Auditory Stress Research Articles

Biosonar activity of the Indo-Pacific humpback dolphin (Sousa chinensis) near the tunnel section of the world’s longest cross-sea bridge—the Hong Kong-Zhuhai-Macao Bridge—is negatively correlated with underwater noise

Underwater noise pollution from the world’s longest cross-sea bridge—the Hong Kong-Zhuhai-Macao Bridge (HZMB)—which stretches across the Chinese White Dolphin National Nature Reserve (of the People’s Republic of China, PRC) in the Pearl River Estuary may affect the distribution of local humpback dolphins. In this study, static passive acoustic monitoring was applied to monitor biosonar activity of humpback dolphins and underwater noise adjacent to the tunnel section of the HZMB for more than one year. During the monitoring period, dolphin biosonar signals were detected on 88.5% of days. A significant temporal pattern occurred in dolphin biosonar activity and in anthropogenic noise. Biosonar activity was significantly higher at night than during the day, whereas underwater noise occurred more in the day than at night. Significantly more echolocation signals were detected in winter-spring than in summer-autumn, and highest acoustic activity occurred significantly more during high tide than at other tidal periods. In addition, the negative correlation between elevated underwater noise and dolphin sonar activity in winter suggests that dolphins may avoid noisy waters for short periods, perhaps due to auditory stress, but fish prey movement cannot be ruled out. These findings facilitate understanding activity patterns of humpback dolphins in the Pearl River Estuary and may contribute to conservation efforts.

Ultrastructural Characteristics of Axodendritic and Axosomatic Synapses in the Orbitofrontal Cortex of White Laboratory Rats Associated with Low-Protein Food after Acute Sound Exposure

This paper investigates the state of axodendritic (ADS) and axosomatic (ASS) synapses in orbitofrontal cortex (OFC) layers I-IV of adult white laboratory rats associated with balanced and low-protein food after acute sound exposure. Experiments were performed on 64 white non-linear sexually mature laboratory male rats weighing 180–230 g (eight intact, 56 experimental). After a continuous call with an intensity of 120 db for 120 seconds, 56 rats were divided into two groups: those receiving balanced (control – 28) and low-protein food (basic – 28). Each of these two groups was divided into two subgroups: stress-resistant (12 animals in each) and stress-unstable animals (16 animals in each). Water intake was unlimited. The animals were removed from the experiment on the 10th, 20th, 30th, and 40th day after sound exposure. Along with histological and immunohistochemical analysis, the samples of OFC layers I–IV were studied by transmission electron microscopy. Electron microscopic changes in the structure of ADS and ASS were found in all OFC layers. Violations of the fine structure of both the presynaptic and postsynaptic poles were noted. The maximum severity of ultrastructural changes was observed in the ADS of the surface (I, molecular), outer granular (II), pyramidal (III), and inner granular (IV) OFC layers. ASS disorganization was noted mainly in contacts, the postsynaptic pole of which was formed by the bodies of small pyramidal neurons of layer III, as well as pyramidal and stellate neurons of layer IV of the OFC. During all periods of observation, violations of fine organization were most pronounced in stress-unstable animals of the main experimental group, especially on the 10th and 20th day after exposure. Acute sound exposure initiates disturbances in the fine organization of axodendritic and axosomatic synapses in OFC layers I–IV of white laboratory rats. Focal destruction of a part of the noted synapses in rats with a low-protein diet after acute auditory stress is irreversible.

Influence of physical and psychological stress on decision-making performance of soccer referees

ABSTRACT Soccer referees have to make quick and accurate decisions while experiencing physical stress (i.e., fatigue) and psychological stress (i.e., pressure from the crowd). Researchers have examined the influence of physical and psychological stress on skilled referees’ decision-making performance separately; however, referees usually experience both types of stress simultaneously. The aim of the study was to investigate the influence of both physical and psychological stress on skilled and less-skilled soccer referees’ decision-making performance. To simulate the physical and psychological stress during a game, 25 referees were asked to make foul decisions while running on a treadmill and/or being exposed to auditory stress. Referees were more physically fatigued in the physical and psychologically stressed in the psychological stress condition. However, this only negatively influenced their decision-making performance in the video test during the submaximal physical stress condition, when compared to the resting condition. The results also indicate that the experienced referees learned to cope with fatigue and psychological stress regarding their cognitive processes. The effects seem to be differentially detrimental, depending on the league level of refereeing, but also whether physical and psychological stress are induced separately. The study protocol could help referees train in a simulated learning environment, besides on-field games.

