Extended just-noticeable difference for ultralow-luminance displays used in diagnostic imaging.

This study investigates the just-noticeable difference (JND) in luminance below the 0.050c d/m 2 threshold not covered by the DICOM standard in medical imaging displays. A total of 21 healthy young adults were tested using an ultralow-luminance liquid crystal display at a viewing distance of 46 cm. The optotype featured a 4 cycle/deg rectangular wave-like stripe. The average percentage of correct responses for JND indices between -18 and 0 was 70.8%. Using the extended JND based on the Barten model that matches the current JND definition, we confirmed the JND at a very low luminance of 0.0500c d/m 2 or less. These findings suggest the feasibility of further refining the gradation differences in medical imaging displays.

Perception of voice cues in school-age children with hearing aids.

The just-noticeable differences (JNDs) of the voice cues of voice pitch (F0) and vocal-tract length (VTL) were measured in school-aged children with bilateral hearing aids and children and adults with normal hearing. The JNDs were larger for hearing-aided than normal-hearing children up to the age of 12 for F0 and into adulthood for all ages for VTL. Age was a significant factor for both groups for F0 JNDs, but only for the hearing-aided group for VTL JNDs. Age of maturation was later for F0 than VTL. Individual JNDs of the two groups largely overlapped for F0, but little for VTL. Hearing thresholds (unaided or aided, 500-400 Hz, overlapping with mid-range speech frequencies) did not correlate with the JNDs. However, extended low-frequency hearing thresholds (unaided, 125-250 Hz, overlapping with voice F0 ranges) correlated with the F0 JNDs. Hence, age and hearing status differentially interact with F0 and VTL perception, and VTL perception seems challenging for hearing-aided children. On the other hand, even children with profound hearing loss could do the task, indicating a hearing aid benefit for voice perception. Given the significant age effect and that for F0 the hearing-aided children seem to be catching up with age-typical development, voice cue perception may continue developing in hearing-aided children.

Numerical Representation for Action in Crows Obeys the Weber-Fechner Law.

The psychophysical laws governing the judgment of perceived numbers of objects or events, called the number sense, have been studied in detail. However, the behavioral principles of equally important numerical representations for action are largely unexplored in both humans and animals. We trained two male carrion crows (Corvus corone) to judge numerical values of instruction stimuli from one to five and to flexibly perform a matching number of pecks. Our quantitative analysis of the crows' number production performance shows the same behavioral regularities that have previously been demonstrated for the judgment of sensory numerosity, such as the numerical distance effect, the numerical magnitude effect, and the logarithmical compression of the number line. The presence of these psychophysical phenomena in crows producing number of pecks suggests a unified sensorimotor number representation system underlying the judgment of the number of external stimuli and internally generated actions.

The BTPI: An online battery for measuring susceptibility to visual illusions.

Visual illusions provide a powerful tool for probing the mechanisms that underlie perception. While most previous studies of visual illusions focused on average group-level performance, less attention has been devoted to individual differences in susceptibility to illusions. Unlike in other perceptual domains, in which there are established, validated tools to measure individual differences, such tools are not yet available in the domain of visual illusions. Here, we describe the development and validation of the BTPI (Ben-Gurion University Test for Perceptual Illusions), a new online battery designed to measure susceptibility to the influence of three prominent size illusions: the Ebbinghaus, the Ponzo, and the height-width illusions. The BTPI also measures perceptual resolution, reflected by the just noticeable difference (JND), to detect size differences in the context of each illusion. In Experiment 1 (N = 143), we examined performance in typical self-paced tasks, whereas in Experiment 2 (N = 69), we employed a fixed presentation duration paradigm. High test-retest reliability scores were found for all illusions, with little evidence for intercorrelations between different illusions. In addition, lower perceptual resolution (larger JND) was associated with a larger susceptibility to the illusory effect. The computerized task battery and analysis codes are freely available online.

How we compare areas: The underlying mechanism of the elongation bias.

