Stimulus Variables Research Articles

Characterization of the C5H11ORF96 gene in chickens: cloning, tissue distribution and investigation of its potential function in stress response regulation

Chicken is an important economic animal that encounter various stressors including high temperature, high stocking density, bacterial infections and transportation, etc. affecting the poultry production with serious economic loss. To be in response to the varied stimulus, the hypothalamic-pituitary-adrenal (HPA) axis is activated through the controlling of the synthesis and secretion of glucocorticoids (GCs). Present study characterized a novel gene C5H11ORF96, that demonstrated significant upregulation after the DEX injection in chicken, which simulates the stress stimulus. Our results showed that: (1) cC5H11ORF96 cDNA encodes a 120 amino acids protein, which shares high sequence identity with that of birds, mammals, reptiles, frogs and fish; (2) cC5H11ORF96 has a fully conserved RFKTQP motif and high proportion of serine, indicating its multiple potential phosphorylation sites; (3) cC5H11ORF96 is widely expressed in various chicken tissues, with high expression levels in the parathyroid gland, adrenal gland, and pituitary; (4) glucocorticoids (GCs) and stress significantly upregulate C5H11ORF96 mRNA and protein expression in the chicken pituitary and hypothalamus, suggesting its involvement in regulating stress response by influencing the negative feedback of GCs on the HPA axis in chickens. The characterization of the C5H11ORF96 gene in the chicken stress response provides potential targets for stress adaptability and poultry production. Meanwhile, our finding provides essential insights into the physiological functions of C11ORF96 gene in vertebrates.

Modality and fidelity: Understanding how creative stimulus combinations impact design outcomes and process across different conceptual design phases

During conceptual design, creative stimuli are an external source of inspiration to support students’ ideation process. Although existing research has explored the roles of creative stimuli, they rarely consider the intertwined influence brought by stimuli’s multiple characteristics, and overlook variations in stimuli’s effectiveness at different design phases. To fill this gap, this research conducted a 3×3 experiment, involving 72 design students in a three-phase design process and presenting combinations of textual and visual stimuli at distinct fidelities. We assessed different stimulus combinations’ influence on creativity, and employed behavior coding and linkograph to reveal students’ behavior and cognitive patterns throughout the process. The results revealed the mutual influence between the fidelity of texts and images, and students commonly needed more concrete stimuli in later design phases. Furthermore, students provided with different stimulus combinations exhibited variations in time allocation for behaviors including task analysis, idea generation, and evaluation, and they employed distinct approaches to generate new ideas. These findings highlight the necessity for design educators to dynamically provide creative stimuli based on the design phase, educational objective, and students’ state.

Significance of spatial variability in heat generation on nonlinear mixed convective Jeffrey nanofluid flows nearby an impermeable plate

The dynamics of Jeffrey nanofluids over an elongated surface heated by convection are addressed adequately under the nonlinear Boussinesq’s sense. Novel attributes of exponential heat source and thermal radiation are included. Buongiorno’s revised nanoliquid model is implemented to study the uneven dispersion and thermophoresis of nanoparticles subjected to passive control of nanoparticles on the surface. Wall suction or injection effects are also considered. Mathematical modeling is developed and treated numerically using the similarity approach. The results are presented considering numerous values of the physical parameters. Stimulus variables that regulate the resulting dimensionless physical quantities are examined graphically. Nonlinear convection has occurred to reinforce the nanofluid motion and reduce the thermal boundary layer thickness. The results of this study are useful in polymer industries.

Stimulation conditions leading to electrical vestibular co-stimulation in cochlear implant users.

