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Results for “Auditory Perceptual Disorders”
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Palinacousis of persistent auditory sensations.
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Selective alpha 7 nicotinic receptor stimulation normalizes chronic cocaine-induced loss of hippocampal sensory inhibition in C3H mice.
BACKGROUND: A physiological alteration associated with schizophrenic and manic psychoses is diminished inhibition of the electrophysiological response to repeated auditory stimuli. This deficit also occurs in cocaine addicts. Studies in animals show that such inhibition is decreased by noradrenergic receptor stimulation and that the inhibition is enhanced by nicotinic cholinergic receptor stimulation. METHODS: C3H mice were treated for 7 days with cocaine. They were then prepared for electrophysiological recording. After the effects of cocaine treatment were observed, they were treated with nicotine agonists. RESULTS: Chronic cocaine administration markedly diminished inhibition of the hippocampal-evoked response to repeated auditory stimuli. The loss of inhibition was reversed by acute treatment with either nicotine or the selective alpha 7 nicotinic agonist 3-(2,4)-dimethoxybenzylidine anabaseine (DMXB; GTS21). The effects of nicotine showed tachyphylaxis, whereas those of DMXB did not. CONCLUSIONS: This reversal of cocaine's effect by nicotinic agonists is consistent with previous pharmacological studies of the inhibition of auditory response. Additionally, the ability of nicotinic agonists to reverse a physiological defect associated with psychosis may have therapeutic implications for the neuropsychiatric sequelae of cocaine addiction in humans.
Perception of facial and vocal affect by people with schizophrenia in early and late stages of illness.
BACKGROUND: Emotion recognition impairments have been demonstrated in schizophrenia, but few studies have examined whether these reflect generalised or specific perceptual deficits or are associated with illness course. AIMS: To examine the nature of emotion recognition abnormalities in patients with schizophrenia at different stages of illness. METHOD: We examined the performance of 50 in-patients with early-stage schizophrenia, 50 with chronic schizophrenia and 50 healthy controls on the Benton Facial Recognition Test, Facial Emotion Recognition Test and Voice Emotion Recognition Test. RESULTS: Patients with chronic schizophrenia were significantly more impaired than other groups on the emotional tasks, even after controlling for impairments in non-emotional stimuli. Individual emotion recognition accuracy for the two sensory modalities was not significantly positively correlated for either group with schizophrenia. CONCLUSIONS: Emotion recognition deficits in schizophrenia are trait features of the disorder and increase with illness duration.
Systematic identification of perceptual disabilities in autistic children.
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The Chirp Train Streaming test. A clinical approach to auditory selectivity and listening.
Traditionally, the auditory system is considered as capable, primarily, of frequency and temporal analysis. We introduce a new test, the CTS test, using tone glides (chirps), which takes into account the ability of the auditory system to form perceptual streams. Based on Békésy tracking, the test gives an auditory selectivity index, the streaming index or STIN. The STIN value together with the tracking pattern provide insight into the nature and cause of the patient's listening problems. In this paper, we use the STIN to develop a working hypothesis about the role of middle-ear silent mucosal metaplasia in presbyacusis. The test is described in detail, and the results for 560 patients (1,109 ears) are given. The validity, reliability, limitations, and interpretation of the test are discussed.
Echolalic speech in childhood autism. Consideration of possible underlying loci of brain damage.
The speech of echolalic autistic children is (1) specifically lacking in appropriate use of expressive-intonational features, but (2) the echolalic child's clear articulation of words and phrases indicates that discrimination of phonemic features is intact. The impairment in aphasic disorders is just the reverse. Failure to attend to auditory stimuli and the characteristic language disorder are among the most consistent findings in autistic children; they could be related. Discrimination of differential stress emphasis is the way the normal young child extracts major morphemic word stems and syntactic features from environmental speech; this may be a primitive perceptual function of brain stem auditory centers. The brain stem auditory system is especially vulnerable to perinatal injury. Damage to this system is an example of the kind of lesion that might lead to behavioral handicaps without neurological signs.
Discrimination in autism within different sensory modalities.
