Higher Detection Thresholds Research Articles

Role of Lung Ultrasound in the Detection of Lung Sequelae in Post-COVID-19 Patients: A Systematic Review and Meta-Analysis.

Background: During the COVID-19 pandemic, several studies demonstrated the effectiveness of lung ultrasound (LUS) as a frontline tool in diagnosing and managing acute SARS-CoV-2 pneumonia. However, its role in detecting post-COVID-19 lung sequelae remains to be fully determined. This study aims to evaluate the diagnostic accuracy of LUS in identifying lung parenchymal damage, particularly fibrotic-like changes, following COVID-19 pneumonia, comparing its performance to that of CT. Methods: Relevant studies published before July 2024 were identified through a comprehensive search of PubMed, Embase, and Cochrane library. The search terms were combinations of the relevant medical subject heading (MeSH) terms, key words and word variants for "lung", "post-COVID", "long-COVID", and "ultrasound". The pooled sensitivity, specificity, diagnostic odds ratio (DOR), and summary receiver-operating characteristic (SROC) curve were used to examine the accuracy of CEUS. The selected works used different thresholds for the detection and counting of B-lines by ultrasound. This led to dividing our analysis into two models, the first based on the lower thresholds for detection of B-lines found in the works, and the second on data obtained using a higher detection threshold. Results: In terms of the diagnostic accuracy of LUS in detecting residual fibrotic-like changes in patients post-COVID-19 infection, a low-threshold model displayed a pooled sensitivity of 0.98 [95% confidence interval (CI): 0.95-0.99] and a pooled specificity of 0.54 (95% CI: 0.49-0.59). The DOR was 44.9 (95% CI: 10.8-187.1). The area under the curve (AUC) of SROC was 0.90. In the second analysis, the model with the higher threshold to detect B-lines showed a pooled sensitivity of 0.90 (95% CI: 0.85-0.94) and a pooled specificity of 0.88 (95% CI: 0.84-0.91). The DOR was 50.4 (95% CI: 15.9-159.3). The AUC of SROC was 0.93. Conclusions: In both analyses (even using the high threshold for the detection of B-lines), excellent sensitivity (98% in model 1 and 90% in model 2) is maintained. The specificity has a significant variation between the two models from 54 (model 1) to 87% (model 2). The model with the highest threshold for the detection of B-lines displayed the best diagnostic accuracy, as confirmed by the AUC values of the SROC (0.93).

Trajectory-based RFI subtraction and calibration for radio interferometry

ABSTRACT Radio interferometry calibration and radio frequency interference (RFI) removal are usually done separately. Here we show that jointly modelling the antenna gains and RFI has significant benefits when the RFI follows precise trajectories, such as for satellites. One surprising benefit is improved calibration solutions, by leveraging the RFI signal itself. We present trajectory-based RFI subtraction and calibration (tabascal), a new algorithm that jointly models the RFI and calibration parameters in visibilities. We test tabascal on simulated MeerKAT calibration observations contaminated by satellite-based RFI. We obtain gain estimates that are both unbiased and up to an order of magnitude better constrained compared to uncontaminated data. When combined with an ad hoc RFI subtraction scheme, tabascal solutions can be further applied to an adjacent target observation: 5 min of calibration data results in an image with about a third the noise achieved when using flagging alone. The recovered flux distribution of RFI subtracted data was on par with uncontaminated data. In contrast, RFI flagging alone resulted in a higher detection threshold and consistent underestimation of source fluxes. For a mean RFI amplitude of 17 Jy, using RFI subtraction leads to less than 1 per cent loss of data compared to 75 per cent data loss from an ideal 3σ flagging algorithm, a very significant increase in data available for science analysis. Although we have examined the case of satellite RFI, tabascal should work for any RFI moving on parametrizable trajectories, relative to the phase centre, such as planes and/or objects fixed to the ground.