The study objective was to investigate the influence of electrical stimulus properties on cervical and ocular vestibular-evoked myogenic potentials to electrical stimulation by cochlear implants (e-cVEMPs, e-oVEMPs). E-VEMPs were recorded in adult Nucleus cochlear implant (CI) patients using electric pulse trains (4 biphasic pulses at 1000 Hz burst rate). Ground path and stimulation electrodes were varied between monopolar stimulation at basal electrode contact E3 (MP1 + 2 E3), monopolar stimulation at apical electrode contact E20 (MP1 + 2 E20), and bipolar transmodiolar stimulation between E3 and E14 (BP E3-E14). The electric pulse train was further varied to 2 pulses at 1000 Hz, 2 pulses at 500 Hz, and a single pulse, in patients with present e-VEMP responses. VEMPs to bone-conducted vibration (BCV) were recorded as reference in all participants. Measurements were conducted in 30 ears of 27 participants (mean age 49.3 years, SD 12.7 years). E-VEMPs were present in 13 ears (43%). 5 of the 13 cases showed e-VEMPs but no BCV evoked VEMPs. Response numbers increased with increasing stimulation levels. The highest response rate of 40% was obtained for MP1 + 2 E3 stimulation. Stimulus variation did not affect response numbers. E-VEMP amplitudes were comparable to BCV-stimulated VEMPs. Latencies were up to 3.1 ms shorter for electric stimulation. Some patients showed e-VEMP thresholds close to or below the electric hearing threshold level. The occurrence of e-VEMPs is dependent on current path and stimulation level. Vestibular co-stimulation by the CI is more likely in patients with high stimulation levels and for monopolar stimulation of basal electrode contacts. 4.

Resting-state functional connectivity involved in tactile orientation processing

BackgroundGrating orientation discrimination (GOD) is commonly used to assess somatosensory spatial processing. It allows discrimination between parallel and orthogonal orientations of tactile stimuli applied to the fingertip. Despite its widespread application, the underlying mechanisms of GOD, particularly the role of cortico-cortical interactions and local brain activity in this process, remain elusive. Therefore, we aimed to investigate how a specific cortico-cortical network and inhibitory circuits within the primary somatosensory cortex (S1) and secondary somatosensory cortex (S2) contribute to GOD. MethodsIn total, 51 healthy young adults were included in our study. We recorded resting-state magnetoencephalography (MEG) and somatosensory-evoked magnetic field (SEF) in participants with open eyes. We converted the data into a source space based on individual structural magnetic resonance imaging. Next, we estimated S1- and S2-seed resting-state functional connectivity (rs-FC) at the alpha and beta bands through resting-state MEG using the amplitude envelope correlation method across the entire brain (i.e., S1/S2-seeds × 15,000 vertices × two frequencies). We assessed the inhibitory response in the S1 and S2 from SEFs using a paired-pulse paradigm. We automatically measured the GOD task in parallel and orthogonal orientations to the index finger, applying various groove widths with a custom-made device. ResultsWe observed a specific association between the GOD threshold (all P < 0.048) and the alpha rs-FC in the S1–superior parietal lobule and S1–adjacent to the parieto-occipital sulcus (i.e., lower rs-FC values corresponded to higher performance). In contrast, no association was observed between the local responses and the threshold. DiscussionThe results of this study underpin the significance of specific cortico-cortical networks in recognizing variations in tactile stimuli.

The Impact of Visual, Thermal, and Acoustic Environments in Urban Public Spaces in Cold Regions on the Psychological Restoration of the Elderly

Optimizing the visual, thermal, and acoustic environments of urban public spaces in severely cold regions can significantly enhance the psychological restoration of the elderly, addressing the increasing mental health demands in an aging society. Despite its importance, the mechanisms, strategies, and seasonal effects of various environmental variables on psychological restoration remain inadequately studied. This research uses Harbin as a case study, employing field surveys and tests to systematically examine the elderly’s psychological restoration across different seasons. By integrating environmental stimulus variables with a psychological restoration evaluation model, the study investigates the impact of urban public spaces on mental health. The key findings are: (1) The spring environment of urban public spaces has the most significant positive effect on psychological restoration, with an effect size of η2 = 0.360. (2) A significant correlation exists between environmental variables and psychological restoration year-round, with the panoramic green view index in winter showing the highest positive impact (correlation coefficient = 0.301, p &lt; 0.01). (3) The influence of environmental stimulus variables on psychological restoration varies notably across seasons; the acoustic environment in spring contributes most significantly, with an R2 = 17.03%, while visual factors dominate in winter and summer. (4) Conditional probability analysis reveals the effects of various environmental variables on psychological restoration, proposing season-specific environment optimization strategies. Based on these findings, the paper presents a model for optimizing urban public space environments in severely cold regions, aiming to maximize elderly psychological restoration by tailoring environmental stimulus variables to their mental health needs.