Prenatal stress dysregulates resting-state functional connectivity and sensory motifs

Prenatal stress (PS) can impact fetal brain structure and function and contribute to higher vulnerability to neurodevelopmental and neuropsychiatric disorders. To understand how PS alters evoked and spontaneous neocortical activity and intrinsic brain functional connectivity, mesoscale voltage imaging was performed in adult C57BL/6NJ mice that had been exposed to auditory stress on gestational days 12–16, the age at which neocortex is developing. PS mice had a four-fold higher basal corticosterone level and reduced amplitude of cortical sensory-evoked responses to visual, auditory, whisker, forelimb, and hindlimb stimuli. Relative to control animals, PS led to a general reduction of resting-state functional connectivity, as well as reduced inter-modular connectivity, enhanced intra-modular connectivity, and altered frequency of auditory and forelimb spontaneous sensory motifs. These resting-state changes resulted in a cortical connectivity pattern featuring disjoint but tight modules and a decline in network efficiency. The findings demonstrate that cortical connectivity is sensitive to PS and exposed offspring may be at risk for adult stress-related neuropsychiatric disorders.

Effects of prolonged night-time light exposure and traffic noise on the behavior and body temperature rhythmicity of the wild desert rodent, Gerbillus tarabuli

ABSTRACT The aim of this study was to demonstrate for the first time in Tarabul’s gerbils (Gerbillus tarabuli), the effects of simultaneous exposure to two major environmental stressors – light and noise pollutions – on the body temperature rhythm and anxious behavior. Seven groups, each consisting of 6 adult male gerbils, were subjected to a standard LD cycle (12 L:12D) with lights on at 08:00 h and off at 20:00 h, constant conditions (total darkness, DD), prolonged nighttime exposure to light (PEL: 18 L:6D) with lights on at 08:00 h and off at 02:00 h, mimicking prolonged exposure to light pollution in peri-urban areas, exposure to auditory stress (TNS) of 80 dB, and conditions combining PEL&TNS. The body temperature circadian rhythm was recorded, and behavioral tests were performed at the end of experimental phases. The results revealed the existence, for the first time in Gerbilus tarabuli, of an endogenous circadian rhythm of body temperature with a period of 23.8 ± 0.04 h. Prolonged exposure to light at night (PEL) induced a significant phase delay (02 h 09 min ± 0.16 h) of the rhythm, with an acrophase (peak time) occurring at 04:42 ± 0.13 h instead of 02:33 ± 0.21 h. Exposure to TNS for 4 hours per night induced a significant increase of the amplitude of the rhythm and a decrease of the rhythm regularity (robustness of 73.26% in TNS vs. 82.32 in control condition). While combining TNS and PEL significantly delayed the phase of the Tb rhythm by 3 h 10 min (acrophase at 06:39 ± 0.37 h instead of 02:33 ± 0.21 h), increased the amplitude, and significantly reduced the stability of the rhythm (robustness of 67.25% in PEL&TNS vs. 82.32 in control condition). PEL&TNS and TNS environments induce an important stress in gerbils highlighted by a significant decrease of the number of line crossings and time spent in the center area of the open field test. Furthermore, elevated plus maze test revealed gerbils of the PEL&TNS and TNS conditions significantly visited the lowest number of open arms and spent a shorter amount of time in it. In addition, these conditions were responsible for less activity (total number of entries in arms) than in the control and PEL conditions. These results indicate clearly that in the desert area, peri-urban light and noise pollutions disturb the circadian rhythm components and alter the behavior of Tarabul’s gerbils inducing an anxious state.

Heat shock response in noise-induced hearing loss: effects of alanyl-glutamine dipeptide supplementation on heat shock proteins status

