discrimination threshold
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2021 ◽  
Vol 2112 (1) ◽  
pp. 012003
Jiaqi Ju ◽  
Ting Xu ◽  
Ke Xu ◽  
Yan Jin

Abstract This article explores the experimental study on the relationship between human eye discrimination threshold of white light under different lighting levels and color temperatures by the psychophysical experimental method. The visual matching method was applied to study the subjective brightness perception under different lighting environments. We try to explore the internal connection between the physical intensity and subjective rating value. The experimental results will do help the development of dimming system for smart lighting.

Dmitry I. Zabolotny ◽  
Viktor I. Lutsenko ◽  
Irina A. Belyakova ◽  
Pavlo V. Nechiporenko ◽  
Maksym I. Situkho ◽  

Background: Tuning fork tests, in particular the Federici test, allow to some extent verifying the correctness of subjective audiometry. During the Federici test patients should compare the volume of the tuning fork placed on the tragus or mastoid process. Federici test is considered positive if the sound seems louder from the tragus than from the mastoid process. Federici test is considered negative if the sound of the tuning fork seems louder from the mastoid process than from the tragus. Literature data indicate that the results of certain tuning fork tests may be different if tuning forks are made of different alloys. Publications describing the characteristics of Federici test at presence different sizes of air-bone gap (ABG) are extremely limited. Aim: improving the effectiveness of the hearing loss diagnosis by clarifying the Federici test value in case of conduction hearing loss. Materials and methods: We analyzed 50 audiograms with a sizes of ABG of 10 dB or more at 125 Hz to clarify when the Federici test can be positive or negative. All tuning fork tests were performed with C128 aluminum tuning forks. The Federici test method: after activation the tuning fork it is placed on the mastoid process, then on the tragus. The forms were marked with the results of the following tuning fork tests: Weber, Federici, Bing; and the distance of the patient's perception of whispered and spoken language, the results of audiometric Weber test, pure tone (in the conventional frequency range) and speech audiometry. Results and discussion: Among the audiograms with ABG, a positive Federici test (group I) was observed in 39 cases (57 %), and a negative test (group II) was observed in 30 cases (43 %). Assessment of hearing loss was performed according to the criteria by Bazarov VH and Rozkladka AI (1989). The results of first group: the first degree of hearing loss was registered in 30 cases (76.9 %), the second degree in 6 cases (15.4 %) and the third degree in 3 cases (7.7 %). The results of the second group were following: the first degree of hearing loss was registered in 24 cases (80 %), the second degree was registered in 2 cases (6.7 %) and the third degree was registered in 3 cases (13.3 %). The article contains tables with data of sizes of ABG at different frequencies in cases of positive and negative Federici tests, as well as the difference between air and bone conduction in speech audiometry (performing the test of 50 % numerals discrimination threshold by Kharshak). There are samples of audiograms for both positive and negative Federici tests with the same ABG size given. Conclusions: We studied the characteristics of the Federici test performed with C128 aluminum tuning forks in patients with different sizes of bone-air gap at a frequency of 125 Hz. When ABG is from 10 to 35 at a frequency of 125 Hz, the Federici test can be both positive and negative, because the result is also affected by size of ABG at frequencies of 250, 500 and 1000 Hz. If Federici test is positive, there is a decrease in a difference between air and bone conduction when performing speech audiometry (performing of the test of 50 % numerals discrimination threshold by Kharshak), and if test is negative there is an increase in the difference. The Federici test is always negative when size of ABG is 40 dB and more at a frequency of 125 Hz. Our results partially different from the literature. In particular, we have shown that a positive Federici test can be with a maximum size of ABG 35 dB at a frequency of 125 Hz and clarified in which cases that can be possible. One of the promising directions of research is the diagnostic value of the Federici test in different middle ear pathology.

2021 ◽  
pp. 014556132110403
Hong-Gang Duan ◽  
Fang Ji ◽  
Mao-Xiao Yan

Objective: This study aimed to analyze the efficacy of different doses and forms of corticosteroids in the treatment of postinfectious olfactory dysfunction and to specify the factors related to the curative effects. Methods: The medical records of patients diagnosed with postinfectious olfactory dysfunction from January 2018 to May 2019 were reviewed. All patients received different doses of oral corticosteroids for 12 days or inhaled corticosteroids for 1 month. Results: A review of the records of 43 patients showed that the mean follow-up time was 6.66 months, and the overall effective rate of treatment was 48.8%. Postinfectious olfactory dysfunction exhibited distinct seasonality, with the highest incidence in March. The curative effect was significantly related to the olfactory discrimination threshold at the first consultation ( P = .022), but not significantly associated with age ( P = .325), sex ( P = .924), duration of disease ( P = .526), follow-up time ( P = .489), or treatment program ( P = .330). Conclusions: Different doses and forms of corticosteroids showed no significant difference in the therapeutic effect on postinfectious olfactory dysfunction. The olfactory discrimination threshold at the first consultation was the most important factor influencing the prognosis.

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Ying Lu ◽  
Xiaojie Ji ◽  
Yu Shu

Automatic crash notification systems (ACNSs) play a key role in post-accident safety. To improve the accuracy and efficiency of ACNSs, a method to correct the velocity variation information of ACNSs was established. First, after the acceleration data of sled crash tests were analysed, the factors affecting the accuracy of the velocity variation information were determined, and the influence of the discrimination threshold and acceleration curve shape on the velocity variation information was examined. Second, according to the acceleration data generated by the simulation model of a sled crash, the correlation between the accuracy of the velocity variation information and influencing factors was modelled. Third, an automatic crash notification algorithm involving a velocity variation correction function (VVCF) was proposed based on the correlation model. Finally, to verify its reliability, the improved algorithm was applied to an automatic crash notification system (ACNS) terminal. The validation results show that the ACNS terminal can accurately identify collisions and transmit accident information. Moreover, more accurate velocity variation information can be retrieved.

