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Accurate characterization of color depth is important for assessing a dye's relative strength, color fastness, and so on. There are several formulas for color depth, however, with evaluation effects that are quite different. In this study, we attempt to investigate the equi‐depth properties of the color depth formulas so as to provide a reference for selection. One thousand two hundred and six color samples were dyed around six standard depths of three hues in SDC Standard Depth Scales. Sixteen observers were recruited for "Pass–Fail" psychophysical experiments. More than 30 000 experimental data points were obtained to calculate the values of discrimination thresholds and acceptable tolerances at six different standard depths for each formula. The equi‐depth properties of five main color depth formulas were statistically analyzed through their coefficients of variation (CV)% values. Results show that the Yang3 formula is optimal for both color depth discrimination threshold and acceptable tolerance, and its average wrong decision is less than the minimum wrong decision of all observers, as well as those of the other four formulas. Overall, Yang3 formula shows the best equi‐depth and highest relatively accuracy among the five formulas. [ABSTRACT FROM AUTHOR]

The sonification of data to communicate information to a user is a relatively new approach that established itself around the 1990s. To date, many researchers have designed their individual sonification from scratch. There are no standards in sonification design and evaluation. But researchers and practitioners have formulated several requirements and established several methods. There is a wide consensus that psychoacocustics could play an important role in the sonification design and evaluation phase. But this requires a) an adaption of psychoacoustic methods to the signal types of sonification and b) a preparation of the sonification for the psychoacoustic experiment procedure. In this method paper, we present a PsychoAcoustical Method for the Perceptual Analysis of multidimensional Sonification (PAMPAS) dedicated to the researchers of sonification. A well-defined and well-established, efficient, reliable, and replicable just noticeable difference (JND) experiment using the maximum likelihood procedure (MLP) serves as the basis to achieve perceptual linearity of parameter mapping during the sonification design stage and to identify and quantify perceptual effects during the sonification evaluation stage, namely the perceptual resolution, hysteresis effects and perceptual interferences. The experiment results are scores from standardized data space and a standardized procedure. These scores can serve to compare multiple sonification designs of a single researcher or even among different research groups. This method can supplement other sonification designs and evaluation methods from a perceptual viewpoint. [ABSTRACT FROM AUTHOR]

Color depth is of great importance to both dyes and dyeing. The assessments of properties such as color fastness, relative dye strengths require dyed fabric to be adjusted to a specific depth level. However, the study of discrimination threshold and acceptable tolerance of color depth is limited. In this study, we attempted to investigate them. Acceptability (Pass/Fail) psychophysical visual experiments were performed twice by 16 normal color version observers on approximately 1206 samples for 6 standard depths in 3 hues, yielding approximately 40,000 visual assessment data points. The color depth formula, Yang3, which performed best in linearity to color depth in a previous study, was selected to calculate the color depth values YCD3 of the samples. The calculated and the visual data were bridged statistically. Experimental results show that the average discrimination threshold and acceptable tolerance of color depth are approximately 0.45 and 2.15 in YCD3, respectively. Furthermore, the details of different hues, lighter and deeper, male and female perspectives were analyzed and discussed. The Yang3 formula exhibited uniformity at different standard depths, as expected. [ABSTRACT FROM AUTHOR]

The sonification of data to communicate information to a user is a relatively new approach that established itself around the 1990s. To date, many researchers have designed their individual sonification from scratch. There are no standards in sonification design and evaluation. But researchers and practitioners have formulated several requirements and established several methods. There is a wide consensus that psychoacocustics could play an important role in the sonification design and evaluation phase. But this requires a) an adaption of psychoacoustic methods to the signal types of sonification and b) a preparation of the sonification for the psychoacoustic experiment procedure. In this method paper, we present a PsychoAcoustical Method for the Perceptual Analysis of multidimensional Sonification (PAMPAS) dedicated to the researchers of sonification. A well-defined and well-established, efficient, reliable, and replicable just noticeable difference (JND) experiment using the maximum likelihood procedure (MLP) serves as the basis to achieve perceptual linearity of parameter mapping during the sonification design stage and to identify and quantify perceptual effects during the sonification evaluation stage, namely the perceptual resolution, hysteresis effects and perceptual interferences. The experiment results are scores from standardized data space and a standardized procedure. These scores can serve to compare multiple sonification designs of a single researcher or even among different research groups. This method can supplement other sonification designs and evaluation methods from a perceptual viewpoint.

