Loud Auditory Stimuli Research Articles

Phonetic variants of Majorcan Catalan /ʒ/: A controlled study in societal language contact

Some Majorcan Catalan speakers produce /ʒ/ as [j] rather than [ʒ]. We hypothesize that variation in the production of /ʒ/ is modulated by whether speakers are dominant speakers of Catalan or not. Majorcan Catalan exists in a contact situation with Spanish, and Catalan-Spanish bilinguals vary, on a spectrum, in terms of their language dominance. We recruited 18 bilinguals and divided them into two groups: Catalan- or Spanish-dominant. The participants repeated out loud auditory stimuli in which /ʒ/ had been produced by model talkers as either [j] or [ʒ]. The results revealed systematic differences between Catalan- and Spanish-dominant bilinguals in terms of two correlates that capture the distinction between [j] and [ʒ]: spectral center of gravity and skewness. While the effects of the subjects’ profile were of a very large magnitude, the effects of imitation—having heard [j] or [ʒ] as the auditory model for /ʒ/—were negligible. This suggests that, in Majorcan Catalan, individual phonological (internalized) representations of /ʒ/, and not only production habits, are modulated by the speaker’s background—some speakers have /j/ and others have /ʒ/.

The interplay of perceptual processing demands and practice in modulating voluntary and involuntary motor responses.

Understanding how sensory processing demands affect the ability to ignore task-irrelevant, loud auditory stimuli (LAS) during a task is key to performance in dynamic environments. For example, tennis players must ignore crowd noise to perform optimally. We investigated how practice affects this ability by examining the effects of delivering LASs during preparatory phase of an anticipatory timing (AT) task on the voluntary and reflexive responses in two conditions: lower and higher visual processing loads. Twenty-four participants (mean age = 23.1, 11 females) completed the experiment. The AT task involved synchronizing a finger abduction response with the last visual stimulus item in a sequence of four Gabor grating patches briefly flashed on screen. The lower demand condition involved only this task, and the higher demand condition required processing the orientations of the patches to report changes in the final stimulus item. Our results showed that higher visual processing demands affected the release of voluntary actions, particularly in the first block of trials. When the perceptual load was lower, responses were released earlier by the LAS compared to the high-load condition. Practice reduced these effects largely, but high perceptual load still led to earlier action release in the second block. In contrast, practice led to more apparent facilitation of eyeblink latency in the second block. These findings indicate that a simple perceptual load manipulation can impact the execution of voluntary motor actions, particularly for inexperienced participants. They also suggest distinct movement preparation influences on voluntary and involuntary actions triggered by acoustic stimuli.

Delayed recovery from general anaesthesia associated with pre-existing neurological disease in a horse

A seven-year-old gelding presented for surgical management of right-sided olecranon bursitis. Preanaesthetic examination revealed a right-sided head tilt which had been present since birth. General anaesthesia and surgery went smoothly...

PP08.9 – 2594: Glycine receptor antibody mediated progressive encephalomyelitis with rigidity and myoclonus (PERM) presenting as an abnormal startle response in an adolescent girl

Objective To describe a young girl in whom stimulus sensitive spasms were a diagnostic clue to the underlying glycine receptor antibody mediated progressive encephalomyelitis with rigidity and myoclonus (PERM) which has been described mainly in adults. Methods We illustrate the clinical data from the case-notes with a video recording of stimulus-sensitive spasms. Results A previously well 15-year-old girl presented with a traumatic head injury after falling down the stairs. The noise from a doorbell had triggered a severe muscle spasm causing the fall. She sustained a complex skull fracture with coup-contrecoup brain injury. She had previously been evaluated over five months for stimulus-sensitive whole body spasms with axial hyperextension without impairment of consciousness. She also had daily stimulus-sensitive myoclonic jerks, headaches and subtle cognitive impairment over the preceding year. Whilst on the paediatric intensive care unit, she was noted to have spontaneous and stimulus-sensitive muscle spasms (EMG duration 360–680 ms with no EEG correlate). She also developed generalised tonic clonic seizures, which were treated with Levetiracetam. A diagnosis of PERM was considered and glycine receptor antibodies were found to be strongly positive in serum and CSF. VGKC-complex antibodies were also weakly positive but GAD and NMDAR antibodies were negative. Oligoclonal bands were positive in CSF but negative in serum. Paraneoplastic antibodies were negative. Brain MRI showed contusions in the right hemisphere. Body imaging did not identify any tumours. Glycine receptor gene analysis is awaited. Her spasms have improved with a residual mild startle response to touch or loud auditory stimuli. She has a residual left hemiparesis. She was not treated with immunomodulation but will be followed up, and immunotherapy considered if she does not continue to improve and antibodies persist. Conclusion Glycine receptor antibody-mediated progressive encephalomyelitis with rigidity and myoclonus can present in children as stimulus-sensitive muscle spasms.

