longer than the simple reaction time by 83 ms and 47 ms longer reaction time of discrimination. This delay is due to the inclusion of acts of sensory discrimination and choice of response. The time required for discrimination varies within fairly wide limits.

So, for example, it takes more time to distinguish between closer colors (red and yellow) than for more distant ones (red and green). The same phenomenon is observed for sounds of different frequencies, differentiation of lines of different lengths, etc.

The VR of discrimination and selection also depends on the number of alternative signals. So, for example, the average VR obtained by I. Merkel with one stimulus (digits were used as stimuli) was 187 msec, with two - 316 msec, with 6 - 532 msec, and when choosing from 10 - increased to 622 msec.

General guidelines

The reaction time measurement technique is extremely simple. It consists in registering, in one technical way or another, the time interval between the onset of the stimulus and the moment the response occurs. (Visual signals (flashing of multi-colored bulbs, presentation of various figures, numbers, etc.) or sound signals are usually used as a stimulus. Simultaneously with the signal, a device that measures time is turned on. The subject, by his response, turns off the latter, and thus VR is recorded .

Currently, in laboratory practice, an electronic millisecond clock of the MS-1 type is widely used. It operates on AC mains with a voltage of 110, 127 and 220 V and a frequency of 50 Hz, has a time measurement range from 0.1 ms to 10,000 s and makes it possible to count time intervals with an accuracy of 0.1 ms with a measurement error throughout range 0.1 ms. Time is counted according to the position of the luminous points on the dials of four dekatrons, the first of which (from left to right) shows tenths, the second - hundredths, the third - thousandths, and the fourth - ten-thousandths of a second. Return to the initial position after the countdown is done by pressing the button on the right side of the front panel. The device is silent in operation.

An important condition for obtaining reliable results when measuring VR is the isolation of the subject from extraneous stimuli. It is desirable that it be in a separate soundproof chamber, where only signal stimuli are supplied.

Before the start of the experiments, a preliminary survey of the subject is carried out, during which the age, education, state of health and the degree of training in this type of reaction are ascertained. After that, the subject is presented with a pre-compiled detailed instruction for the experiments. The purpose of the instruction is to explain to the subject what his task is, that is, what and how he should do when signals appear. It is especially important that all elements of the instructions are clearly understood and firmly mastered by the subject.

When conducting experiments, before each successive signal, a so-called “attention” warning signal is usually given, enabling the subject to prepare for the expected test signal and the corresponding reaction. A warning signal can be given either in verbal form (“there is”, “attention”), or in the form of a special stimulus (call, flash of light). Special studies have shown that the most effective interval between a warning and a test signal is 1.5-2 seconds. In a situation of a simple reaction, in order to avoid the development of a conditioned reflex for time and the appearance of premature reactions, this interval should be somewhat varied (2 sec ± 400 ms).

Since the reaction time depends on a large number of factors (including random ones) acting during the experiment, it is subject to noticeable fluctuations and, in this sense, is a statistical quantity. In order for the experimental results to be statistically reliable, the estimation of the reaction time must be based on a sufficiently large number of measurements under constant experimental conditions. The obtained values ​​of the reaction time are then averaged and subjected to appropriate statistical processing: the arithmetic mean, the standard deviation and the coefficient of variation are calculated.

As a result of the experiments, it was found that human VR cannot be lower than a certain physiological limit or "irreducible minimum" of a simple reaction, which is about 100 msec.

For simplicity and convenience of presentation, when classifying arbitrary reactions, we use the terminology of W. Wundt, recognizing its inadequacy to modern ideas.

Laboratory work "Measuring the time of a simple sensorimotor reaction"

The purpose of the laboratory work:

Measurement of the time of a simple sensorimotor reaction to light and sound stimuli.

Instruments and accessories:

Device for psychophysiological testing "Reflexometer".

Brief theory:

Human reaction time - the time interval from the beginning of exposure to the body of any stimulus to the response of the body.

It consists of three phases: the time of passage of nerve impulses from receptors to the cerebral cortex; the time required for the perception of nerve impulses by the brain and the organization of a response in the central nervous system; response time of the body. The reaction time depends on the type of stimulus (sound, light, temperature, pressure, etc.) and its intensity, the fitness of the body to perceive this stimulus, its expectation, etc.

The response time to stimuli of different modality is different. The shortest reaction time is obtained in response to auditory stimuli, longer - to light, the longest - to olfactory and tactile.