In this study, the effect of discrimination threshold on velocity variation is investigated, and a self-tuning algorithm for velocity variation is proposed to improve the accuracy of an advanced automatic crash notification (AACN) system. First, after determining the factors affecting driver injury, an injury prediction model for the driver is developed. Second, the prediction accuracy affected by the discrimination threshold in the AACN system is analyzed using a finite element model for a sled crash test. Third, the self-tuning occupant injury prediction algorithm is presented based on an association model for the velocity variation error, discrimination threshold, and acceleration peak. Fourth, a vehicle terminal is designed by embedding a self-tuning algorithm into the system. Finally, a sled test and vehicle crash test are conducted to verify the reliability of the self-tuning algorithm. The test results show that the self-tuning algorithm can increase the accuracy of the probability of driver injury. [ABSTRACT FROM AUTHOR]

The delay discounting perspective, which assumes analternative-wise processing of attribute information, has longdominated research on intertemporal choice. Recent studies,however, have suggested that intertemporal choice is based onattribute-wise comparison. This line of research culminated inthe tradeoff model (Scholten & Read, 2010; Scholten, Read,& Sanborn, 2014), which can accommodate most establishedbehavioral regularities in intertemporal choice. One drawbackof the tradeoff model, however, is that it is static, providingno account of the dynamic process leading to a choice. Herewe develop a dynamic tradeoff model that can qualitativelyaccount for empirical findings in intertemporal choiceregarding not only choices but also response times. Thedynamic model also outperforms the original, static tradeoffmodel when quantitatively fitting choices from representativedata sets, and even outperforms the best-performing dynamicmodel derived from Decision Field Theory in Dai andBusemeyer (2014) when fitting both choices and responsetimes.

In this paper results of chromatic discrimination measurements obtained in two lighting scenarios are compared. Chromatic discrimination thresholds were measured in relation with systematically manipulated chromaticities seen under different visual angles. In both cases the Ellipse module of the Cambridge Colour Test (CCT) was obtained binocularly by normal colour-observers. Discrimination ellipses fitted to the measured thresholds were compared in terms of the adapting chromaticity and the visual angle of the adapting stimulus. Our findings show that changes in the reference chromaticity of the CCT have stronger effect on the elongation of the chromatic discrimination ellipses compared to the effect of the adapting chromaticity obtained in a light booth. Further comparison of discrimination thresholds estimated towards the confusion directions and the corresponding radii of the Ellipse test results suggests that the reliability of the Ellipse test results depends on the relation between the measurement directions and the confusion directions. [ABSTRACT FROM AUTHOR]

Touch shape discrimination is not only closely related to tactile mechanoreceptors but also higher cognitive function. However, previous shape discrimination methods are difficult to complete in a short time, and the devices are complicated to operate and not user-friendly for nonprofessionals. Here, we propose a new method, the evaluation quantity of which is the angle discrimination threshold. In addition, to make this method easy to use for nonprofessionals, we designed a haptic angle sorting system, including the device and software. To evaluate this method, the angle sorting and two-angle discrimination experiments were compared, and it was found that participants spent significantly less time in the former experiment than in the latter. At the same time, there is a strong correlation between the performance of angle sorting and two-angle discrimination, which shows that the angle threshold obtained by the new method can also be used to evaluate the ability of touch discrimination. Moreover, the angle sorting results of different age groups also further demonstrate the feasibility of the method. The efficiency of this new method and the effectiveness of the system also provide a convenient means for evaluating haptic shape discrimination, which may have potential clinical application value in the early diagnosis of peripheral neuropathy and even in the evaluation of cognitive function. [ABSTRACT FROM AUTHOR]

Background: A previously acquired fear response often spreads to perceptually or conceptually close stimuli or contexts. This process, known as fear generalization, facilitates the avoidance of danger, and dysregulations in this process play an important role in anxiety disorders. Oxytocin (OT) has been shown to modulate fear learning, yet effects on fear generalization remain unknown. Methods: We employed a randomized, placebo-controlled, double-blind, between-subject design during which healthy male participants received either intranasal OT or placebo (PLC) following fear acquisition and before fear generalization with concomitant acquisition of skin conductance responses (SCRs). Twenty-four to 72 h before the fear learning and immediately after the fear generalization task, participants additionally complete a discrimination threshold task. Results: Relative to PLC, OT significantly reduced perceived risk and SCRs towards the CS+ and GS1 (the generalization stimulus that is most similar to CS+) during fear generalization, whereas the discrimination threshold was not affected. Conclusions: Together, the results suggest that OT can attenuate fear generalization in the absence of effects on discrimination threshold. This study provides the first evidence for effects of OT on fear generalization in humans and suggests that OT may have therapeutic potential in anxiety disorders characterized by dysregulated fear generalization. [ABSTRACT FROM AUTHOR]