Across four experiments, we investigate the mechanism that underlies the elongation bias. We find individuals tasked with assessing the area of two objects do so by comparing the objects' dimensions, and thus subtle changes in the objects' dimensions can impact area assessments. Because a typical elongation bias experiment places two objects side-by-side horizontally and varies the elongation ratio while maintaining the same area, height is generally easier to compare than width. Thus, there will exist a region where the change in height noticeably crosses a perceptual just noticeable difference boundary, but the corresponding change in width does not, and individuals will tend to perceive that the taller object has a greater area or volume. Consistent with this proposed process, we suggest that, although the elongation bias occurs under a comparative judgment, it does not do so under a single judgment situation. This research contributes to our wider understanding of the visual processes underlying area comparisons.

RF-Alphabet: Cross Domain Alphabet Recognition System Based on RFID Differential Threshold Similarity Calculation Model.

Gesture recognition can help people with a speech impairment to communicate and promote the development of Human-Computer Interaction (HCI) technology. With the development of wireless technology, passive gesture recognition based on RFID has become a research hotspot. In this paper, we propose a low-cost, non-invasive and scalable gesture recognition technology, and successfully implement the RF-alphabet, a gesture recognition system for complex, fine-grained, domain-independent 26 English letters; the RF-alphabet has three major advantages: first, this paper achieves complete capture of complex, fine-grained gesture data by designing a dual-tag, dual-antenna layout. Secondly, to overcome the disadvantages of the large training sets and long training times of traditional deep learning. We design and combine the Difference threshold similarity calculation prediction model to extract digital signal features to achieve real-time feature analysis of gesture signals. Finally, the RF alphabet solves the problem of confusing the signal characteristics of letters. Confused letters are distinguished by comparing the phase values of feature points. The RF-alphabet ends up with an average accuracy of 90.28% and 89.7% in different domains for new users and new environments, respectively, by performing feature analysis on similar signals. The real-time, robustness, and scalability of the RF-alphabet are proven.

Grasping follows Weber's law: How to use response variability as a proxy for JND.

Weber's law is a fundamental psychophysical principle. It states that the just noticeable difference (JND) between stimuli increases with stimulus magnitude; consequently, larger stimuli should be estimated with larger variability. However, visually guided grasping seems to violate this expectation: When repeatedly grasping large objects, the variability is similar to that when grasping small objects. Based on this result, it was often concluded that grasping violated Weber's law. This astonishing finding generated a flurry of research, with contradictory results and potentially far-reaching implications for theorizing about the functional architecture of the brain. We show that previous studies ignored nonlinearities in the scaling of the grasping response. These nonlinearities result from, for example, the finger span being limited such that the opening of the fingers reaches a ceiling for large objects. We describe how to mathematically take these nonlinearities into account and apply this approach to our own data, as well as to the data of three influential studies on this topic. In all four datasets, we found that-when appropriately estimated-JNDs increase with object size, as expected by Weber's law. We conclude that grasping obeys Weber's law, as do essentially all sensory dimensions.

Inadequate pitch-difference sensitivity prevents half of all listeners from discriminating major vs minor tone sequences.

Substantial evidence suggests that sensitivity to the difference between the major vs minor musical scales may be bimodally distributed. Much of this evidence comes from experiments using the "3-task." On each trial in the 3-task, the listener hears a rapid, random sequence of tones containing equal numbers of notes of either a G major or G minor triad and strives (with feedback) to judge which type of "tone-scramble" it was. This study asks whether the bimodal distribution in 3-task performance is due to variation (across listeners) in sensitivity to differences in pitch. On each trial in a "pitch-difference task," the listener hears two tones and judges whether the second tone is higher or lower than the first. When the first tone is roved (rather than fixed throughout the task), performance varies dramatically across listeners with median threshold approximately equal to a quarter-tone. Strikingly, nearly all listeners with thresholds higher than a quarter-tone performed near chance in the 3-task. Across listeners with thresholds below a quarter-tone, 3-task performance was uniformly distributed from chance to ceiling; thus, the large, lower mode of the distribution in 3-task performance is produced mainly by listeners with roved pitch-difference thresholds greater than a quarter-tone.

A study of the just noticeable difference of early decay time for symphonic halls.

