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At least 19 recordsLinked to original sources
PubMed1996

J. Plateau: on the measurement of physical sensations and on the law which links the intensity of these sensations to the intensity of the source. J. Plateau: report on 'Psychophysical study: theoretical and experimental research on the measurement of sensations, particularly sensations of light and of fatigue' by Mr. Delboeuf. 1872.

Two papers published in 1872 by the Belgian physicist Plateau are here translated into English. The first paper contains the earliest published suggestion that the relation between physical stimulus magnitude and the strength of the internal sensation evoked is a power law and has been much cited for this reason. It also describes the earliest experiment to be performed, though not the first to be reported, on the subject of the psychophysical law. The performance of that experiment antedated Fechner's Elemente der Psychophysik by about 20 years. The second paper summarises a memoir in which a colleague, Delboeuf, reports his more extensive experiments on the subject and commends that memoir to the Belgian Royal Academy. In this second paper Plateau concludes that he was mistaken in supposing the psychophysical law to be a power relation.

Habituation, Psychophysiologic↗
PubMed1990

[Experimental studies on the transitional characteristics from touch sensation to pressure sensation in the mechanoreceptive sensation of periodontium].

Many studies have made on the physiological significance of the periodontium in relation to oral functions. But, although its importance to oral functions has been pointed out, few investigations have been carried out on the periodontal pressoreceptive information system. To help rectify this situation, as a link in investigations of soft-food textures, the author attempted to determine how a sense of pressure was perceived when loads gradually increasing from very small were applied to the tooth surface. In addition, the author attempted to clarify the way the periodontium discerns differences between initial and secondary loadings in a range of small loads between the touch sensation and the pressure sensation. Subjects were 10 males with sound, natural dentition and no disorders in mandibular functions. In order to eliminate intervention from pressoreceptors in the masticatory muscles and the mandibular joints, the upper first premolar was chosen as the test tooth. Small loads were applied in 2 directions: parallel to the first premolar vertical axis (vertical) and from the lingual to the buccal sides parallel to the occlusal plane (horizontal). For vertical loading, the mesial pit on the occlusal surface was chosen as the loading point. The middle point on the lingual surface was chosen as loading point for horizontal loading. First, loading on the tooth surface was gradually increased to obtain (1) threshold value for touch sensation; that is, minimal load required to incite a touch sensation, and (2) critical value for pressure sensation; that is, minimal load required to incite the pressure sensation subsequent to the touch sensation. Each subject was requested to press a hand switch in the moment he experienced the sensation of being touched and then again when, during increases of load, the touch sensation changed to the pressure sensation. The loading device was built into an electric strain gauge. Loads were increased gradually from 0 g to 60 g, with an increase ratio of about 10 g/sec. Loading wave and switching signal were simultaneously recorded on an oscillograph. Second, in order to determine the ability to discriminate small loads, with the same loading device, initial load was applied to the tooth. This load served as control. As soon as the load was sensed, it was removed. Then the secondary (testing) load was applied. Subjects were requested to say whether the secondary load was larger, smaller than or same as the initial one.(ABSTRACT TRUNCATED AT 400 WORDS)

Bite Force↗
PubMed2001

Does bladder tone influence sensation of filling and electro-sensation in the bladder? A blind controlled study in young healthy volunteers using bethanechol.

PURPOSE: The influence of bladder tone on filling sensation and electro-sensation in the bladder was studied in young healthy volunteers. MATERIALS AND METHODS: A total of 22 healthy volunteers 18 to 30 years old were included in our study, of whom 15 received a subcutaneous injection of 5 mg bethanechol and 7 received a subcutaneous injection of water to serve as randomly selected controls. In each group filling perception was evaluated during medium fill cystometry before and 25 minutes after injection. The bladder electrical threshold was determined in each group by constant current stimulation before and 25 minutes after injection. RESULTS: In the study group there was a marked decrease in the volume at which various filling sensations occurred after bethanechol was given. The pressure at which all filling sensations were perceived was higher after bethanechol than at baseline cystometry. The electrical threshold decreased with bethanechol. In the control group no change was noted in the perception of filling or electro-sensation. CONCLUSIONS: Bethanechol has a distinct influence on the filling sensation and on electrical bladder stimulation. Each sensation is sharpened after the administration of bethanechol. Several hypotheses are possible to explain these effects.