• Beef fat was quantified by alternative methods and compared to the Folch's reference. • Validity domains and measurement uncertainties were determined by accuracy profile. • Bias correction for the alternative methods ensure continuity with the reference method. • The validity domains of the alternative methods were adapted to most commercial meats. • The discrimination threshold was calculated and applied to previous studies. Many studies on beef nutritional qualities require the quantification of intramuscular fat. To reduce the sample amount, solvent use and time of analysis, two alternative methods to the Folch et al. (1957) reference method were studied: a miniaturised Folch's method and a near-infrared spectroscopic method. Performances and acceptability limits were evaluated with accuracy profiles for each of the methods. Equations to correct bias between the alternative and reference methods were calculated. Uncertainties associated with measurements were determined, and the validity domains were defined. From a previous set of studies, the ability of each method to discriminate samples from bovines of different breeds or receiving diverse treatments was tested. The validity domain of the miniaturised Folch's method ranged from 1.9 to 13.8 g of total lipids/100 g of tissue, and that of the near-infrared spectroscopic method ranged from 4.8 to 13.8 g of total lipids/100 g of tissue, with less than 20% difference from the reference method's results. Thus, the two alternative methods could be used depending on the research objectives: the miniaturised Folch's method could be used for detailed quantification of intramuscular fat and the near-infrared spectroscopic method for a quick classification of a large number of muscles. The precise knowledge of uncertainties associated with each measurement was determined, and perfect continuity with the results obtained so far with the reference Folch's method was confirmed. [ABSTRACT FROM AUTHOR]

Human’s ability to work upon, or manipulate objects in the environment depends on the psychological function to perceive objects’ size appropriately. In daily situation, human recognizes object size by using visual and haptic cues concurrently. In experimental psychology, human visual information processing of object size has long been a major research area, and substantial amount of knowledge has been accumulated, but relatively little is known concerning the haptic information processing. In this study, characteristics of haptic size perception were examined in discrimination and magnitude estimation (ME) experiments for ‘one-dimensional (1D)‘ stimuli (bars of which lengths were varied) and ‘two-dimensional (2D)’ stimuli (circles, triangles and squares of which areas were varied). In the experiments, participants held the 1D standard and comparison stimuli with two fingers (thumb and index or middle finger), or 2D stimuli with three (or four) fingers (thumb, index, and middle (plus third) fingers), and discriminated or evaluated the sizes of the stimuli. The results of the discrimination experiment showed that Weber ratios, defined as discrimination threshold/standard stimulus size, for the two 2D stimuli (circles and squares, but not for triangles) were lower (i.e., discrimination sensitivities were higher) than those for the 1D stimuli. The difference in the discrimination sensitivities was explained by taking into account probability summation between multiple inter-finger distance cues available for the 2D stimuli. Weber ratio for the triangles may be affected by the uncertain factor that the figures were not identified only by the information of contact points. The results of the ME experiment showed that the evaluated value vs. stimulus size functions had different slopes for the 1D and 2D stimuli, suggesting that size perception for the 1D and 2D stimuli may be mediated by different mechanisms specialized for processing of the length and the area of haptic stimuli.

There are color vision barrier-free conversion algorithms that are used to improve the contrast in images for dichromats. The algorithms focus on whether dichromats can distinguish a combination of colors and often use a simulation model of color appearance for dichromats. To adjust the algorithms for individual dichromats, it is necessary to investigate whether the simulation model used is suitable for them in the vicinity of the color discrimination threshold Θ ; however, there have been few such studies. In this paper, we propose a method of judging the suitability of a simulation model for dichromatic color appearance in the vicinity of Θ using psychophysical measurements. In our method, gradually changing colors in the RGB color space are presented (Presentation A) to a dichromat and Θ A is obtained. Moreover, colors that are simulated by a target model are also presented (Presentation B) to the dichromat and Θ B is obtained. The suitability of the simulation model for the dirchromat is quantitatively judged by comparing Θ A and Θ B using statistical methods. An application example of the proposed method is also described to concretely show the procedure of the method. [ABSTRACT FROM AUTHOR]

