CDP-choline and galantamine, a personalized α7 nicotinic acetylcholine receptor targeted treatment for the modulation of speech MMN indexed deviance detection in healthy volunteers: a pilot study

RATIONALE

The combination of CDP-choline, an α7 nicotinic acetylcholine receptor (α7 nAChR) agonist, with galantamine, a positive allosteric modulator of nAChRs, is believed to counter the fast desensitization rate of the α7 nAChRs and may be of interest for schizophrenia (SCZ) patients. Beyond the positive and negative clinical symptoms, deficits in early auditory prediction-error processes are also observed in SCZ. Regularity violations activate these mechanisms that are indexed by electroencephalography-derived mismatch negativity (MMN) event-related potentials (ERPs) in response to auditory deviance.

OBJECTIVES/METHODS

This pilot study in thirty-three healthy humans assessed the effects of an optimized α7 nAChR strategy combining CDP-choline (500 mg) with galantamine (16 mg) on speech-elicited MMN amplitude and latency measures. The randomized, double-blinded, placebo-controlled, and counterbalanced design with a baseline stratification method allowed for assessment of individual response differences.

RESULTS

Increases in MMN generation mediated by the acute CDP-choline/galantamine treatment in individuals with low baseline MMN amplitude for frequency, intensity, duration, and vowel deviants were revealed.

CONCLUSIONS

These results, observed primarily at temporal recording sites overlying the auditory cortex, implicate α7 nAChRs in the enhancement of speech deviance detection and warrant further examination with respect to dysfunctional auditory deviance processing in individuals with SCZ.

Neural processing of amplitude and formant rise time in dyslexia

This study aimed to investigate how children with dyslexia weight amplitude rise time (ART) and formant rise time (FRT) cues in phonetic discrimination. Passive mismatch responses (MMR) were recorded for a/ba/-/wa/contrast in a multiple deviant odd-ball paradigm to identify the neural response to cue weighting in 17 children with dyslexia and 17 age-matched control children. The deviant stimuli had either partial or full ART or FRT cues. The results showed that ART did not generate an MMR in either group, whereas both partial and full FRT cues generated MMR in control children while only full FRT cues generated MMR in children with dyslexia. These findings suggest that children, both controls and those with dyslexia, discriminate speech based on FRT cues and not ART cues. However, control children have greater sensitivity to FRT cues in speech compared to children with dyslexia.

California Verbal Learning Test-II performance in schizophrenia as a function of ascertainment strategy: comparing the first and second phases of the Consortium on the Genetics of Schizophrenia (COGS)

The first phase of the Consortium on the Genetics of Schizophrenia (COGS-1) showed performance deficits in learning and memory on the California Verbal Learning Test, Second Edition (CVLT-II) in individuals with schizophrenia (SZ), compared to healthy comparison subjects (HCS). A question is whether the COGS-1 study, which used a family study design (i.e. studying relatively intact families), yielded "milder" SZ phenotypes than those acquired subsequently in the COGS-2 case-control design that did not recruit unaffected family members. CVLT-II performance was compared for the COGS-1 and COGS-2 samples. Analyses focused on learning, recall and recognition variables, with age, gender and education as covariates. Analyses of COGS-2 data explored effects of additional covariates and moderating factors in CVLT-II performance. 324 SZ subjects and 510 HCS had complete CVLT-II and covariate data in COGS-1, while 1356 SZ and 1036 HCS had complete data in COGS-2. Except for recognition memory, analysis of covariance showed significantly worse performance in COGS-2 on all CVLT-II variables for SZ and HCS, and remained significant in the presence of the covariates. Performance in each of the 5 learning trials differed significantly. However, effect sizes comparing cases and controls were comparable across the two studies. COGS-2 analyses confirmed SZ performance deficits despite effects of multiple significant covariates and moderating factors. CVLT-II performance was worse in COGS-2 than in COGS-1 for both the SZ and the HCS in this large cohort, likely due to cohort effects. Demographically corrected data yield a consistent pattern of performance across the two studies in SZ.