According to the degree of complexity, voluntary human reactions can be divided into the following four types:

1 simple sensorimotor reaction;

2 sensorimotor reaction differences;

3 sensorimotor reaction of choice;

4 reaction to a moving object.

1 A simple sensorimotor reaction in psychology is a reaction that is carried out under the conditions of presenting one previously known signal and receiving one definite answer.

For example, in response to sound, light, tactile, etc. signals, a person must perform a certain action as soon as possible - press a key or pronounce a certain syllable. Studies show that at suprathreshold stimulus intensity, the time of a simple reaction is determined mainly by the physical nature of the stimulus and the characteristics of the perceiving receptor. The highest speed of a simple reaction was obtained using sound and tactile signals (105 - 180 ms). The reaction rate to the visual signal turned out to be significantly lower (150–225 ms).

This is explained by the fact that the time of reception of sound and tactile stimuli is much shorter than the reaction time of a visual stimulus, since in the latter case a significant portion of the time is occupied by the photochemical process that converts light energy into a nerve impulse.

2 The sensorimotor reaction of discrimination refers to a reaction that is produced under conditions when a person must respond only to one of two or more signals (letters, sounds, syllables), and, accordingly, the response action must be performed only on this signal.

3 The sensorimotor reaction of choice also takes place when two or more signals are presented, but on the condition that you need to respond to each of them with your own specific action. Compared to the simple reaction time, the reaction time of discrimination and the reaction time of choice are markedly longer.

The response time to stimuli of different modality is different. The shortest reaction time is obtained in response to auditory stimuli, longer - to light, the longest - to olfactory and tactile.

When controlling equipment, in addition to the reaction time, it is also necessary to take into account the time of movement of the organs of the human body and the time of interaction of the operator with the controls (Table 4).

Table 4 - The value of the reaction time for various body movements

The dependence of reaction time on the level of fitness, gender, age and various kinds of influences on the body.

It has been experimentally shown (N.I. Krylov, 1957, N.I. Chuprikova, 1957, E.I. Boyko, 1964, E.N. Surkov, 1984, V.P. Ozerov, 1989) that:

1 Under the influence of training, the reaction time is not only shortened, but also stabilized, i.e. becomes less susceptible to various kinds of influences.

2 The shortening of the reaction time is most significant in the first days of the corresponding exercises.

3 The simple response is much less influenced by exercise than the choice response. In particular, after only one day of training, the choice reaction time can be reduced by 30-40%, while a simple sensorimotor reaction can be reduced by only 10%.

What are the reasons for the shortened reaction time after appropriate training? It is known that any new stimulus first causes an orienting reaction with a more or less extensive and prolonged irradiation of the excitatory process through the cerebral cortex, which is then replaced by a phase of concentration. As the stimulus is repeated, habituation takes place, which is accompanied by less and less pronounced irradiation of excitation with a simultaneous increase in the dynamism of the emerging nervous processes. The gradual reduction of the irradiation phase and the achievement of a certain level of chronic (or static) concentration of the excitatory process in the cortex, apparently, are one of the most important reasons for the shortening of the reaction time during training.

The second reason, closely related to the first, is the increasing stability of the cortical foci of excitation as the conditioned connections become stronger. The third reason is related to the change in the very structure of temporary connections, the replacement of more complex second-signal associations with simpler first-signal ones.

Starting from 3.5-4 and up to 18-20 years, the reaction time is steadily decreasing. Then it stabilizes, and after 40 years, with aging, it gradually increases by about 1.5 times (A.G. Usov, 1960).

In a number of studies (E.P. Ilyin, 1983, E.N. Surkov, 1984, Ozerov, 1989), gender differences are noted, consisting in the fact that the average reaction time in girls, compared with boys, and in women, compared with men, somewhat longer.

Table 5 - Dependence of the time of a simple sensorimotor reaction of a person on the physical and psycho-emotional state of a person

Installation description:

Time can be measured by the "Reflexometer" device, in which light and sound signals are used as an irritant.

The installation consists of a signal conditioning unit with an alphanumeric indicator (1); a control unit with start (stop) buttons for the recording device (3) and a light (sound) signal unit (2). The test results are displayed on an alphanumeric indicator and stored in the microcontroller's memory.

In this device, the microcontroller performs all the main functions, namely, it sends test signals, measures the reaction time, displays information on an alphanumeric indicator and stores it in its non-volatile memory (EEPROM - electrically erasable reprogrammable Read Only Memory (ROM)).