Dopamine D2-like receptors modulate unconditioned fear: role of the inferior colliculus.

BackgroundA reduction of dopamine release or D2 receptor blockade in the terminal fields of the mesolimbic system clearly reduces conditioned fear. Injections of haloperidol, a preferential D2 receptor antagonist, into the inferior colliculus (IC) enhance the processing of unconditioned aversive information. However, a clear characterization of the interplay of D2 receptors in the mediation of unconditioned and conditioned fear is still lacking.MethodsThe present study investigated the effects of intra-IC injections of the D2 receptor-selective antagonist sulpiride on behavior in the elevated plus maze (EPM), auditory-evoked potentials (AEPs) to loud sounds recorded from the IC, fear-potentiated startle (FPS), and conditioned freezing.ResultsIntra-IC injections of sulpiride caused clear proaversive effects in the EPM and enhanced AEPs induced by loud auditory stimuli. Intra-IC sulpiride administration did not affect FPS or conditioned freezing.ConclusionsDopamine D2-like receptors of the inferior colliculus play a role in the modulation of unconditioned aversive information but not in the fear-potentiated startle response.

Subthalamic nucleus activity optimizes maximal effort motor responses in Parkinson's disease.

The neural substrates that enable individuals to achieve their fastest and strongest motor responses have long been enigmatic. Importantly, characterization of such activities may inform novel therapeutic strategies for patients with hypokinetic disorders, such as Parkinson's disease. Here, we ask whether the basal ganglia may play an important role, not only in the attainment of maximal motor responses under standard conditions but also in the setting of the performance enhancements known to be engendered by delivery of intense stimuli. To this end, we recorded local field potentials from deep brain stimulation electrodes implanted bilaterally in the subthalamic nuclei of 10 patients with Parkinson's disease, as they executed their fastest and strongest handgrips in response to a visual cue, which was accompanied by a brief 96-dB auditory tone on random trials. We identified a striking correlation between both theta/alpha (5-12 Hz) and high-gamma/high-frequency (55-375 Hz) subthalamic nucleus activity and force measures, which explained close to 70% of interindividual variance in maximal motor responses to the visual cue alone, when patients were ON their usual dopaminergic medication. Loud auditory stimuli were found to enhance reaction time and peak rate of development of force still further, independent of whether patients were ON or OFF l-DOPA, and were associated with increases in subthalamic nucleus power over a broad gamma range. However, the contribution of this broad gamma activity to the performance enhancements observed was only modest (≤13%). The results implicate frequency-specific subthalamic nucleus activities as substantial factors in optimizing an individual's peak motor responses at maximal effort of will, but much less so in the performance increments engendered by intense auditory stimuli.

A block to pre-prepared movement in gait freezing, relieved by pedunculopontine nucleus stimulation

Gait freezing and postural instability are disabling features of Parkinsonian disorders, treatable with pedunculopontine nucleus stimulation. Both features are considered deficits of proximal and axial musculature, innervated predominantly by reticulospinal pathways and tend to manifest when gait and posture require adjustment. Adjustments to gait and posture are amenable to pre-preparation and rapid triggered release. Experimentally, such accelerated release can be elicited by loud auditory stimuli—a phenomenon known as ‘StartReact’. We observed StartReact in healthy and Parkinsonian controls. However, StartReact was absent in Parkinsonian patients with severe gait freezing and postural instability. Pedunculopontine nucleus stimulation restored StartReact proximally and proximal reaction times to loud stimuli correlated with gait and postural disturbance. These findings suggest a relative block to triggered, pre-prepared movement in gait freezing and postural instability, relieved by pedunculopontine nucleus stimulation.