Psychophysiological Analysis of the Influence of Vasopressin on Speech in Patients with Post-Stroke Aphasias

Speech is an attribute of the human species. Central speech disorders following stroke are unique models for the investigation of the organization of speech. Achievements in neurobiology suggest that there are possible neuroendocrine mechanisms involved in the organization of speech. It is known that the neuropeptide vasotocin, analogous of vasopressin in mammals, modulates various components of vocalization in animals. Furthermore, the positive influence of vasopressin on memory, which plays an important role in the formation of speech, has been described. In this study, speech organization processes and their recovery with the administration of vasopressin (1-desamino-8-D-arginin-vasopressin) to 26 patients with chronic aphasias after stroke were investigated. Results showed that sub-endocrine doses of the neuropeptide with intranasal administration had positive influence primarily on simple forms of speech and secondarily on composite forms. There were no statistically significant differences between the sensory and integrative components of the organization of speech processes with vasopressin. In all cases, the positive effect of the neuropeptide was demonstrated. As a result of the effects, speech regulated by both brain hemispheres improved. It is suggested that the neuropeptide optimizes the activity both in the left and right hemispheres, with primary influence on the right hemisphere. The persistence of the acquired effects is explained by an induction of compensatory processes resulting in the reorganization of the intra-central connections by vasopressin.

Prenatal exposure to antidepressants and depressed maternal mood alter trajectory of infant speech perception

Language acquisition reflects a complex interplay between biology and early experience. Psychotropic medication exposure has been shown to alter neural plasticity and shift sensitive periods in perceptual development. Notably, serotonin reuptake inhibitors (SRIs) are antidepressant agents increasingly prescribed to manage antenatal mood disorders, and depressed maternal mood per se during pregnancy impacts infant behavior, also raising concerns about long-term consequences following such developmental exposure. We studied whether infants' language development is altered by prenatal exposure to SRIs and whether such effects differ from exposure to maternal mood disturbances. Infants from non-SRI-treated mothers with little or no depression (control), depressed but non-SRI-treated (depressed-only), and depressed and treated with an SRI (SRI-exposed) were studied at 36 wk gestation (while still in utero) on a consonant and vowel discrimination task and at 6 and 10 mo of age on a nonnative speech and visual language discrimination task. Whereas the control infants responded as expected (success at 6 mo and failure at 10 mo) the SRI-exposed infants failed to discriminate the language differences at either age and the depressed-only infants succeeded at 10 mo instead of 6 mo. Fetuses at 36 wk gestation in the control condition performed as expected, with a response on vowel but not consonant discrimination, whereas the SRI-exposed fetuses showed accelerated perceptual development by discriminating both vowels and consonants. Thus, prenatal depressed maternal mood and SRI exposure were found to shift developmental milestones bidirectionally on infant speech perception tasks.

Cisplatin ototoxicity affecting cochlear implant benefit

OBJECTIVE

Report a case of loss of cochlear implant benefit after cisplatin therapy to treat osteosarcoma. Examine the implications for the loci of cisplatin-associated cochleotoxicity.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Single case study.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Cochlear implant programming levels.

RESULTS

Increase in cochlear implant programming T- and C-levels after cisplatin therapy.

CONCLUSION

Cisplatin therapy likely affects spiral ganglion cells. It seems that auditory cells other than outer hair cells in the organ of Corti are affected by cisplatin because the hearing sensitivity of this patient with nonfunctioning outer hair cells declined after receiving chemotherapy. Implications of these findings are discussed.

[Modern aspects of diagnosis of presbycusis and its treatment in elderly patients]

This study was designed to evaluate the efficacy of tanakan used to treat tympanophonia in elderly women. The entire spectrum of modern audiological technique was employed to examine the patients. It was shown that tanakan therapy decreases intensity of typmanytis and improves speech hearing in aged patients. The results of the study give reason to recommend the treatment with tanakan for the elderly patients presenting with either presbiacusis or normal tonal hearing.

Regression equations for predicting scores of persons over 65 on the Rey Auditory Verbal Learning Test, the mini-mental state examination, the trail making test and semantic fluency measures

OBJECTIVES

Scores on neuropsychological tests are often used to detect abnormal changes in cognition in older persons. Accordingly, it is important to have normative data that allow the abnormality of a test score to be determined precisely and accurately. Regression equations that estimate an expected score based on demographic or premorbid factors can be an efficient method of making normative comparisons. Our aim was to compute regression equations with age, gender and estimated premorbid IQ as predictors of scores on the Rey Auditory Verbal Learning Test (AVLT), the Trail Making Test (TMT), Mini-mental State Examination (MMSE) and measures of semantic fluency.

DESIGN

All measures were administered to a group of 272 healthy older persons aged between 65 and 90 during the pre-treatment phase of a study evaluating the effect of nutritional supplements on cognition. Premorbid IQ was estimated using the National Ault Reading Test (NART). Stepwise multiple regression procedures were used to determine the weights to be applied to the predictor variables.

