Acoustic deficits and elderly

Elderly patients have medical and psychological problems affecting all major organ systems. These problems may alter the pharmacokinetics and/or pharmacodynamics of medications, or expose previous neurologic deficits simply as a result of sedation. Delayed arousal, therefore, may arise from structural problems that are pre-existent or new, or metabolic or functional disorders such as convulsive or nonconvulsive seizures. Determining the cause of delayed arousal may require clinical, chemical, and structural tests...

People with dementia of the Alzheimer type (DAT) may well be emotionally soothed by listening to music. However, very few systematic studies have been conducted to support the anecdotal evidence. DAT does damage certain cerebral structures that subsume emotional processing, and some studies have demonstrated deficits affecting emotional judgments of facial expression and prosody in DAT. Accordingly, this study addressed the question of whether DAT might leave musical emotional judgment intact. Twelve early DAT participants and 12 healthy elderly participants took part in this study...

The changes of visual, acoustic and cognitive evoked potentials of brain in 78 elderly patients were studied. Chronic ischemia of the heart and the brain with clinical signs of mild cognitive impairment was present in all patients. Distinct pathomorphologycal sings of structure disorders in brain were absent, and this fact was confirmed with the help of neuroimaging investigations. It was determined that deflections in the indexes of evoked potentials from the age according standard are objective and reliable diagnostic criterions both structural and functional changes in brain and initial cognitive deficit in the elderly patients with cardiovascular pathology...

While the low-density lipoprotein receptor (LDLR) is best known for its role in regulating serum cholesterol, LDLR is expressed in brain, suggesting that it may play a role in CNS function as well. Here, using mice with a null mutation in LDLR (LDLR-/-), we investigated whether the absence of LDLR affects a series of behavioral functions. We also utilized the fact that plasma cholesterol levels can be regulated in LDLR-/- mice by manipulating dietary cholesterol to investigate whether elevated plasma cholesterol might independently affect behavioral performance...

Although many studies have shown diminished performance in verbal short-term memory tasks in normal aging and Alzheimer's disease (AD), the cognitive processes responsible for this verbal short-term storage (STS) impairment are still unclear for both populations. We explored verbal STS functioning in patients with AD, elderly participants, and young participants, by investigating a series of processes that could underlie STS impairments in normal elderly and AD populations. The processes we investigated were (a) the influence of lexical and sublexical language knowledge on short-term storage performance, (b) functioning of the phonological loop component via word length and phonological similarity effects, and (c) executive control processes (coordination and integration)...

Sensory gating is defined as the brain's ability to inhibit repetitive and irrelevant incoming sensory stimuli and is supposed to be related to cholinergic transmission. Indeed, Alzheimer's disease (AD) is characterized by a cholinergic deficit that is believed to be involved in cerebral cortex hyperexcitability and short latency afferent inhibition deficit. Therefore, a sensory gating deficit may be supposed present in AD within the frame of cortex hyperexcitability and loss of cortex modulation of sensory inputs...

PURPOSE: The relationship between auditory temporal-order perception and phoneme discrimination has been discussed for several years, based on findings, showing that patients with cerebral damage in the left hemisphere and aphasia, as well as children with specific language impairments, show deficits in temporal-processing and phoneme discrimination. Over the last years several temporal-order measurement procedures and training batteries have been developed. However, there exists no standard diagnostic tool for adults that could be applied to patients with aphasia...

The mismatch negativity (MMN) component of the auditory event-related potential has been used in the past to study between group differences in the accuracy and retention of information in auditory sensory memory (ASM). The MMN is elicited by infrequent 'deviant' tones that differ from a repeating 'standard' tone. In the present study, the type of deviant and the time interval between tones (stimulus-onset asynchrony: SOA) were manipulated in a study of normal aging. MMN responses of an elderly (mean age = 69) and a young group (mean age = 21) to both a duration and a frequency deviant tone were measured at a short (450 ms) and long (3 s) SOA...

In the present study, dichotic listening performance of 31 older adults was compared with performance of 25 younger adults under free and focused attention conditions. In addition to an age-related general decrease in performance, we observed in the focused attention condition increased asymmetry in the elderly group: the decrease of recall performance was stronger for the left ear (LE) then for the right ear (RE), while the increase of localisation errors were greater for the RE than for LE. Identifying and localising digits appear to be different process mediated predominantly by the left and right hemisphere, respectively...

Elderly humans often not only experience peripheral hearing loss but also suffer from more central deficits in temporal auditory processing affecting speech perception. Impaired auditory temporal resolution has also been observed in old rodents. Other studies have demonstrated a reduction of GABAergic function in the auditory pathway of old animals. Here we test the hypothesis that deficits in the GABAergic system affect central auditory processing. Our data suggests that pharmacological augmentation of the GABAergic system ameliorates impaired temporal auditory processing in the gerbil and might be a strategy for the treatment of at least some forms of central hearing loss in humans...