Sensing diversity in halogen-bonded multi-stimuli responsive materials: Light, pH, magnetism, and electron-rich species

The present study delves into the synthesis and characterization of multi-stimuli responsive polymers, demonstrating their sensitivity towards magnetic field, pH level, light irradiation, and electron-rich species through halogen bonding (XB). Detailed X-ray analyses of two azobenzene derivatives, each incorporating a tetrafluoroiodobenzene group, provided the compelling evidence of engagement of the building blocks in the formation of halogen bonds. Interestingly, the investigation of an ammonium analog, featuring a tetrahalogenoferrate(III) anion, not only showcased a magnetic response even upheld its ability to undergo isomerization under UV irradiation. These functional properties were subsequently harnessed in the form of multi-responsive compounds through the random quaternization of poly(2-(N,N-dimethylamino) ethyl methacrylate) (PDMAEMA), and by employing varying proportions of XB-donor dye (8, 11, 15, 21, and 43 %) followed by magnetic anion exchange. Leveraging the presence of free ternary amino groups and diazobenzene moieties, the resulting polymers demonstrated pronounced sensitivity towards a variation of pH and UV light stimuli, while a careful modulation of magnetic susceptibility was found to be directly proportional to the degree of quaternization. An NMR titration, conducted using a synthetic intermediate, revealed the formation of I⋯Cl‾ interactions in the solution state, thereby underscoring the materials' sensitivity to electron-rich species. Moreover, the electron microscopic analysis displayed an alteration in morphology upon the application of a magnetic field and UV irradiation. Thus, the presented strategic framework offers an avenue for the development of multi-stimuli responsive materials for remotely controlled smart devices to act in response to a diverse set of four stimuli, and heralding a significant advancement in the realm of responsive material design.

Generalization of food devaluation following food-specific go/no-go training

The benefit of food-specific inhibition training on modulating food valuation and eating behaviors has been established, but generalization to untrained foods is seldomly examined. This study investigated whether stimulus variability and practice order, found to effect generalization in motor learning, can improve generalization following food-specific inhibition training. Ninety-three young adults practiced the Go/No-Go task online in three training conditions: 1) Constant (N = 30): inhibition practiced on one food stimulus; 2) Variable-Blocked (N = 32): inhibition practiced on 6 food stimuli, each in a separate block; and 3) Variable-Random (N = 31): inhibition practiced on 6 food stimuli in random order. Consistent with our hypothesis, the Variable-Random group showed better generalization of inhibition to untrained foods than the Constant and the Variable-Blocked groups immediately after training, demonstrating the benefit of stimulus variability and random practice order. This effect was not present 24 h after training. The Variable-Random group also showed decreased desire to eat untrained foods, exhibiting generalization of food devaluation. However, this effect was only present 24 h after training. The Constant group showed increased desire to eat untrained foods immediately and 24 h after training. The Variable-Blocked group did not differ from either group in the desire to eat to untrained foods, suggesting that random order is important for exposing the benefit of variability. The findings illustrate that presenting various training items in random order can improve generalization of food-specific inhibition training. However, inconsistencies found in the timing of generalization effects and modest effect sizes warrant additional investigation into generalization principles of food-specific inhibition training.