Recent studies have suggested that unusual visual processing in autism might stem from enhanced visual discrimination. Although there are also many anecdotal reports of auditory and tactile processing disturbances in autism these have received comparatively little attention. It is possible that the enhanced discrimination ability in vision in autism might extend to other modalities and further that they may underlie many reports of unusual touch and audition. The present study investigated the performance of children with and without autism on auditory and tactile discrimination tasks and revealed superior auditory but comparable tactile discrimination in autism relative to controls. These results extend previous findings of perceptual discrimination in autism and may be relevant for a neuro-developmental hypothesis of the disorder.
Epilepsy and disorders of perception.
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The specific relation between perception and production errors for place of articulation in developmental apraxia of speech.
Developmental apraxia of speech is a disorder of phonological and articulatory output processes. However, it has been suggested that perceptual deficits may contribute to the disorder. Identification and discrimination tasks offer a fine-grained assessment of central auditory and phonetic functions. Seventeen children with developmental apraxia (mean age 8:9, years:months) and 16 control children (mean age 8:0) were administered tests of identification and discrimination of resynthesized and synthesized monosyllabic words differing in place-of-articulation of the initial voiced stop consonants. The resynthetic and synthetic words differed in the intensity of the third formant, a variable potentially enlarging their clinical value. The results of the identification task showed equal slopes for both subject groups, which indicates no phonetic processing deficit in developmental apraxia of speech. The hypothesized effect of the manipulation of the intensity of the third formant of the stimuli was not substantiated. However, the children with apraxia demonstrated poorer discrimination than the control children, which suggests affected auditory processing. Furthermore, analyses of discrimination performance and articulation data per apraxic subject demonstrated a specific relation between the degree to which auditory processing is affected and the frequency of place-of-articulation substitutions in production. This indicates the interdependence of perception and production. The results also suggest that the use of perceptual tasks has significant clinical value.
Re: "Development of SCAN-A: test of auditory processing disorders in adolescents and adults" (J Am Acad Audiol 1996;6:286-292)
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Perception metamorphosis phenomenon in autism.
It is well known that various perceptual abnormalities exist in autism. However, because perceptual phenomena are intersubjective, a phenomenological approach is required for getting hold of the reality of the modes of perception involved in autism. From this standpoint, the author has proposed the concept of 'perception metamorphosis phenomenon' (PMP) as the mode of perception peculiar to autistics. This mode of perception is notable to some degree in infancy and adolescence, and points to the appearance of behavior that is indicative of the environmental world being perceived in a manner different from before by the autistic child. The phenomenon has been classified into three basic categories according to the aspect of perception: (i) visual PMP; (ii) auditory PMP; and (iii) situational PMP. The proposal of this concept was made with the objective of capturing the onset of autism or the mechanism of appearance of the various symptoms from a more phenomenological viewpoint, to serve as a possible starting point for understanding the inner world of autistics. The proposal was made emphasizing the validity of this approach in mapping out new therapeutic approaches and for re-investigating the relationship between autism and schizophrenia.
Clinical predictors of course and outcome in delusional psychosis.
The purpose of the study was to examine whether clinical variables of first-admitted patients with delusional psychosis were of predictive importance of course and outcome illuminated through the dimensions: psychotic symptoms, impairment, remission, and relapse at 2-year follow-up. Male, sex, age below 30 years, unmarried, long duration of psychosis, and absence of psychosocial stress prior to first admission were all statistically predictive of poor outcome. Concerning nonspecific psychological distress high mean values on the subscales of helplessness-hopelessness, dread and antisocial history were correlated to poor outcome as was low mean value of active expression of hostility. Concerning psychopathology assessed by PSE individual items as lost emotions, thought insertion, thought broadcast, primary delusions and certain auditory hallucinations (voices discussing/commenting subject in third person) predicted poor outcome. Further classes of PSE symptoms as perceptual disorder, thought disorder, and delusions of influence predicted poor outcome too. Other prognostic unfavourable variables were systematisation of delusions, severe preoccupation with present delusions and no suspicion of attempt at concealment of delusions and hallucinations.
