OBJECTIVETo evaluate the effect of circumcision on the glans penis sensitivity by comparing the changes of the glans penis vibrotactile threshold between normal men and patients with simple redundant prepuce and among the patients before and after the operation.

METHODSThe vibrotactile thresholds were measured at the forefinger and glans penis in 73 normal volunteer controls and 96 patients with simple redundant prepuce before and after circumcision by biological vibration measurement instrument, and the changes in the perception sensitivity of the body surface were analyzed.

RESULTSThe G/F (glans/finger) indexes in the control and the test group were respectively 2.39 +/- 1.72 and 1.97 +/- 0.71, with no significant difference in between (P > 0.05). And those of the test group were 1.97 +/- 0.71, 2.64 +/- 1.38, 3.09 +/-1.46 and 2.97 +/- 1.20 respectively before and 1, 2 and 3 months after circumcision, with significant difference between pre- and post-operation (P < 0.05).

CONCLUSIONThere is a statistic difference in the glans penis vibration perception threshold between normal men and patients with simple redundant prepuce. The glans penis perception sensitivity decreases after circumcision.

Adult ; Circumcision, Male ; Humans ; Male ; Penile Erection ; physiology ; Sensory Thresholds

Cross-modal stochastic resonance is a ubiquitous phenomenon, that is, a weak signal from one sensory pathway can be enhanced by the noise from a different sensory pathway. It is a special multisensory integration (MI) that can not be explained by the inverse-effectiveness rule. According to cross-modal stochastic resonance, the detection of signal is an inverted U-like function of the intensity of noise at different levels. In this paper, we reviewed the research of cross-modal stochastic resonance and put forward some possible explanations for it. These efforts raise a new idea for neural encoding and information processing of the brain.
Acoustic Stimulation ; Auditory Perception ; physiology ; Brain ; physiology ; Humans ; Mental Processes ; physiology ; Sensory Thresholds ; physiology ; Stochastic Processes ; Visual Perception ; physiology

Electric and electronic products are required to pass through the certification on electrical safety performance before entering into the market in order to reduce electrical shock and electrical fire so as to protect the safety of people and property. The leakage current is the most important factor in testing the electrical safety performance and the test theory is based on the perception current effect and threshold. The traditional method testing the current threshold for perception only depends on the sensing of the human body and is affected by psychological factors. Some authors filter the effect of subjective sensation by using physiological and psychological statistical algorithm in recent years and the reliability and consistency of the experiment data are improved. We established an experiment system of testing the human hody's current threshold for perception based on EEG feature analysis, and obtained 967 groups of data. We used wavelet packet analysis to detect a wave from EEG, and used FFT to do spectral analysis on alpha wave before and after the current flew through the human body. The study has shown that about 97.72% alpha wave energy changes significantly when electrical stimulation occurs. It is well proved that when the EEG feature identification is applied to test the human body current threshold for perception, and meanwhile alpha wave energy change and human body sensing are used together to confirm if the current flowing through the human body reaches the perception threshold, the measurement of the human body current threshold for perception could be carried out objectively and accurately.
Algorithms ; Electric Stimulation ; Electroencephalography ; Humans ; Reproducibility of Results ; Sensory Thresholds ; physiology ; Wavelet Analysis

Electroretinograms (ERGs) were measured in 65 patients with diabetes and 10 control subjects. The single flash ERGs were recorded as a function of the stimulus intensity. A Naka-Rushton-type function was fit to b-wave amplitudes, measured as a function of stimulus intensity, to evaluate changes in ERG amplitude and sensitivity. We also measured the temporal aspects of the ERG b-waves. The ERG sensitivity tended to decrease as the retinopathy progressed. An average sensitivity loss in eyes with diabetic retinopathy was statistically significant. However, the eyes of diabetic patients without visible retinopathy did not show significant ERG sensitivity loss. There was less variability in temporal compared with amplitude measurements of ERG components, and significantly prolonged b-wave implicit times were found in all stages of retinopathy and in eyes of diabetic patients without retinopathy.
Adolescent ; Adult ; Aged ; Diabetic Retinopathy/*physiopathology ; Electroretinography ; Humans ; Middle Aged ; Retina/physiology ; Sensitivity and Specificity ; Sensory Thresholds/physiology

OBJECTIVETo explicate the spinal nerve source of the rabbit penis cutaneous sensation.