IntroductionThe 72kDa heat shock protein, HSP72, located intracellularly provides cochlear cytoprotective and anti-inflammatory roles in the inner ear during stressful noise challenges. The expression of intracellular HSP72 (iHSP72) can be potentiated by alanyl-glutamine dipeptide supplementation. Conversely, these proteins act as pro-inflammatory signals in the extracellular milieu (eHSP72). ObjectiveWe explore whether noise-induced hearing loss promotes both intracellular and extracellular HSP72 heat shock response alterations, and if alanyl-glutamine dipeptide supplementation could modify heat shock response and prevent hearing loss. MethodsFemale 90 day-old Wistar rats (n=32) were randomly divided into four groups: control, noise-induced hearing loss, treated with alanyl-glutamine dipeptide and noise-induced hearing loss plus alanyl-glutamine dipeptide. Auditory brainstem responses were evaluated before noise exposure (124dB SPL for 2h) and 14days after. Cochlea, nuclear cochlear complex and plasma samples were collected for the measurement of intracellular HSP72 and extracellular HSP72 by a high-sensitivity ELISA kit. ResultsWe found an increase in both iHSP72 and eHSP72 levels in the noise-induced hearing loss group, which was alleviated by alanyl-glutamine dipeptide treatment. Furthermore, H-index of HSP72 (plasma/cochlea eHSP72/iHSP72 ratio) was increased in the noise-induced hearing loss group, but prevented by alanyl-glutamine dipeptide treatment, although alanyl-glutamine dipeptide had no effect on auditory threshold. ConclusionsOur data indicates that cochlear damage induced by noise exposure is accompanied by local and systemic heat shock response markers. Also, alanyl-glutamine reduced stress markers even though it had no effect on noise-induced hearing loss. Finally, plasma levels of 72kDa heat shock proteins can be used as a biomarker of auditory stress after noise exposure.

Effect of Predator Stress on the Reproductive Performance of Female Mice After Nonsurgical Embryo Transfer.

Predator Stress Can Exert Detrimental Effects on Female Mammals, Leading to Disrupted Reproduction. Although Many Studies Have Addressed the Effects of Predator Stress on Reproductive Output in Rodents, Few Studies Have Focused on the Effect of Visual or Auditory Stress on Pregnant Females. in This Study, We Investigated the Possible Effect of Predator Stress, Either Visual Only or Combined Visual and Auditory (visual+auditory), on the Reproductive Performance of Female Mice After Nonsurgical Embryo Transfer. Reproductive Performance Was Assessed As Pregnancy Rate, Implantation Rate, Gestation Length, Live Pup Rate, and Neonatal Birth Weight. Moreover, Serum Cortisol and Progesterone Levels in Dams Were Measured by Using Electrochemiluminescence Immunoassay. Exposure to Predator (cat) Stress Did Not Lead to a Significant Change in Pregnancy Rates in the Tested Mice. However, the Stressed Mice Showed Significantly Decreased Implantation Rates Compared with the Control Group. Similarly, the Live Pup Rate and Neonatal Birth Weight Were Significantly Lower in the Group Exposed to Preda- Tor Stress Than in the Control Group. Furthermore, Mice Exposed to Visual+auditory Stress Showed a Significant Reduction in Gestation Length Compared with the Control Mice. Our Data Showed That Predator Visual+auditory Stress As Combined Stimuli Significantly Increased Serum Cortisol Level. in Contrast, Progesterone Levels Did Not Significantly Vary Among the Experimental Groups. Taken Together, Our Findings Imply That Predator Stress Adversely Affects the Reproductive Efficiency of Pregnant Mice By Decreasing the Implantation Rate, Live Birth Rate, and Neonatal Birth Weight and by Prolonging Gestation Length.

Eyetracking-based assessment of affect-related decay of human performance in visual tasks

Computerized recognition of human emotions enriches the man–machine interaction with a new personal and behavioral aspect. Firstly, because the influence of emotions on the human performance can be objectively assessed and predicted using standardized stimuli, secondly, because an emotion-sensitive computer system can be programmed to react adequately. This paper presents an investigation of emotional influence on the human scanpath. The proposed method assumes that the emotional state of the observer can distract his or her visual attention and can be reliably expressed in parameters of eye movements. We performed visual task experiments in order to record scanpaths from volunteers under auditory stress of controlled intensity. We used a calibrated set of stimuli and controlled the response of volunteers’ central nervous system expressed by the heart rate. For each efficiently stimulated participant, we related the scanpath parameters to the accuracy of solving a given task and to participant’s comment. As a principal result, we obtained a significant change of (1) saccade frequency in 90% and (2) maximum velocity in fixation phase in 80% of participants under stress. These results prove the influence of emotions on visual acuity, feasibility of eyetracking-based assessment of emotional state and motivate further investigations.