Detection of limited-energy α particles using CR-39 in laser-induced p −11B reaction

Due to the harsh radiation environment produced by strong laser plasma, most of the detectors based on semiconductors cannot perform well. So, it is important to develop new detecting techniques with higher detection thresholds and highly charged particle resolution for investigating nuclear fusion reactions in laser-plasma environments. The Columbia Resin No. 39 (CR-39) detector is mainly sensitive to ions and insensitive to the backgrounds, such as electrons and photons. The detector has been widely used to detect charged particles in laser-plasma environments. In this work, we used a potassium–ethanol–water (PEW) etching solution to reduce the proton sensitivity of CR-39, by raising the detection threshold for the research of laser-induced 11B(p, α)2α reaction. We calibrated the 3–5 MeV α particles in an etching condition of 60°C PEW-25 solution (17% KOH + 25%C2H5OH + 58%H2O) and compared them with the manufacturer’s recommended etching conditions of 6.25 N NaOH aqueous solution at 98°C in our laser-induced nuclear reaction experiment. The results indicate, with the PEW-25 solution, that CR-39 is more suitable to distinguish α tracks from the proton background in our experiment. We also present a method to estimate the minimum detection range of α energy on specific etching conditions in our experiment.

RD53B Wafer Testing for the ATLAS ITk Pixel Detector

RD53B/ITkPix-V1 is the most recent hybrid pixel readout chip development for the ATLAS pixel detector at the HL-LHC. It is the first full-scale 65 nm hybrid pixel-readout chip of its kind. ITkPix-V1 consists of more than one billion transistors with a high memory triplication ratio to cope with the high particle density at the heart of ATLAS. Chips will be as close to the interaction point as possible to optimize the resolution of impact parameters. The ITkPix-V1 chip features a 5-Gbit connection, with special data compression to deal with high hit intensities. In addition, a low-power, low-noise analog front-end is used to ensure high readout speeds and low detection thresholds. Failure of chips in ATLAS would be problematic. Therefore, a thorough test is necessary before and during production. For this purpose, the Bonn ATLAS group has developed BDAQ53, a fast and versatile simulation and testing environment that allows small and large-scale testing for ITkPix-V1 and its successor chips. This conference note will give an overview of the testing environment while focusing on large-scale wafer testing to evaluate ITkPix-V1’s suitability for its deployment at the HL-LHC.

Polarization based discrete variables quantum key distribution via conjugated homodyne detection

Optical homodyne detection is widely adopted in continuous-variable quantum key distribution for high-rate field measurement quadratures. Besides that, those detection schemes have been being implemented for single-photon statistics characterization in the field of quantum tomography. In this work, we propose a discrete-variable quantum key distribution (DV-QKD) implementation that combines the use of phase modulators for high-speed state of polarization (SOP) generation, with a conjugate homodyne detection scheme which enables the deployment of high speed QKD systems. The channel discretization relies on the application of a detection threshold that allows to map the measured voltages as a click or no-click. Our scheme relies also on the use of a time-multiplexed pilot tone—quantum signal architecture which enables the use of a Bob locally generated local oscillator and opens the door to an effective polarization drift compensation scheme. Besides that, our results shows that for higher detection threshold values we obtain a very low quantum bit error rate (QBER) on the sifted key. Nevertheless, due to huge number of discarded qubits the obtained secure key length abruptly decreases. From our results, we observe that optimizing the detection threshold and considering a system operating at 500 MHz symbol generation clock, a secure key rate of approximately 46.9 Mbps, with a sifted QBER of 1.5% over 40 km of optical fiber. This considering the error correction and privacy amplification steps necessary to obtain a final secure key.

Examining central biases in somatosensory localization: Evidence from brain-damaged individuals

How does the brain localize touch under conditions of uncertainty caused by brain damage? By testing single cases, previous work found mislocalization of touch toward the center of the hand. We investigated whether such central bias changes as a function of uncertainty in somatosensory system. Fifty-one brain-damaged individuals were presented with a tactile detection task to establish their tactile threshold, and a tactile localization task in which they localized suprathreshold stimuli presented at different locations on the hand. We predicted that with increased somatosensory uncertainty, indexed by higher detection thresholds, participants would more likely to localize the stimuli toward the center of the hand. Consistent with this prediction, participants’ localization errors were biased towards the center of the hand and, importantly, this bias increased as detection threshold increased. These findings provide evidence that instead of showing random errors, uncertainty leads to systematic localization errors toward the center of the hand or the center of the stimulus distribution, which overlapped in the present study. We discuss these findings under different frameworks as potential mechanisms to explain biases in tactile localization subsequent to brain damage.

Basic taste sensitivity, eating behaviour, and propensity of dairy foods of preadolescent children: How are they related?

