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Pempek is a typical food from Palembang, Indonesia. It is commonly consumed with cuko, a dipping sauce containing acetic acid which is corrosive. The research aimed to determine the absolute and recognition threshold, as well as changes in tongue sensitivity to sweet, salty and sour taste of the pempek-cuko consumers. The threshold measurements used the ASTM method. There were 78 panelists whom grouped based on the frequency of eating pempek-cuko per week, namely twice and more than twice per week. The results showed that the absolute threshold of panelists with the frequency of eating pempek-cuko twice per week for sweet, salty and sour tastes were 0.827%, 0.071%, and 0.041% respectively, while the recognition threshold were 1.241%, 0.107%, and 0.061% respectively. For panelists with a frequency of eating pempek-cuko more than twice per week, the absolute thresholds for sweet, salty and sour tastes were 1.581%, 0.243% and 0.066% respectively, while the recognition threshold were 2.371%, 0.365% and 0.099% respectively. The absolute and recognition threshold of all tastes for panelists whose frequency of eating pempek-cuko was more than twice per week was higher compared to panelists whose frequency of eating pempek and cuko was twice per week. Continuous exposure of the tongue to the sour taste with low acidity of cuko contributed to a decrease in tongue sensitivity to all of the tastes.

Objectives: To investigate the prognostic capacity of baseline 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) metabolic parameters in extranodal natural killer/T-cell lymphoma (ENKTCL), and the influence of relative thresholds (RT) and absolute thresholds (AT) selection on prognostic capacity. Materials and methods: Metabolic tumor volume (MTV)-based parameters were defined using RTs (41 % or 25 % of maximum standardized uptake value [SUVmax]), ATs (SUV 2.5, 3.0, 4.0, or mean liver uptake) in 133 patients. Metabolic parameters were classified into avidity-related parameters (SUVmax, mean SUV [SUVmean], standard deviation of SUV [SUVsd]), volume-related parameters (RT-MTV), and avidity- and volume-related parameters (total lesion glycolysis [TLG] and AT-MTV). The prognostic capacity of the metabolic parameters and the effects of different threshold types (RT vs. AT) were evaluated. Results: All metabolic parameters were moderately associated with prognosis. However, the area under the receiver operating characteristic curve of MTV and TLG was slightly higher than that of avidity-related parameters for predicting 5-year progression-free survival (PFS) (0.614–0.705 vs. 0.563–0.609) and overall survival (OS) (0.670–0.748 vs. 0.562–0.593). Correlations of MTV and avidity-related parameters differed between RTs (r

Recently, non-invasive proximal nerve stimulation has been widely investigated to restore tactile sensations. It has been demonstrated that tactile sensations in the hand could be elicited by nerve stimulation on the upper arm. However, it is still unknown whether tactile sensations could be elicited by stimulation at a proximal location close to the neck. In this study, non-invasive proximal nerve stimulation tests were performed to elicit tactile sensations in the hand of subjects. Six Ag/AgCl gel electrodes (2 × 3) were placed on the supraclavicular fossa where the proximal parts of the brachial plexus nerves were located. Then, fifteen potential electrode pairs were tested to explore whether tactile sensations could be elicited by non-invasive proximal nerve stimulation. Eight able-bodied subjects (male) were recruited to participate in the test. The stimulated sensation regions in the hand and the sensory intensity were reported and recorded during the experiment. The results demonstrated that the tactile sensations in various regions in the hand could be elicited through non-invasive nerve stimulation at the proximal location close to the neck. [ABSTRACT FROM AUTHOR]

Auditory filter (AF) shape has traditionally been estimated with a combination of a notched-noise (NN) masking experiment and a power spectrum model (PSM) of masking. However, there are several challenges that remain in both the simultaneous and forward masking paradigms. We hypothesized that AF shape estimation would be improved if absolute threshold (AT) and a level-dependent internal noise were explicitly represented in the PSM. To document the interaction between NN threshold and AT in normal hearing (NH) listeners, a large set of NN thresholds was measured at four center frequencies (500, 1000, 2000, and 4000 Hz) with the emphasis on low-level maskers. The proposed PSM, consisting of the compressive gammachirp (cGC) filter and three nonfilter parameters, allowed AF estimation over a wide range of frequencies and levels with fewer coefficients and less error than previous models. The results also provided new insights into the nonfilter parameters. The detector signal-to-noise ratio (K) was found to be constant across signal frequencies, suggesting that no frequency dependence hypothesis is required in the postfiltering process. The ANSI standard "Hearing Level-0dB" function, i.e., AT of NH listeners, could be applied to the frequency distribution of the noise floor for the best AF estimation. The introduction of a level-dependent internal noise could mitigate the nonlinear effects that occur in the simultaneous NN masking paradigm. The new PSM improves the applicability of the model, particularly when the sound pressure level of the NN threshold is close to AT. [ABSTRACT FROM AUTHOR]

