-
European Archives of... Jan 2022In most cases, tinnitus co-exists with hearing loss, suggesting that poorer speech understanding is simply due to a lack of acoustic information reaching the central...
PURPOSE
In most cases, tinnitus co-exists with hearing loss, suggesting that poorer speech understanding is simply due to a lack of acoustic information reaching the central nervous system (CNS). However, it also happens that patients with tinnitus who have normal hearing also report problems with speech understanding, and it is possible to suppose that tinnitus is to blame for difficulties in perceptual processing of auditory information. The purpose of the study was to evaluate the auditory processing abilities of normally hearing subjects with and without tinnitus.
METHODS
The study group comprised 97 adults, 54 of whom had normal hearing and chronic tinnitus (the study group) and 43 who had normal hearing and no tinnitus (the control group). The audiological assessment comprised pure-tone audiometry and high-frequency pure-tone audiometry, impedance audiometry, and distortion product oto-acoustic emission assessment. To evaluate possible auditory processing deficits, the Frequency Pattern Test (FPT), Duration Pattern Test (DPT), Dichotic Listening Test (DLT), and Gap Detection Threshold (GDT) tests were performed.
RESULTS
The tinnitus subjects had significantly lower scores than the controls in the gap detection test (p < 0.01) and in the dichotic listening test (p < 0.001), but only for the right ear. The results for both groups were similar in the temporal ordering tests (FPT and DPT). Right-ear advantage (REA) was found for the controls, but not for the tinnitus subjects.
CONCLUSION
In normally hearing patients, the presence of tinnitus may be accompanied with auditory processing difficulties.
Topics: Adult; Audiometry, Pure-Tone; Auditory Perception; Auditory Threshold; Hearing; Humans; Psychoacoustics; Tinnitus
PubMed: 34363504
DOI: 10.1007/s00405-021-07023-w -
Scientific Reports Jul 2021Mechanoreceptors on the skin are heterogeneously distributed, and the sampling of neural signals in the brain can vary depending on the part of the body. Therefore, it... (Comparative Study)
Comparative Study
Mechanoreceptors on the skin are heterogeneously distributed, and the sampling of neural signals in the brain can vary depending on the part of the body. Therefore, it can be challenging for the brain to consistently represent stimuli applied to different body sites. Here, we report an example of a regional perceptual distortion of the tactile space. We used a piezoelectric braille display to examine shape perception on the volar surface of the arm and to compare it to that on the palm. We found that the orientation of perceived stimuli on the arm was distorted in certain areas. In particular, an inwardly-inclined line shape was perceived as being more inwardly-inclined than it actually was. On the other hand, an outwardly-inclined line was perceived accurately. When the same stimuli were applied to the palm, this anisotropic bias was not observed. We also found that changing the posture of the arm changed the angle at which this anisotropic distortion occurred, suggesting the influence of the skin frame of reference on this illusion. This study showed a clear example of how the representation of even simple stimuli is complexly distinct when the stimuli are applied to different body sites.
Topics: Adult; Anisotropy; Arm; Female; Hand; Humans; Illusions; Male; Mechanoreceptors; Middle Aged; Orientation, Spatial; Perception; Perceptual Distortion; Physical Stimulation; Posture; Space Perception; Touch; Touch Perception; Young Adult
PubMed: 34272414
DOI: 10.1038/s41598-021-93959-2 -
Animals : An Open Access Journal From... May 2021Although we live on the same planet, there are countless different ways of seeing the surroundings that reflect the different individual experiences and selective... (Review)
Review
Although we live on the same planet, there are countless different ways of seeing the surroundings that reflect the different individual experiences and selective pressures. In recent decades, visual illusions have been used in behavioural research to compare the perception between different vertebrate species. The studies conducted so far have provided contradictory results, suggesting that the underlying perceptual mechanisms may differ across species. Besides the differentiation of the perceptual mechanisms, another explanation could be taken into account. Indeed, the different studies often used different methodologies that could have potentially introduced confounding factors. In fact, the possibility exists that the illusory perception is influenced by the different methodologies and the test design. Almost every study of this research field has been conducted in laboratories adopting two different methodological approaches: a spontaneous choice test or a training procedure. In the spontaneous choice test, a subject is presented with biologically relevant stimuli in an illusory context, whereas, in the training procedure, a subject has to undergo an extensive training during which neutral stimuli are associated with a biologically relevant reward. Here, we review the literature on this topic, highlighting both the relevance and the potential weaknesses of the different methodological approaches.