The Adverse Effects of Auditory Stress on Mouse Uterus Receptivity and Behaviour

Stress during gestation has harmful effects on pregnancy outcome and can lead to spontaneous abortion. Few studies, however, have addressed the impact of gestational stress, particularly auditory stress, on behavioural performance and pregnancy outcome in mice. This study aimed to examine the effect of two types of gestational stress on uterus receptivity and behavioural performance. Pregnant C57BL/6 mice were randomly assigned to either auditory or physical stress conditions or a control condition from gestational days 12–16. The auditory stress regimen used loud 3000 Hz tone, while the physical stressor consisted of restraint and exposure to an elevated platform. Three behavioural tests were performed in the dams after weaning. Uterine receptivity was investigated by counting the number of sites of implantation and fetal resorption. Also, the offspring survival rates during the early postnatal period were calculated. Auditory stress caused an increase in anxiety-like behaviour, reduced time spent exploring new object/environment, and reduced balance when compared to the physical stress and control groups. Auditory stress also caused higher rates of resorbed embryos and reduction of litter size. Our results suggest that the adverse effect of noise stress is stronger than physical stress for both uterus receptivity and behavioural performance of the dams.

Music and natural sounds in an auditory steady-state response based brain–computer interface to increase user acceptance

Patients with total locked-in syndrome are conscious; however, they cannot express themselves because most of their voluntary muscles are paralyzed, and many of these patients have lost their eyesight. To improve the quality of life of these patients, there is an increasing need for communication-supporting technologies that leverage the remaining senses of the patient along with physiological signals. The auditory steady-state response (ASSR) is an electro-physiologic response to auditory stimulation that is amplitude-modulated by a specific frequency. By leveraging the phenomenon whereby ASSR is modulated by mind concentration, a brain–computer interface paradigm was proposed to classify the selective attention of the patient. In this paper, we propose an auditory stimulation method to minimize auditory stress by replacing the monotone carrier with familiar music and natural sounds for an ergonomic system. Piano and violin instrumentals were employed in the music sessions; the sounds of water streaming and cicadas singing were used in the natural sound sessions. Six healthy subjects participated in the experiment. Electroencephalograms were recorded using four electrodes (Cz, Oz, T7 and T8). Seven sessions were performed using different stimuli. The spectral power at 38 and 42Hz and their ratio for each electrode were extracted as features. Linear discriminant analysis was utilized to classify the selections for each subject. In offline analysis, the average classification accuracies with a modulation index of 1.0 were 89.67% and 87.67% using music and natural sounds, respectively. In online experiments, the average classification accuracies were 88.3% and 80.0% using music and natural sounds, respectively. Using the proposed method, we obtained significantly higher user-acceptance scores, while maintaining a high average classification accuracy.

Effect of Different Sound Genres on Seed Germination of and Orchids

Auditory stress has been known to affect the development of plants. Recent findings have shown that the stress produced by music induced a positive effect on plants growth. However, different types of music have different kinds of stimulation on plant development. The aim of this study was to examine the in vitro seed germination of two Grammatophyllum species when exposed to five different music genres. The Grammatophyllum species used were G. hybrid and G. stapeliiflorum while the music genres were Instrumental, Rock, Hip hop, Yassin (Quranic reciting) and Ballad. Green capsules of Grammatophyllum hybrid and Grammatophyllum stapeliiflorum were obtained from Triang Botanical Valley, Pahang, Malaysia. Each group of seed cultures were exposed to different music genre for 8 hours starting from 9 am until 5 pm, each for a 6 months period. Seed cultures were kept in the dark for the first 3 months. One untreated (no music) group was kept as a control. All cultures were maintained on half-strength Murashige and Skoog (MS) media supplemented with 30 g/L sucrose, 0.5 mg/L 6-benzylaminopurine (BAP), 2 g/L peptone, 1 g/L activated charcoal and 2.5 g/L gelrite. Observations were recorded every month for the number of shoots emerged and shoot length. Data was analysed by using a one-way ANOVA. At the end of the experiment, it was found that music exposure had a positive effect on the seeds’ germination as compared to the untreated control group. For G. hybrid species, the highest shoots number counted was 19.33±3.79 which was observed on seeds exposed to Yassin. The highest shoot length measured was 2.02±1.10 cm when it was exposed to Rocks music. In contrast, G. stapeliiflorum species showed the highest number of shoots of 12.00±2.64 when exposed to Ballad and the highest shoot length achieved by this species was 0.99±0.38 cm when it was exposed to Instrumental music. Analysis by using Kruskal-Wallis H and one-way ANOVA showed that p < 0.05 for all parameters. The findings showed that different species of orchids need a different type of music to influence the rate of its germination and growth.