The just noticeable differences (JNDs) of room acoustic parameters are important for the design of concert halls and, in general, research of room acoustics. Precise knowledge of JNDs helps the concert hall designer in assessing the impact that changes in the geometry or materials of the hall will have on its perceived acoustics. When designing a concert hall, creating an appropriate feeling of reverberance for the audience is of prime importance. The early decay time (EDT) parameter has proved to be a better predictor of the perception of reverberance than the classical reverberation time (T30), but no studies have been conducted to specifically determine the EDT JND. In the present study, the EDT JND was investigated for broadband conditions and assessed for individual frequency ranges. A subjective study was conducted with 26 subjects with musical training, in which 21 were considered reliable. The participants listened to orchestral music convolved with measured spatial room impulse responses from three concert halls. The stimuli were auralized in an anechoic chamber using third-order Ambisonic reproduction. The obtained values show that the JNDs for the broadband conditions are lower than those for the individual frequency ranges. The EDT JND for the broadband conditions was found to be approximately 18% of the EDT value.

Similar masking effects of natural backgrounds on detection performances in humans, macaques, and macaque-V1 population responses.

Visual systems evolve to process the stimuli that arise in the organism's natural environment, and hence, to fully understand the neural computations in the visual system, it is important to measure behavioral and neural responses to natural visual stimuli. Here, we measured psychometric and neurometric functions in the macaque monkey for detection of a windowed sine-wave target in uniform backgrounds and in natural backgrounds of various contrasts. The neurometric functions were obtained by near-optimal decoding of voltage-sensitive-dye-imaging (VSDI) responses at the retinotopic scale in primary visual cortex (V1). The results were compared with previous human psychophysical measurements made under the same conditions. We found that human and macaque behavioral thresholds followed the generalized Weber's law as function of contrast, and that both the slopes and the intercepts of the threshold as a function of background contrast match each other up to a single scale factor. We also found that the neurometric thresholds followed the generalized Weber's law with slopes and intercepts matching the behavioral slopes and intercepts up to a single scale factor. We conclude that human and macaque ability to detect targets in natural backgrounds are affected in the same way by background contrast, that these effects are consistent with population decoding at the retinotopic scale by down-stream circuits, and that the macaque monkey is an appropriate animal model for gaining an understanding of the neural mechanisms in humans for detecting targets in natural backgrounds. Finally, we discuss limitations of the current study and potential next steps.NEW & NOTEWORTHY We measured macaque detection performance in natural images and compared their performance to the detection sensitivity of neurophysiological responses recorded in the primary visual cortex (V1), and to the performance of human subjects. We found that 1) human and macaque behavioral performances are in quantitative agreement and 2) are consistent with near-optimal decoding of V1 population responses.

Excitability and Threshold Mechanism for Enhanced Neuronal Response Induced by Inhibition Preceding Excitation.

Postinhibitory facilitation (PIF) of neural firing presents a paradoxical phenomenon that the inhibitory effect induces enhancement instead of reduction of the firing activity, which plays important roles in sound location of the auditory nervous system, awaited theoretical explanations. In the present paper, excitability and threshold mechanism for the PIF phenomenon is presented in the Morris-Lecar model with type I, II, and III excitabilities. Firstly, compared with the purely excitatory stimulations applied to the steady state, the inhibitory preceding excitatory stimulation to form pairs induces the firing rate increased for type II and III excitabilities instead of type I excitability, when the interval between the inhibitory and excitatory stimulation within each pair is suitable. Secondly, the threshold mechanism for the PIF phenomenon is acquired. For type II and III excitabilities, the inhibitory stimulation induces subthreshold oscillations around the steady state. During the middle and ending phase of the ascending part and the beginning phase of the descending part within a period of the subthreshold oscillations, the threshold to evoke an action potential by an excitatory stimulation becomes weaker, which is the cause for the PIF phenomenon. Last, a theoretical estimation for the range of the interval between the inhibitory and excitatory stimulation for the PIF phenomenon is acquired, which approximates half of the intrinsic period of the subthreshold oscillations for the relatively strong stimulations and becomes narrower for the relatively weak stimulations. The interval for the PIF phenomenon is much shorter for type III excitability, which is closer to the experiment observation, due to the shorter period of the subthreshold oscillations. The results present the excitability and threshold mechanism for the PIF phenomenon, which provide comprehensive and deep explanations to the PIF phenomenon.