PubMed: 34070792
DOI: 10.3390/ani11061618 -
Frontiers in Psychiatry 2021Of the perceptual distortions characteristic of Alice in Wonderland syndrome, substantial alterations in the immediate experience of time are probably the least known...
Of the perceptual distortions characteristic of Alice in Wonderland syndrome, substantial alterations in the immediate experience of time are probably the least known and the most fascinating. We reviewed original case reports to examine the phenomenology and associated pathology of these time distortions in this syndrome. A systematic search in PubMed, Ovid Medline, and the historical literature yielded 59 publications that described 168 people experiencing time distortions, including 84 detailed individual case reports. We distinguished five different types of time distortion. The most common category comprises slow-motion and quick-motion phenomena. In 39% of all cases, time distortions were unimodal in nature, while in 61% there was additional involvement of the visual (49%), kinaesthetic (18%), and auditory modalities (14%). In all, 40% of all time distortions described were bimodal in nature and 19% trimodal, with 1% involving four modalities. Underlying neurological mechanisms are varied and may be triggered by intoxications, infectious diseases, metabolic disorders, CNS lesions, paroxysmal neurological disorders, and psychiatric disorders. Bizarre sensations of time alteration-such as time going backwards or moving in circles-were mostly associated with psychosis. Pathophysiologically, mainly occipital areas appear to be involved, although the temporal network is widely disseminated, with separate component timing mechanisms not always functioning synchronously, thus occasionally creating temporal mismatches within and across sensory modalities (desynchronization). Based on our findings, we propose a classification of time distortions and formulate implications for research and clinical practice.
PubMed: 34025485
DOI: 10.3389/fpsyt.2021.668633 -
Journal of Vision May 2021The vision sciences literature contains a large diversity of experimental and theoretical approaches to the study of visual attention. We argue that this diversity...
The vision sciences literature contains a large diversity of experimental and theoretical approaches to the study of visual attention. We argue that this diversity arises, at least in part, from the field's inability to unify differing theoretical perspectives. In particular, the field has been hindered by a lack of a principled formal framework for simultaneously thinking about both optimal attentional processing and capacity-limited attentional processing, where capacity is limited in a general, task-independent manner. Here, we supply such a framework based on rate-distortion theory (RDT) and optimal lossy compression. Our approach defines Bayes-optimal performance when an upper limit on information processing rate is imposed. In this article, we compare Bayesian and RDT accounts in both uncued and cued visual search tasks. We start by highlighting a typical shortcoming of unlimited-capacity Bayesian models that is not shared by RDT models, namely, that they often overestimate task performance when information-processing demands are increased. Next, we reexamine data from two cued-search experiments that have previously been modeled as the result of unlimited-capacity Bayesian inference and demonstrate that they can just as easily be explained as the result of optimal lossy compression. To model cued visual search, we introduce the concept of a "conditional communication channel." This simple extension generalizes the lossy-compression framework such that it can, in principle, predict optimal attentional-shift behavior in any kind of perceptual task, even when inputs to the model are raw sensory data such as image pixels. To demonstrate this idea's viability, we compare our idealized model of cued search, which operates on a simplified abstraction of the stimulus, to a deep neural network version that performs approximately optimal lossy compression on the real (pixel-level) experimental stimuli.
Topics: Bayes Theorem; Cues; Humans; Neural Networks, Computer; Task Performance and Analysis; Visual Perception
PubMed: 33944906
DOI: 10.1167/jov.21.5.3 -
PloS One 2021Concurrent body movements have been shown to enhance the accuracy of spatial judgment, but it remains unclear whether they also contribute to perceptual estimates of...