2021 ◽  
Aili Roetterud Loechen ◽  
Knut Kolskaar ◽  
Ann-Marie Glasoe de Lange ◽  
Markus Sneve ◽  
Beathe Haatveit ◽  

Objective: Low-level sensory disruption is hypothesized as a precursor to clinical and cognitive symptoms in severe mental disorders. We compared visual discrimination performance in patients with schizophrenia spectrum disorder or bipolar disorder with healthy controls, and investigated associations with clinical symptoms and IQ. Methods: Patients with schizophrenia spectrum disorder (n=32), bipolar disorder (n=55) and healthy controls (n=152) completed a computerized visual discrimination task. Participants responded whether the latter of two consecutive grids had higher or lower spatial frequency, and discrimination thresholds were estimated using an adaptive maximum likelihood procedure. Case-control differences in threshold were assessed using linear regression, F-test and post-hoc pair-wise comparisons. Linear models were used to test for associations between visual discrimination threshold and psychotic symptoms derived from the PANSS and IQ assessed using the Matrix Reasoning and Vocabulary subtests from the Wechsler Abbreviated Scale of Intelligence (WASI). Results: Robust regression revealed a significant main effect of diagnosis on discrimination threshold (robust F=6.76, p=.001). Post-hoc comparisons revealed that patients with a schizophrenia spectrum disorder (mean=14%, SD=0.08) had higher thresholds compared to healthy controls (mean=10.8%, SD = 0.07, β = 0.35, t=3.4, p=0.002), as did patients with bipolar disorder (12.23%, SD=0.07, β= 0.21, t=2.42, p=0.04). There was no significant difference between bipolar disorder and schizophrenia (β=-0.14, t=-1.2, p=0.45). Linear models revealed negative associations between IQ and threshold across all participants when controlling for diagnostic group (β = -0.3, t=-3.43, p=0.0007). This association was found within healthy controls (t=-3.72, p=.0003) and patients with bipolar disorder (t=-2.53, p=.015), and no significant group by IQ interaction on threshold (F=0.044, p=.97). There were no significant associations between PANSS domain scores and discrimination threshold. Conclusion: Patients with schizophrenia spectrum or bipolar disorders exhibited higher visual discrimination thresholds than healthy controls, supporting early visual deficits among patients with severe mental illness. Discrimination threshold was negatively associated with IQ among healthy controls and bipolar disorder patients. These findings elucidate perception-related disease mechanisms in severe mental illness, which warrants replication in independent samples.

2021 ◽  
Vol 9 ◽  
Jair E. Garcia ◽  
Detlef H. Rohr ◽  
Adrian G. Dyer

The ability of visual generalists to see and perceive displayed colour signals is essential to understanding decision making in natural environments. Whilst modelling approaches have typically considered relatively simple physiological explanations of how colour may be processed, data on key bee species reveals that colour is a complex multistage perception largely generated by opponent neural representations in a brain. Thus, a biologically meaningful unit of colour information must consider the psychophysics responses of an animal engaged in colour decision making. We extracted previously collected psychophysics data for a Violet-Sensitive (VS) bird, the pigeon (Columba livia), and used a non-linear function that reliably represents the behavioural choices of hymenopteran and dipteran pollinators to produce the first behaviourally validated and biologically meaningful representation of how VS birds use colour information in a probabilistic way. The function describes how similar or dis-similar spectral information can lead to different choice behaviours in birds, even though all such spectral information is above discrimination threshold. This new representation of bird vision will enable enhanced modelling representations of how bird vision can sense and use colour information in complex environments.

2021 ◽  
Vol 30 (1) ◽  
pp. 160-169
Yang-Soo Yoon ◽  
Callie Michelle Boren ◽  
Brianna Diaz

Purpose To measure the effect of testing conditions (in the soundproof booth vs. quiet room), test order, and number of test sessions on spectral and temporal processing in normal-hearing (NH) listeners. Method Thirty-two adult NH listeners participated in the three experiments. For all three experiments, the stimuli were presented to the left ear at the subjects' most comfortable level through headphones. All tests were administered in an adaptive three-alternative forced-choice paradigm. Experiment 1 was designed to compare the effect of soundproof booth and quiet room test conditions on amplitude modulation detection threshold and modulation frequency discrimination threshold with each of the five modulation frequencies. Experiment 2 was designed to compare the effect of two test orders on the frequency discrimination thresholds under the quiet room test conditions. The thresholds were first measured in the ascending and descending order of four pure tones, and then with counterbalanced order. For Experiment 3, the amplitude discrimination threshold under the quiet room testing condition was assessed 3 times to determine the effect of the number of test sessions. Then the thresholds were compared over the sessions. Results Results showed no significant effect of test environment. The test order is an important variable for frequency discrimination, particularly between piano tunes and pure tones. Results also show no significant difference across test sessions. Conclusions These results suggest that a controlled test environment may not be required in spectral and temporal assessment for NH listeners. Under the quiet test environment, a single outcome measure is sufficient, but test orders should be counterbalanced.

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