Witnessing traumatic events and post-traumatic stress disorder: Insights from an animal model

It is becoming increasingly recognized that post-traumatic stress disorder (PTSD) can be acquired vicariously from witnessing traumatic events. Recently, we published an animal model called the “Trauma witness model” (TWM) which mimics PTSD-like symptoms in rats from witnessing daily traumatic events (social defeat of cage mate) [14]. Our TWM does not result in any physical injury. This is a major procedural advantage over the typical intruder paradigm in which it is difficult to delineate the inflammatory response of tissue injury and the response elicited from emotional distress. Using TWM paradigm, we examined behavioral and cognitive effects in rats [14] however, the long-term persistence of PTSD-like symptoms or a time-course of these events (anxiety and depression-like behaviors and cognitive deficits) and the contribution of olfactory and auditory stress vs visual reinforcement were not examined. This study demonstrates that some of the features of PTSD-like symptoms in rats are reversible after a significant time lapse of the witnessing of traumatic events. We also have established that witnessing is critical to the PTSD-like phenotype and cannot be acquired solely due to auditory or olfactory stresses.

Effect of auditory stress agents on heterozygous German waltzing guinea pigs

The German waltzing guinea pig is a strain of animals expressing deafness and severe balance disorders at birth. The mutation arose spontaneously in a breeding facility in Germany and as the affected animals show a characteristic waltzing behavior, the strain is named the German waltzing guinea pig. The strain is presently bred only at Karolinska Institutet.The hereditary inner ear impairment has a recessive mode of inheritance and the strain thus produces not only affected homozygotes but also symptom-free heterozygotes and fully normal offspring. The outcome depends solely on the genotype of the parents. The heterozygotes, which have obtained the “waltzing” gene from one parent only, have normal hearing and no balance dysfunction. The heterozygous animals appear normal but will, in turn, carry the genetic defect to the next generation. The present thesis is focused on these animals.Noise and ototoxic drugs are well known stress factors that interfere negatively with the hearing organ in both humans and animals, causing hearing impairment. However, the inter-individual variability in susceptibility to auditory stress factors is surprisingly large, most likely due to different genetic predisposition. In this study, heterozygous animals of the German waltzing guinea pig, animals carrying a genetic defect known to cause severe hearing impairment, were used to study how an unexplored gene for deafness interacts with auditory stress agents, i.e. noise exposure and the ototoxic drugs gentamicin and cisplatin.Animals were exposed to both narrowband as well as broadband noise at different ages and hearing thresholds were measured using ABRs. Heterozygotes of the German waltzing guinea pig showed less threshold shifts compared to control strains. Older animals were less affected by the noise trauma than younger animals.To test the hypothesis that the efferent system contributes to protection of the inner ear against noise trauma, measurements using a new method of post onset adaptation of DPOAEs and maximum adaptation magnitude were conducted. The post onset adaptation of DPOAEs detected a strain difference at the higher frequency region while in the maximum adaptation magnitude method showed no difference between the strains.The heterozygous German waltzing guinea pigs displayed a distinctly increased resistance to noise exposures, manifested as reduced threshold shifts and faster recovery following acoustic overstimulation. However, when exposed to ototoxic drugs, the heterozygous carriers suffered from a more pronounced hearing loss.It is concluded that endogenous resistance to noise in the heterozygotes does not offer any protection against ototoxic drugs. The detailed mechanisms remain to be explored.

Prenatal stress increases the striatal and hippocampal expression of correlating c-FOS and serotonin transporters in murine offspring

Prenatal stress (PS) is a known risk factor for several psychiatric diagnoses, including schizophrenia, attention deficit hyperactivity disorder, autism, anxiety, and depression which have been associated with serotonin transporter (SERT) dysregulation. Moreover, long-term effects in animal models associate with higher levels of immediate early genes, e.g. c-FOS (up-regulated in response to neuronal activity), in the brain of PS offspring. We therefore quantified the expression of both protein related mRNAs in adolescent BALB/c mice subjected to mild auditory stress on two separate days in mid gestation. SERT and c-FOS consistently correlated in most brain regions of PS mice and controls. Moreover, two-way ANOVAs revealed concomitantly increased levels of proteins, as well as of FOSL1 and FOSL2 mRNA, especially in the striatum and hippocampus of the PS offspring. Sex affected only and less consistently mRNA expression, yet interacted with PS, demonstrating that glucocorticoid receptor mRNA expression decreased in PS males but increased in PS females compared to the respective controls. This first finding of a correlation between SERT and c-FOS protein expression affected by PS, together with related mRNAs, may be considered a new target for behavioral and treatment studies in offspring.