Concurrent body movements have been shown to enhance the accuracy of spatial judgment, but it remains unclear whether they also contribute to perceptual estimates of gravitational space not involving body movements. To address this, we evaluated the effects of static or dynamic arm movements during prolonged whole-body tilt on the subsequent perceptual estimates of visual or postural vertical. In Experiment 1, participants were asked to continuously perform static or dynamic arm movements during prolonged tilt, and we assessed their effects on the prolonged tilt-induced shifts of subjective visual vertical (SVV) at a tilted position (during-tilt session) or near upright (post-tilt session). In Experiment 2, we evaluated how static or dynamic arm movements during prolonged tilt subsequently affected the subjective postural vertical (SPV). In Experiment 1, we observed that the SVV was significantly shifted toward the direction of prolonged tilt in both sessions. The SVV shifts decreased when performing dynamic arm movements in the during-tilt session, but not in the post-tilt session. In Experiment 2, as well as SVV, the SPV was shifted toward the direction of prolonged tilt, but it was not significantly attenuated by the performance of static or dynamic arm movements. The results of the during-tilt session suggest that the central nervous system utilizes additional information generated by dynamic body movements for perceptual estimates of visual vertical.
Topics: Adult; Arm; Female; Gravitation; Head Movements; Humans; Male; Movement; Orientation; Perceptual Distortion; Posture; Space Perception; Visual Perception; Young Adult
PubMed: 33930085
DOI: 10.1371/journal.pone.0250851 -
Frontiers in Neuroscience 2021The objective of the study was to identify the acute high-intensity recreational noise-induced effects on auditory function, especially the cochlear synaptopathy-related...
OBJECTIVES
The objective of the study was to identify the acute high-intensity recreational noise-induced effects on auditory function, especially the cochlear synaptopathy-related audiological metrics, in humans with normal hearing.
METHODS
This prospective cohort study enrolled 32 young adults (14 males and 18 females); the mean age was 24.1 ± 2.4 years (ranging from 20 to 29). All participants with normal hearing (audiometric thresholds ≤25 dB HL at frequencies of 0.25, 0.5, 1, 2, 3, 4, 6, and 8 kHz for both ears) had already decided to participate in the outdoor music festival. Participants were asked to measure the noise exposure dose and complete auditory examinations, including the air-conduction pure-tone audiometry (PTA), distortion product otoacoustic emission (DPOAE), contralateral suppression (CS) on transient evoked otoacoustic emission (TEOAE), auditory brainstem response (ABR) test and Mandarin Hearing in Noise Test (MHINT), at baseline and 1 day and 14 days after music festival noise exposure.
RESULTS
The mean time of attending the music festival was 7.34 ± 0.63 h (ranging from 6.4 to 9.5), the mean time-weighted average (TWA) of noise exposure dose was 93.2 ± 2.39 dB(A) (ranging from 87.9 to 97.7). At neither 1 day nor 14 days post exposure, there were no statistically significant effects on PTA thresholds, DPOAE amplitudes, CS on TEOAEs, or MHINT signal-to-noise ratios (SNRs) of acute outdoor music festival noise exposure, regardless of sex. While the ABR wave I amplitudes significantly decreased at 1 day after exposure and recovered at 14 days after exposure, the exposed/unexposed ABR wave I amplitude ratio was significantly correlated with MHINT SNR change at 1 day after exposure, although it was not correlated with the noise exposure dose.
CONCLUSION
In young adults with normal hearing, we found the self-compared decrement of ABR wave I amplitudes at 1 day post acute recreational noise exposure at high intensity, which also contributes to the change in speech perceptual ability in noisy backgrounds. This study indicated that auditory electrophysiological metric changes might be a more sensitive and efficient indicator of noise-induced cochlear synaptic dysfunction in humans. More attention should be paid to the recreational noise-induced cochlear synaptopathy and auditory perceptual disorder.
PubMed: 33897366
DOI: 10.3389/fnins.2021.659011 -
Ear and Hearing 2021As humans age, compressive nonlinearity-a hallmark of healthy cochlear function-changes. The nonlinear distortion-component of the distortion product otoacoustic...