Abnormal passenger behavior in rail transit has become a top priority, as it affects operational safety. Passenger travel time is the main basis for identifying abnormal behavior while considering the flexibility of travel time. Currently, the main method is to use absolute threshold discrimination based on the distribution of travel time. However, there is a problem of missing abnormal passenger behavior due to the large difference in travel time between the Origin-Destinations (ODs). Therefore, this paper proposes a method of setting corresponding thresholds for each OD. By analyzing the percentile curves of the overall and individual OD pairs, it was found that the turning point of the curve had a significant feature, and the difference between the two sides of the curve was obvious. This paper proposes a bilateral fitting method, and the results show that this method can calculate the relative threshold for different OD pairs. The significant advantages of this method are its low cost and wide coverage. [ABSTRACT FROM AUTHOR]

Background: The activation of the medial olivocochlear reflex reduces the cochlear gain, which is manifested perceptually as decreased auditory sensitivity. However, it has remained unclear whether the extent of this suppression varies according to the cochlear region involved. Here we aims to assess the magnitude of contralateral efferent suppression across human cochlea, at low levels, and its impact on hearing sensitivity. Methods: Assuming that acoustic stimulation activates the contralateral medial olivocochlear reflex, we evaluated the magnitude of the suppressive effect as a function of frequency in 17 subjects with normal hearing. Absolute thresholds were measured for bursts tones of various durations (10, 100, and 500 ms) and frequencies (250, 500, 1000, 4000, and 8000 Hz) in the presence or absence of contralateral white noise at 60 dB SPL. Results: We found that contralateral noise raised the absolute threshold for the burst tones evaluated. The effect was greater at lower than higher frequencies (3.85 dB at 250 Hz vs. 2.22 dB at 8000 Hz). Conclusions: Our findings suggest that in humans, the magnitude of this suppression varies according to the cochlear region stimulated, with a greater effect towards the apex (lower frequencies) than the base (higher frequencies) of the cochlea.

Auditory filter (AF) shape has traditionally been estimated with a combination of a notched-noise (NN) masking experiment and a power spectrum model (PSM) of masking. However, there are several challenges that remain in both the simultaneous and forward masking paradigms. We hypothesized that AF shape estimation would be improved if absolute threshold (AT) and a level-dependent internal noise were explicitly represented in the PSM. To document the interaction between NN threshold and AT in normal hearing (NH) listeners, a large set of NN thresholds was measured at four center frequencies (500, 1000, 2000, and 4000 Hz) with the emphasis on low-level maskers. The proposed PSM, consisting of the compressive gammachirp (cGC) filter and three nonfilter parameters, allowed AF estimation over a wide range of frequencies and levels with fewer coefficients and less error than previous models. The results also provided new insights into the nonfilter parameters. The detector signal-to-noise ratio (K) was found to be constant across signal frequencies, suggesting that no frequency dependence hypothesis is required in the postfiltering process. The ANSI standard "Hearing Level-0dB" function, i.e., ATof NH listeners, could be applied to the frequency distribution of the noise floor for the best AF estimation. The introduction of a level-dependent internal noise could mitigate the nonlinear effects that occur in the simultaneous NN masking paradigm. The new PSM improves the applicability of the model, particularly when the sound pressure level of the NN threshold is close to AT. [ABSTRACT FROM AUTHOR]

Abnormal passenger behavior in rail transit has become a top priority, as it affects operational safety. Passenger travel time is the main basis for identifying abnormal behavior while considering the flexibility of travel time. Currently, the main method is to use absolute threshold discrimination based on the distribution of travel time. However, there is a problem of missing abnormal passenger behavior due to the large difference in travel time between the Origin-Destinations (ODs). Therefore, this paper proposes a method of setting corresponding thresholds for each OD. By analyzing the percentile curves of the overall and individual OD pairs, it was found that the turning point of the curve had a significant feature, and the difference between the two sides of the curve was obvious. This paper proposes a bilateral fitting method, and the results show that this method can calculate the relative threshold for different OD pairs. The significant advantages of this method are its low cost and wide coverage.