Adolescent↗
PubMed1981

Peripheral neural basis of tactile sensations in man: I. Effect of frequency and probe area on sensations elicited by single mechanical pulses on hairy and glabrous skin of the hand.

Tactile thresholds and sensation magnitudes for single mechanical pulses of varying frequency and probe area were studied in order to provide psychophysical data for correlations of tactile sensations with functional properties of different types of human peripheral nerve fibers. Single mechanical pulses were delivered to the hairy or glabrous skin of the hand by means of a perspex probe (area 0.07, 0.7, 3.1, or 12.5 sq.-mm) fixed to the moving coil of an electromechanical vibrator. The frequency of the single pulse was 20, 60 or 150 HZ. Absolute and touch thresholds were measured with a method of production. Suprathreshold sensations were measured with the method of magnitude estimation (6 predetermined displacement amplitudes ranging from 50 to 950 micrometers). Both absolute and touch thresholds were significantly higher on the hairy than on the glabrous skin. The absolute thresholds varied between 44 and 140 micrometers on the hairy and between 9 and 45 micrometers on the glabrous skin; the touch threshold varied between 75 and 300 micrometers and 24 and 153 micrometers, respectively. Lower threshold values were obtained on both skin areas with increasing frequency of the pulse and probe area, the latter effect being significant only for the hairy skin. Standardized magnitude estimation functions could be described with power functions on both skin areas, the exponents of the functions varying between 0.70 and 1.41 on the hairy and between 0.55 and 0.86 on the glabrous skin. The equi-sensation contours showed the difference of sensitivity between the skin areas. Larger sensation magnitudes were obtained with increasing frequency of the pulse and probe area on both skin areas. These psychophysical findings indicate that there is a functional difference at absolute sensation thresholds between hairy and glabrous skin. This difference, however, disappears at higher sensation levels.

Adult↗
PubMed1994

The effects of masking on the growth of vibrotactile sensation magnitude and on the amplitude difference limen: a test of the equal sensation magnitude-equal difference limen hypothesis.

In this study, the hypothesis that the difference limen (DL) for the detection of differences in amplitude of vibrotactile stimuli is independent of the slope of the sensation magnitude function was tested. The slope of the sensation magnitude function was varied by presenting test stimuli in the presence of or in the absence of vibrotactile noise. The slopes of the sensation magnitude functions were determined through a matching technique in which the subject adjusted stimulus amplitudes of a 250-Hz stimulus presented alone and a 250-Hz stimulus presented simultaneously with a masking noise, so that their sensation magnitudes were equated. The slope of the matching function was found to increase as a function of the intensity of the masking noise. In the second phase of the experiment, the amplitude DL was measured by the gated-pedestal method for test stimuli presented under the same stimulus conditions as used in the matching procedure. At all levels of stimulus intensity, the DL was found to be independent of the masking condition provided the sensation magnitudes of the stimuli were the same. This finding supports the hypothesis that the size of the DL is independent of the slope of the sensation magnitude function, provided the sensation magnitudes of stimuli are the same. The generality of this principle, first discovered in hearing, is thus extended to another sense modality.

Auditory Perception↗
PubMed1988

Multistage evaluation scale, differential threshold steps and equivalent sensation contours of respiratory flow-resistive load sensation.