Expanding the indications for the bone anchored hearing system (BAHS) in patients with single sided deafness.

PURPOSE: Provide data to support expansion of FDA indications for the Bone anchored hearing system (BAHS). MATERIALS AND METHODS: This retrospective study in a tertiary otologic referral center included106 consecutive subjects who were implanted with a Bone Anchored Hearing System (BAHS) between January 2009 and January 2015 for single sided deafness. Subjects were divided into three groups by bone conduction pure tone average (PTA) of the better hearing ear: 0-20 dB (group 1), 21-40 dB (group 2) and 41-55 dB (group 3). All patients underwent BAHS implantation. Speech perception data (Hearing In Noise Test and Consonant-Nucleus-Consonant testing) was collected before and after surgical intervention. Patient-reported quality of life measures were obtained at least 6 months after activation. These included the Abbreviated Profile of Hearing Aid Benefit and Glasgow Benefit Inventory. RESULTS: All three groups of subjects demonstrated statistically significant improvement in outcome measures following BAHS. Subject reported quality of life outcome measures demonstrated significant improvement in disability from hearing loss and in quality of life. CONCLUSIONS: Patients with single sided deafness who have bone conduction thresholds worse than 20 dB in their contralateral ear are still able to benefit significantly from BAHS.

Effects of interaural decoherence on sensitivity to interaural level differences across frequency.

The interaural level difference (ILD) is a robust indicator of sound source azimuth, and human ILD sensitivity persists under conditions that degrade normally-dominant interaural time difference (ITD) cues. Nonetheless, ILD sensitivity varies somewhat with both stimulus frequency and interaural correlation (coherence). To further investigate the combined binaural perceptual influence of these variables, the present study assessed ILD sensitivity at frequencies 250-4000 Hz using stimuli of varied interaural correlation. In the first of two experiments, ILD discrimination thresholds were modestly elevated, and subjective lateralization slightly reduced, for both half-correlated and uncorrelated narrowband noise tokens relative to correlated tokens. Different from thresholds in the correlated condition, which were worst at 1000 Hz [Grantham, D.W. (1984). J. Acoust. Soc. Am. 75, 1191-1194], thresholds in the decorrelated conditions were independent of frequency. However, intrinsic envelope fluctuations in narrowband stimuli caused moment-to-moment variation of the nominal ILD, complicating interpretation of measured thresholds. Thus, a second experiment employed low-fluctuation noise tokens, revealing a clear effect of interaural decoherence per se that was strongly frequency-dependent, decreasing in magnitude from low to high frequencies. Measurements are consistent with known integration times in ILD-sensitive neurons and also suggest persistent influences of covert ITD cues in putative "ILD" tasks.

Using Differential Threshold Effects of Individual and Combined Periconceptional Methyl Donor Status on Maternal Genomic LINE-1 and Imprinted H19 DNA Methylation to Predict Birth Weight Variance in the Taiwan Pregnancy-Newborn Epigenetics (TPNE) Cohort Study.

BACKGROUND: Few studies have comprehensively examined the effect of methyl donor status on maternal DNA methylation and birth outcomes. OBJECTIVES: This study examined associations between periconceptional methyl donor status and genome-wide and specific imprinted gene methylation and fetal growth indices in the Taiwan Pregnancy-Newborn Epigenetics cohort. METHODS: Plasma folate, choline (free form), and betaine concentrations of the participants enrolled at 7-10 weeks of gestation were analyzed. DNA methylation at regulatory sequences of the imprinted H19 gene and genomic long interspersed nuclear element 1 (LINE-1) were measured in maternal lymphocytes using bisulfite/high-resolution melt polymerase chain reaction. Associations with birth weight (BW) were estimated through multiple regressions from 112 mother-newborn pairs. RESULTS: A nonlinear "L-shaped" relation and an inverse association between maternal plasma folate in T1 (mean ± SE: 17.6 ± 5.1 nmol/L) and lymphocytic LINE-1 methylation (ß: -0.49, P = 0.027) were characterized. After adjusting for LINE-1 methylation, individual maternal folate concentrations were positively associated with BW variance (ß = 0.24, P = 0.035), and the association was more pronounced in mothers with choline in T1 (mean ± SE: 5.4 ± 0.6 µmol/L; ß: 0.40, P = 0.039). Choline status of the mothers in T2 (mean ± SE: 7.2 ± 0.6 µmol/L) was inversely associated with LINE-1 methylation (ß: -0.43, P = 0.035), and a positive association was evident between T1 choline and H19 methylation (ß: 0.48, P = 0.011). After adjusting for epigenetic modification, maternal choline status predicted a positive association with BW (ß: 0.56, P = 0.005), but the effect was limited to mothers with high betaine concentrations in T3 (mean ± SE: 36.4 ± 8.8 µmol/L), depending on folate status. CONCLUSIONS: Our data highlight the differential threshold effects of periconceptional folate, choline, and betaine status on genomic LINE-1 and H19 DNA methylation and how their interplay has a long-term effect on BW variance.