OBJECTIVE
As humans age, compressive nonlinearity-a hallmark of healthy cochlear function-changes. The nonlinear distortion-component of the distortion product otoacoustic emission (DPOAE) provides a noninvasive gauge of cochlear nonlinearity. Earlier published work has suggested that weakened nonlinearity begins in middle age; the current work extends this investigation into the eight decade of life using advanced DPOAE data collection and analysis methods as well as multiple metrics of nonlinearity, including a test of loudness scaling.
DESIGN
The 2f1-f2 DPOAE was recorded in 20 young adults, 25 middle-aged adults and 32 older adults from f2 = 0.78 to 9.4 kHz with primary tones (f2/f1 = 1.22) swept upward at a rate of 0.5 octave/sec. Only frequencies with audiometric thresholds ≤20 dB HL were included in the analysis and to the extent possible, ears were audiometrically matched to eliminate hearing threshold as a contributing factor to the observed age effects. Input/output functions were generated for the separated distortion-component of the DPOAE to probe compressive nonlinearity of the cochlea, and ipsilateral suppression of the DPOAE was conducted to probe two-tone suppression. To investigate the perceptual effects of weakening nonlinearity on loudness perception, the same subjects performed categorical loudness scaling. Age effects on both DPOAE and loudness scaling variables were assessed, and correlations were conducted between key OAE and perceptual metrics.
RESULTS
Age × Frequency ANOVAs revealed that the compression knee of the DPOAE I/O function occurred at higher stimulus levels in both groups of older adults compared to young adults, suggesting an expanded linear range with aging; also, the compressive slope (growth beyond the knee point) was steeper in older-adults compared to young adults. These results were most notable at high frequencies. ANOVAs including age and auditory threshold as factors confirmed that the age effect observed was independent of threshold. Additionally, in smaller subsets of subjects with audiometrically matched data, these same trends persisted, further ruling out hearing threshold as an influential factor. The growth of DPOAE ipsilateral suppression was shallower near 4 kHz in middle-aged and older adults compared to young adults and elevated suppression thresholds were observed. Results of categorical loudness scaling showed steeper growth of loudness for older adults and, at fixed sensation levels (dB SL), the older-adult group rated tones as louder than did their young-adult counterparts, suggesting abnormal loudness growth and perception. Several correlations between the compression knee of the DPOAE I/O function and key metrics of loudness scaling were significant and accounted for up to one-third of the variance.
CONCLUSIONS
Results indicate that the aging cochlea begins to show weakened nonlinearity in middle age and it progressively weakens further into senescence. The perceptual impact of weakened nonlinearity during aging is manifested as abnormal loudness judgments; that is, in older-adult ears, a tone considered comfortable or medium in young-adult ears can be considered loud. The biophysical origin of this weakened nonlinearity is not known. It is hypothesized to reflect aging-related damage to, or loss of, outer hair cells and their stereocilia. More work is warranted to better define the perceptual impact of a linearized cochlear response in older adults and to consider how this deficit might impact the fitting of hearing aids and other intervention strategies.
Topics: Aged; Aging; Auditory Threshold; Cochlea; Hair Cells, Auditory, Outer; Humans; Middle Aged; Otoacoustic Emissions, Spontaneous; Young Adult
PubMed: 33886169
DOI: 10.1097/AUD.0000000000001014 -
American Journal of Speech-language... Jun 2021Purpose Understanding what limits speech development in minimally verbal (MV) children with autism spectrum disorder (ASD) is important for providing highly effective...