RESULTS

Age and premorbid IQ were found to be significantly correlated with all test variables; gender correlated significantly with most scores. Regression equations based on the 3 predictor variables explained between 10% and 30% of the variance of the range of test scores. The use of these equations in clinical practice was illustrated.

CONCLUSION

The significant correlations between the predictor variables and test scores justified computing a set of equations for use in interpreting data from older persons. The abnormality of the difference between predicted and obtained scores provides a convenient index of an individual's current level of neuropsychological functioning.

Auditory measures in clinically depressed individuals. II. Auditory evoked potentials and behavioral speech tests

This is the second paper in a series of two papers comparing auditory measures in depressed and non-depressed individuals. In this paper, we describe the auditory brainstem responses (ABRs), auditory late responses (ALRs) and behavioral speech measures obtained from the same set of 36 individuals as in our previous paper. No changes were made to the inclusion criteria or subject classification. The results indicated a significantly larger amplitude growth with increase in intensity for ABR peak V and ALR peak N1P2 in the unmedicated group compared to the normal group. The unmedicated group performed less favorably on most behavioral speech tests administered compared to the control group, but the difference was significant only in the left ear for the Low Predictability Sentence List of the R-SPIN (Revised-Speech Perception in Noise) test. The mean test scores of the medicated group were closer to the scores of the control group.

Paroxetine-induced modulation of cortical activity supporting language representations of action

INTRODUCTION

Previous studies have shown that paroxetine, a selective serotonin reuptake inhibitor, affects brain motor pathway activity in healthy subjects using simple motor tasks. In this study, we explored the effects of paroxetine on the activity of cortical areas implicated in higher-order representations of goal-directed movements, i.e., action-related language processing.

MATERIALS AND METHODS

A double-blind, crossover, randomized paradigm was used to compare two 1-month treatment phases with either paroxetine (20 mg per day) or placebo. A functional magnetic resonance imaging experiment on 12 healthy subjects, conducted at the end of each treatment phase, comprised a single list of verbs and three tasks that consisted in repeating the verbs aloud, generating verbs depicting actions aloud, and mentally simulating the corresponding actions. The effects of the drug, i.e., paroxetine-placebo>0 (hyperactivation) and placebo-paroxetine >0 (hypoactivation) were assessed on the basis of the activation-rest contrast for each task.

RESULTS AND DISCUSSION

For both verb generation and mental simulation of action which both engaged higher-order representations of action, we observed hypoactivation in the left-sided prefrontal and right-sided medial premotor cortex. By contrast, we observed hyperactivation in the right-sided Brodmann's area 6 for the less demanding verb repetition task.

CONCLUSION

Chronic treatment with paroxetine may modulate the cerebral activities elicited by action-related language tasks depending on the cognitive components involved in such tasks.

Predicting therapeutic response to secondary treatment with bupropion: dichotic listening tests of functional brain asymmetry

Studies using neuroimaging, electrophysiologic and cognitive measures have raised hopes for developing predictors of therapeutic response to antidepressants. Pretreatment measures of functional brain asymmetry have been found to be related to response to the selective serotonin reuptake inhibitor fluoxetine. This report examines the extent to which dichotic listening tests also predict clinical response to an antidepressant with a different mechanism of action, i.e., bupropion. Dichotic listening data were obtained for 17 unmedicated depressed patients who were subsequently treated with bupropion. Right-handed outpatients were tested on dichotic fused-words and complex-tones tests. Seven patients who responded to bupropion and 10 nonresponders did not differ in gender, age or education. Bupropion responders had significantly larger left-hemisphere advantage for perceiving words when compared to nonresponders, but there was no difference in their right-hemisphere advantage for tones. All patients having a left-hemisphere advantage above the normal mean responded to bupropion, whereas only 9% of patients below the normal mean responded to treatment. These findings should encourage further study of the clinical value of dichotic listening and other measures of functional brain asymmetry for identifying depressed patients who most benefit from treatment with different classes of antidepressants.

Effect of atorvastatin on progression of sensorineural hearing loss and tinnitus in the elderly: results of a prospective, randomized, double-blind clinical trial

OBJECTIVE

To test whether the 3-hydroxy-3-methylglutaryl- coenzyme A reductase inhibitor atorvastatin can slow down the progression of presbycusis.

PATIENTS

Fifty patients 60- to 75-years-old with presbycusis and moderately elevated serum cholesterol.

INTERVENTION(S)

In a double-blind design, patients were randomly assigned to treatment with either atorvastatin (40 mg/d orally) or placebo.