Decoding the task specificity of post-error adjustments: Features and determinants

Errors typically trigger post-error adjustments aimed at improving subsequent reactions within a single task, but little work has focused on whether these adjustments are task-general or task-specific across different tasks. We collected behavioral and electrophysiological (EEG) data when participants performed a psychological refractory period paradigm. This paradigm required them to complete Task 1 and Task 2 separated by a variable stimulus onset asynchrony (SOA). Behaviorally, post-error slowing and post-error accuracy exhibited task-general features at short SOAs but some task-specific features at long SOAs. EEG results manifest that task-general adjustments had a short-lived effect, whereas task-specific adjustments were long-lasting. Moreover, error awareness specifically conduced to the improvement of subsequent sensory processing and behavior performance in Task 1 (the task where errors occurred). These findings demonstrate that post-error adjustments rely on both transient, task-general interference and longer-lasting, task-specific control mechanisms simultaneously, with error awareness playing a crucial role in determining these mechanisms. We further discuss the contribution of central resources to the task specificity of post-error adjustments.

Choice enhances touch pleasantness

We value what we choose more than what is imposed upon us. Choice-induced preferences are extensively demonstrated using behavioural and neural methods, mainly involving rewarding objects such as money or material goods. However, the impact of choice on experiences, especially in the realm of affective touch, remains less explored. In this study, we specifically investigate whether choice can enhance the pleasure derived from affective touch, thereby increasing its intrinsic rewarding value. We conducted an experiment in which participants were being touched by an experimenter and asked to rate how pleasant their experience of touch was. They were given either a choice or no choice over certain touch stimulus variables which differed in their relevance: some were of low relevance (relating to the colour of the glove that the experimenter would use to touch them), while others were of high relevance (relating to the location on their arm where they would be stroked). Before and during touching, pupillometry was used to measure the level of arousal. We found that having a choice over aspects of tactile stimuli—especially those relevant to oneself—enhanced the pleasant perception of the touch. In addition, having a choice increases arousal in anticipation of touch. Regardless of how relevant it is to the actual tactile stimulus, allowing one to choose may positively enhance a person’s perception of the physical contact they receive.

Identifying conceptual neural responses to symbolic numerals.

The goal of measuring conceptual processing in numerical cognition is distanced by the possibility that neural responses to symbolic numerals are influenced by physical stimulus confounds. Here, we targeted conceptual responses to parity (even versus odd), using electroencephalogram (EEG) frequency-tagging with a symmetry/asymmetry design. Arabic numerals (2-9) were presented at 7.5 Hz in 50 s sequences; odd and even numbers were alternated to target differential, 'asymmetry' responses to parity at 3.75 Hz (7.5 Hz/2). Parity responses were probed with four different stimulus sets, increasing in intra-numeral stimulus variability, and with two control conditions composed of non-conceptual numeral alternations. Significant asymmetry responses were found over the occipitotemporal cortex to all conditions, even for the arbitrary controls. The large physical-differences control condition elicited the largest response in the stimulus set with the lowest variability (one font). Only in the stimulus set with the highest variability (20 drawn, coloured exemplars/numeral) did the response to parity surpass both control conditions. These findings show that physical differences across small sets of Arabic numerals can strongly influence, and even account for, automatic brain responses. However, carefully designed control conditions and highly variable stimulus sets may be used towards identifying truly conceptual neural responses.

Productions of Goldman-Fristoe Test of Articulation–Third Edition Stimulus Words Among Teenage Speakers of Anguillian Eastern Caribbean English