Background: Taste sensitivity has been reported to influence children’s eating behaviour and contribute to their food preferences and intake. This study aimed to investigate the associations between taste sensitivity and eating behaviour in preadolescents. Methods: Children’s taste sensitivity was measured by detection threshold with five different concentration levels of sweetness (sucrose), sourness (citric acid), saltiness (sodium chloride), bitterness (caffeine, quinine), and umami (monosodium glutamate). In addition, the Child Eating Behaviour Questionnaire (CEBQ), the Food Propensity Questionnaire (FPQ), and the children’s body weight and height were completed by the parents. Children conducted the sensory evaluation test at schools while parents completed the questionnaires online. Results: A total of 69 child-parent dyads participated. Taste sensitivity was significantly associated with eating behaviour in food responsiveness, emotional overeating, and desire to drink. Children who were less sensitive to caffeine bitterness (higher detection threshold) had higher food responsiveness scores, while those who were less sensitive to sweetness and caffeine bitterness had higher emotional overeating scores. In addition, children who were less sensitive to sourness and bitterness of both caffeine and quinine demonstrated to have higher scores in desire to drink. There was no association between taste sensitivity and FPQ, but significant differences were observed across children’s body mass index (BMI) regarding their FPQ of dairy food items, indicating higher consumption of low-fat milk in the overweight/obese compared to the normal-weight subjects. There was no significant difference in taste sensitivity according to BMI. Children’s eating behaviour differed across BMI, demonstrating a positive association between BMI and food approach, and a negative association between BMI and food avoidance. Conclusions: This study contributes to the preliminary understanding of the relationships between taste sensitivity and eating behaviour in preadolescents which could be used to develop effective strategies to promote healthy eating practices in children by considering their taste sensitivity.

Identification of aroma compounds in a commonly prescribed oral nutritional supplement and associated changes in olfactory abilities with human ageing

Undernutrition is prevalent in the older adult population. Oral nutritional supplements (ONS) are a clinically effective nutritional intervention, however, patient acceptance of ONS can be limited by their palatability. While sensory attributes such as sweetness and mouthfeel have been investigated, the contribution made by aroma to the perceived flavour of ONS has not been studied. Firstly, this research aimed to identify the aroma active compounds within a commonly prescribed ONS using estimated odour activity values (OAV) and gas chromatography olfactometry mass spectrometry (GC-O-MS). Secondly, age related differences in olfactory detection were explored. Eight aroma active compounds were identified within the ONS, including diacetyl (sweet), isoamyl acetate (banana), dimethyl trisulfide (sulfur) and methanethiol (sulfur). When compared with younger adults (n = 24, 18–44 years), older adults (n = 24, 62–80 years) had higher detection thresholds for all aroma compounds and this was significant for isoamyl acetate (sweet, fruity) and methanethiol (sulfur) (p = 0.01 and p = 0.03, respectively). Thus, a decline in olfactory sensitivity was present in the older subjects included in the study, and this reduced detection sensitivity was aroma specific. Thus, older adults’ flavour perception of ONS likely depends on the combined effect of product factors (the aroma profile) along with age related consumer factors (the degree of impairment in perception). This is a fundamental study which will aid future research into how the aroma profile, and associated age related impairments in perception, shape the global perception of ONS for nutritionally at risk older individuals.

New Technologies Can Cost Effectively Reduce Oil and Gas Methane Emissions, but Policies Will Require Careful Design to Establish Mitigation Equivalence.

Reducing methane emissions from oil and gas systems is a central component of US and international climate policy. Leak detection and repair (LDAR) programs using optical gas imaging (OGI)-based surveys are routinely used to mitigate fugitive emissions or leaks. Recently, new technologies and platforms such as planes, drones, and satellites promise more cost-effective mitigation than existing approaches. To be approved for use in LDAR programs, new technologies must demonstrate emissions mitigation equivalent to existing approaches. In this work, we use the FEAST modeling tool to (a) identify cost vs mitigation trade-offs that arise from using new technologies and (b) provide a framework for effective design of alternative LDAR programs. We identify several critical insights. First, LDAR programs can trade sensitivity for speed without sacrificing mitigation outcomes. Second, low sensitivity or high detection threshold technologies have an effective upper bound on achievable mitigation that is independent of the survey frequency. Third, the cost effectiveness of tiered LDAR programs using site-level detection technologies depends on their ability to distinguish leaks from routine venting. Finally, "technology equivalence" based on mitigation outcomes differs across basins and should be evaluated independently. The FEAST model will enable operators and regulators to systematically evaluate new technologies in next-generation LDAR programs.