Psychophysical methods allow us to measure the relationship between stimuli and sensory perception. Of these, Detection Threshold (DT) allows us to know the minimum concentration to produce taste identification. Given this, we wonder whether, for example, wine tasting experts are more capable of perceiving their sensory properties than other people, or whether they can distinguish them because they are better able to “describe” them. To verify this, this study analyses the influence of having prior knowledge of the name astringency and, failing that, to detect it and distinguish it between the four basic tastes. One-hundred-and-sixty-two university students with an average age of 19.43 (SD = 2.55) years were assigned to three experimental conditions: an experimental group (G.2) without previous knowledge of the name astringency and with alimentary satiety, and two control groups, both with previous knowledge of the name, these being G.1, with satiety, and G.3, with hunger. DT was collected for the four basic tastes and astringencies. Results showed significant differences in the identification of astringency, being the least identified experimental group with respect to the control groups. It is striking that G.2, without prior knowledge of the name, identified astringency as a bitter taste in most cases. This supports our hypothesis of the importance of attending to linguistic cognitive processes when psychophysically estimating taste in humans. [ABSTRACT FROM AUTHOR]

The study investigated the effects of an 8 Hz infrasound sinusoid, presented at a sensation level (SL) of 9 decibels (dB), on the detection of i) a 64 Hz pure tone and ii) an 8 Hz sinusoidal amplitude modulation imposed on a 64 Hz sinusoidal carrier, presented at an SL of 25 dB. Two phase relations between infrasound and amplitude modulation were used: 0° (in phase) and 180° (in antiphase). Detection thresholds of the 64 Hz pure tone were, on average across 19 normal-hearing listeners, 4.6 dB higher in the presence than in the absence of the infrasound. Modulation detection thresholds also increased in the presence of the infrasound, on average by about 3 dB. Large individual differences in modulation detection thresholds were observed with respect to the two phase relations. On average across all listeners, however, the difference in modulation detection thresholds between in-phase and antiphase infrasound was not significant. The study shows that supra-threshold infrasound masks frequency components in the low audio-frequency range and affects the perception of amplitude modulations imposed on them.

At the absolute threshold of vision, Hecht, Shlaer and Pirenne estimate that 5-14 photons are absorbed within a retinal area containing ~500 rods. Other estimates of scotopic threshold vision based on stimuli with different durations and focal areas range up to ~100,000 photons. Given that rod density varies with retinal eccentricity and the magnitude of the intrinsic noise increases with increasing stimulus area and duration, here we determine whether the scotopic threshold estimates with focal stimuli can be extended to full-field stimulation and whether summation explains inter-study differences. We show that full-field threshold vision (~1018 mm2, 10 ms duration) is more sensitive than at absolute threshold, requiring the absorption of ~1000 photons across ~91.96 million rods. A summation model is presented integrating our and published data and using a nominal exposure duration, criterion frequency of seeing, rod density, and retinal area that largely explains the inter-study differences and allows estimation of rods per photon ratio for any stimulus size and duration. The highest signal to noise ratio is defined by a peak rod convergence estimated at 53:4:1:2 (rods:rod bipolar cells:AII amacrine cells:retinal ganglion cells), in line with macaque anatomical estimates that show AII amacrine cells form the bottleneck in the rod pathway to set the scotopic visual limit. Our model estimations that the rods per photon ratio under full-field stimulation is ~3000X higher than at absolute threshold are in accordance with visual summation effects and provide an alternative approach for understanding the limits of scotopic vision. [ABSTRACT FROM AUTHOR]

Psychophysical methods allow us to measure the relationship between stimuli and sensory perception. Of these, Detection Threshold (DT) allows us to know the minimum concentration to produce taste identification. Given this, we wonder whether, for example, wine tasting experts are more capable of perceiving their sensory properties than other people, or whether they can distinguish them because they are better able to “describe” them. To verify this, this study analyses the influence of having prior knowledge of the name astringency and, failing that, to detect it and distinguish it between the four basic tastes. One-hundred-and-sixty-two university students with an average age of 19.43 (SD = 2.55) years were assigned to three experimental conditions: an experimental group (G.2) without previous knowledge of the name astringency and with alimentary satiety, and two control groups, both with previous knowledge of the name, these being G.1, with satiety, and G.3, with hunger. DT was collected for the four basic tastes and astringencies. Results showed significant differences in the identification of astringency, being the least identified experimental group with respect to the control groups. It is striking that G.2, without prior knowledge of the name, identified astringency as a bitter taste in most cases. This supports our hypothesis of the importance of attending to linguistic cognitive processes when psychophysically estimating taste in humans.