Haptic object perception is still poorly understood up to now. This study investigated the ability of human fingers to discriminate the volume of objects by passive touch. Experiments measured the discrimination threshold of volume using three tasks: passive tactile volume perception, passive tactile area perception, and active tactile volume perception. In each trial, we utilized two plastic cubes to successively stimulate the fingers, and participants were instructed to make comparisons between the stimulus objects' volume and area. Results showed that there was no significant difference in the discrimination thresholds of tactile volume perception between passive touch and active touch, whereas significant differences in the discrimination thresholds between fingertips, such as the thumb versus the pinky finger. In passive touch, the discrimination thresholds of volume perception were larger than that with surface area perception. We found that the discrimination of the volume of objects is more difficult than the discrimination of the area of the objects. [ABSTRACT FROM AUTHOR]

Credit risk prediction should maximize a bank's loan profit. This paper performs modified profit-based logistic regression (MPLR) by constructing an objective function with the maximum profit as the objective. The optimal weights of two kinds of samples are obtained by constructing an objective function based on the sum of the weighted profit acquired in default and nondefault cases. To obtain greater loan profit, each customer's optimal discrimination threshold is determined by comparing the expected profit that the customer is predicted to produce in the default and nondefault scenarios. The research results show that the predicted and real profits obtained by our model are significantly higher than those obtained by 16 other classification models. The utilized weights can improve the accuracy and profit of the MPLR model, but the discrimination threshold is more important than the weights. The sample balancing process may not necessarily improve the classification accuracy and profit because it can reduce the Type-II error while increasing the induced Type-I error. [Display omitted] • An improved logistic regression model (MPLR) is used to predict credit risk. • Each customer's discrimination threshold is obtained by the expected profit. • The optimal weights of two kinds of samples are obtained by the Lagrange function. • The outcomes have been compared with other approaches on different metrics. • The empirical results in three datasets confirm the robustness of the MPLR model. [ABSTRACT FROM AUTHOR]

• Intertemporal preference elicited by matching tasks shows behavioral regularities. • Non-evidence-accumulation models are developed for such matching tasks. • These models outperform evidence-accumulation models in explaining the regularities. • Evidence accumulation is not essential for generating intertemporal preference. Intertemporal preference has been investigated mainly with a choice paradigm. However, a matching paradigm might be more informative for a proper inference about intertemporal preference and a deep understanding of the underlying cognitive mechanisms. This research involved two empirical studies using the matching paradigm and compared various corresponding dynamic models. These models were developed under either the framework of decision field theory, an exemplar theory assuming evidence accumulation, or a non-evidence-accumulation framework built upon the well-established notions of random utility and discrimination threshold (i.e., the RUDT framework). Most of these models were alternative-based whereas the others were attribute-based ones. Participants in Study 1 were required to fill in the amount of an immediate stimulus to make it as attractive as a delayed stimulus, whereas those in Study 2 needed to accomplish a more general matching task in which either the payoff amount or delay length of one stimulus was missing. Consistent behavioral regularities regarding both matching values and response times were revealed in these studies. The results of model comparison favored in general the RUDT framework as well as an attribute-based perspective on intertemporal preference. In addition, the predicted matching values and response times of the best RUDT model were also highly correlated with the observed data and replicated most observed behavioral regularities. Together, this research and previous modeling work on intertemporal choice suggest that evidence accumulation is not essential for generating intertemporal preference. Future research should examine the validity of the new framework in other preferential decisions for a more stringent test of the framework. [ABSTRACT FROM AUTHOR]

Touch shape discrimination is not only closely related to tactile mechanoreceptors but also higher cognitive function. However, previous shape discrimination methods are difficult to complete in a short time, and the devices are complicated to operate and not user-friendly for nonprofessionals. Here, we propose a new method, the evaluation quantity of which is the angle discrimination threshold. In addition, to make this method easy to use for nonprofessionals, we designed a haptic angle sorting system, including the device and software. To evaluate this method, the angle sorting and two-angle discrimination experiments were compared, and it was found that participants spent significantly less time in the former experiment than in the latter. At the same time, there is a strong correlation between the performance of angle sorting and two-angle discrimination, which shows that the angle threshold obtained by the new method can also be used to evaluate the ability of touch discrimination. Moreover, the angle sorting results of different age groups also further demonstrate the feasibility of the method. The efficiency of this new method and the effectiveness of the system also provide a convenient means for evaluating haptic shape discrimination, which may have potential clinical application value in the early diagnosis of peripheral neuropathy and even in the evaluation of cognitive function.