Purpose Understanding what limits speech development in minimally verbal (MV) children with autism spectrum disorder (ASD) is important for providing highly effective targeted therapies. This preliminary investigation explores the extent to which developmental speech deficits predicted by Directions Into Velocities of Articulators (DIVA), a computational model of speech production, exemplify real phenotypes. Method Implementing a motor speech disorder in DIVA predicted that speech would become highly variable within and between tokens, while implementing a motor speech plus an auditory processing disorder predicted that DIVA's speech would become highly centralized (schwa-like). Acoustic analyses of DIVA's output predicted that acoustically measured phoneme distortion would be similar between the two cases, but that in the former case, speech would show more within- and between-token variability than in the latter case. We tested these predictions quantitatively on the speech of children with MV ASD. In Study 1, we tested the qualitative predictions using perceptual analysis methods. Speech pathologists blinded to the purpose of the study tallied the signs of childhood apraxia of speech that appeared in the speech of 38 MV children with ASD. K-means clustering was used to create two clusters from the group of 38, and analysis of variance was used to determine whether the clusters differed according to perceptual features corresponding to within- and between-token variability. In Study 2, we employed acoustic analyses on the speech of the child from each cluster who produced the largest number of analyzable tokens to test the predictions of differences in within-token variability, between-token variability, and vowel space area. Results Clusters produced by k-means analysis differed by perceptual features that corresponded to within-token variability. Nonsignificant differences between clusters were found for features corresponding to between-token variability. Subsequent acoustic analyses of the selected cases revealed that the speech of the child from the high-variability cluster showed significantly more quantitative within- and between-token variability than the speech of the child from the low-variability cluster. The vowel space of the child from the low-variability cluster was more centralized than that of typical children and that of the child from the high-variability cluster. Conclusions Results provide preliminary evidence that subphenotypes of children with MV ASD may exist, characterized by (a) comorbid motor speech disorder and (b) comorbid motor speech plus auditory processing disorder. The results motivate testable predictions about how these comorbidities affect speech. Supplemental Material https://doi.org/10.23641/asha.14384432.
Topics: Apraxias; Autism Spectrum Disorder; Child; Humans; Language Development Disorders; Speech; Speech Disorders
PubMed: 33852328
DOI: 10.1044/2021_AJSLP-20-00121 -
Frontiers in Neuroscience 2021Although animal studies and studies on Parkinson's disease (PD) suggest that dopamine deficiency slows the pace of the internal clock, which is corrected by dopaminergic...
Although animal studies and studies on Parkinson's disease (PD) suggest that dopamine deficiency slows the pace of the internal clock, which is corrected by dopaminergic medication, timing deficits in parkinsonism remain to be characterized with diverse findings. Here we studied patients with PD and progressive supranuclear palsy (PSP), 3-4 h after drug intake, and normal age-matched subjects. We contrasted perceptual (temporal bisection, duration comparison) and motor timing tasks (time production/reproduction) in supra- and sub-second time domains, and automatic versus cognitive/short-term memory-related tasks. Subjects were allowed to count during supra-second production and reproduction tasks. In the time production task, linearly correlating the produced time with the instructed time showed that the "subjective sense" of 1 s is slightly longer in PD and shorter in PSP than in normals. This was superposed on a prominent trend of underestimation of longer (supra-second) durations, common to all groups, suggesting that the pace of the internal clock changed from fast to slow as time went by. In the time reproduction task, PD and, more prominently, PSP patients over-reproduced shorter durations and under-reproduced longer durations at extremes of the time range studied, with intermediate durations reproduced veridically, with a shallower slope of linear correlation between the presented and produced time. In the duration comparison task, PD patients overestimated the second presented duration relative to the first with shorter but not longer standard durations. In the bisection task, PD and PSP patients estimated the bisection point (BP50) between the two supra-second but not sub-second standards to be longer than normal subjects. Thus, perceptual timing tasks showed changes in opposite directions to motor timing tasks: underestimating shorter durations and overestimating longer durations. In PD, correlation of the mini-mental state examination score with supra-second BP50 and the slope of linear correlation in the reproduction task suggested involvement of short-term memory in these tasks. Dopamine deficiency didn't correlate significantly with timing performances, suggesting that the slowed clock hypothesis cannot explain the entire results. Timing performance in PD may be determined by complex interactions among time scales on the motor and sensory sides, and by their distortion in memory.
PubMed: 33815049
DOI: 10.3389/fnins.2021.648814