When single pulse transcranial magnetic stimulation (TMS) is applied over the primary motor cortex (M1) with sufficient intensity, it evokes muscular contractions (motor-evoked potentials, MEPs) and muscle twitches (TMS-evoked movements). Participants may also report various hand sensations related to TMS, but the perception elicited by TMS and its relationship to MEPs and evoked movements has not been systematically studied. The main aim of this work is to evaluate participants' kinesthetic and somatosensory hand perceptions elicited by single-pulse TMS over M1-hand area at different intensities of stimulation and their relation with MEPs and TMS-evoked movements. We compared the number of MEPs (measured by electromyography), TMS-evoked movements (measured by an accelerometer) and participants' hand perception (measured by verbal report) elicited by TMS at different intensity of stimulation. This way, we estimated the amplitude of MEPs and the acceleration of TMS-evoked movements sufficient to trigger TMS evoked hand perceptions. We found that TMS-evoked hand perceptions are induced at 105% of the individual resting motor threshold, a value significantly different from the threshold inducing MEPs (about 100%) and TMS-evoked movements (about 110%). Our data indicate that only MEPs with an amplitude higher than 0.62 mV and TMS-evoked movements with acceleration higher than 0.42 m/s2 were associated with hand perceptions at threshold. Our data reveal the main features of TMS-evoked hand perception and show that in addition to MEPs and TMS-evoked movements, this is a separate discernible response associated to single-pulse TMS over M1. • Single pulse TMS over M1 elicits quantifiable and reliable hand perceptions. • Hand perceptions are described in terms of kinesthetic, somatic or mixed sensations. • MEPs, movements and hand perceptions are evoked by different stimulation intensities. • The detectability of hand perception is comparable to that of MEPs (logistic curve fitting). [ABSTRACT FROM AUTHOR]

Objectives: To investigate the prognostic capacity of baseline 18 F-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) metabolic parameters in extranodal natural killer/T-cell lymphoma (ENKTCL), and the influence of relative thresholds (RT) and absolute thresholds (AT) selection on prognostic capacity., Materials and Methods: Metabolic tumor volume (MTV)-based parameters were defined using RTs (41 % or 25 % of maximum standardized uptake value [SUVmax]), ATs (SUV 2.5, 3.0, 4.0, or mean liver uptake) in 133 patients. Metabolic parameters were classified into avidity-related parameters (SUVmax, mean SUV [SUVmean], standard deviation of SUV [SUVsd]), volume-related parameters (RT-MTV), and avidity- and volume-related parameters (total lesion glycolysis [TLG] and AT-MTV). The prognostic capacity of the metabolic parameters and the effects of different threshold types (RT vs. AT) were evaluated., Results: All metabolic parameters were moderately associated with prognosis. However, the area under the receiver operating characteristic curve of MTV and TLG was slightly higher than that of avidity-related parameters for predicting 5-year progression-free survival (PFS) (0.614-0.705 vs. 0.563-0.609) and overall survival (OS) (0.670-0.748 vs. 0.562-0.593). Correlations of MTV and avidity-related parameters differed between RTs (r < 0.06, P  = 0.324-0.985) and ATs (r 0.56-0.84, P  ≤ 0.001). AT-MTV was the optimal predictor for PFS and OS, while RT-TLG was the optimal predictor for PFS, and the combination of RT-MTV with SUVmax was the optimal predictor for OS., Conclusion: The incorporation of volume and avidity significantly improved the prognostic capacity of PET in ENKTCL. Composite parameters that encompassed both avidity and volume were recommended., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 Published by Elsevier Ltd.)

Introduction: in sensory perception of taste, it is difficult to learn the concepts of absolute threshold (AT), the psychophysical methods to estimate it and the influence exerted by prior knowledge on their perception and recognition, because they have little awareness.Objective: to assess absolute thresholds of four basic flavors in a sample of healthy young people, in conditions of food restriction/without restriction, and to analyze the influence of prior knowledge of astringency in its detection-identification.Methods: one hundred and fourteen participants with an average of 20.03 years old (SD = 5.45), 75.4% of them women, were put in direct contact with chemical substances of basic flavors and astringency through a theoretical-practical tasting. An inverted treatment design was applied with experimental conditions on food restriction and knowledge of astringency.Results: all identified their AT for basic flavors. The group with restriction was significantly more sensitive (Tb = -3.305, p = 0.001) to sweet (AU = 2 g/l) than the group without restriction (AU = 5 g/l). The detection-identification of astringency was significantly higher (t = -13.323, p = 0.000) with previous information of the name (79.31%) than without this information (19.64%), confusing or describing it as bitter taste (80.36).Conclusion: taste learning is facilitated with the performance of psychophysical measurements of chemical senses, together with training of certain theoretical concepts about taste perception and flavor denomination, because it facilitates the cognitive process for detection-identification. In addition, the process for the previous internal homeostasis of participants must be considered as their AU results vary according to the hunger/satiety conditions prior to the psychophysical estimation. [ABSTRACT FROM AUTHOR]