This research was guided by the working hypothesis that the aging auditory system progressively loses its ability to process rapid acoustic transients efficiently, and in elderly listeners, this results in difficulties in speech perception. Neural correlates of age-related deficits in temporal processing were investigated by recording from inferior colliculus (IC) neurons from young adult and old CBA mice. Single-unit responses were recorded to sinusoidally amplitude-modulated (SAM) noise carriers, presented at 65-80 dB SPL, having modulation frequencies (MFs) that ranged from 10 to 800 Hz...

OBJECTIVE: To define brain activity and behavioral changes in mild cognitive impairment (MCI), an isolated memory deficit in the elderly that is a major risk factor for Alzheimer's disease. METHODS: Brain potentials and reaction time were examined in elderly controls (n=12) and MCI (n=15) using a target detection paradigm. Subjects listened to a sequence of tones and responded to high-pitched target tones (P=0.20) that were randomly mixed with low-pitched tones (P=0...

OBJECTIVE: To determine if an "observation" protocol with serial scanning is a safe and effective management paradigm for acoustic neuromas in the elderly. STUDY DESIGN: A retrospective case review was performed. SETTING: This study was performed in an academic, tertiary care center. PATIENTS: Forty-one patients over the age of 65 years were identified with the primary diagnosis of unilateral acoustic neuroma, without prior treatment or observation...

Between 20 and 30% of AIDS patients have neurological symptoms characterized by motor impairment, memory loss and progressive dementia. Previous studies have implicated the HIV derived gp120, which produces behavioral deficits and electrophysiological alterations in rats. The goal of the present study was to describe the effect of this protein on the P3 event-related potential (ERP), evoked by a passive discrimination task in rats. We used II rats divided into two groups: HIV gp120 (n = 6) and control (n = 5)...

Responses to standard stimuli presented during a dichotic listening task were analysed in 53 healthy subjects from 20 to 86 years of age. The aim was to determine whether N1 and P2 waves showed changes attributable to attention or more general changes underlying the electrophysiological processing of such stimuli under attended and unattended conditions. N1 was larger at midline frontal and central electrodes in middle-aged and in elderly subjects without changes in its topographical distribution. These changes were independent of attention...

BACKGROUND: The results of previous studies comparing the middle-latency auditory evoked potentials (MAEPs) of young and elderly subjects have suggested that thalamic inhibitory deficits underlie age-related increases in MAEP amplitudes. METHODS: MAEPs were recorded from 73 healthy subjects aged between 20 and 86 years. The latencies of MAEPs recorded at Fz were subjected to two-way analyses of variance for the effects of age group and sex. Amplitude data were subjected to analyses of covariance with age group and sex as between-subjects factors, electrode position as within-subject factor, and individual perceptual thresholds as covariates...

After listening to multiple-episode stories that promoted coherence inferences, right hemisphere-damaged patients answered Inference questions about the stories less accurately than Explicit questions, whereas normal elderly subjects answered both question types equally well. In addition, while subjects listened to the stories they made lexical decisions to tests words that were related to the promoted inferences or were unrelated to the stories. Right hemisphere-damaged patients responded more slowly to inference-related words than to unrelated words, whereas normal elderly subjects responded more quickly to interference-related words than to unrelated words...

Previously we observed that the P3 component of the event-related brain potential (ERP) elicited by startling noises, and to a lesser extent P3 to target tones, is reduced in the elderly (Ford & Pfefferbaum, 1991). In the current experiment, we tried to eliminate possible effects of age-related hearing deficits on the responses to noises by filtering them to include only frequencies heard best by the elderly (0-1000 Hz) and by setting noise intensity relative to each subject's threshold (sensation level, SL)...

Age-related hearing loss (presbycusis) is a complex state that reflects pathologic changes along the entire auditory neuraxis. Loss of speech understanding, decreased ability to localize sounds, and a decreased ability to detect and extract signals in noise are characteristic problems encountered by the elderly. Central (neural) presbycusis frequently results in a dramatic loss in speech understanding without a parallel change in pure-tone thresholds. In spite of evidence that suggests these deficits cannot be fully explained by peripheral changes alone, few studies have examined the neurochemical basis of central auditory dysfunction in aging...

Recent findings of missing or markedly attenuated P50 (or P1) auditory ERPs in Alzheimer's disease (AD) patients suggest this may be a useful diagnostic and/or prognostic marker of AD cholinergic deficits. Those studies used repetitive 1/sec clicks. Given P50's long recovery time, all but the first click in that paradigm was presented during the recovery of the P50 generation system from the response to the prior click. We studied 8 AD patients and 17 elderly controls using a paradigm incorporating 7-8 sec intervals between clicks, which allows examination of P50 generation separate from P50 recovery...