MAIN OUTCOME MEASURE(S)

Pure-tone audiometry and tinnitus evaluation at enrolment and after 7 and 13 months.

RESULTS

Development of hearing thresholds after 7 and 13 months showed no significant differences between the groups. Tinnitus score continuously improved in the atorvastatin group (34.8 at 7 and 27.6 at 13 mo), whereas it slightly deteriorated in the placebo group (24.8 at 7 and 26.8 at 13 mo). The effect on tinnitus was a tendency without statistic significance (p = 0.0833).

CONCLUSION

Atorvastatin had no effect on the development of hearing thresholds, but resulted in a trend toward a relief of tinnitus.

Preliminary evidence of beneficial effects of methylphenidate on listening comprehension in children with attention-deficit/hyperactivity disorder

OBJECTIVE

The effect of methylphenidate (MPH) on listening comprehension for information passages, and on working memory, was examined in a clinical sample of 16 children with attention-deficit/hyperactivity disorder (ADHD).

METHOD

Drug effects on comprehension of spoken language at the levels of single sentences and passages, and on verbal and visual-spatial working memory (WM) skills were assessed over a 4-day placebo-controlled, double-blind, crossover treatment trial of MPH at low, medium, and high doses. Concurrent behavior ratings were also completed. Data were analyzed at both group and individual levels; individual improvements using average change scores were analyzed to explore interrelationships among comprehension, WM, and behavioral responses to MPH.

RESULTS

There was a significant effect of drug on comprehension of inferences from challenging listening passages (F = 3.1, p ,0.05), and on visual-spatial working memory performance (F = 3.3, p ,0.05), with significant linear dose-response relationships evident for both domains. Individual improvements in comprehension using averaged placebo-dose change scores were not related to improvements in behavior with MPH, or to improvements in WM in this sample.

CONCLUSIONS

Findings provide preliminary evidence that MPH affects higher-level language comprehension skills, which require sustained attention and mental effort. If generalizable to classroom listening skills, these findings have implications for clinicians and teachers involved with children with ADHD.

Assessment of central auditory processing in a group of workers exposed to solvents

CONCLUSION

Despite having normal hearing thresholds and speech recognition thresholds, results for central auditory tests were abnormal in a group of workers exposed to solvents. Workers exposed to solvents may have difficulties in everyday listening situations that are not related to a decrement in hearing thresholds. A central auditory processing disorder may underlie these difficulties.

OBJECTIVE

To study central auditory processing abilities in a group of workers occupationally exposed to a mix of organic solvents.

MATERIALS AND METHODS

Ten workers exposed to a mix of organic solvents and 10 matched non-exposed workers were studied. The test battery comprised pure-tone audiometry, tympanometry, acoustic reflex measurement, acoustic reflex decay, dichotic digit, pitch pattern sequence, masking level difference, filtered speech, random gap detection and hearing-in-noise tests.

RESULTS

All the workers presented normal hearing thresholds and no signs of middle ear abnormalities. Workers exposed to solvents had lower results in comparison with the control group and previously reported normative data, in the majority of the tests.

Characterizing Impaired Functional Alertness From Diphenhydramine in the Elderly With Performance and Neurophysiologic Measures

STUDY OBJECTIVES

Psychometric task performance measures can be highly sensitive to manipulations that impair functional alertness in young adults; such measures have been shown to be less sensitive to reduced alertness in older adults. The purpose of this study is to determine whether neurophysiologic measures can aid in the detection and characterization of impairments in functional alertness in the elderly.

DESIGN

Double-blind, placebo-controlled, counter-balanced, crossover study.

SETTING

Research laboratory.

PARTICIPANTS

Twelve healthy older adults (62-75 years of age).

INTERVENTIONS

Diphenhydramine, 50 mg.

MEASUREMENTS AND RESULTS

Behavioral performance and electroencephalogram measures were obtained while participants completed spatial working memory and word recognition episodic memory tasks in a baseline interval before drug ingestion and in 4 hourly test intervals following drug ingestion. Relative to placebo, diphenhydramine had marginal effects on task performance yet was effective in reducing alertness, as evidenced by subjective ratings and objective neurophysiologic (electroencephalogram) markers. Diphenhydramine significantly reduced the amplitude of alertness-sensitive event-related potentials recorded during working memory task performance, including the N160 and P300. It also affected neurophysiologic processes underlying episodic memory, as evidenced by a reduction in the difference in event-related potentials between old and new words in the word recognition task. Discriminant analyses incorporating neurophysiologic measures showed that the time course of the central effects of diphenhydramine in older subjects was similar to that previously observed in young adults.