METHODSTwelve adult male rabbits were randomly divided into two groups of equal number. While mechanical stimuli were given to the penis by different von Frey hairs, single fiber activities were recorded in vivo in the left (Group A) and right (Group B) S1-S4 spinal nerves, respectively. The mechanical threshold, adaptability and conduction velocity of the fibers were analyzed.

RESULTSWhen the ipsilateral penis was mechanically stimulated, discharges were detected in S2 and S3 spinal nerve fibers, but not in S1 and S4. The discharge fibers were 39.67 +/- 3.14 (S2) and 21.00 +/- 2.19 (S3) in the left spinal nerve and 40.00 +/- 3.16 (S2) and 19.67 +/- 2.58 (S3) in the right. There was no obvious difference between the numbers of the left spinal nerves and the right ones (P > 0.05).

CONCLUSIONThe rabbit penis cutaneous sensation originates from S2 and S3 spinal nerves.

Animals ; Electrophysiology ; Male ; Neurons, Afferent ; physiology ; Penis ; Rabbits ; Random Allocation ; Sensory Thresholds ; Skin ; innervation ; Spinal Nerves ; physiology

Cerebral Cortex ; growth & development ; physiology ; Evoked Potentials, Visual ; physiology ; Humans ; Infant, Newborn ; Infant, Premature ; growth & development ; Sensory Thresholds ; physiology ; Vision, Ocular ; physiology ; Visual Acuity ; physiology ; Visual Perception ; physiology

BACKGROUNDSubjective olfactory tests are easy to perform and popularly applied in the clinic, but using only these, it is difficult to diagnose all disorders of the olfactory system. The olfactory event related potentials technique offers further insight into the olfactory system and is an ideal objective test. This analysis was of subjective and objective data on the olfactory function of twelve patients with loss of smell associated with an upper respiratory infection (URI).

METHODSWe tested the twelve patients with URI induced olfactory loss by medical history, physical examination of the head and neck, olfactory tests and medical imaging. Olfactory function was assessed by Toyota and Takagi olfactometry including olfactory detection and recognition thresholds and olfactory event-related potentials (OERPs) recorded with OEP-98C Olfactometer.

RESULTSAn unusual phenomenon was observed in five patients in whom the subjective detection and recognition thresholds were normal, while the expected OERPs were not detectable.

CONCLUSIONSWe suggest that the discordance between olfactory psychophysical measurements and OERPs might be the results of abnormal electrophysiology related with olfactory neuropathy caused by viral URI. In addition, the measurement of OERPs might play a significant role in evaluating olfactory dysfunction.

Adult ; Evoked Potentials ; Female ; Humans ; Male ; Middle Aged ; Olfaction Disorders ; diagnosis ; Respiratory Tract Infections ; complications ; Sensory Thresholds ; Smell ; physiology

We quantitatively analyzed the changes of the (retinal) threshold sensitivities between normal status and dilated emmetropic status, and between dilated emmetropic status and -1.0D induced myopic status. Three consecutive visual field examinations by Humphrey Field Analyzer C-30-2 threshold test and STATPAC program were performed in 36 eyes of 21 normal subjects who ranged in age from 23 to 40 years. The results were as follows: 1) There was a statistically significant decrease (0.87 +/- 0.91dB)in the mean threshold sensitivity within the central 30 degrees at the dilated emmetropic status (27.90dB) as compared with the normal status (28.77dB)(p = 0.0001). 2) There was a statistically significant decrease(0.99 +/- 0.61dB) at -1.0D induced myopic status(26.91dB) as compared with the dilated emmetropic status(27.90dB)(p = 0.0001). 3) After dilation, the mean threshold sensitivity between 20 and 30 degrees of field showed statistically significant decrease as compared with those within the central 20 degrees of visual field(p < 0.05). In case of -1.0D induced myopia, there were uniform decreases in the mean threshold sensitivities within the central 30 degrees of visual field (p > 0.05). Therefore, we emphasize the importance of consistent pupillary size and correct refractive state in performing the serial automated visual field tests.
Adult ; Female ; Humans ; Male ; Myopia/etiology/*physiopathology ; Pupil/drug effects ; Pupil Disorders/chemically induced/*physiopathology ; Retina/physiology ; Sensory Thresholds/*physiology ; Tropicamide/pharmacology ; Visual Field Tests ; Visual Fields/*physiology