The device is controlled using the button (Start / Reset), by pressing which the operating modes are sequentially switched, or with a computer mouse. Pressing is accompanied by a sound signal.

The scheme of the device is shown in Figure 6.

Figure 6 - Electrical diagram of the reflexometer

The clock frequency of the microcontroller is stabilized by a ZQ1 quartz resonator. Its frequency (4.096 MHz) is chosen so that it is convenient to use it for measuring time intervals. The SB1 button is connected to the RA0 port line (pin 17) of the microcontroller through the current-limiting resistor R3. If its contacts are open, there is a low level on this port line, if it is closed, it is high. To display information, an HG1 LCD with a built-in controller is used. It displays two lines of sixteen characters each and is equipped with an LED backlight.

The indicator is controlled by the DD1 microcontroller via the RBO, RB1 and RB4--RB7 lines, the data is loaded in nibbles. A selection of resistor R7 sets the desired image contrast. On the port line RB2, a control signal is generated for the field-effect transistor VT1, which turns on (turns off) the LCD backlight, the resistor R6 is a current-limiting resistor. A pulse signal with a frequency of 4 kHz is formed on the RB3 port line, which is fed through the resistor R4 to the acoustic emitter HA1.

The device is powered from an external source of direct or alternating voltage 8 ... 12 V, the current consumption does not exceed 130 mA. Diode bridge VD1 rectifies alternating voltage or supplies direct voltage to the elements of the device in the required polarity. The supply voltage of the microcontroller and the LCD is stabilized by the integral stabilizer DA1, the capacitors C1 - C3, C6, C7 are smoothing.

After the supply voltage is applied, data is read from the EEPROM of the microcontroller. A short one-time beep sounds and the HG1 indicator lights up. The inscription “Record Record” appears in its top line. On the right, the best result of the current session is displayed - when you first turn it on, this is the maximum possible measured time interval - 9.999 s. On the left - the best result for the entire time of operation of the device, at the first start also 9.999 s.

Before pressing the SB1 button, the value of the duration of the pre-launch pause is generated. It ranges from 1 to 8.2 s and is random. After pressing the SB1 button and releasing it, the countdown of the pre-launch pause will begin, resetting the LCD information, turning off its backlight. Then the acoustic emitter gives a single sound signal. After the pause, the start moment comes - the LCD backlight turns on, a sound signal (light signal) sounds and the countdown begins. The device measures the reaction time in the range of 0.001...9.999 with a step of 0.001 s.

If the subject does not press the button within 9.999 seconds, the beep stops and the instrument resets to display the best results. When the button is pressed within the specified time interval, the counting stops, the sound signal turns off. On the upper line of the LCD, the inscription "Reaction Reaction" appears, on the lower left - the number of measurements (maximum 255), on the right - the measured reaction time.

Next, the obtained result is compared with the best results for the current and for the entire time of operation of the device. When fixing a new record, the data is overwritten in the EEPROM of the microcontroller. After pressing the button SB 1 and releasing it, the device goes into the initial state. If you press the button before the start (false start), a double beep will sound, the LCD backlight will turn on and the inscription “F.start F.start” will appear in the top line. After a few seconds, the device will return to the initial state.

Working process:

1 Turn on the device by setting the toggle switch to the “On” position. After the supply voltage is applied, a short one-time beep sounds and the indicator backlight turns on. The inscription “Record Record” appears in its top line. The best result of the current session is displayed on the right, the best result for the entire time of the device operation is displayed on the left.

2 Sit at a table in a comfortable position. The subject must look only at the block of light (sound) signals. Move the right toggle switch to the "Sound" position.

3 Place your hand on the unit's control panel (Start/Reset button, computer mouse) so that the index finger of your right (left) hand rests freely on the button.

4 Press the Start/Reset button. After pressing the button and releasing it, the countdown of the pre-launch pause will begin, resetting the LCD information, turning off its backlight. Then the acoustic emitter gives a single sound signal and the countdown begins. After the pause, the start moment comes - the LCD backlight turns on, a sound signal sounds and the countdown begins. The device measures the reaction time in the range of 0.001...9.999 with a step of 0.001 s.

5 When a sound signal appears, it is necessary to press the mouse button as soon as possible and stop the count, the sound signal is turned off. On the upper line of the LCD, the inscription "Reaction Reaction" appears, on the lower left - the number of measurements (maximum 255), on the right - the measured reaction time.