This research work demonstrates compositional engineering of an organic-inorganic hybrid nano-composites for modifying absolute threshold of humidity sensors. Vanadyl-2,9,16,23-tetraphenoxy-29H,31H-phthalocyanine (VOPcPhO), an organic semiconductor, doped with Titanium-dioxide nanoparticles (TiO 2 NPs) has been employed to fabricate humidity sensors. The morphology of the VOPcPhO:TiO 2 nano-composite films has been analyzed by atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM). The sensors have been examined over a wide range of relative humidity i.e. 20–99% RH. The sensor with TiO 2 (90 nm) shows reduced sensitivity-threshold and improved linearity. The VOPcPhO:TiO 2 (90 nm) nano-composite film is comprised of uniformly distributed voids which makes the surface more favorable for adsorption of moisture content from environment. The VOPcPhO:TiO 2 nano-composite based sensor demonstrates remarkable improvement in the sensing parameter when equated with VOPcPhO sensors. [ABSTRACT FROM AUTHOR]

Thresholds for detecting sounds in quiet decrease with increasing sound duration in every species studied. The neural mechanisms underlying this trade-off, often referred to as temporal integration, are not fully understood. Here, we probe the human auditory system with a large set of tone stimuli differing in duration, shape of the temporal amplitude envelope, duration of silent gaps between bursts, and frequency. Duration was varied by varying the plateau duration of plateau-burst (PB) stimuli, the duration of the onsets and offsets of onset-offset (OO) stimuli, and the number of identical bursts of multiple-burst (MB) stimuli. Absolute thresholds for a large number of ears (>230) were measured using a 3-interval-3-alternative forced choice (3I-3AFC) procedure. Thresholds decreased with increasing sound duration in a manner that depended on the temporal envelope. Most commonly, thresholds for MB stimuli were highest followed by thresholds for OO and PB stimuli of corresponding durations. Differences in the thresholds for MB and OO stimuli and in the thresholds for MB and PB stimuli, however, varied widely across ears, were negative in some ears, and were tightly correlated. We show that the variation and correlation of MB-OO and MB-PB threshold differences are linked to threshold microstructure, which affects the relative detectability of the sidebands of the MB stimuli and affects estimates of the bandwidth of auditory filters. We also found that thresholds for MB stimuli increased with increasing duration of the silent gaps between bursts. We propose a new model and show that it accurately accounts for our results and does so considerably better than a leaky-integrator-of-intensity model and a probabilistic model proposed by others. Our model is based on the assumption that sensory events are generated by a Poisson point process with a low rate in the absence of stimulation and higher, time-varying rates in the presence of stimulation. A subject in a 3I-3AFC task is assumed to choose the interval in which the greatest number of events occurred or randomly chooses among intervals which are tied for the greatest number of events. The subject is further assumed to count events over the duration of an evaluation interval that has the same timing and duration as the expected stimulus. The increase in the rate of the events caused by stimulation is proportional to the time-varying amplitude envelope of the bandpass-filtered signal raised to an exponent. We find the exponent to be about 3, consistent with our previous studies. This challenges models that are based on the assumption of the integration of a neural response that is directly proportional to the stimulus amplitude or proportional to its square (i.e., proportional to the stimulus intensity or power). [ABSTRACT FROM AUTHOR]

Three experiments were carried out to determine absolute and differential thresholds for vibrotactile forces and external influences in the frequency range of 5 to 1,000 Hz at the tip of the index finger. Differential thresholds were obtained for reference stimuli of 0.5, 0.25 N, and near the individual threshold. Frequency, temperature, age, fingertip size, and contact force were investigated as parameters in a full-factorial design. Experiments were conducted with at least 27 subjects and a 1up-2down staircase procedure with 3IFC paradigm. We find absolute thresholds ranging from 1.7 to 19 mN with the lowest threshold at 320 Hz. Weber fractions from 18 to 41 dB are found near the absolute threshold. For larger references, they range from 4.9 to 23 dB. ANOVA finds frequency as significant medium effect for both absolute and differential thresholds. Results imply impact of age on the absolute threshold, but no effect of motor skill, temperature, fingertip size, and contact force. Differential thresholds are affected by frequency only, which is attributed to saturation effects of the Pacinian channel. Fingertip size and motor skill are not able to explain effects on thresholds and the interpersonal variance. Results of this work are intended as requirement source for the design of task-specific haptic interfaces. [ABSTRACT FROM PUBLISHER]