Learned self-regulation of EEG frequency components affects attention and event-related brain potentials in humans.
Learned enhancement of EEG frequency components in the lower beta range by means of biofeedback has been reported to alleviate attention deficit hyperactivity disorder (ADHD) symptoms. In order to elucidate frequency-specific behavioural effects and neurophysiological mediators, this study applied neurofeedback protocols to healthy volunteers, and assessed impact on behavioural and electrocortical attention measures. Operant enhancement of a 12-15 Hz component was associated with reduction in commission errors and improved perceptual sensitivity on a continuous performance task (CPT), while the opposite relation was found for 15-18 Hz enhancement. Both 12-15 Hz and 15-18 Hz enhancement were associated with significant increases in P300 event-related brain potential amplitudes in an auditory oddball task. These relations are interpreted as stemming from band-specific effects on perceptual and motor aspects of attention measures.
Language impairment in children with perceptual-motor dysfunction.
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On the effect of cross-hearing and clinical masking on the auditory brain-stem evoked response.
The effects of cross-hearing from the non-test ear were examined during the acquisition of the auditory brain-stem evoked response (ABR). Effective masking levels were derived from a normal hearing subject and the results used to obtain masked versus unmasked ABR thresholds in varying types of unilateral hearing loss. The results indicate that in the presence of a hearing loss adequate masking of the non-test ear is essential for valid ABR results.
Effects of interval duration on temporal processing in schizophrenia.
INTRODUCTION: Temporal processing has received scant attention in the literature pertaining to cognitive deficits in patients with schizophrenia. Previous research suggests that patients with schizophrenia exhibit temporal perception deficits on both auditory and visual stimuli. The current study investigated the effects of interval manipulation to (1) replicate the original findings with a larger sample and an increased number of trials (2) assess the degree to which both patients and controls can differentiate temporal changes in a range of experimental interstimulus intervals, and (3) explore whether different interstimulus interval durations pose different levels of difficulty for the patients with schizophrenia. METHODS: Participants were asked to decide whether temporal intervals were shorter or longer than standard intervals on a computer-based auditory temporal perception task. The standard interval remained the same duration throughout the various tasks. The interstimulus interval separating the standard and experimental intervals varied in the range of 500, 1000, or 3000 ms. Data are presented for a sample of 16 patients with schizophrenia and 15 controls. RESULTS: Data suggest that patients with schizophrenia exhibit deficits in differentiating interval durations across all paradigms compared to their control-group peers on a range of auditory tasks (p<.001). CONCLUSIONS: These results are consistent with a general temporal deficit in schizophrenia. However, the roles of medication and localization are also addressed.
Overshoot effects using Schroeder-phase harmonic maskers in listeners with normal hearing and with hearing impairment.
Overshoot was examined in normal-hearing listeners and in listeners with sensorineural hearing loss using positive (m(+)) and negative (m(-)) Schroeder-phase harmonic maskers and brief (5-ms) 1000-Hz and 4000-Hz signals. Maskers were 460 ms in duration and contained equal-amplitude harmonics of a 100-Hz fundamental frequency. For each masker, probes were presented at temporal locations near the start of the masker (probe onsets 3, 5.5, 8, 10.5, and 13 ms following masker onset) and at the same positions (relative to masker fine structure) 150 ms later, near the temporal center of each masker. Probes were held constant at either 60 or 80 dB sound-pressure level (SPL) and masker levels were varied adaptively to determine masked thresholds at each position within the 10-ms masker period. Overshoot effects were greatest for conditions where cochlear processing was likely to be highly nonlinear, i.e., for normal-hearing listeners tested at moderate presentation levels (60 dB SPL probes). In addition, greater overshoot was observed for m(+) than for m(-) maskers. These findings are consistent with earlier suggestions that masking effectiveness of m(+) complexes is particularly influenced by cochlear nonlinearity (Summers, V. and Leek, M.R., 1998. Hear. Res. 188, 139-150) and with evidence linking overshoot to nonlinearity in peripheral auditory processing.