The effect of acute auditory stress on gastric motor responses to a meal in healthy volunteers

Stress is believed to play a role in the pathogenesis of functional gastrointestinal disorders. The aim of the present study was to investigate the effect of acute auditory stress on gastric motor responses to a meal in healthy subjects. A total of eight healthy volunteers (seven men and one woman; median age, 33.4 years [30-35 years]) who had no recurrent gastrointestinal symptoms participated in the prospective, randomized, crossover study. Gastric half-emptying time and meal-induced proximal gastric accommodation were measured using gastric scintigraphy under the auditory stress and control conditions in a randomized crossover design. The gastric half-emptying time under the stress condition was significantly longer than that under the control condition (130.8 ± 16.6 vs. 105.0 ± 13.1 min; P = 0.005 by paired t-test). Under the stress and control conditions, the proximal gastric volume significantly increased after a meal (P < 0.001 by repeated measures analysis of variance). The degree of the postprandial increase in proximal gastric volume did not significantly differ between both conditions (P = 0.598 by tests of between-subjects effects using repeated measures analysis of variance). The severity scores of postprandial epigastric discomfort and fullness were significantly higher under the stress condition than under the control condition (P = 0.001 and P = 0.039, respectively, by paired t-test). Acute auditory stress delays gastric emptying and increases the severity of postprandial symptoms in the healthy subjects, suggesting the relevance of psychological stress to the pathophysiological mechanism of functional dyspepsia.

Noise and children′s health: Research in Central, Eastern and South-Eastern Europe and Newly Independent States

Many reviews have documented the adverse effects of noise on children's health, but the international scientific community was previously unfamiliar with noise research in Central and Eastern Europe (CEE), South-East Europe (SEE), and Newly Independent States (NIS). The aim of this review was to present studies on the effects of noise on children's health, conducted in aforementioned countries in the second half of the 20 th century, interpret their findings, and criticize their methodology and results wherever possible. This review focused on 30 papers published in national journals in the period from 1965 to 2000. By design, 22 studies were observational and cross-sectional, and eight studies were experimental. The outcomes under the study included auditory changes, stress reactions, sleep disturbances, school performance, upright posture, and vegetative functions. Researchers from CEE, SEE, and NIS were the pioneers in the assessment of noise-induced changes of vegetative functions and blood pressure of children in urban areas, as well as of infants exposed to noise in incubators. Future research should focus on intervention studies and follow-up of children's health in relation to noise exposure.

A Quality Improvement Study on Avoidable Stressors and Countermeasures Affecting Surgical Motor Performance and Learning

To explore how the 2 most important components of surgical performance--speed and accuracy-are influenced by different forms of stress and what the impact of music is on these factors. On the basis of a recently published pilot study on surgical experts, we designed an experiment examining the effects of auditory stress, mental stress, and music on surgical performance and learning and then correlated the data psychometric measures to the role of music in a novice surgeon's life. Thirty-one surgeons were recruited for a crossover study. Surgeons were randomized to 4 simple standardized tasks to be performed on the SurgicalSIM VR laparoscopic simulator (Medical Education Technologies, Inc, Sarasota, FL), allowing exact tracking of speed and accuracy. Tasks were performed under a variety of conditions, including silence, dichotic music (auditory stress), defined classical music (auditory relaxation), and mental loading (mental arithmetic tasks). Tasks were performed twice to test for memory consolidation and to accommodate for baseline variability. Performance was correlated to the brief Musical Experience Questionnaire (MEQ). Mental loading influences performance with respect to accuracy, speed, and recall more negatively than does auditory stress. Defined classical music might lead to minimally worse performance initially but leads to significantly improved memory consolidation. Furthermore, psychologic testing of the volunteers suggests that surgeons with greater musical commitment, measured by the MEQ, perform worse under the mental loading condition. Mental distraction and auditory stress negatively affect specific components of surgical learning and performance. If used appropriately, classical music may positively affect surgical memory consolidation. It also may be possible to predict surgeons' performance and learning under stress through psychological tests on the role of music in a surgeon's life. Further investigation is necessary to determine the cognitive processes behind these correlations.