Practice Makes Transfer Imperfect: Evidence From Auditory Learning.

BACKGROUND: Evidence from motor and visual studies suggests that the ability to generalize learning gains to untrained conditions decreases as the training progresses. This decrease in generalization was suggested to reflect a shift from higher to lower levels of neuronal representations of the task following prolonged training. In the auditory modality, however, the few studies that tested the influence of prolonging training on generalization ability showed no decrease and sometimes even an increase in generalization. OBJECTIVE: To test the impact of extending training in a basic psychoacoustic task on the ability to generalize the gains attained in training to untrained conditions. DESIGN: Eighty-two young adults participated in two experiments that differed in the specific training regimen. In both experiments, training was conducted using a difference limen for frequency (DLF) task with an adaptive forced-choice procedure, for either a single- or nine-session training. Following training, generalization to the untrained ear and to an untrained frequency was assessed. RESULTS: (a) Training induced significant learning (i.e., smaller DLF thresholds) following a single session of training, and more so following nine training sessions; (b) results from the combined data from both experiments showed that the ability to generalize the learning gains to the untrained ear and frequency was limited after the extended DLF training; (c) larger improvements under the trained condition resulted in smaller generalization to the untrained conditions. CONCLUSIONS: The findings of increased specificity with training in the auditory modality support the notion that gradual changes, both quantitative and qualitative, occur in the neural representations of an auditory task during its acquisition. These findings suggest common underlying mechanisms in basic skill learning across different modalities.

Consciously monitored grasping is vulnerable to perceptual intrusions.

The idea of functional differentiation between vision-for-action and vision-for-perception has been supported by evidence from different domains. According to this account, perception is based on consciously accessible, relative representations, whereas vision-for-action is performed in an analytic, automatic manner. Support for this idea comes from studies that showed that unlike perception, grasping movements are refractory to illusions and to Weber's law. Yet, interactions between the systems may occur when an action is performed in a less automated fashion. To test this idea, we asked participants to monitor their fingers apertures in flight and to halt their movement for a short duration when they felt that their aperture reached a maximum amount. The results showed that movements in the monitored condition were biased by the Ponzo illusion and showed atypical adherence to Weber's law. These results show that action and perception are more likely to interact when movements are performed in a controlled manner.

Children's Social Information Seeking is Sensitive to Referential Ambiguity.

We examined children's spontaneous information seeking in response to referential ambiguity. Children ages 2-5 (n = 160) identified the referents of familiar and novel labels. We manipulated ambiguity by changing the number of objects present and their familiarity (Experiments 1 and 2), and the availability of referential gaze (Experiment 2). In both experiments, children looked to the face of the experimenter more often while responding, specifically when the referent was ambiguous. In Experiment 2, 3- to 4-year olds also demonstrated sensitivity to graded referential evidence. These results suggest that social information seeking is an active learning behavior that could contribute to language acquisition in early childhood.

Patterns of audiometric threshold shifts from pulsatile tinnitus due to sigmoid sinus wall anomalies.