Body–machine interfaces (BMIs) provide a non-invasive way to control devices. Vibrotactile stimulation has been used by BMIs to provide performance feedback to the user, thereby reducing visual demands. To advance the goal of developing a compact, multivariate vibrotactile display for BMIs, we performed two psychophysical experiments to determine the acuity of vibrotactile perception across the arm. The first experiment assessed vibration intensity discrimination of sequentially presented stimuli within four dermatomes of the arm (C5, C7, C8, and T1) and on the ulnar head. The second experiment compared vibration intensity discrimination when pairs of vibrotactile stimuli were presented simultaneously vs. sequentially within and across dermatomes. The first experiment found a small but statistically significant difference between dermatomes C7 and T1, but discrimination thresholds at the other three locations did not differ. Thus, while all tested dermatomes of the arm and hand could serve as viable sites of vibrotactile stimulation for a practical BMI, ideal implementations should account for small differences in perceptual acuity across dermatomes. The second experiment found that sequential delivery of vibrotactile stimuli resulted in better intensity discrimination than simultaneous delivery, independent of whether the pairs were located within the same dermatome or across dermatomes. Taken together, our results suggest that the arm may be a viable site to transfer multivariate information via vibrotactile feedback for body–machine interfaces. However, user training may be needed to overcome the perceptual disadvantage of simultaneous vs. sequentially presented stimuli. [ABSTRACT FROM AUTHOR]

• The psychophysical method was used to quantify the subjective perception of temperature. • Pinewood, oakwood, and ceramic tiles are compared on thermal touch sensation. • The method could be useful for evaluating the thermal quality of building materials. • The results seem promising for energy modelling. When touched, dissimilar materials, such as metal and wood, evoke different thermal sensations when both are maintained at room temperature due to the inherent differences in their thermo-physical properties. In this study, we employed psychophysical experiments to quantify the tactile perception of surface temperature using pine wood, oak wood and ceramic floor tile. Twenty-four participants (10 female, 14 male; age 27+- 5 years) took part in the experiment. The results showed that a pine surface at 20.0 ºC feels equally cold to that of an oak surface with a temperature of 20.9 ºC. After increasing or decreasing the oak surface temperature by 1.2 °C (from 20.9 °C) it began to feel, respectively, either warmer or colder than the pine surface at 20 °C. Similarly, the pine surface at 20.0 °C and ceramic tile surface at 22.8 °C evoked an equal sensation of cold and, by raising the temperature of the ceramic tile by 0.9 °C from 22.8 °C, it began to feel warmer than the pine at 20 °C. On the other hand, by decreasing the temperature of the ceramic tile by the same amount (0.9 °C), the pine surface at 20 °C began to feel warmer. The quantification of temperature perception seems to offer a promising approach to precisely evaluating the tactile warmth and thermal behaviour of building materials used in diverse applications. We further discuss how these results might offer insights into how the heating/cooling energy required in buildings might be reduced with the careful selection of construction materials. [ABSTRACT FROM AUTHOR]

The development of an easy to implement, quantitative measure to examine vibration perception would be useful for future application in clinical settings. Vibration sense in the lower limb of younger and older adults was examined using the method of constant stimuli (MCS) and the two-alternative forced choice paradigm. The focus of this experiment was to determine an appropriate stimulation site on the lower limb (tendon versus bone) to assess vibration threshold and to determine if the left and right legs have varying thresholds. Discrimination thresholds obtained at two stimulation sites in the left and right lower limbs showed differences in vibration threshold across the two ages groups, but not across sides of the body nor between stimulation sites within each limb. Overall, the MCS can be implemented simply, reliably, and with minimal time. It can also easily be implemented with low-cost technology. Therefore, it could be a good candidate method to assess the presence of specific deep sensitivity deficits in clinical practice, particularly in populations likely to show the onset of sensory deficits. [ABSTRACT FROM AUTHOR]

To study the effect of the passband of a digital filter on the nature of the attenuation of the amplitude of an acoustic emission (AE) pulse and on the change in the group velocity of a wave packet in the near zone of up to 300 mm from the radiation source, studies were conducted on a multilayered polymer-composite-material (PCM) panel and an AMG-2 aluminum alloy plate with a thickness of 6 mm. In the course of the experiments, it has been established that narrowing the passband of the digital filter from 30–500 to 100–200 kHz can significantly affect the accuracy of the coordinate location of AE-event radiation sources situated near AE transducers, at a distance of less than 100 mm. As the passband of the digital filter narrows and the low- and high-frequency components of the spectrum are cut off, the wave front of the recorded pulse becomes more gently sloping, resulting in an increase in the difference of arrival times (DAT) of pulses to the AE transducers and in a decrease in the calculated group velocity of the wave packet. The error arising in this case is greater than the passband of the filter applied. [ABSTRACT FROM AUTHOR]