Changes in retinal sensitivity within central 30 degrees following panretinal photocoagulation (PRP) for more severe diabetic retinopathy were investigated. Twenty-five eyes with visual acuity of 0.4 or better and minimal maculopathy were studied prospectively. All underwent PRP in two sittings, and Humphrey field analyzer 30-2 threshold test was done before and 1 week, 1 and 3 months after the treatment. The mean retinal sensitivity threshold was obtained from each hemifield between 15 and 30 degrees and from the central 15 degree area, and the changes in the values were analyzed. Mean sensitivity threshold in the upper visual field at pre-PRP, post-PRP 1 week, 1, 3 months were 15.62, 13.81, 14.31, 14.85, respectively. Values in the lower field were 18.71, 17.25, 17.10, 18.17. Difference between pre-PRP and post-PRP was statistically significant at 1 week but no longer thereafter. Retinal sensitivity within the central 15 degrees remained stable. The data show that retinal sensitivity decreases significantly 1 week after PRP but recovers upto 95% of pre-PRP level over the following 3 months.
Adult ; Aged ; Diabetic Retinopathy/*physiopathology/surgery ; Female ; Follow-Up Studies ; Humans ; *Laser Coagulation ; Male ; Middle Aged ; Prospective Studies ; Retina/*physiopathology ; Sensory Thresholds ; Visual Acuity/physiology ; Visual Fields/*physiology

OBJECTIVETo measure passive tactile threshold of implant-supported single crowns (ISSC) in six orthogonal orientations, to analyze impact factors, and to guide the occlusal adjustment in a personalized manner.

METHODSThe passive tactile thresholds of 24 implant-supported single crowns (5 maxillary anterior teeth, 7 maxillary posterior teeth and 12 mandibular posterior teeth) from 19 ISSC patients (8 men and 11 women, from 25 years old to 56 years old) were measured in six orthogonal orientations (four horizontal orientations of labial or buccal, lingual, mesial and distal, and two axial orientations of apical and coronal) using a digital test system for tactile function of teeth.SPSS 19.0 for windows was used to analyze impact factors, using double-sided test, with a significance level of 0.05. Paired-samples t test was used to test the difference between implant-supported single crowns and the controlled natural teeth, and between different time points. One-way ANOVA was used to test the difference between different orientations, maxilla-mandibular anterior-posterior, and men-women.

RESULTSThe passive tactile thresholds of ISSC and control teeth were (1282 ± 709) and (40 ± 40) mN respectively. The difference was of statistical significance (P < 0.001). The passive tactile thresholds of buccal-lingual, mesial-distal and axial of ISSC were (1334 ± 696), (1102 ± 605) and (1412 ± 791) mN respectively, of which, the difference between mesial-distal and axial was of statistical significance (P < 0.05). The passive tactile thresholds of ISSC of maxillary anterior teeth, posterior teeth and mandibular posterior teeth were (1003 ± 616), (1302 ± 620) and (1386 ± 769) mN respectively, of which, the difference between maxillary anterior teeth and posterior teeth was of statistical significance (P < 0.05). The passive tactile thresholds of ISSC of men and women were (1751 ± 784) and (946 ± 393) mN respectively, the difference was of statistical significance (P < 0.001). The passive tactile thresholds of ISSC of one-week and one-month after wearing the teeth were (1421 ± 826) and (1411 ± 814) mN respectively, the difference was of no statistical significance (P > 0.05).

CONCLUSIONSThe passive tactile threshold of ISSC was more than 65 times as much as that of the natural teeth. There was statistical significance between different orientations, between maxillary anterior and posterior teeth, and between men and women. No statistical significance was found between maxillary and madibular posterior teeth and between one-week and one-month after wearing the teeth.

Adult ; Analysis of Variance ; Bicuspid ; physiology ; Crowns ; Cuspid ; physiology ; Dental Implants, Single-Tooth ; Dental Prosthesis, Implant-Supported ; Female ; Humans ; Incisor ; physiology ; Male ; Mandible ; physiology ; Maxilla ; physiology ; Middle Aged ; Molar ; physiology ; Sensory Thresholds ; Sex Factors ; Tooth ; physiology ; Touch ; physiology