PURPOSE: To determine the severity and nature of audiometric threshold shifts for patients with pulsatile tinnitus (PT) due to sigmoid sinus wall anomalies (SSWA). MATERIALS AND METHODS: 38 patients with SSWAs and available pre-operative audiograms were examined. Low- and high-frequency pure tone averages (LF-PTA, HF-PTA) were calculated. Audiometric data were compared between affected and unaffected ears, with the interaural difference (affected-unaffected PTA) representing the change in hearing due to PT. Additionally, post-operative change was examined in 14 patients with available data. RESULTS: The average pre-operative air conduction (AC) LF-PTA was 17.04 dB on the affected side and 11.38 dB on the unaffected side (p < 0.001). The mean AC HF-PTA was significantly higher on the affected side as well (16.45 dB vs. 14.08 dB, p = 0.008). All shifts were sensorineural, with no significant air-bone gaps, and most subjects still had low-frequency thresholds in the normal range. Though the post-op change was not significant due to attrition, 5/14 patients (35.7%) had complete resolution of their pre-op interaural difference. A similar number developed a HF-PTA post-op threshold elevation in the surgical ear. CONCLUSIONS: PT due to SSWAs causes a mean 6 dB low-frequency bone-conduction threshold elevation, and smaller high-frequency threshold shifts, due to masking. Patients with larger threshold shifts should have other potential causes of hearing loss explored. LEVEL OF EVIDENCE: Level IV.

Dexamethasone eardrop with grommet placement vs intratympanic steroid injection for sudden sensorineural hearing loss: A randomized prospective clinical trial.

OBJECTIVES: The purpose of this study was to compare different means of intratympanic steroid delivery in the treatment of idiopathic sudden sensorineural hearing loss. DESIGN: Prospective, multicentered, randomized controlled trial. SETTING AND PARTICIPANTS: Fifty-six patients who fulfilled the inclusion criteria for idiopathic sudden sensorineural hearing loss who failed or were contraindicated for oral steroids were included in this study. Patients were randomly divided into 2 groups according to delivery methods: group A received 4 sections of intratympanic dexamethasone injection and group B received grommet placement with dexamethasone delivery followed by 3 sections of dexamethasone ear drop application. Self-administered paper-based questionnaires were filled out to measure subjective pain scores, vertigo, anxiety, and overall satisfaction immediately after each procedure. Hearing threshold was measured with pure tone audiogram in the follow-up. RESULTS: There was no statistical significance detected in hearing threshold improvement between both groups (P = 0.30). Grommet placement followed by dexamethasone eardrop application demonstrated a significant difference in shorter waiting time (24 min in grommet group vs 52 min in injection group; P < 0.01); and better overall satisfaction (1.6 in grommet group vs 2.5 in injection group; P < 0.05). CONCLUSIONS: Grommet placement followed by dexamethasone eardrop application is a good alternative for a patient indicated for intratympanic steroid, with less administrative cost, shorter waiting time, and more satisfaction.

Cochlear implantation after traumatic brain injury without otic capsule fracture: A case report and literature review.

OBJECTIVE: The aim of this study was to report a case of cochlear implantation (CI) for a patient with an otic capsule-sparing traumatic brain injury (TBI) and to review the relevant literature. METHODS: A patient with history of TBI received a CI for bilateral profound hearing loss. A systematic review of the literature was performed to identify and compare similar cases. RESULTS: A 36-year-old male with a history of hearing loss from right acute labyrinthitis was referred for bilateral profound sensorineural hearing loss (SNHL) after a fall with associated injury to the central auditory nervous system (CANS) including the brainstem. On the right, behavioral acoustic threshold measurements were in the profound range with absent OAEs. On the left, testing revealed no measurable behavioral acoustic thresholds and variable physiologic measures. A right unilateral cochlear implant was performed with most recent follow-up demonstrating speech awareness thresholds of 25 dB HL with excellent detection of all 6 Ling sounds. However, the patient also continues to suffer from other neurologic sequelae related to his TBI, which challenge his ability to demonstrate objective and subjective benefit. A systematic review of the literature demonstrates variable outcomes for patients with TBI and SNHL. CONCLUSIONS: Patients with profound SNHL and TBI present a distinct rehabilitative challenge for clinicians. CI may provide meaningful benefit in this population, though care should be taken in patient selection and counseling.