Purpose: This study documents consonant and vowel variation in typically developing teenage speakers of Anguillian English, demonstrates how consonant variation impacts performance on the Goldman-Fristoe Test of Articulation–Third Edition (GFTA-3), and provides culturally responsive clinical recommendations for GFTA-3 scoring involving native speakers of Anguillian English. Method: Twenty Anguillian teenagers (14;3–17;9 [years;months]) completed the GFTA-3 Sounds in Words subtest. The audio-recorded productions were phonetically transcribed and analyzed to determine consonant and vowel variations that differed from Mainstream U.S. English. To demonstrate the importance of culturally responsive assessment, deficit scores were compared with language-appropriate scores. Results: Anguillian consonant variation heavily impacted GFTA-3 stimuli that were meant to elicit /ɚ/, postvocalic /ɹ/, interdental fricatives, and present participle /ŋ/. Vowel variations included production of /ʌɪ/ in knife, /ɑɪ/ in boy, and /oʊ/ in house. Some speakers demonstrated more consistent use of Anguillian speech variation than others. When language-appropriate scoring was not used, 19 of the 20 participants scored below the first percentile in the Sounds in Words subtest. Conclusions: Culturally and linguistically responsive practices and tools are needed throughout the Eastern Caribbean region. This study's description of Anguillian English speech variation in GFTA-3 stimuli is a resource that will improve culturally responsive speech sound assessment in Anguillian children. We encourage clinicians and researchers to replicate this study with speakers of other Eastern Caribbean English languages.

A Picture May Be Worth 1,000 Words, but Is It Worth a Letter? Examining Whether the Choice of Label Affects the Perception of Speech Sounds.

Researchers often use identification or goodness rating tasks to assess speech perception for different populations. These tasks provide useful information about a listener's willingness to accept a range of acoustically variable stimuli as belonging to the same category and also about assessing how stimuli that are labeled the same may not be perceived as equally good versions of a particular speech sound. Many methodological aspects of these simple tasks have been tested, but one aspect that has not is the choice of label. In this study, we examine response patterns to images versus letters, as studies with different populations (children vs. adults) or different methods (typical behavioral study vs. visual world paradigm) may vary in the type of label used. Eighty-one adult listeners completed phoneme identification and goodness ratings tasks with either images of response options (a picture of a bear and a picture of a pear) or with letter labels (a capital B and P). The results suggest that choice of label does not alter performance within the tasks studied here. In addition, the results did show the expected finding that the slope of the response curve is steeper in an identification task than in a goodness rating task. These results suggest that it is possible to compare across studies that use different response options, a benefit to research and practice because letter labels can be used for nonimageable words and nonwords, whereas images may be best used for participants who are younger or have poorer reading skills.

What Fechner could not do: Separating perceptual encoding and decoding with difference scaling.

A key question in perception research is how stimulus variations translate into perceptual magnitudes, that is, the perceptual encoding process. As experimenters, we cannot probe perceptual magnitudes directly, but infer the encoding process from responses obtained in a psychophysical experiment. The most prominent experimental technique to measure perceptual appearance is matching, where observers adjust a probe stimulus to match a target in its appearance along the dimension of interest. The resulting data quantify the perceived magnitude of the target in physical units of the probe, and are thus an indirect expression of the underlying encoding process. In this paper, we show analytically and in simulation that data from matching tasks do not sufficiently constrain perceptual encoding functions, because there exist an infinite number of pairs of encoding functions that generate the same matching data. We use simulation to demonstrate that maximum likelihood conjoint measurement (Ho, Landy, & Maloney, 2008; Knoblauch & Maloney, 2012) does an excellent job of recovering the shape of ground truth encoding functions from data that were generated with these very functions. Finally, we measure perceptual scales and matching data for White's effect (White, 1979) and show that the matching data can be predicted from the estimated encoding functions, down to individual differences.

Towards Improved Auditory-Perceptual Assessment of Timbres: Comparing Accuracy and Reliability of Four Deconstructed Timbre Assessment Models

