Auditory-motor mapping for pitch control in singers and nonsingers

Little is known about the basic processes underlying the behavior of singing. This experiment was designed to examine differences in the representation of the mapping between fundamental frequency (F0) feedback and the vocal production system in singers and nonsingers. Auditory feedback regarding F0 was shifted down in frequency while participants sang the consonant-vowel /ta/. During the initial frequency-altered trials, singers compensated to a lesser degree than nonsingers, but this difference was reduced with continued exposure to frequency-altered feedback. After brief exposure to frequency altered auditory feedback, both singers and nonsingers suddenly heard their F0 unaltered. When participants received this unaltered feedback, only singers’ F0 values were found to be significantly higher than their F0 values produced during baseline and control trials. These aftereffects in singers were replicated when participants sang a different note than the note they produced while hearing altered feedback. Together, these results suggest that singers rely more on internal models than nonsingers to regulate vocal productions rather than real time auditory feedback.     

Vocal analysis related to changes in frequency of pure tone auditory feedback

Purpose

Many studies have shown that subjects show a change of vocal fundamental frequency (F0) when phonating subjects hear their vocal pitch feedback shifted upward or downward. This study was performed to demonstrate whether vocal parameters [F0, intensity, jitter, shimmer, and noise to harmonic ratio (NHR)] in normal males respond to changes in frequency of pure tone masking.

Materials and Methods

Twenty healthy male subjects participated in this study. Subjects vocalized /a/ vowel sounds while listening to a pitch-shift pure tone through headphones (upward pitch-shift in succession: 1kHz to 2 kHz and 1 kHz to 4 kHz at 50 dB or 80 dB, respectively, downward pitch-shift in succession: 1 kHz to 250 Hz and 1 kH to 500 Hz at 50 dB or 80 dB, respectively).

Results

Vocal intensity, F0, was increased, whereas jitter was decreased as the pitch of pure tone was shifted upward. However, there was no correlation between shimmer and NHR with pitch-shift feedback for pure tones. Unlike vocal pitch-shift feedback in other studies, upward pitch-shift feedback of pure tones caused the vocal F0 and intensity to change in the same direction as pitch-shift.

Conclusion

The results of this study demonstrated that auditory kinesthetic feedback is affected by pitch-shift in pure tone.     

螺旋CT实际层厚的影响因素与CT图像质量的关系

目的 通过实验分析影响螺旋CT实际层厚的因素，并分析实际层厚与CT图像质量的关系。方法 应用GE Hispeed DX/1 CT机及Elscinet的QC水模在不同扫描层厚及不同螺距情况下进行扫描，测量螺旋CT实际层厚并分析。结果 螺旋CT实际层厚随扫描层厚及螺距减小而减小：Z轴分辨率及扫描时间、病人接受的放射剂量随螺距增大而增大；螺旋扫描图像噪声与螺距呈非线性关系，螺距为1、5时噪声较螺距为1.0时要小。结论 螺旋CT实际层厚与扫描层厚、螺距有密切关系，选择合适的扫描层厚及螺距对提高CT图像质量、减少扫描时间、减少病人接受的放射剂量均大有益处。     

Profile and aetiology of children diagnosed with auditory processing disorder (APD)

OBJECTIVE: Auditory processing disorder (APD) is characterised by listening difficulties despite a normal audiogram. APD is becoming ever more widely diagnosed in children, though there is a controversy over definition, diagnosis and aetiology. This study sought to describe presenting features and investigate aetiological factors for children diagnosed with APD compared to those for whom APD was excluded. METHODS: Medical notes for children referred to a specialist hospital-based APD clinic were reviewed in relation to presenting features and potential aetiological factors. RESULTS: 32 children diagnosed with APD and 57 non-APD children were compared. They reported similar symptoms and similarly had high rates of co-morbid learning problems. No aetiological factor (including history of otitis media, adverse obstetric history or familial history of listening problems) predicted APD group membership. CONCLUSIONS: Children identified with APD on the basis of commonly used APD tests cannot be distinguished on the basis of presenting features or the aetiological factors examined here. One explanation is that learning problems exist independently of auditory processing difficulties and the aetiological factors do not have a strong causal role in APD. However, no gold standard for APD testing exists and an alternative explanation is that the commonly used APD tests used as selection criteria in this study may be unreliable.     