This paper presents and discusses the methodology and results of studies on respiratory sensation by using a fuzzy set category judgement model and applying the concept of just noticeable difference (JND) step and equivalent sensation. A new kind of category scale, the multistage evaluation scale (MES), based on a fuzzy set category judgement model for quantifying respiratory sensory magnitude has been put forward and verified in 37 subjects. The perceived magnitude of added resistance estimated using MES could reflect properly the difference in sensory perception caused by added loads with equal intensity but applied to different phases of the breathing cycle. In addition, the psychophysical function obtained conforms to the Stevens' power law. On the contrary, the classical category scale does not possess some of these attributes. In 9 subjects, we determined that the sensory continuum corresponding to either inspiratory or expiratory added resistive load, ranging 10-500 mm H2O.1(-1).s, consisted of 6 or 7 JND steps. The sensory magnitude corresponding to each step was estimated by the MES. Relating the results of JND step measurements with that of magnitude estimation using MES, we could elucidate systematically the relationship between perceived magnitude and discrimination for respiratory sensation. In 13 subjects, the equivalent respiratory resistive load sensation contours of 2, 3 and 4 JND step above basal level, respectively, were obtained through experimentation and by quadratic polynomial approximation of experimental data. The results suggest that as regards the human tolerance to various added resistive loads the combined resistive load is the most tolerable among the three; the expiratory, the least. The equivalent sensation contour can be used to predict the changes in respiratory sensation determined by both the intensity of the total added load and the ratio of inspiratory versus expiratory load. In brief, we have proposed a new way to elucidate the physiological and psychophysical effects of various added resistive loads.

Humans↗
PubMed1992

Phantom limb sensations in adolescents: a case study to illustrate the utility of sensation and pain logs in pediatric clinical practice.

Although the nature of pain following amputations has been well documented for adults, little research has been conducted to determine the incidence, prevalence, and nature of phantom limb sensations and pains in children and adolescents. This case study documents the nature of phantom limb sensation (intensity, quality, location, duration, and frequency) for a 15-yr-old adolescent after leg amputation. She completed a brief sensation/pain log, consisting of quantitative and qualitative scales, for 28 days after surgery. She experienced phantom limb sensations, which spread from her toes to encompass her entire leg by day 10 after surgery. The pattern of spread was not consistent throughout this period. The quality of sensations remained relatively constant and was described as itching and tingling. The phantom sensations were not experienced consistently throughout the day, but were experienced as discreet episodes. Both the duration and frequency of these episodes decreased throughout the 28 days. Similarly, the intensity of her phantom sensations decreased gradually throughout this period. This case study illustrates how it is possible to integrate research with health care delivery in a practical manner, to obtain prospective information about the nature of childhood sensory experiences.

Adolescent↗
PubMed1996

Paradoxical heat sensation in patients with multiple sclerosis. Evidence for a supraspinal integration of temperature sensation.

Temperature thresholds were determined in 16 patients with probable or definite multiple sclerosis, in six patients with possible but unconfirmed multiple sclerosis and in 34 healthy subjects, using the method of limits and the thermal sensory limen (TSL) of the MarStock technique. A significant proportion of the patients had thresholds outside the 2.5 SD range for normal subjects, both for warmth detection threshold and TSL. In addition, 10 patients with probable or definite multiple sclerosis and one patient with possible multiple sclerosis reported a paradoxical heat sensation, i.e. a sensation of warmth elicited by a cold stimulus. This illusion was almost exclusively observed with the alternating warm and cold stimuli of the TSL procedure. In contrast to experimental nerve block or peripheral demyelinating neuropathy, where paradoxical heat sensation has been described by various authors, in the patients with multiple sclerosis the demyelination sites were located in the central nervous system. The observation that multiple sclerosis patients had paradoxical heat sensation in addition to threshold abnormalities supports the view that supraspinal sites are important for the integration of temperature sensation.

Adult↗
PubMed1992

[Preliminary observation on the relation among needling sensation, propagated sensation along meridian (PSM), and acupuncture effect when acupuncture neiguan].

This paper reports 300 coronary heart disease patients with different needling sensations, mainly with distension, when acupuncturing Neiguan by identical acupuncture doctor with same manipulation. The higher rate of PSM appearance and better acupuncture effect were observed, in patients with compound sensation, such as sourness-distension and distension-numbness. All of the patients who felt pain did not appear PSM and the acupuncture effect was poor. The appearance rate of PSM and acupuncture effect of other kind needling sensations were between the two. The results showed the kind of needling sensation while acupuncture had close relation with the appearance of PSM and the acupuncture effect.

Acupuncture Points↗
PubMed1981

Peripheral neural basis of tactile sensations in man: II. Characteristics of human mechanoreceptors in the hairy skin and correlations of their activity with tactile sensations.

