Temporal Integration of Vibrotactile Stimulation

1967 ◽  
Vol 25 (2) ◽  
pp. 549-560 ◽  
Author(s):  
Birgitta Berglund ◽  
Ulf Berglund ◽  
Goesta Ekman
Keyword(s):  
Power Function ◽  
Stimulus Duration ◽  
Temporal Integration ◽  
Logarithmic Function ◽  
Vibrotactile Stimulation ◽  
Scaling Method ◽  
Perceived Intensity ◽  
Psychophysical Scaling

The perceived intensity of vibrotactile stimulation at 250 c/s was measured by a psychophysical scaling method under different conditions of intensity (32–54 db) and duration (30–1200 msec.) of stimulation. It was found (1) that perceived intensity grows as a logarithmic function of stimulus duration up to about 1 sec., whereafter it remains constant, and (2) that the exponent of the psychophysical power function decreases from 0.7 at the shortest duration and approaches a constant value of about 0.4 for the longest durations.

Effects of Psychophysical Scaling Method, Body Test-Site, and Skin-Contactor Surface Area on Vibrotactile Magnitude Functions

1987 ◽  
Vol 64 (3_suppl) ◽  
pp. 1127-1138 ◽  
Author(s):  
Donald Fucci ◽  
Linda Petrosino ◽  
Daniel Harris ◽  
Elise Mc Math
Keyword(s):  
Surface Area ◽  
Test Site ◽  
Thenar Eminence ◽  
Interactive Effects ◽  
Vibrotactile Stimulation ◽  
Scaling Method ◽  
Anterior Midline ◽  
Contactor Area ◽  
Psychophysical Scaling ◽  
Scaling Methods

This study was designed to focus on possible interactive effects that scaling method, body test-site, and skin-contactor surface area might have on vibrotactile magnitude functions. The psychophysical scaling methods of magnitude estimation and magnitude production were used to apply vibrotactile stimulation to the anterior midline of the tongue and the thenar eminence of the hand through the use of three skin-contactor areas (.128, .320, and 1.30 cm3). Ten subjects, ranging in age from 19 to 21 yr. ( M age = 19.8 yr.) were employed. Data obtained from the 10 subjects suggested that the suprathreshold-scaling method chosen can be a significant determinant of the findings obtained. They further suggested that the tongue and hand may respond differently to suprathreshold vibrotactile stimulation and that the effects of varying skin-contactor area may be different for the two body-sites tested.

Anisotropic Temporal Integration in the Perception of Stereoscopic Corrugations

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 170-170 ◽  
Author(s):  
M R Hegarty ◽  
P B Hibbard ◽  
M F Bradshaw ◽  
B De Bruyn ◽  
A D Parton
Keyword(s):  
Linear Relationship ◽  
Stimulus Duration ◽  
Exposure Duration ◽  
Temporal Integration ◽  
Surface Orientation ◽  
Similar Relationship ◽  
Spatial Frequencies ◽  
Do So

Disparity sensitivity for horizontal depth corrugations increases with exposure duration for presentations of up to 1 s (Tyler, 1990 Vision Research30 1877 – 1895). To extend the work of Parton et al (1996 Perception25 67) we investigated whether differences existed in the effects of exposure for corrugations at different orientations. Disparity thresholds were measured for horizontal, vertical, and diagonal gratings with spatial frequencies ranging between 0.1 cycle deg−1 and 0.8 cycle deg−1, as a function of stimulus duration. Stimuli were presented for exposures of between 50 ms and 32 s, and were followed by a random disparity mask, which served the important function of disrupting further processing of stimulus disparity. Thresholds were greatest for vertical gratings. This effect was particularly pronounced for the lowest frequencies. In all conditions, disparity sensitivity improved as exposure duration increased, and continued to do so for all durations tested. For vertical and diagonal gratings, log - log plots of threshold against time showed a linear relationship with a slope of −1 up to 1.0 s, after which time improvements in sensitivity reduced. Horizontal gratings showed a similar relationship, but with thresholds ceasing to decrease significantly after 0.5 s. Temporal integration limits differ with surface orientation, and represent another important difference in our ability to detect and encode depth in stereoscopic surfaces.