Improvements in rate of development and magnitude of force with intense auditory stimuli in patients with Parkinson’s disease

Patients with Parkinson's disease can show brief but dramatic normalization of motor activity in highly arousing situations, a phenomenon often termed paradoxical kinesis. We sought to mimic this in a controlled experimental environment. Nine patients with Parkinson's disease and nine age-matched healthy controls were asked to grip a force dynamometer as quickly and strongly as possible in response to a visual cue. A loud (96 dB) auditory stimulus was delivered at the same time as the visual cue in ~50% of randomly selected trials. In patients with Parkinson's disease, the experiment was conducted after overnight withdrawal of antiparkinsonian drugs and again 1 h after patients had taken their usual morning medication. Patients showed improvements in the peak rate of force development and the magnitude of force developed when loud auditory stimuli accompanied visual cues. Equally, they showed improvements in the times taken to reach the peak rate of force development and their maximal force. The paradoxical facilitatory effect of sound was similar whether patients were off or on their usual antiparkinsonian medication, and could be reproduced in age-matched healthy controls. We conclude that motor improvement induced by loud auditory stimuli in Parkinson's disease is related to a physiological phenomenon which survives both with and after withdrawal of antiparkinsonian medication. The potential independence of the mediating pathways from the dopaminergic system provides impetus for further investigation as it may yield a novel nondopaminergic target for therapeutic manipulation in Parkinson's disease.

Primary Sleep Disorders and Paroxysmal Nocturnal Nonepileptic Events in Adults With Epilepsy From the Perspective of Sleep Specialists

Sleep specialists are frequently referred adults with epilepsy to evaluate their sleep/wake complaints, sometimes to determine whether their paroxysmal nocturnal behaviors are epileptic or not. Many patients with epilepsy have at least one parasomnia (some more than one), and the sleep specialists are often asked to differentiate and treat these. Sleep specialists review which primary sleep disorders are more common in adults with epilepsy and how to evaluate and best treat these. The authors summarize (1) how to evaluate and differentiate parasomnias using video-polysomnography; (2) the value of sleep deprivation and loud auditory stimuli to increase the likelihood of provoking a non-rapid eye movement arousal parasomnia with a single night of video-polysomnography; and (3) how to score excessive muscle activity during rapid eye movement sleep to confirm a diagnosis of rapid eye movement sleep behavior disorder. The clinical semiology and video-polysomnography features of simple and complex sleep-related movement disorders and parasomnias are reviewed.

Doing better than your best: loud auditory stimulation yields improvements in maximal voluntary force

Could task performance be constrained by our ability to fully engage necessary neural processing through effort of will? The StartReact phenomenon suggests that this might be the case, as voluntary reaction times are substantially reduced by loud sounds. Here, we show that loud auditory stimulation can also be associated with an improvement in the force and speed of force development when 18 healthy subjects are repeatedly asked to make a maximal grip as fast and as strongly as possible. Peak grip force was increased by 7.2 ± 1.4% (SEM) (P < 0.0001), and the rate of force development was increased by 17.6 ± 2.0% (P < 0.00001), when imperative visual cues were accompanied by a loud auditory stimulus rather than delivered alone. This implies that loud auditory stimuli may allow motor pathways to be optimised beyond what can be achieved by effort of will alone.