Development of an Injury Burden Prediction Model in Professional Baseball Pitchers

BackgroundBaseball injuries are a significant problem and have increased in incidence over the last decade. Reporting injury incidence only gives context to rate but not in relation to severity or injury time loss.Hypothesis/PurposeThe purpose of this study was to 1) incorporate both modifiable and non-modifiable factors to develop an arm injury burden prediction model in Minor League Baseball (MiLB) pitchers; and 2) understand how the model performs separately on elbow and shoulder injury burden.Study DesignProspective longitudinal studyMethodsThe study was conducted from 2013 to 2019 on MiLB pitchers. Pitchers were evaluated in spring training arm for shoulder range of motion and injuries were followed throughout the season. A model to predict arm injury burden was produced using zero inflated negative binomial regression. Internal validation was performed using ten-fold cross validation. Subgroup analyses were performed for elbow and shoulder separately. Model performance was assessed with root mean square error (RMSE), model fit (R2), and calibration with 95% confidence intervals (95% CI).ResultsTwo-hundred, ninety-seven pitchers (94 injuries) were included with an injury incidence of 1.15 arm injuries per 1000 athletic exposures. Median days lost to an arm injury was 58 (11, 106). The final model demonstrated good prediction ability (RMSE: 11.9 days, R²: 0.80) and a calibration slope of 0.98 (95% CI: 0.92, 1.04). A separate elbow model demonstrated weaker predictive performance (RMSE: 21.3; R²: 0.42; calibration: 1.25 [1.16, 1.34]), as did a separate shoulder model (RMSE: 17.9; R²: 0.57; calibration: 1.01 [0.92, 1.10]).ConclusionsThe injury burden prediction model demonstrated excellent performance. Caution should be advised with predictions between one to 14 days lost to arm injury. Separate elbow and shoulder prediction models demonstrated decreased performance. The inclusion of both modifiable and non-modifiable factors into a comprehensive injury burden model provides the most accurate prediction of days lost in professional pitchers.Level of Evidence2     

医用X射线CT辐射剂量影响因素研究

目的分析不同管电压、管电流、模体直径、模体内深度、螺距、准直宽度、照射野、算法及管电流调制技术等因素对多层CT辐射剂量的影响。方法用CT笔形电离室、头部和体部剂量模体及国人仿真人体模型．在CT机上测量在不同管电压、管电流、模体直径、模体内深度、螺距、准直宽度、照射野、算法及管电流调制技术条件下的CT剂量学表征量。结果当其它参数一定时．管电压与CT剂量成正比;管电流与CT剂量成线性正相关;模体直径与CT剂量成反比;CT剂量随模体内径向深度的增加而减少;螺距与剂量成反比,螺距的增加使超成像范围的剂量增加;准直宽度与剂量成反比;照射野和算法对CT剂量没有影响;采用管电流调制技术可降低CT剂量。结论降低管电压、降低管电流、增加螺距、限制分段扫描、增加准直宽度、降低体形瘦小受检者的扫描条件及采用管电流调制技术可使CT剂量降低。     

Auditory processing abnormalities in schizotypal personality disorder: an fMRI experiment using tones of deviant pitch and duration

BACKGROUND: One of the cardinal features of schizotypal personality disorder (SPD) is language abnormalities. The focus of this study was to determine whether or not there are also processing abnormalities of pure tones differing in pitch and duration in SPD. METHODS: Thirteen neuroleptic-na?ve male subjects met full criteria for SPD and were group-matched on age and parental socio-economic status to 13 comparison subjects. Verbal learning was measured with the California Verbal Learning Test. Heschl's gyrus volumes were measured using structural MRI. Whole-brain fMRI activation patterns in an auditory task of listening to tones including pitch and duration deviants were compared between SPD and control subjects. In a second and separate ROI analysis we found that peak activation in superior temporal gyrus (STG), Brodmann Areas 41 and 42, was correlated with verbal learning and clinical measures derived from the SCID-II interview. RESULTS: In the region of the STG, SPD subjects demonstrated more activation to pitch deviants bilaterally (p<0.001); and to duration deviants in the left hemisphere (p=0.005) (two-sample t). SPD subjects also showed more bilateral parietal cortex activation to duration deviants. In no region did comparison subjects activate more than SPD subjects in either experiment. Exploratory correlations for SPD subjects suggest a relationship between peak activation on the right for deviant tones in the pitch experiment with odd speech and impaired verbal learning. There was no difference between groups on Heschl's gyrus volume. CONCLUSIONS: These data suggest that SPD subjects have inefficient or hyper-responsive processing of pure tones both in terms of pitch and duration deviance that is not attributable to smaller Heschl's gyrus volumes. Finally, these auditory processing abnormalities may have significance for the odd speech heard in some SPD subjects and downstream language and verbal learning deficits.     