CONCLUSIONS

These results demonstrate that diphenhydramine has adverse neurocognitive effects in elderly individuals and highlights the utility of incorporating direct measures of brain function into assessments of functional alertness.

Using Audiometric Thresholds and Word Recognition in a Treatment Study

OBJECTIVES

First, to examine a possible limit on significant results imposed by a progressive floor effect for hearing threshold improvement in a treatment study. This floor effect for hearing recovery suggests that if inclusion criteria are not set sufficiently high, the superiority of a treatment group may not be detectable. Second, to examine the outcomes when using two different types of criteria for significant change in a subject's word recognition score.

METHODS

Several single-number criteria (e.g., 15 percentage points) are compared with the 95% (p=0.05) criteria from the binomial critical difference table for monosyllables. Critical differences for binomial variables change depending on whether the starting value lies in the middle (near 50% correct) or at either extreme of the range of scores (0 or 100%). Different judgments of significant word recognition improvement (or decrease) using binomial versus single-value criteria are presented.

DATA SOURCE

A recent treatment study of sudden sensorineural hearing loss (n=318) is used to illustrate these effects.

CONCLUSION

First, there is a progressive floor effect of presenting severity that co-varies with the outcome measure hearing threshold recovery. In some designs, this may act to constrain the ability to detect a significant difference. Second, in the example data set, the use of single-value criteria for significant within-subject change in word recognition (e.g., 15 percentage points) introduced a miscategorization error rate of approximately 9% when compared with the result of the binomial 95% critical difference table.

SSRIs and cognitive performance in a working sample

BACKGROUND

Studies of the impact of antidepressant use on cognitive performance have frequently been carried out among the elderly or on healthy volunteers. Comparatively little research has considered their impact on a relatively young, working population, particularly within the context of everyday life.

AIMS

To examine any association between SSRI use and cognitive performance, mood and human error at work.

METHODS

SSRI users and controls completed a battery of laboratory based computer tasks measuring mood and cognitive function pre- and post-work at the start and end of a working week. They also completed daily diaries reporting their work performance.

RESULTS

SSRI use was associated with memory impairment: specifically poorer episodic, though not working or semantic memory. Effects of SSRI use on recognition memory seemed to vary according to the underlying psychopathology, while effects on delayed recall were most pronounced among those whose symptoms had not (yet) resolved. There were no detrimental effects on psychomotor speed, attention, mood or perceived human error at work.

CONCLUSIONS

The findings lend support to the SSRIs comparative safety, even among workers, particularly as the symptoms of the underlying psychopathology are successfully addressed. Possible memory impairments may, however, be found in those taking SSRIs.

Clinical application of neurotrophic factors: the potential for primary auditory neuron protection

Sensorineural hearing loss, as a result of damage to or destruction of the sensory epithelia within the cochlea, is a common cause of deafness. The subsequent degeneration of the neural elements within the inner ear may impinge upon the efficacy of the cochlear implant. Experimental studies have demonstrated that neurotrophic factors can prevent this degeneration in animal models of deafness, and can even provide functional benefits. Neurotrophic factor therapy may therefore provide similar protective effects in humans, resulting in improved speech perception outcomes among cochlear implant patients. There are, however, numerous issues pertaining to delivery techniques and treatment regimes that need to be addressed prior to any clinical application. This review considers these issues in view of the potential therapeutic application of neurotrophic factors within the auditory system.

The acute effect of alcohol on decision making in social drinkers

RATIONALE

Many studies have reported the long-term adverse effects of alcohol on executive cognitive function in chronic alcohol abusers, yet little research has investigated the acute effects of alcohol in social drinkers. Studies on acute effects report alcohol-induced deficits on tasks that require executive cognitive processes, with alcohol acting to increase preservative errors and reduce planning.

AIM

The present investigation examines the acute effects of a moderate dose of alcohol on a decision-making task that involves participants making a forced choice between two simultaneously presented binary-outcome gambles.

METHODS

Alcohol (0.6 g/kg) or placebo was administered to 32 social drinkers. Participants completed the task, making a total of 80 decisions about gambles that varied in the magnitude of expected gains, losses and the probability with which these outcomes were delivered. Participants also chose between gambles probing identified non-normative biases in human decision making, namely, risk aversion for choosing between gains and risk seeking for choosing between losses.

RESULTS

All participants picked the experimental gamble more frequently when the probability of winning was high vs low, when the gains were large vs small and when the losses were small vs large; the alcohol group had an impaired ability to factor in the magnitude of gains and the likelihood of winning when the losses were large. Deliberation time did not differ between the groups.