6 Press the "Start/Reset" button, causing the instrument to reset. If you press the mouse button before the start (false start), a double beep will sound, the LCD backlight will turn on and the inscription “F.start F.start” will appear in the top line. After a few seconds, the device will return to its original state.

7 The measurement should be carried out 10 to 30 times, then find the average value of the reaction time. After switching the toggle switch to the “Light” position, repeat steps 1-13.

8 From the results, subtract the time spent on the movement of the phalanx of the finger (0.17 sec.). The obtained value of the reaction time to light and sound stimuli, compare with the values ​​given in table 3.

Conclusions: for this laboratory work, a device for psychophysiological testing "Reflexometer" was created with a detailed description of the tasks, with instructions for performing the work.

To determine the speed of the sensorimotor reaction, volunteers of both sexes aged 19 to 23 years were studied in various psycho-emotional states. The test was carried out in silence and the absence of other stimuli, in a comfortable position of the body and the presence of a support for the elbow, in order to reduce the effect of static contraction of the muscles of the arm. To determine the speed of a simple sensorimotor reaction, the subjects were presented with visual stimuli in the form of a green lamp 0.3 cm in diameter and a sound signal. When the necessary signal appears - green, the task of the volunteer is to press the key as quickly as possible. The time between the appearance of signals was random and ranged from 1 to 7 seconds. The subjects were warned that in each series of the study, they would first be presented with 10 light signals (a study of the time of a simple sensorimotor reaction), then 10 sound signals.

The test was carried out on 15 subjects, 5 of which were in an inhibited state.

Only the time of the sensorimotor reaction was assessed, and errors in the performance of the task were excluded. In order to combat artifacts, the first values ​​in each reaction, the time of which exceeded 2000 ms, were excluded. The latter obviously exceed the time of the sensorimotor reaction and are most often associated with the distraction of the subjects from the test.

According to the results of the research, it follows that for ten students, the average reaction time to a light stimulus is approximately 0.327 s, to a sound stimulus - 0.302 s. These values ​​correspond to the norm for an ordinary, untrained person. In five students who were in a state of inhibition caused by a short sleep, the average reaction time to a light stimulus was 0.497, to a sound stimulus - 0.472 s. These values ​​correspond to a low simple sensorimotor reaction.

However, these results are normal, because the reaction time of a person is in the range from 0.1 to 0.5 seconds. For example, the duration of the formation of the driver's response to traffic lights in a populated area is 0.3-0.4 s. The reaction time depends on the degree of training of a person. In more trained people, the reaction time is quite low, about 0.13-0.15 s. Reaction time is affected by factors such as fatigue, inattention, use of tonic substances or alcohol. When taking a small dose of alcohol, the reaction time increases by 2-4 times.

Practical work No. 1 Determination of human reaction time Purpose - page No. 1/1

Practical work No. 1

Determination of human reaction time
Target : get acquainted with the types of measurements and types of errors, learn how to determine them.

Tasks : 1. Determine your reaction time.

2. Calculate random and relative errors.

Equipment : student ruler
Brief theory

Human reaction time is the time during which a person reacts to some kind of signal, irritation. To determine the reaction of a person, we will use the fall of the ruler from rest, i.e. the initial speed is zero. From the path formula when moving in the gravitational field H=g t 2 /2, we express the time:

(1)

where H is the height of the fall, g is the acceleration of free fall - 9.8 m / s 2, t is the reaction time.

Physics establishes a relationship between quantities, and expresses it in the form of formulas that show how the numerical values ​​of some quantities can be found from the numerical values ​​of others. Accordingly, measurements are divided into direct and indirect. Direct measurements are made using instruments that directly measure the value itself: length with a ruler, time with a stopwatch, speed with a speedometer. The same quantities can be measured by recalculating other quantities, and these will already be indirect measurements.

The accuracy of measurements is characterized by their error. There are absolute, relative, and random errors.

Absolute error(ΔX) is the difference between the value found in the experiment (X exp) and the true (X ist) value of the physical quantity.
ΔX \u003d X exp - X ist (2)
As a true value for the measured value, either the tabular value or the arithmetic mean Xav is usually taken.

(3)

ΔX \u003d X exp - X cf (4)

To obtain more reliable results, it is necessary to conduct a series of experiments, and for them to calculate random error.