Apparent Duration as a Function of Intensity of Vibrotactile Stimulation

1969 ◽  
Vol 28 (1) ◽  
pp. 151-156 ◽  
Author(s):  
Goesta Ekman ◽  
Marianne Frankenhaeuser ◽  
Birgitta Berglund ◽  
Michael Waszak
Keyword(s):  
Electrical Stimulation ◽  
Stimulus Intensity ◽  
Index Finger ◽  
Left Index Finger ◽  
Estimation Technique ◽  
Logarithmic Function ◽  
Vibrotactile Stimulation ◽  
Apparent Duration ◽  
Fixed Standard ◽  
Stimulation Of

8 Ss were exposed to vibrotactile stimulation of 250 Hz, applied to the tip of the left index finger. Seven stimulus intensities, ranging from 26 to 48 db, were each combined with three stimulus durations, 50, 250, and 1200 msec. A magnitude-estimation technique with fixed standard was employed to obtain scale values of the apparent duration of each stimulus. The results indicate that apparent duration can be described as a logarithmic function of stimulus intensity. This conclusion is in line with our previous findings concerning apparent duration of electrical stimulation.

On Scaling of Future Time

1976 ◽  
Vol 43 (3_suppl) ◽  
pp. 1235-1241 ◽  
Author(s):  
Johan Von Wright ◽  
Riitta Kinnunen
Keyword(s):  
Power Function ◽  
Temporal Distance ◽  
Time Range ◽  
Future Time ◽  
Scaling Method ◽  
Different Types ◽  
Chronological Time

Five future points of time (range: 1977 to 2034), described in terms of either (A) year number, or (B) “after N years,” were scaled using two different types of scaling method. Subjective temporal distance was in each case a power function of chronological time, the exponent being consistently lower in Condition A than in B. A corresponding difference was found when subjects rated how threatening they experienced each of three events to be when the events were assumed to take place at the five alternative points of time. Experienced threat decreased exponentially with increasing temporal distance.

Using Psychophysics to Design Speech Warnings

2000 ◽  
Vol 44 (22) ◽  
pp. 698-701
Author(s):  
E. Hellier ◽  
B. Weedon ◽  
J. Edworthy ◽  
K. Walters
Keyword(s):  
Power Function ◽  
Magnitude Estimation ◽  
Power Law ◽  
Warning Signal ◽  
Acoustic Parameter ◽  
Psychophysical Scaling ◽  
The Relationship ◽  
Power Function Exponent

An experiment is reported which applies psychophysical scaling techniques to the design of speech warnings. Participants used magnitude estimation to rate the perceived urgency of computer generated warning signal words (Deadly, Danger, Warning, Caution, Note) that varied systematically in speed. Stevens (1957) Power Law was used to model the relationship between changes in the acoustic parameter and changes in the perceived urgency of a particular signal word. The value for warning designers of the power function exponent, which quantifies and predicts the effect of acoustic changes on perceived urgency, is discussed.

Perceptual and Electrophysiological Correlates of Fixed Versus Moving Sound Source Lateralization

2020 ◽  
Vol 63 (9) ◽  
pp. 3176-3194
Author(s):  
Barrett Victor St. George ◽  
Barbara Cone
Keyword(s):  
Stimulus Duration ◽  
Stimulus Type ◽  
Right Hemisphere ◽  
Temporal Integration ◽  
Perceptual Bias ◽  
P300 Amplitude ◽  
Hemispheric Dominance ◽  
Interaural Level Difference ◽  
Moving Targets ◽  
Fixed Type

Purpose The aims of the study were (a) to evaluate the effects of systematically varied factors of stimulus duration, interaural-level difference (ILD), and direction on perceptual and electrophysiological metrics of lateralization for fixed versus moving targets and (b) to evaluate the hemispheric activity underlying perception of fixed versus moving auditory targets. Method Twelve normal-hearing, young adult listeners were evaluated using perceptual and P300 tests of lateralization. Both perceptual and P300 tests utilized stimuli that varied for type (fixed and moving), direction (right and left), duration (100 and 500 ms), and magnitude of ILD (9 and 18 dB). Listeners provided laterality judgments and stimulus-type discrimination (fixed vs. moving) judgments for all combinations of acoustic factors. During P300 recordings, listeners discriminated between left- versus right-directed targets, as the other acoustic parameters were varied. Results ILD magnitude and stimulus type had statistically significant effects on laterality ratings, with larger magnitude ILDs and fixed type resulting in greater lateralization. Discriminability between fixed versus moving targets was dependent on stimulus duration and ILD magnitude. ILD magnitude was a significant predictor of P300 amplitude. There was a statistically significant inverse relationship between the perceived velocity of targets and P300 latency. Lateralized targets evoked contralateral hemispheric P300 activity. Moreover, a right-hemisphere enhancement was observed for fixed-type lateralized deviant stimuli. Conclusions Perceptual and P300 findings indicate that lateralization of auditory movement is highly dependent on temporal integration. Both the behavioral and physiological findings of this study suggest that moving auditory targets with ecologically valid velocities are processed by the central auditory nervous system within a window of temporal integration that is greater than that for fixed auditory targets. Furthermore, these findings lend support for a left hemispatial perceptual bias and right hemispheric dominance for spatial listening.