CONCLUSION

These data suggest that alcohol given acutely impairs risky decision making. In particular, alcohol impairs one's ability to alter responding in light of changing prospective rewards in order to make favourable decisions.

Selective serotonin reuptake inhibitors treatment effects on auditory measures in depressed female subjects

The purpose of this study was to evaluate the auditory effects of selective serotonin reuptake inhibitors (SSRI), known to enhance serotonin (5-HT) transmission in the brain. The experimental group consisted of 14 clinically depressed female subjects, and the control group consisted of 11 non-depressed females. A battery of tests was administered to the experimental group while on and off of SSRI medication. The control group was also administered the test battery twice. Results indicated no significant differences in the control group between sessions. The experimental group showed significantly smaller transient evoked emissions, higher SCAN-A (auditory processing test) composite scores, and smaller amplitude growth functions for Auditory brainstem response peak V and Auditory late response peak N(1)P(2) while on SSRI medication. The increased 5-HT levels in the presence of SSRI (due to reduced reuptake of 5-HT) may be contributing to the significant changes seen in auditory measures with the experimental group.

Pharmacological Enhancement of Aural Habilitation in Adult Cochlear Implant Users

OBJECTIVE

The purpose of this report was to examine the preliminary data collected under a larger on-going feasibility study conducted with cochlear implant patients exploring the potential benefit of pharmacologically-enhanced aural rehabilitation therapy as a means of increasing speech tracking skills.

DESIGN

Eight adult cochlear implant participants participated in a randomized, double-blind study and received either 10 mg d-amphetamine (Treatment group, N = 4) or a placebo (Placebo group, N = 4) 60 minutes prior to a 1.5 hour intensive aural rehabilitation session occurring twice a week for two months. Treatment consisted of a multi-step rehabilitation program individualized for each participant to develop auditory-only speech tracking skills. Prior to and at the conclusion of the therapy sessions, SPECT rCBF imaging and speech tracking assessments were conducted.

RESULTS

Speech tracking scores of the placebo and treatment groups were similar before the aural habilitation intervention. In the placebo group, speech tracking performance increased 13.5% for visual plus auditory and auditory only presentations as a function of aural habilitation alone. The 10 mg d-amphetamine-facilitated program resulted in minimal increases in visual plus auditory tracking scores (2%) but led to a 43% increase for auditory-only speech tracking. Regional cerebral blood flow measures indicated no substantial improvement of brain activation in the placebo group while both the extent and magnitude of primary and associative auditory cortex activations increased significantly with the pharmacologically enhanced treatment program.

CONCLUSIONS

These data support previous studies indicating an accelerated acquisition of speech and language abilities in stroke patients receiving traditional speech therapy in combination with d-amphetamine. Data, however, are preliminary and further study is warranted.

Acute effect of nicotine on auditory gating in smokers and non-smokers

This paper investigates the role of cholinergic mechanisms in auditory gating by assessing the acute effects of nicotine, an acetylcholinomimetic drug, on behavioral and electrophysiological measures of consonant-vowel (CV) discrimination in quiet and in broadband noise (BBN). In a single-blind procedure, categorical boundaries and mismatch negativity (MMN) in two conditions (quiet, BBN) were obtained from 10 non-smokers and 4 smokers with normal hearing under two drug conditions (nicotine, placebo). After the nicotine sessions, plasma tests revealed a subject's nicotine concentration and subjects reported any symptoms. Larger MMN areas and steeper slopes at the boundary were interpreted as reflecting better electrophysiological and behavioral CV discrimination, respectively. Results indicate that, in non-smokers, the effects of nicotine on electrophysiological CV discrimination in quiet increase with an increase in severity of symptoms. Specifically, asymptomatic non-smokers (N = 5) demonstrate little improvement (and sometimes decrements) in performance while symptomatic non-smokers (N = 5) exhibit nicotine-enhanced discrimination, as do smokers. In noise, all subjects demonstrate nicotine-enhanced behavioral and electrophysiological discrimination. Additionally, in noise, smokers exhibit a larger number of measurable categorical boundaries as well as larger MMN areas than non-smokers in both placebo and nicotine sessions. Results are consistent with the hypothesis that nicotinic cholinergic mechanisms play a role in the gating of auditory stimuli.

