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Biomedical subjects

V I Lupandin

Publications and source records attributed to V I Lupandin.

18 recordsLinked to original sources
PubMed1980

[Relationship between electroretinogram parameters and the intensity of a photic stimulus].

The dependence of frog's and cat's electroretinogram (ERG) amplitude upon intensity of light stimuli within the range from 3.5-10(-3) to 3.5-10(3) lk, had a logarithmic character within the limited range of about 1.5--2.0 log. units (from 3--5 to 150--200 lk). This range corresponded to the maximal increase of the ERG amplitude upon a unit of light intensity, i.e., the maximal sensitivity of the retina. In accordance with some psychophysical facts, the range from 3--5 to 150--200 lk seems to be the most informative in respect to encoding light intensity in visual system.

Animals↗
PubMed1980

[Study of the Stevens exponential function for brightness perception].

Study of the brightness scaling function within the range from 2.10(-2) to 3.5.10(3) lk revealed that the total curve of brightness estimation was not exactly Stevens power function within this range: the exponent's value and its deviation was variable in different light regions. Presumably, the luminance's region with minimal value of exponent is the most information for brightness perception. There seems to exist a certain interrelationship between both Veber--Fechner's and Stevens' laws.

Adolescent↗
PubMedDate not supplied

[Evaluation and reproduction of time intervals in 7-10-year old children].

We examined 200 children at the age of 7-10 (100 boys and 100 girls). The subjects had to estimate and reproduce time intervals in the range of 15-90 s. It was found that the children reproduced the intervals better and with lesser deviations than they estimated the intervals. The precision of time estimation increased with age and was best in ten-ear-old children. The findings confirm the authors' hypothesis about the "active" and "passive" time perception.

Age Factors↗
PubMedDate not supplied

[Diagnosis of mental retardation in children by the reaction time recording method].

The paper deals with the use computer-aided recording the time of visual and motor responses to estimate the severity of mental retardation (MR) in children. It presents standard temporary indices of simple and two differential responses and data on children with MR, obtained by an original computer procedure. In mentally retarded children, the time of responses has been shown to significantly differ from the standard values; the children make more mistakes in differentiation. The children with MR of cerebral organic genesis were found to fall behind in forming differential responses to a greater extent whereas those with MR of polygenic etiology did in forming both simple and differential responses equally.

Age Factors↗
PubMedDate not supplied

[Reaction time to visual stimuli in child development].

The simple and differential reaction time and time of cognitive processes were studied in 3-7-year-old children using age-adapted computer technique. The reaction time significantly decreased with age in parallel with improvement of cognitive processes. An experimental method is proposed, which makes it possible to determine what kind of cognitive process is responsible for age-related decrease in the reaction time.

Child↗
PubMedDate not supplied

[Computerized method for study of temporal characteristics of sensorimotor reactions in preschool and first-grade schoolchildren].

A computerized technique for estimation of the reaction time of motor responses to visual stimuli was advanced. The testing includes three stages. The following kinds of reactions were studied: simple reactions at the first stage, simple choice between 2 and 4 alternatives at the second stage, and, finally, reactions of the complex choice between 2 and 4 alternatives at the third stage. The authors think that each kind of reactions reflects specific components of child's sensorimotor activity. It is planned to study the rate of ontogenetic development of different links included into the functional system of voluntary sensorimotor reactions (perceptual, motor, decision making and others) using the proposed technique.

Aging↗
PubMedDate not supplied

[The invariance of subjective time scales].

Organization of subjective time scales was studied by various methods of duration scaling (reproduction, fractionation, multiplication, evaluation, measuring and cross-model selection). Computation of linear correlation coefficients between physical time and its subjective expression for various methods of scaling in different coordinate systems allows to make a conclusion about a degree form of psychophysical dependence. The value of function degree index varies in the range of 0.80-0.88 for verbal evaluation and 0.93-1.07 for other methods. The concept is suggested about the "active" and "passive" time.

Adolescent↗
PubMedDate not supplied

[The subjective evaluation of time intervals by 3- to 6-year-old children].

The investigation of 3-6 aged children's time perception shows that subjective scaling methods, which except the direct magnitude estimates (cross-modality matching, categorization and duration production) reveal the reliable results. These methods may be used for the age, when the "conceptual time" (the concepts of physical time units) has not be developed yet.

Acoustic Stimulation↗
PubMedDate not supplied

[Sex and age differences in the subjective assessment of time by preschoolers].

Time perception was studied in children under school age from 2.5 to 6 years. Using cross-modal matching, the children assessed durations of 1-, 3-, 5-, 7-, and 10-sec sound signals. It was found out that children under school age, irrespective of sex, more accurately estimated the extreme durations in the internal range (1 and 10 sec). In contrast to girls, boys reveal a clear-cut tendency to minimize the variability of assessments with age. Nevertheless, this tendency is not related with the attention level.

Acoustic Stimulation↗
PubMedDate not supplied

[The capacity to distinguish short durations of time intervals in children and adults].

Two groups of children (5-6-year-old and 7-8-year-old) were presented with pairs of sound signals of the same or different durations. Sound signal durations in pairs could be 1.0, 1.2, 1.5, and 2.0 sec. The children had to detect the difference between the sounds in a pair. The obtained data were compared to the analogous results shown by the 18-39-year-old subjects. It was found out that the ability to discriminate intervals of short duration substantially improved with age. This phenomenon in presumably connected with perfection of the short-term memory. Independently of the subject's age, the order of presentation of signals in a pair influences the ability to discriminate between their durations.

Acoustic Stimulation↗