Salt taste perception and blood pressure levels in population-based samples: the Circulatory Risk in Communities Study (CIRCS).

To examine the associations of salt perception with salt intake and blood pressure levels in general populations, we performed a cross-sectional study in two communities where salt intake level is different, Akita and Osaka in Japan. Taste perception (detection for certain taste and recognition for salt taste) was determined using a Na-impregnated test strip for 1024 Akita and 1199 Osaka adults aged 30-74 years. The proportions of detection for 0·1 % salt were 61, 62, 79, and 79 % in Akita men, Osaka men, Akita women and Osaka women, respectively. The corresponding proportions of not recognising of 1·6 % salt taste (>1·6 %) were 34, 30, 16 and 21 %. Detection threshold was higher in Akita than in Osaka for women aged 60-74 years, and recognition threshold was lower in Akita than in Osaka for women aged 30-59 and 60-74 years. The high detection (≥0·4 %) and recognition (>1·6 %) thresholds of salt taste were associated with higher salt intake scores for Akita men aged 30-59 years, whose detection and recognition thresholds tended be positively associated with systolic and diastolic blood pressures (SBP and DBP) after adjustment for potential confounders. Among Akita elderly men, detection threshold tended to be positively associated with SBP and DBP, while among Akita middle-aged women, recognition threshold was associated with SBP. In conclusion, the high thresholds of salt perception were inversely associated with salt intake for Akita middle-aged men and with blood pressure levels for Akita middle-aged and elderly men and middle-aged women.

Relationship between Sucrose Taste Detection Thresholds and Preferences in Children, Adolescents, and Adults.

To address gaps in knowledge, our objectives were to (1) to determine whether there are age-related changes in sweet taste detection thresholds, as has been observed for sweet taste preferences, and (2) determine whether detection thresholds and taste preferences were significantly related to each other from childhood to adulthood. We combined data from studies that used the same validated psychophysical techniques to measure sucrose taste detection threshold and the most preferred sucrose concentration in children (n = 108), adolescents (n = 172), and adults (n = 205). There were significant effects of age group on both sucrose detection thresholds (p < 0.001) and most preferred sucrose concentration (p < 0.001). While children had higher sucrose detection thresholds than adolescents, who in turn tended to have higher detection thresholds than adults, both children and adolescent most preferred sucrose concentrations were higher than that of adults (all p < 0.05). Among each age group, and when combined, the lowest sucrose concentration detected was not significantly correlated with the most preferred sucrose concentration (all p > 0.18). These data provide further evidence that age-related changes in sucrose taste preferences that occur during adolescence cannot be explained by changes in taste sensitivity and that these two dimensions of sweet taste undergo distinct developmental trajectories from childhood to adulthood.

CD36 and GPR120 Methylation Associates with Orosensory Detection Thresholds for Fat and Bitter in Algerian Young Obese Children.

Background: The spontaneous preference for dietary fat is regulated by two lingual lipid sensors (CD36 and GPR120) in humans and rodents. Our objective was to investigate whether obesity in children is associated with methylation of lipid sensor genes, and whether this alteration was implicated in altered gustatory perception of fat and bitter and increased preference of palatable foods. Methods: School children were recruited and classified according to their body mass index (BMI) z-score into two groups: obese and lean children. The detection of orosensory perception for oleic acid and 6-n-propylthiouracil was assessed by using a 3-alternative forced-choice test. After blood DNA extraction, methylation patterns were investigated by methylation-specific PCR. The children were also subjected to a food habit questionnaire. Results: Obese children showed higher lipid and bitter detection thresholds than lean children. Besides, more obese children presented higher methylation level of the CpG sites than lean participants. Interestingly, CD36 and GPR120 gene methylation was associated with high lipid detection thresholds in obese participants. The obese participants preferred highly palatable fat-rich food items, associated with CD36 and GPR120 gene methylation. Conclusion: Epigenetic changes in CD36 and GPR120 genes might contribute to low orosensory perception of fat and bitter taste, and might be, consequently, critically involved in obesity in children

Bitter-Induced Salivary Proteins Increase Detection Threshold of Quinine, But Not Sucrose.