Adaptation and Recovery in Vibrotactile Perception

1970 ◽  
Vol 30 (3) ◽  
pp. 843-853 ◽  
Author(s):  
Ulf Berglund ◽  
Birgitta Berglund
Keyword(s):  
Sinusoidal Vibration ◽  
Scaling Method ◽  
Perceived Intensity ◽  
Complete Adaptation ◽  
Vibrotactile Perception ◽  
Stimulation Of

Adaptation and recovery were studied under conditions of constant stimulation of sinusoidal vibration (250 c/s) at three different intensity levels: 40, 47, and 54 db above threshold. A two-step scaling method involving cross-modality matching and numerical scaling of the matching continuum was used. It was found that (1) the perceived intensity decreases exponentially with increased time of stimulation, (2) the decrease in perceived intensity is greater at higher intensity levels, (3) longer time was required for complete adaptation at higher intensities, and (4) the process of recovery is fast, requiring only 2 or 3 minutes.

Mean characteristics of the process of multiple production at 1011–1012 eV

1968 ◽  
Vol 46 (10) ◽  
pp. S675-S677 ◽  
Author(s):  
N. A. Dobrotin ◽  
I. N. Fetisov ◽  
V. V. Guseva ◽  
K. A. Kotelnikov ◽  
A. M. Lebedev ◽  
...  
Keyword(s):  
Angular Distribution ◽  
Power Function ◽  
Cosmic Ray ◽  
Primary Energy ◽  
Tien Shan ◽  
Logarithmic Function ◽  
Multiple Production ◽  
The Mean ◽  
Fireball Model

The dependence of the mean characteristics of multiple production at 1011–1012 eV (i.e., [Formula: see text] = multiplicity of charged secondaries, [Formula: see text] = energy of secondaries in the c.m.s., σc = parameter of anisotropy) on the primary energy E0 is studied experimentally. The analysis is based on 73 interactions of cosmic-ray particles with LiH and C targets observed in two sets of experiments (Pamir and Tien-Shan). The main conclusions are as follows: (1) the dependence of [Formula: see text] on E0 is compatible with both a power function ns ~ E01/4[Formula: see text] and a logarithmic function ns ~ log E0 (theory of peripheral interactions); [Formula: see text] the increase of [Formula: see text] and σc with E0 is compatible with predictions of the fireball model; (3) in coordinates log tan θlab 10% of the interactions have a bimodal angular distribution.

scholarly journals Ants’ Mental Positioning of Amounts on a Number Line

2019 ◽  
Vol 12 (1) ◽  
pp. 35
Author(s):  
Roger Cammaerts ◽  
Marie-Claire Cammaerts
Keyword(s):  
Power Function ◽  
Number Line ◽  
Relative Difference ◽  
Logarithmic Function ◽  
Training Time ◽  
Number Magnitude ◽  
Large Fluctuations ◽  
Non Linear ◽  
The Difference ◽  
The Right

Myrmica sabuleti ants have a mental number line on which numbers (non-symbolic displayed amounts) are ranked, the smaller on the left and the larger on the right. Here we try to know if the difference between two successive numbers is identically estimated all along this line or is less and less well estimated with increasing number magnitude. Ants were trained to distinguish two successive numbers differing by one unit (1 vs 2, 2 vs 3, …, 6 vs 7) during 72 hours and tested after 7, 24, 31, 48, 55 and 72 h. The ants responded less well for larger numbers (e.g. their response to 6 vs 7 was weaker than that to 1 vs 2). The relation between the ants’ ability in discriminating two successive numbers according to their size, ratio or relative difference was best described by a non-linear, power function and somewhat less well by a logarithmic function. A linear function could only significantly better fit the data when large fluctuations in the ants’ discrimination score appeared in the course of increasing training time. The ants’ mental positioning of numerosity on their number line appears thus to be compressed along a non-linear scale, most likely according to a power function of the numbers’ magnitude characteristics.

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