Timbre is a central quality of singing, yet remains a complex notion poorly understood in psychoacoustic studies. Previous studies note how no single acoustic variable or combinations of variables consistently predict timbre dimensions. Timbre varies on a continuum from darkest to lightest. These extremes are associated with laryngeal and vocal tract adjustments related to smaller and larger vocal tract area and variations in vocal fold vibratory characteristics. Perceptually, timbre assessment is influenced by spectral characteristics and formant frequency adjustments, though these dimensions are not independently perceived. Perceptual studies repeatedly demonstrate difficulties in correlating variations in timbre stimuli to specific measures. A recent study demonstrated how acoustic predictive salience of voice category and voice weight across pitches contribute to timbre assessments and concludes that timbre may be related to as-of-yet unknown factor(s). The purpose of this study was to test four different models for assessing timbre; one model focused on specific anatomy, one on listener intuition, one utilising auditory anchors, and one using expert raters in a deconstructed timbre model with 5 specific dimensions. MethodsFour independent panels were conducted with separate cohorts of professional singing teachers. 41 assessors took part in the anatomically focused panel, 54 in the intuition-based panel, 30 in the anchored panel, and 12 in the expert listener panel. Stimuli taken from live performances of well-known singers were used for all panels, representing all genders, genres, and styles across a large pitch range. All stimuli are available as supplementary materials. Fleiss’ kappa values, descriptive statistics, and significance tests are reported for all panel assessments. ResultsPanel 1 through 4 varied in overall accuracy and agreement. The intuitionbased model showed overall 45% average accuracy (SD ±4%), k=0.289 (<0.001) compared to overall 71% average accuracy (SD ±3%), k=0.368 (<0,001) of the anatomical focused panel. The auditory-anchored model showed overall 75% average accuracy (SD ±8%), k=0.54 (<0.001) compared with overall 83% average accuracy and agreement of k=0.63 (<0.001) for panel 4. Results revealed that highest accuracy and reliability was achieved in a deconstructed timbre model and that providing anchoring improved reliability but with no further increase in accuracy. ConclusionDeconstructing timbre into specific parameters improved auditory perceptual accuracy and overall agreement. Assessing timbre along with other perceptual dimensions improves accruacy and reliability. Panel assessors’ expert level of listening skills remain an important factor in obtaining reliable and accurate assessments of auditory stimuli for timbre dimensions. Anchoring improved reliability but with no further increase in accuracy. The study suggests that timbre assessment can be improved by approaching the percept through a prism of 5 specific dimensions each related to specific physiology and auditory-perceptual subcategories. Further tests are needed with framework-naïve listeners, non-musically educated listeners, artificial intelligence comparisons, and synthetic stimuli to further test the reliability.

When stimulus variability accelerates the learning of task knowledge in adults and school-aged children.

Experience with instances that vary in their surface features helps individuals to form abstract task knowledge, leading to transfer of that knowledge to novel contexts. The current study sought to examine the role of this variability effect in how adults and school-aged children learn to engage cognitive control. We focused on the engagement of cognitive control in advance (proactive control) and in response to conflicts (reactive control) in a cued task-switching paradigm, and conducted four preregistered online experiments with adults (Experiment 1A: N = 100, Experiment 1B: N = 105) and 9- to 10-year-olds (Experiment 2A: N = 98, Experiment 2B: N = 97). It was shown that prior task experience of engaging reactive control makes both adults and 9- to 10-year-olds respond more slowly in a subsequent similar-structured condition with different stimuli in which proactive control could have been engaged. 9- to 10-year-olds (Experiment 2B) exhibited more negative transfer of a reactive control mode when uninformative cue and pre-target stimuli, which do not convey task-relevant information, were changed in each block, compared with when they were fixed. Furthermore, adults showed suggestive evidence of the variability effect both when cue and target stimuli were varied (Experiment 1A) and when uninformative cue and pre-target stimuli were varied (Experiment 1B). The collective findings of these experiments provide important insights into the contribution of stimulus variability to the engagement of cognitive control.

Aged Tendons Exhibit Altered Mechanisms of Strain-Dependent Extracellular Matrix Remodeling.