Exposures to dietary tannic acid (TA, 3%) and quinine (0.375%) upregulate partially overlapping sets of salivary proteins which are concurrent with changes in taste-driven behaviors, such as rate of feeding and brief access licking to quinine. In addition, the presence of salivary proteins reduces chorda tympani responding to quinine. Together these data suggest that salivary proteins play a role in bitter taste. We hypothesized that salivary proteins altered orosensory feedback to bitter by decreasing sensitivity to the stimulus. To that end, we used diet exposure to alter salivary proteins, then assessed an animal's ability to detect quinine, using a 2-response operant task. Rats were asked to discriminate descending concentrations of quinine from water in a modified forced-choice paradigm, before and after exposure to diets that alter salivary protein expression in a similar way (0.375% quinine or 3% TA), or 1 of 2 control diets. Control animals received either a bitter diet that does not upregulate salivary proteins (4% sucrose octaacetate), or a nonbitter diet. The rats exposed to salivary protein-inducing diets significantly decreased their performance (had higher detection thresholds) after diet exposure, whereas rats in the control conditions did not alter performance after diet exposure. A fifth group of animals were trained to detect sucrose before and after they were maintained on the 3% TA diet. There was no significant difference in performance, suggesting that these shifts in threshold are stimulus specific rather than task specific. Taken together, these results suggest that salivary proteins reduce sensitivity to quinine.

An update of radial dose distribution theory for the detection threshold of Kapton as a nuclear track detector irradiated with 345 MeV/u U and other heavy ions

We aim to determine the detection threshold of Kapton as an Etched Track Detector irradiated with 345 MeV/u U ion, as well as other several heavy ions of Al, Si, Ar, Kr and Xe. The heavier ions are found to have higher detection threshold in the stopping power. At the same stopping power, the track registration sensitivity decreases with increasing the nuclear charge of ions. U ion has the lowest sensitivity as S = 0.04 at the detection threshold of 3400 keV/μm. We have updated the conventional radial dose distribution theory using a relatively new experimentally supported formula for the effective charge up to U ion. The local doses at a track radius of 0.8 nm, which is half of the length of a repeat unit of Kapton, is useful to understand the relation between the sensitivity of heavy ions and the stopping power at each detection threshold.

Fast and accurate sensitivity estimation for continuous-gravitational-wave searches

This paper presents an efficient numerical sensitivity-estimation method and implementation for continuous-gravitational-wave searches, extending and generalizing an earlier analytic approach by Wette [1]. This estimation framework applies to a broad class of F-statistic-based search meth- ods, namely (i) semi-coherent StackSlide F-statistic (single-stage and hierarchical multi-stage), (ii) Hough number count on F-statistics, as well as (iii) Bayesian upper limits on (coherent or semi-coherent) F-statistic search results. We test this estimate against results from Monte-Carlo simulations assuming Gaussian noise. We find the agreement to be within a few % at high (i.e. low false-alarm) detection thresholds, with increasing deviations at decreasing (i.e. higher false- alarm) detection thresholds, which can be understood in terms of the approximations used in the estimate. We also provide an extensive summary of sensitivity depths achieved in past continuous- gravitational-wave searches (derived from the published upper limits). For the F-statistic-based searches where our sensitivity estimate is applicable, we find an average relative deviation to the published upper limits of less than 10%, which in most cases includes systematic uncertainty about the noise-floor estimate used in the published upper limits.

Using detection received level as a guide for odontocete density estimation

Odontocete echolocation clicks have been used for density estimation using cue-counting. We present an approach for assessment of the appropriate threshold for click detection based on the click received sound-pressure-level distribution. Under the assumption of random spatial distribution of echolocating animals with respect to the sensor, the number of detections should decrease with increasing received level. This pattern is verified by simulation modeling, even after incorporating diving behavior and sound production directionality. When measured received level distributions show peaks at values above the detection threshold, errors in the detection process are the most likely explanation. Potential remedies involve setting a higher detection threshold and/or fully characterizing both missed and false positive rates.Odontocete echolocation clicks have been used for density estimation using cue-counting. We present an approach for assessment of the appropriate threshold for click detection based on the click received sound-pressure-level distribution. Under the assumption of random spatial distribution of echolocating animals with respect to the sensor, the number of detections should decrease with increasing received level. This pattern is verified by simulation modeling, even after incorporating diving behavior and sound production directionality. When measured received level distributions show peaks at values above the detection threshold, errors in the detection process are the most likely explanation. Potential remedies involve setting a higher detection threshold and/or fully characterizing both missed and false positive rates.