Depth of sedation using Cerebral State Index in infants undergoing spinal anesthesia

Infants are noted to frequently sleep during spinal anesthesia, with a concomitant fall in Bispectral Index. However, there are suggestions that EEG derived anesthesia depth monitors have inferior performance in infants. The aim of this study was to quantify the degree of sedation during spinal anesthesia in infants using another EEG derived measure of anesthesia effect--the Cerebral State Index (CSI). Twelve infants, <52 weeks postconceptual menstrual age, scheduled for bilateral inguinal hernia repair under spinal anesthesia were enrolled. Patients received a standard anesthetic protocol with a subarachnoid dose of 1 mg x kg(-1) of levobupivacaine 0.5%. No premedication, sedatives, opioids or anticholinergics were administrated during the perioperative period and patients were left undisturbed during the surgical time, without tactile stimulation or loud auditory stimuli. CSI score (0-100) and bust suppression (BS) (0-100%) were continuously recorded during the surgical time and then statistically re-evaluated. In all patients the CSI fell during the procedure and there were significant levels of BS recorded by the CSI monitor. The BS occurred between 12 and 34 min after spinal anesthesia with the peak being at 30 min and mean onset time being 15 (2.6) min after spinal block. A statistical significant difference was found between the lowest mean CSI as well as the highest BS if compared with their baseline values. A negative correlation was found between CSI and BS. The degree of burst suppression detected by the CSI in our study supports the hypothesis that infants may have discontinuous patterns of EEG during spinal anesthesia similar to those seen during emergence from general anesthesia. Moreover, the limitations in the application of the adult algorithms to infant EEG may lead to an overestimation of the degree of sedation.

Functional Locus of Intensity Effects in Choice Reaction Time Tasks

Long reaction times (RT) paradoxically occur with extremely loud auditory stimuli ( Van der Molen &amp; Keuss, 1979 , 1981 ) or with ultrabright and large visual stimuli ( Jaśkowski &amp; Włodarczyk, 2006 ) when the task requires a response choice. Van der Molen and Keuss (1981 ) hypothesized that this effect results from an arousal-driven elongation of response-selection processes. We tested this hypothesis using visual stimuli and chronopsychophysiological markers. The results showed that the latency of both early (P1 recorded at Oz) and late (P300) evoked potentials decreased monotonically with intensity. In contrast, the latency of stimulus-locked lateralized readiness potentials (LRP) abruptly increased for the most intense stimuli, thus mirroring the reaction time–intensity relationship. Response-locked LRPs revealed no dependency on intensity. These findings suggest that the processes responsible for the van der Molen-Keuss effect influence processing stages that are completed before the onset of LRP. The van der Molen-Keuss effect likely occurs later than those represented by early sensory potentials. This is in keeping with the hypothesis of van der Molen-Keuss.

Task modulation of the effects of brightness on reaction time and response force

Van der Molen and Keuss [van der Molen, M.W., Keuss, P.J.G., 1979. The relationship between reaction time and intensity in discrete auditory tasks. Quarterly Journal of Experimental Psychology 31, 95–102; van der Molen, M.W., Keuss, P.J.G., 1981. Response selection and the processing of auditory intensity. Quarterly Journal of Experimental Psychology 33, 177–184] showed that paradoxically long reaction times (RT) occur with extremely loud auditory stimuli when the task is difficult (e.g. needs a response choice). It was argued that this paradoxical behavior of RT is due to active suppression of response prompting to prevent false responses. In the present experiments, we demonstrated that such an effect can also occur for visual stimuli provided that they are large enough. Additionally, we showed that response force exerted by participants on response keys monotonically grew with intensity for large stimuli but was independent of intensity for small visual stimuli. Bearing in mind that only large stimuli are believed to be arousing this pattern of results supports the arousal interpretation of the negative effect of loud stimuli on RT given by van der Molen and Keuss.

Influence of Sleep Deprivation and Auditory Intensity on Reaction Time and Response Force

Arousal and activation are two variables supposed to underlie change in response force. This study was undertaken to explain these roles, specifically, for strong auditory stimuli and sleep deficit. Loud auditory stimuli can evoke phasic overarousal whereas sleep deficit leads to general underarousal. Moreover, Van der Molen and Keuss (1979, 1981) showed that paradoxically long reaction times occurred with extremely strong auditory stimuli when the task was difficult, e.g., choice reaction or Simon paradigm. It was argued that this paradoxical behavior related to reaction time is due to active disconnecting of the coupling between arousal and activation to prevent false responses. If so, we predicted that for extremely loud stimuli and for difficult tasks, the lengthening of reaction time should be associated with reduction of response force. The effects of loudness and sleep deficit on response time and force were investigated in three different tasks: simple response, choice response, and Simon paradigm. According to our expectation, we found a detrimental effect of sleep deficit on reaction time and on response force. In contrast to Van der Molen and Keuss, we found no increase in reaction time for loud stimuli (up to 110 dB) even on the Simon task.