Cross-sectional study of differences in speech understanding between users and nonusers of estrogen replacement therapy

The purpose of this study was to examine whether women who use estrogen replacement therapy (ERT) differ from women not using ERT on several measures of speech understanding. Participants (n = 38, 60 to 74 years) completed a battery of tests including pure-tone audiometry, the Dichotic Sentence Identification (DSI) test, a test of auditory-only and auditory-visual sentence recognition, and a measure of speech understanding in reverberation. In general, women who used ERT were better able to understand distorted speech than were nonusers of ERT.

Effects of citalopram on worry and brain activation in patients with generalized anxiety disorder

The effects of auditory statements describing a personal worry on brain activation as measured by functional magnetic resonance imaging were examined in patients with generalized anxiety disorder (GAD) before and after anxiety reduction with citalopram. Six patients were imaged while listening to verbal descriptions of a personal worry or a neutral statement before treatment with citalopram and after 7 weeks of treatment. Pre-post drug analyses showed treatment with citalopram reduced self-reported anxiety and reduced BOLD responses to a pathology-specific worry and a neutral stimulus. After treatment, worry sentences, compared to neutral statements, elicit reduced BOLD responses in prefrontal regions, the striatum, insula and paralimbic regions. In addition, contrasts before and after treatment revealed reductions in the differential response that existed between worry and neutral statements. Overall reduction of BOLD response was most prominent during neutral statements, particularly in the left hemisphere. These findings support the clinical impression that GAD patients overreact to both pathology-specific and non-specific cues and that the reduction of anxiety attenuates the response to both types of cues.

Cortical bases of speech perception:evidence from functional lesion studies

Functional lesion studies have yielded new information about the cortical organization of speech perception in the human brain. We will review a number of recent findings, focusing on studies of speech perception that use the techniques of electrocortical mapping by cortical stimulation and hemispheric anesthetization by intracarotid amobarbital. Implications for recent developments in neuroimaging studies of speech perception will be discussed. This discussion will provide the framework for a developing model of the cortical circuitry critical for speech perception.

Ménière's disease: effects of glycerol on tasks involving temporal processing

The present study examined the effect of glycerol ingestion on aspects of auditory performance in subjects having Ménière's disease. It was hypothesized that Ménière's disease may be associated with abnormal firing in the auditory nerve and that this should result in a decreased ability to code the auditory temporal fine structure. Psychoacoustical measures of interaural time discrimination and quasi frequency modulation rate discrimination were used as measures of temporal coding, and performance on these tasks was examined both before and after glycerol ingestion. Pre- and postglycerol measures of speech recognition and audiometric thresholds were also obtained. In agreement with previous results, glycerol-related changes in audiometric thresholds were modest or absent, but improvements in speech recognition were relatively reliable. Improvements in interaural time discrimination and quasi frequency modulation rate discrimination were also observed. The results provide limited support for the hypothesis that Ménière's disease may be associated with a reduced ability to code the temporal fine structure of sound.

Sequential effects of propofol on functional brain activation induced by auditory language processing: an event-related functional magnetic resonance imaging study

BACKGROUND

We have investigated the effect of propofol on language processing using event-related functional magnetic resonance imaging (MRI).

METHODS

Twelve healthy male volunteers underwent MRI scanning at a magnetic field strength of 3 Tesla while performing an auditory language processing task. Functional images were acquired from the perisylvian cortical regions that are associated with auditory and language processing. The experiment consisted of three blocks: awake state (block 1), induction of anaesthesia with 3 mg kg(-1) propofol (block 2), and maintenance of anaesthesia with 3 mg kg(-1) h(-1) propofol (block 3). During each block normal sentences and pseudo-word sentences were presented in random order. The subjects were instructed to press a button to indicate whether a sentence was made up of pseudo-words or not. All subjects stopped responding during block two. The data collected before and after the subjects stopped responding during this block were analyzed separately. In addition, propofol plasma concentrations were measured and the effect-site concentrations of propofol were calculated.

RESULTS

During wakefulness, language processing induced brain activation in a widely distributed temporofrontal network. Immediately after unresponsiveness, activation disappeared in frontal areas but persisted in both temporal lobes (block 2 second half, propofol effect-site concentration: 1.51 microg ml(-1)). No activation differences related to the task were observed during block 3 (propofol effect-site concentration: 4.35 microg ml(-1)).

CONCLUSION

Our findings suggest sequential effects of propofol on auditory language processing networks. Brain activation firstly declines in the frontal lobe before it disappears in the temporal lobe.