Selective attention to sound location or pitch studied with fMRI

We used 3-T functional magnetic resonance imaging to compare the brain mechanisms underlying selective attention to sound location and pitch. In different tasks, the subjects (N = 10) attended to a designated sound location or pitch or to pictures presented on the screen. In the Attend Location conditions, the sound location varied randomly (left or right), while the pitch was kept constant (high or low). In the Attend Pitch conditions, sounds of randomly varying pitch (high or low) were presented at a constant location (left or right). Both attention to location and attention to pitch produced enhanced activity (in comparison with activation caused by the same sounds when attention was focused on the pictures) in widespread areas of the superior temporal cortex. Attention to either sound feature also activated prefrontal and inferior parietal cortical regions. These activations were stronger during attention to location than during attention to pitch. Attention to location but not to pitch produced a significant increase of activation in the premotor/supplementary motor cortices of both hemispheres and in the right prefrontal cortex, while no area showed activity specifically related to attention to pitch. The present results suggest some differences in the attentional selection of sounds on the basis of their location and pitch consistent with the suggested auditory "what" and "where" processing streams.     

Experience-dependent neural substrates involved in vocal pitch regulation during singing

Proper singing requires the integration of auditory feedback mechanisms with the vocal motor system, such that vocal pitch can be precisely controlled. To determine the neural substrates involved in audio-vocal integration, non-musicians and experienced singers underwent fMRI scanning while they sang a single tone with either unaltered (“simple”) or pitch-shifted auditory feedback; in pitch-shifted trials, subjects were instructed either to ignore or compensate for the shifted feedback. We hypothesized that the anterior cingulate cortex (ACC), superior temporal gyrus (STG), and anterior insula may be involved in audio-vocal integration due to their functional roles during singing and their anatomical connectivity. Although singers were more accurate than non-musicians in simple singing, both groups recruited similar functional networks. Singers ignored the shifted feedback better than non-musicians, and both groups also displayed different patterns of neural activity for this task: singers recruited bilateral auditory areas and left putamen, while non-musicians recruited the left supramarginal gyrus and primary motor cortex. While there were no significant group differences in performing the compensate task, singers displayed enhanced activity in the ACC, superior temporal sulcus, and putamen, whereas non-musicians exhibited increased activity in the dorsal premotor cortex, a region involved with sensorimotor interactions. We propose two neural substrates for audio-vocal integration: the dorsal premotor cortex may act as a basic interface, but with vocal training and practice, the ACC, auditory cortices, and putamen may be increasingly recruited as people learn to monitor their auditory feedback and adjust their vocal output accordingly.     

Local and global auditory processing: behavioral and ERP evidence

Differential processing of local and global visual features is well established. Global precedence effects, differences in event-related potentials (ERPs) elicited when attention is focused on local versus global levels, and hemispheric specialization for local and global features all indicate that relative scale of detail is an important distinction in visual processing. Observing analogous differential processing of local and global auditory information would suggest that scale of detail is a general organizational principle of the brain. However, to date the research on auditory local and global processing has primarily focused on music perception or on the perceptual analysis of relatively higher and lower frequencies. The study described here suggests that temporal aspects of auditory stimuli better capture the local-global distinction. By combining short (40 ms) frequency modulated tones in series to create global auditory patterns (500 ms), we independently varied whether pitch increased or decreased over short time spans (local) and longer time spans (global). Accuracy and reaction time measures revealed better performance for global judgments and asymmetric interference that were modulated by amount of pitch change. ERPs recorded while participants listened to identical sounds and indicated the direction of pitch change at the local or global levels provided evidence for differential processing similar to that found in ERP studies employing hierarchical visual stimuli. ERP measures failed to provide evidence for lateralization of local and global auditory perception, but differences in distributions suggest preferential processing in more ventral and dorsal areas respectively.