(5)

Relative error- dimensionless value equal to the ratio of the absolute error to the arithmetic mean value of the measured value. the relative error can be used to judge the accuracy of the experiment and the reliability of the results.

(6)

Work order

1. Experiments are carried out in pairs. One holds the ruler vertically, the other sets the thumb and forefinger at 0 level at a distance of 1 cm. The first releases the ruler, and the second catches it and writes the result to the table. The experiment is carried out 10 times. The data is entered into a table.

experience number	H,m	t, s	t cf, s	t- t cf, s	, with	σ, s
1

2. Calculate the fall time of the ruler in each experiment using formula (2). Enter the data in the table.

3. Calculate the average time using the formula (3), Write the value in the table.

4. Calculate the deviation from the mean value and its absolute value (module). Data, write in the 5th and 6th columns of the table.

5. Using formula (5), calculate the random error. Enter the value in the table.

6. Determine the relative error of the experiment. Use formula (6).

7. Write a conclusion on the work done, present the result as:

t = t cf ± σ t ,

indicate the relative error and explain the reasons for the error, Is the result reliable.
test questions

1. 
   Which measurements are called indirect, which direct?
2. 
   What measurements can be attributed to the definition of human reaction time?
3. 
   What is called absolute error?
4. 
   What is called random error?
5. 
   What is referred to as relative error?
6. 
   In what case can we consider that a reliable result has been obtained?

Municipal budgetary institution "Rabocheostrovskaya secondary school" of the Kemsky district of the Republic of Karelia "Measurement of human reaction time using a ruler" Research work in physics Completed by: Karyapin Alexander. Student 10 "B" class Project manager: Bukhalova Marina Nikolaevna Rabocheostrovsk, 2013

Relevance of the work: With an increase in the pace of life, the problem of reducing the reaction time to a stimulus is becoming more and more urgent every year, so many researchers are turning to this topic. Our research will be useful to students, drivers of vehicles, as well as people in those professions where a quick response is needed.

Definition of the problem How to measure the reaction time of a person with the help of an ordinary student ruler (!)? Do you know what human reaction time is? Did you know that the reaction depends on the age, fitness and well-being of a person ... Reaction time is one of the important criteria for the selection of drivers, operators, pilots, astronauts.

Research objectives: to find educational material in additional literature, in Internet resources and the media; study the laws of free fall of bodies; use a ruler to explore the reaction time of students in our class during the school day; analyze the results of the experiment; draw conclusions.

Physical foundations of the research method If immediately after the start of the fall the ruler is caught, then by its section “between the fingers” - the mark where we held it at the beginning, and from which it was caught, we can judge how long it fell. This will be the reaction time of the person. It remains to connect the path h and the time t. How to do it?

Program for calculating data: The next stage of my work is the preparation of a microcalculator and the compilation of a sequence of operations on it. We get such a program: we put the number 0.04515 into the memory of the microcalculator, type h (in cm) on the indicator, extract the root from h, multiply by 0.04515 (from memory), we get the answer. we calculate the time t 1 (at h 1 = 1 cm), t 2 (at h 2 = 2 cm). We round each answer to three significant figures and enter it in the table.

Table of results Distance, cm Time, s

Results table: Distance, cm Time, s

Surname Lesson 1 Lesson 2 Lesson 3 Lesson 4 Albul Markitantov Kuntu Vereshchagina Kupriyanova Karyapin Ipatova Staina Emelyanova Egorov Boyarchenko Experimental data

Lesson 1 Lesson 2 Lesson 3 Lesson 4 Lesson Average value Experimental data

Results of the study The largest value of the reaction time, and hence the slow reaction of the students in our class, falls on the first lesson in the schedule. The response to external influences and the perception of the learning process in the second and fourth lessons are significantly improved. At the third lesson according to the schedule, the reaction decreases again, the assimilation of educational material worsens

Subject Coefficient of difficulty Physics 12 Geometry, chemistry 11 Algebra 10 Russian 9 Literature, foreign language 8 Biology 7 Informatics, economics 6 History, social science, MHC5 Astronomy 4 Geography, ecology 3 Life safety, local history 2 Physical education 1 Subject difficulty scale

Good to know Age has a significant effect on reaction time Smoking habit increases reaction time to an event Reaction time in women is not significantly better than in men Reaction time in the presence of external stimuli increases significantly

Resources vremya-reakcii-cheloveka/ vremya-reakcii-cheloveka/