Many biological studies seek to confirm the effect of a treatment on the levels of chemical markers in biological tissues. This requires choosing the analytical method best able to detect the difference between basal levels and those found after treatment. We propose a new approach to calculate a criterion we call the ‘discrimination threshold’ ( DT ), and we applied it to an analytical method that we developed to determine cortisol in cattle plasma to detect stress. DT is derived from the measurement uncertainty (MU), and combines the variabilities of both the analytical method and the marker. The uncertainty of the analytical method comes from the method validation study. The marker variability (here cortisol) is modeled from a literature review. The graphical representation of DT allows estimating the applicability of the method. Our analytical method is shown to perform well when the difference in blood cortisol exceeds 18 ng. mL −1 . [ABSTRACT FROM AUTHOR]

Afferent input from the periphery to the cortex contributes to the control of grasping. How sensory input is gated along the ascending sensory pathway and its functional role during gross and fine grasping in humans remain largely unknown. To address this question, we assessed somatosensory-evoked potential components reflecting activation at subcortical and cortical levels and psychophysical tests at rest, during index finger abduction, precision, and power grip. We found that sensory gating at subcortical level and in the primary somatosensory cortex (SI), as well as intracortical inhibition in the SI, increased during power grip compared with the other tasks. To probe the functional relevance of gating in the SI, we examined somatosensory temporal discrimination threshold by measuring the shortest time interval to perceive a pair of electrical stimuli. Somatosensory temporal discrimination threshold increased during power grip, and higher threshold was associated with increased intracortical inhibition in the SI. These novel findings indicate that humans gate sensory input at subcortical level and in the St largely during gross compared with fine grasping. Inhibitory processes in the St may increase discrimination threshold to allow better performance during power grip. [ABSTRACT FROM AUTHOR]

Traditionally, descriptive accounts of intertemporal choice have relied on static and deterministic models that assume alternative-wise processing of the options. Recent research, by contrast, has highlighted the dynamic and probabilistic nature of intertemporal choice and provided support for attribute-wise processing. Currently, dynamic models of intertemporal choice—which account for both the resulting choice and the time course over which the construction of a choice develops—rely exclusively on the framework of evidence accumulation. In this article, we develop and rigorously compare several candidate schemes for dynamic models of intertemporal choice. Specifically, we consider an existing dynamic modeling scheme based on decision field theory and develop two novel modeling schemes—one assuming lexicographic, noncompensatory processing, and the other built on the classical concepts of random utility in economics and discrimination thresholds in psychophysics. We show that all three modeling schemes can accommodate key behavioral regularities in intertemporal choice. When empirical choice and response time data were fit simultaneously, the models built on random utility and discrimination thresholds performed best. The results also indicated substantial individual differences in the dynamics underlying intertemporal choice. Finally, model recovery analyses demonstrated the benefits of including both choice and response time data for more accurate model selection on the individual level. The present work shows how the classical concept of random utility can be extended to incorporate response dynamics in intertemporal choice. Moreover, the results suggest that this approach offers a successful alternative to the dominating evidence accumulation approach when modeling the dynamics of decision making. [ABSTRACT FROM AUTHOR]

Humans exhibit a remarkable ability to discriminate variations in object volume based on natural haptic perception. The discrimination thresholds for the haptic volume perception of the whole hand are well known, but the discrimination thresholds for haptic volume perception of fingers and phalanges are still unknown. In the present study, two psychophysical experiments were performed to investigate haptic volume perception in various fingers and phalanges. The configurations of both experiments were completely dependent on haptic volume perception from the fingers and phalanges. The participants were asked to blindly discriminate the volume variation of regular solid objects in a random order by using the distal phalanx, medial phalanx, and proximal phalanx of their index finger, middle finger, ring finger, and little finger. The discrimination threshold of haptic volume perception gradually decreases from the little finger to the index finger as well as from the proximal phalanx to the distal phalanx. Overall, both the shape of the target and the part of the finger in contact with the target significantly influence the precision of haptic perception of volume. This substantial data set provides detailed and compelling perspectives on the haptic system, including for discrimination of the spatial size of objects and for performing more general perceptual processes. [ABSTRACT FROM AUTHOR]