Properties of the human mechanoreceptors in the hairy skin of the back of the hand were studied by microelectrode measurements from the radial nerve. Correlations of unit activity with sensations elicited by tactile pulses (single cycle sinusoids of 20, 60 and 150 HZ) were examined with simultaneous measurements of unit activity and sensation thresholds and magnitude. A total of 264 mechanoreceptive units were identified. Of all units 66% were classified as slowly adapting (SA) and 34% as rapidly adapting (RA) units. Mechanical thresholds of the units as well as simultaneously measured sensation thresholds decreased with increasing frequency of the pulse. The thresholds of several SA units were identical with the subjective thresholds. The responses of the units to supraliminal pulses consisted maximally of 7 impulses. Most SAI and RA units were able to code to some extent the stimulus amplitude on the basis of number of impulses, but only RA units had stimulus-response functions indicating velocity coding. Comparisons of the estimates of sensation magnitude with the number of impulses in the response indicated that the estimate may be based mainly on activity in a population of RA units. The comparison of the present results with earlier reports on properties of receptors in the glabrous skin of the human hand indicates that there are some differences between the characteristics of receptors in the hairy and glabrous skin. However, human receptors in the hairy skin do not seem to differ from the corresponding receptors in the animals.

Adult↗
PubMed1989

Partial masking in electrocutaneous sensation: a model for sensation matching, with applications to loudness recruitment.

A model for partial masking and other threshold-elevation effects is presented in the context of a sensation-matching paradigm. The model is applied to an electrocutaneous experiment in which the subjects adjusted stimulus intensity on the right-hand fingertip to match sensation levels of standard stimuli presented to the left fingertip. Concurrent mechanical stimulation on the right fingertip masked sensation magnitude in a way consistent with the model. Similarities between this tactile masking effect and analogous auditory phenomena are explored. When applied to loudness matching, the model describes the general shape of loudness contours and it shows that the steep slopes observed in auditory masking and "recruitment" can be a consequence of a threshold shift alone, without a supranormal growth in loudness. The model also shows that a small response bias can distort plots of sensation matching, leading to the suggestion that some varieties of loudness recruitment may not have a sensory basis.

Discrimination Learning↗
PubMed1975

The sensation seeker and anxiety reactivity: relationships between the sensation-seeking scales and the activity preference questionnaire.

The five scales of the Zuckerman Sensation-Seeking Scale and Lykken's Activity Preference Questionnaire were administered to 83 male and female college students to test the hypothesis that there is an inverse relationship between sensation seeking and anxiety reactivity. The data were intercorrelated separately for males and females. Results were, in general, consistent with expectations: individuals high in optimal level of stimulation are low in anxiety reactivity in situations that involve physical danger and in situations related to social fears or embarrassment. This relationship was found for most of the dimensions of sensation seeking for males, but was confined to specific subscales for females.

Adolescent↗
PubMed1994

Application of a new, self-recording, vibratory sensation meter to measure temporary threshold shift of vibratory sensation caused by local vibration exposure.

A new, self-recording, vibratory sensation meter measures temporary threshold shifts of vibratory sensation (TTSv) on a finger tip. After exposure to hand-transmitted vibration with exposure frequencies 63 Hz, 200 Hz and 500 Hz, and levels of acceleration 1 g, 2 g, 4 g and 8 g, fingertip measurements were obtained. Temporary threshold shift immediately after the vibratory exposure (TTSv,0) was estimated for each exposure from the regression analysis by approximation of an exponential function. Time constant (tc) was also estimated at the same time by the analysis. The coefficients of determination were large. Thus, the fit of the exponential function is very good for each exposure. The tc corresponds to the recovering velocity of the temporary shift and implies the half-life period of TTSv. These parameters enable us to examine more generally the relationships of TTSv to the characteristics of exposure vibration, subject and other conditions. On this basis, the estimated TTSv,0 and tc were used to examine the dependency of TTSv on the characteristics of the exposure vibration and the subject. The most effective frequency under the level of 4 g is thought to be between 200 Hz and 500 Hz. TTSv,0 of each subject proportionally increased with power of acceleration. The coefficient of determination on regression analysis was large. This result enables us to estimate TTSv,0 at an arbitrary level of acceleration by use of a regression equation derived from experimental data.

Acceleration↗