Reducing parasitic capacitance in single‐photon avalanche diodes

Page ***, ‘Triple epitaxial single-photon avalanche diode for multichannel timing applications’, Ivan Labanca, Francesco Ceccarelli, Angelo Gulinatti, Massimo Ghioni and Ivan Rech. Cross section of the new SPAD structure. A lightly doped n- Intermediate Layer has been introduced between the Buried Layer and the Substrate to reduce the parasitic capacitance. An array of SPADs that have been fabricated using the new custom technology. A single-photon avalanche diode with picosecond temporal resolution and low parasitic capacitance is presented by researchers at the Politecnico di Milano, Italy. Single-photon avalanche diodes (SPADs) are solid-state devices that provide a digital current pulse every time they are hit by a single photon. They record not only the number of photons impinging on the detector but they also determine the arrival time of each photon within an accuracy of tens of picoseconds. SPAD development is driven by the widespread and growing interest in low-level light detection in several scientific and industrial applications, such as fluorescence spectroscopy in life and material sciences, quantum computing and cryptography, profiling of remote objects with optical radar techniques, particle sizing, and more. In particular, the use of fluorescence lifetime spectroscopy as an analytical research tool has increased substantially in recent years, finding remarkable applications in chemistry, biochemistry and biology. In this Issue of Electronics Letters, Francesco Ceccarelli and colleagues have modified the typical structure of SPADs to introduce an additional layer that reduces the parasitic capacitance between the detector anode and the chip substrate. This was made possible due to the use of a fully custom technology, namely a fabrication process in which each step can be finely optimised in order to achieve the best overall device performance. The new structure reported by the authors increases the fraction of avalanche current that can be fed into the front-end electronics. This means that the same timing jitter can be attained with a higher detection threshold and is especially important when more than one SPAD is integrated on the same chip and the disturbances generated by a detector during operation can degrade the timing jitter on adjacent pixels. “By simplifying the problem of reading the avalanche current with a low timing jitter, the device structure reported in this Letter opens the way to fabricating photon detection systems that are based on custom-technology SPADs with a large number of pixels and picosecond temporal resolution” explains Ceccarelli. The fabrication of large arrays of SPADs, which are truly parallel and attain high detection efficiency and picosecond timing resolution, is certainly a long-term objective in this field. This work represents one of the milestones towards achieving this goal. Ceccarelli says “we aim at arrays with many thousands of pixels which can have a dramatic impact on very critical fields like new drugs discovery.” Ceccarelli and his colleagues at the Politecnico di Milano will now work on combining this new technology with a recently developed integrated front-end circuit to build a multichannel time-resolved single-photon detection module. They will also continue to develop the detector to improve its performance. Ceccarelli explains “we are looking in particular at very high detection efficiency in the visible / near infrared region and at removing the slow components in the temporal response.” The interest in single-photon detection has grown considerably in the last few years and is expected to increase even further in the coming decade, due to emerging consumer and scientific applications, like autonomous cars and new drug discoveries. Most of the attention will likely be devoted to the development of a high-throughput, time-resolved, single-photon imager with a large number of pixels. On the one hand, this requires the design of detectors with always increasing performance, especially in terms of detection efficiency, temporal response and scalability. On the other hand, a lot of work must be done to devise new architectures for handling the huge amount of data produced by large, time-resolved arrays. “Beside this mainstream development, we expect also a lot of activity in emerging fields, especially in quantum information processing” concludes Ceccarelli.

Links between Gestures and Multisensory Processing: Individual Differences Suggest a Compensation Mechanism.