INFLUENCE OF SLEEP DEPRIVATION AND AUDITORY INTENSITY ON REACTION TIME AND RESPONSE FORCE

Arousal and activation are two variables supposed to underlie change in response force. This study was undertaken to explain these roles, specifically, for strong auditory stimuli and sleep deficit. Loud auditory stimuli can evoke phasic over-arousal whereas sleep deficit leads to general underarousal. Moreover, Van der Molen and Keuss. (1979, 1981) showed that paradoxically long reaction times occurred with extremely strong auditory stimuli when the task was difficult, e.g., choice reaction or Simon paradigm. It was argued that this paradoxical behavior related to reaction time is due to active disconnecting of the coupling between arousal and activation to prevent false responses. If so, we predicted that for extremely loud stimuli and for difficult tasks, the lengthening of reaction time should be associated with reduction of response force. The effects of loudness and sleep deficit on response time and force were investigated in three different tasks: simple response, choice response, and Simon paradigm. According to our expectation, we found a detrimental effect of sleep deficit on reaction time and on response force. In contrast to Van der Molen and Keuss, we found no increase in reaction time for loud stimuli (up to 110 dB) even on the Simon task.

Bone-conducted vestibular evoked myogenic potentials in patients with congenital atresia of the external auditory canal

Objective: The purpose of this study was to determine whether vestibular evoked myogenic potentials from the sternocleidomastoid muscle in response to bone-conducted clicks and short tone-bursts can be used to assess vestibular apparatus function in patients with conductive hearing problems, particularly bilateral external auditory canal atresia. Design: Evoked-potential responses to bone-conducted auditory stimuli were recorded from the sternocleidomastoid muscle of 15 patients (11 male and four female, aged 4–20 years) with congenital bilateral atresia of the external auditory canal, with or without the middle ear anomalies. Setting: This study was conducted in the outpatient clinic of the Tokyo University Hospital, Department of Otolaryngology, University of Tokyo. Intervention: Diagnostic. Outcome measures: Bone-conducted vestibular evoked myogenic potentials in response to clicks and short tone-bursts were recorded with surface electrodes over both sternocleidomastoids in each patient. Results: In all patients, bone-conducted clicks and short tone-bursts evoked larger biphasic responses from the sternocleidomastoid ipsilateral to the stimulated ear. Short tone-bursts evoked vestibular evoked myogenic potentials with higher amplitude and better waveform morphology than clicks at the same subjective intensity. Conclusion: Loud auditory stimuli delivered by bone conduction can evoke myogenic potentials from the sternocleidomastoid. This method is a noninvasive, rapid, and convenient test for investigating the vestibular system function in patients with bilateral external auditory canal atresia, with or without the middle ear anomalies.

Bone-Conducted Evoked Myogenic Potentials from the Sternocleidomastoid Muscle

The aim of this study was to show that bone-conducted clicks and short tone bursts (STBs) can evoke myogenic potentials from the sternocleidomastoid muscle (SCM) and that these responses are of vestibular origin. Evoked potential responses to bone-conducted auditory stimuli were recorded from the SCMs of 20 normal volunteers and from 12 patients with well-defined lesions of the middle or inner ear or the VIIIth cranial nerve. The subjects, who had various labyrinthine and retro-labyrinthine pathologies, included five patients with bilateral profound conductive hearing loss, two with bilateral acoustic neuroma post-total neurectomy and five with bilateral sensorineural hearing loss. Air- and bone-conducted evoked myogenic potentials in response to clicks and STBs were recorded with surface electrodes over each SCM of each subject. In normal subjects, bone- and air-conducted clicks and STBs evoked biphasic responses from the SCM ipsilateral to the stimulated ear. The bone-conducted clicks evoked short-latency vestibular-evoked myogenic potential (VEMP) responses only in young subjects or in subjects with conductive hearing loss. STBs evoked VEMPs with higher amplitude and better waveform morphology than clicks with the same acoustic intensity. Patients with total VIIIth cranial nerve neurectomy showed no responses to air- or bone-conducted click or STB stimuli. Clear VEMP responses were evoked from patients with conductive or sensorineural hearing loss. It is concluded that loud auditory stimuli delivered by bone- as well as air conduction can evoke myogenic potentials from the SCM. These responses seem to be of vestibular origin