Aging is a primary risk factor for degenerative tendon injuries, yet the etiology and progression of this degeneration are poorly understood. While aged tendons have innate cellular differences that support a reduced ability to maintain mechanical tissue homeostasis, the response of aged tendons to altered levels of mechanical loading has not yet been studied. To address this question, we subjected young and aged murine flexor tendon explants to various levels of in vitro tensile strain. We first compared the effect of static and cyclic strain on matrix remodeling in young tendons, finding that cyclic strain is optimal for studying remodeling in vitro. We then investigated the remodeling response of young and aged tendon explants after 7 days of varied mechanical stimulus (stress deprivation, 1%, 3%, 5%, or 7% cyclic strain) via assessment of tissue composition, biosynthetic capacity, and degradation profiles. We hypothesized that aged tendons would show muted adaptive responses to changes in tensile strain and exhibit a shifted mechanical setpoint, at which the remodeling balance is optimal. Interestingly, we found that 1% cyclic strain best maintains native physiology while promoting extracellular matrix (ECM) turnover for both age groups. However, aged tendons display fewer strain-dependent changes, suggesting a reduced ability to adapt to altered levels of mechanical loading. This work has a significant impact on understanding the regulation of tissue homeostasis in aged tendons, which can inform clinical rehabilitation strategies for treating elderly patients.

Multilevel Information Encryption Based on Thermochromic Perovskite Microcapsules via Orthogonal Photic and Thermal Stimuli Responses.

Increasing modal variations of stimulus-responsive materials ensure the high capacity and confidentiality of information storage and encryption systems that are crucial to information security. Herein, thermochromic perovskite microcapsules (TPMs) with dual-variable and quadruple-modal reversible properties are designed and prepared on the original oil-in-fluorine (O/F) emulsion system. The TPMs respond to the orthogonal variations of external UV and thermal stimuli in four reversible switchable modes and exhibit excellent thermal, air, and water stability due to the protection of perovskites by the core-shell structure. Benefiting from the high-density information storage TPMs, multiple information encryptions and decryptions are demonstrated. Moreover, a set of devices are assembled for a multilevel information encryption system. By taking advantage of TPMs as a "private key" for decryption, the signal can be identified as the corresponding binary ASCII code and converted to the real message. The results demonstrate a breakthrough in high-density information storage materials as well as a multilevel information encryption system based on switchable quadruple-modal TPMs.

The Directional Effects of Marker Frequencies on Across-Channel Temporal Gap Detection Tasks: An Experimental Study

Plain Language SummaryGap detection tests are essential while performing hearing assessments that are aimed to tap central auditory processing abilities. Different varieties of gap detection tests are evaluated for their sensitivity, and across-channel gap detection is noted to have high potential to detect central auditory processing disorders. However, any variations in the stimulus frequencies would impact the results of gap detection thresholds. Present study would enlighten the reader with the impact of such variations in stimuli on the outcome gap detection measures. The result of the study indicates when the two marker frequencies are close in nature (one-octave difference), then the order of their presentation did not change the outcome measures significantly. But, when the two marker frequencies are wide in nature (two-octave difference), then the order of their presentation changed the outcome measures significantly. The measured gap detection thresholds are better if high-frequency segment presented initially followed by the low frequency. Further, the study also provides valuable discussions on the results obtained. The study would add necessary understanding and precautions about the stimulus while using gap detection measures.

TDCS over PPC or DLPFC does not improve visual working memory capacity

Non-invasive brain stimulation has been highlighted as a possible intervention to induce cognitive benefits, including on visual working memory (VWM). However, findings are inconsistent, possibly due to methodological issues. A recent high-profile study by Wang et al.1 reported that anodal transcranial direct current stimulation (tDCS) over posterior parietal cortex (PPC), but not over dorsolateral prefrontal cortex (DLPFC), selectively improved VWM capacity but not precision, especially at a high VWM load. Thus, in the current pre-registered conceptual replication study, we accounted for the key potential methodological issues in the original study and tested an adequate number of participants required to demonstrate the previously reported effects (n = 48 compared to n = 20). Participants underwent counterbalanced PPC, DLPFC and sham stimulation before completing 360 trials of a continuous orientation-reproduction task with a slight variation of task stimuli and setup. We found no evidence for the selective effect of PPC stimulation. Instead, our results showed that tDCS effects were absent regardless of stimulation region and VWM load, which was largely supported by substantial to strong Bayesian evidence. Therefore, our results challenge previously reported benefits of single-session anodal PPC-tDCS on VWM.