Involvement of L-Selectin in Contact Hypersensitivity Responses Augmented by Auditory Stress

Stress affects the pathophysiology of cutaneous immune reactions, including contact hypersensitivity (CH) in individuals sensitized with sensitizing hapten, where local endothelial cell activation plays a critical role. To clarify the effects of stress in cutaneous immune reactions, we selected a CH model using annoying sound as a stress. Furthermore, we conducted the stress experiments by using selectin-deficient mice to determine the involvement of selectin molecules regarding local endothelial activation. Auditory stress augmented CH responses in the present study. Namely, ear thickness and mast cell numbers were significantly increased in stressed CH mice. mRNA expression of preprotachykinin-A, a precursor of substance-P; interferon-gamma; interleukin (IL)-4; IL-6; and tumor necrosis factor-alpha significantly increased in stressed CH mice. Furthermore, stressed L-selectin-deficient mice showed significant decreases in all parameters mentioned above relative to stressed wild-type mice in CH response. Meanwhile, treatment with anti-L-selectin Ab resulted in a significant decrease in ear thickness and mRNA levels of interferon-gamma, IL-4, IL-6, and tumor necrosis factor-alpha, but failed to significantly reduce preprotachykinin-A mRNA levels and mast cell numbers. Our results indicated that auditory stress enhances CH response and that the augmentation of this CH response might be mediated through L-selectin, but not through P- or E-selectin pathways.

The effect of defined auditory conditions versus mental loading on the laparoscopic motor skill performance of experts

Music and noise are frequent occurrences in the operating room. To date, the effects of these auditory conditions on the performance of laparoscopic surgery experts have not been evaluated. Eight internationally recognized experts were recruited for a crossover study. The experts were randomized to perform three simple tasks on a laparoscopic simulator, SurgicalSIM VR. The tasks were equal in difficulty and performed under the following conditions: silence, dichaotic music (auditory stress), classical music (auditory relaxation), and mental loading (mental arithmetic tasks). Permutations of the conditions were created to account for a learning effect. The tasks were performed twice to test for memory consolidation and to accommodate baseline variability. Time until task completion and task accuracy via instrument tip trajectory (path of the tip through space) were recorded. Performance was correlated with responses on the Brief Musical Experience Questionnaire (MEQ). The study demonstrated that dichaotic music has a negative impact on time until task completion but not on task accuracy. In addition, memory consolidation of accuracy is negatively influenced. Classical music has a variable effect on experts' time until task completion, yet all the experts performed the tasks more accurately. Classical music had no effect on recall of a procedure. Mental loading increased time until completion, but did not affect accuracy or recall. The experience of music varied among experts and influenced how each of the conditions affected their performance. The study demonstrated that, contrary to common belief, proficiency in surgery does not protect against stressful auditory influences or the influence of mental preoccupation. Interestingly, relaxing auditory influences such as classical music can even have a positive impact on the accuracy of experts. Previous musical experience could help to identify surgeons whose performance may be specifically affected by music or noise.

Impaired word stress pattern discrimination in very‐low‐birthweight infants during the first 6 months of life

Prosodic information, such as word stress and speech rhythm, is important in language acquisition, and sensitivity to stress patterns is present from birth onwards. Exposure to prosodic properties of the native language occurs prenatally. Preterm birth and an associated lack of exposure to prosodic information are suspected to affect language acquisition in preterm infants. Fifty healthy very low birthweight (<1500 g) preterm German infants (24 males, 26 females; mean gestational age [GA] 27.6 wks, range 26.4-29.9) and 103 comparison term infants (48 males, 55 females; mean GA 40 wks, range 39.4-40.8) were recruited. Prosodic discrimination performance was assessed using the head-turn preference paradigm, an objective behavioural psycholinguistic test for measuring orientation time (OT) to auditory stress patterns. Among matched preterm and term infants, preterm infants (n=30) did not differentiate stress patterns at the corrected age of 4 or 6 months. In term infants (n=30), the OT was longer towards the trochaic (stress on first syllable, characteristic for German) than the iambic (second syllable) stress patterns (11.64 vs 9.18s, p<0.001, and 11.02 vs 8.32s, p<0.001, at 4 and 6 mo respectively). Neurodevelopmental scores (Bayley Scales of Infant Development, 2nd edn) were not different from reference values in both groups of infants. Preterm birth and deficient early prosodic information affect prosodic processing during the first half year of life.