Comparison of clinical and genetic variables of cardiac events associated with loud noise versus swimming among subjects with the long QT syndrome

Acute auditory stimuli and swimming activities are frequently associated with syncope, aborted cardiac arrest, and death in the long QT syndrome (LQTS). We investigated the clinical and genetic findings associated with cardiac events precipitated by these arousal factors. The study population involved 195 patients with an index cardiac event associated with a loud noise (n = 77) or swimming activity (n = 118). Patients with events associated with loud auditory stimuli were older at their index event and were more likely to be women than patients who experienced events during swimming-related activities. Patients with an index event associated with loud noise were likely to have subsequent events related to auditory stimuli; patients with an index event associated with swimming were likely to have recurrent events related to swimming or physical activities. Family patterning of auditory and swimming and/or physical activity-related events was evident. Genotype analyses in 25 patients revealed a significant difference in the distribution of index cardiac events by genotype (p <0.001), with all 19 patients with swimming-related episodes associated with LQT1 genotype and 5 of 6 patients with auditory-related events associated with LQT2 genotype. The clinical profile and genotype findings of patients with LQTS who experience cardiac events related to acute auditory stimuli are quite different from those who experience events accompanying swimming activities.

Persistent Neonatal Borna Disease Virus (BDV) Infection of the Brain Causes Chronic Emotional Abnormalities in Adult Rats

Neonatal Borna disease virus (BDV) brain infection results in selective developmental damage to the hippocampal dentate gyrus and the cerebellum. When mature, neonatally BDV-infected rats show extreme locomotor hyperactivity and reduced freezing behavior in novel environments. Traditional interpretation of both of these behavioral abnormalities would suggest decreased anxiety in infected rats compared to normal animals. However, it also possible that the locomotor hyperactivity in infected rats reflects higher rather than reduced anxiety, and is the result of increased escape responses to aversive stimuli. The present experiments were undertaken to test a hypothesis about elevated anxiety in neonatally BDV-infected adult Lewis rats by studying their species-specific fear-related responses. Compared to normal subjects, BDV-infected rats exhibited locomotor hyperactivity and elevated defecation in a highly aversive, brightly lit open field. As expected, in a less aversive, dimly lit open field, uninfected controls increased ambulation, whereas infected rats significantly decreased locomotor activity and defecation. Unlike uninfected rats, BDV-infected rats exhibited an attenuated freezing response immediately after loud auditory stimuli. On the contrary, immediate freezing responses following footshock were comparable in the two groups of animals indicating an intact ability to freeze in BDV-infected rats. Despite a decreased baseline startle responsiveness, BDV-infected rats demonstrated increased sensitization of the startle response by preceding footshocks, suggesting a tendency toward elevated escape responses. Compared to normal subjects, BDV-infected rats showed decreased conditional freezing and elevated conditional defecation response in the context previously paired with aversive stimulation indicating sparing of an autonomic component of fear conditioning. The findings indicate that neonatally BDV-infected adult rats are hyperreactive to aversive stimuli, possibly as a result of chronic emotional abnormalities.

The relationship between latency of auditory evoked potentials, simple reaction time, and stimulus intensity.

The effects of loudness on the latency of evoked potentials and on simple reaction time were compared. It was found that both reaction time and the evoked-potential latency increases with decreasing stimulus intensity. However, different slopes of the curves were found. This is explained in terms of the arousal effect of loud auditory stimuli.