Speech-associated gestures represent an important communication modality. However, individual differences in the production and perception of gestures are not well understood so far. We hypothesized that the perception of multisensory action consequences might play a crucial role. Verbal communication involves continuous calibration of audio–visual information produced by the speakers. The effective production and perception of gestures supporting this process could depend on the given capacities to perceive multisensory information accurately. We explored the association between the production and perception of gestures and the monitoring of multisensory action consequences in a sample of 31 participants. We applied a recently introduced gesture scale to assess self-reported gesture production and perception in everyday life situations. In the perceptual experiment, we presented unimodal (visual) and bimodal (visual and auditory) sensory outcomes with various delays after a self-initiated (active) or externally generated (passive) button press. Participants had to report whether they detected a delay between the button press and the visual stimulus. We derived psychometric functions for each condition and determined points of subjective equality, reflecting detection thresholds for delays. Results support a robust link between gesture scores and detection thresholds. Individuals with higher detection thresholds (lower performance) reported more frequent gesture production and perception and furthermore profited more from multisensory information in the experimental task. We propose that our findings indicate a compensational function of multisensory processing as a basis for individual differences in both action outcome monitoring and gesture production and perception in everyday life situations.

Altered tactile sensitivity in children with attention-deficit hyperactivity disorder.

Attention-deficit hyperactivity disorder (ADHD) is characterized by an inability to concentrate, heightened activity, and hypermotoric behavior, but sensory (e.g., tactile) problems are common. The literature on tactile impairments in ADHD is limited, with most work employing clinical observations or questionnaires. We studied tactile processing in children with ADHD and hypothesized that children with ADHD would show reduced performance in tasks closely linked to inhibition. Sixty-seven children with ADHD and 62 typically developing children (TDC) performed a battery of tasks grouped in domains: simple and choice reaction time; static and dynamic detection threshold (probing feedforward inhibition); amplitude discrimination without adaptation and with dual and single-site adaptation (probing lateral inhibition and adaptation); sequential and simultaneous frequency discrimination (previously linked to GABA); and temporal order judgment with and without a synchronous carrier stimulus. Children with ADHD could discriminate different amplitudes without adaptation, suggesting lateral inhibition is intact, but were negatively affected in all adaptation conditions, whereas TDC were only affected during single-site adaptation. Children with ADHD also showed normal frequency discrimination. Children with ADHD showed slower reaction times and higher detection threshold, likely driven by IQ and inattention, because reaction time and detection thresholds correlated with IQ and subtle motor signs. Children with ADHD showed a pattern of altered tactile processing on specific tasks, suggesting that higher cognitive function and cortical mechanisms related to adaptation are affected in ADHD, but no clear conclusion can be drawn toward impaired inhibition.NEW & NOTEWORTHY This manuscript presents the first tactile psychophysical study testing different aspects of tactile processing in attention-deficit hyperactivity disorder (ADHD), using large cohort sizes of 67 children with ADHD and 65 Typically Developing Children. This study demonstrates impaired tactile processing in children with ADHD, on some, but not all tasks (showing this is not just due to attention), related to impaired cortical mechanisms. Furthermore, both IQ and soft motor skill abnormalities (common in ADHD) are correlated with tactile abnormalities.

Reach-relevant somatosensory signals modulate tactile suppression.

Tactile stimuli on moving limbs are typically attenuated during reach planning and execution. This phenomenon has been related to internal forward models that predict the sensory consequences of a movement. Tactile suppression is considered to occur due to a match between the actual and predicted sensory consequences of a movement, which might free capacities to process novel or task-relevant sensory signals. Here, we examined whether and how tactile suppression depends on the relevance of somatosensory information for reaching. Participants reached with their left or right index finger to the unseen index finger of their other hand (body target) or an unseen pad on a screen (external target). In the body target condition, somatosensory signals from the static hand were available for localizing the reach target. Vibrotactile stimuli were presented on the moving index finger before or during reaching or in a separate no-movement baseline block, and participants indicated whether they detected a stimulus. As expected, detection thresholds before or during reaching were higher compared with baseline. Tactile suppression was also stronger for reaches to body targets than external targets, as reflected by higher detection thresholds and lower precision of detectability. Moreover, detection thresholds were higher when reaching with the left than with the right hand. Our results suggest that tactile suppression is modulated by position signals from the target limb that are required to reach successfully to the own body. Moreover, limb dominance seems to affect tactile suppression, presumably due to disparate uncertainty of feedback signals from the moving limb.NEW & NOTEWORTHY Tactile suppression on a moving limb has been suggested to release computational resources for processing other relevant sensory events. In the current study, we show that tactile sensitivity on the moving limb decreases more when reaching to body targets than external targets. This indicates that tactile perception can be modulated by allocating processing capacities to movement-relevant somatosensory information at the target location. Our results contribute to understanding tactile processing and predictive mechanisms in the brain.