Speech and language deterioration in benign rolandic epilepsy

A 5-year-old boy presented with typical clinical and electrophysiologic features of benign rolandic epilepsy. His neurodevelopment, language, and behavior prior to the onset of epilepsy were appropriately normal. He demonstrated marked deterioration of language and cognitive function during the course to a mild and then a moderate disability range. Serial sleep electroencephalographic recordings initially showed continuous and bilateral rolandic discharges with evolution to localized left rolandic spikes. Language and cognitive improvements were subsequently seen. Educational support and evolution of the electroencephalogram to a localized focus could have been contributory. It is anticipated, however, that he will have significant long-term problems in complex language.

Effects of sevoflurane versus TIVA on gastric intramucosal pH and hemodynamic status in colon cancer surgery

BACKGROUND

Gastric tonometry is a minimally invasive device by which the adequacy of splanchnic blood flow is assessed indirectly. Patients undergoing major abdominal surgery are under the risk of developing splanchnic ischemia. The aim of this study was to compare gastric intramucosal pH and hemodynamic effects between sevoflurane and TIVA achieved by propofol.

METHODS

Forty patients of ASA I-II were studied. Twenty patients received sevoflurane (Group S) and 20 patients received TIVA by propofol (Group P). Continuous measurements were made at four intervals: (a) 30 minutes before the starting of the surgery, (b) at the first hour of the surgery, (c) at the second hour of the surgery, (d) at the first hour after ending of the surgery. The mean arterial pressure, heart rate, SpO2, EtCO2, body temperature, central venous pressure, urine output, intramucosal and arterial pH were monitored.

RESULTS

There were no significant differences between two groups regarding the studied parameters.

CONCLUSIONS

Sevoflurane and propofol did not cause any significant difference in hemodynamic effects and splanchnic circulation measured by gastric tonometry in ASA I-II patients operated on for colon cancer.

Improved neural representation of vowels in electric stimulation using desynchronizing pulse trains

Current cochlear implant processors poorly represent sound waveforms in the temporal discharge patterns of auditory-nerve fibers (ANFs). A previous study [Litvak et al., J. Acoust. Soc. Am. 114, 2079-2098 (2003)] showed that the temporal representation of sinusoidal stimuli can be improved in a majority of ANFs by encoding the stimuli as small modulations of a sustained, high-rate (5 kpps), desynchronizing pulse train (DPT). Here, these findings are extended to more complex stimuli by recording ANF responses to pulse trains modulated by bandpass filtered vowels. Responses to vowel modulators depended strongly on the discharge pattern evoked by the unmodulated DPT. ANFs that gave sustained responses to the DPT had period histograms that resembled the modulator waveform for low (< 5%) modulation depths. Spectra of period histograms contained peaks near the formant frequencies. In contrast, ANFs that gave a transient (< 1 min) response to the DPT poorly represented the formant frequencies. A model incorporating a linear modulation filter, a noisy threshold, and neural refractoriness predicts the shapes of period histograms for both types of fibers. These results suggest that a DPT-enhanced strategy may achieve good representation of the stimulus fine structure in the temporal discharge patterns of ANFs for frequencies up to 1000 Hz. It remains to be seen whether these temporal discharge patterns can be utilized by cochlear implant subjects.

Improved incidental memory with nicotine after semantic processing, but not after phonological processing

RATIONALE

A number of lines of evidence suggest that a nicotinic cholinergic system is mediating attentional processing. However, the evidence is less clear for a nicotinic system being involved in mnemonic processing.

OBJECTIVES

The present study investigated the effects of nicotine on memory using a depth of processing paradigm.

METHODS

A double-blind design was used with participants (n = 40) smoking either a nicotine containing cigarette (n = 20) and a denicotinized cigarette (n = 20). After smoking, each set of these participants was further subdivided into two groups (n = 10 for each). One group were presented with a series of trials each beginning with the presentation of a "decision word" which they had to say whether it represented something which was living or non-living (semantic-orienting). The second group had to say whether the word had one syllable or two syllables (phonological or non-semantic orienting condition). This decision was followed by a word in coloured ink whose colour participants were required to name as quickly as possible. On completion of the whole task the participants were given an unexpected free recall test.

RESULTS

The nicotine-containing cigarette reduced the latencies for decision-making and colour naming in comparison with the denicotinized cigarette. The free recall test showed that nicotine-containing cigarette increased the number of words remembered, but only for the semantic-orienting condition and not the non-semantic condition.

CONCLUSIONS

There is a nicotinic cholinergic system that mediates effortful processing. It can be deployed for attentional processing, including the associative processing required for memory encoding.

Auditory sensori-neural alterations induced by salicylate

Early after the development of aspirin, almost 150 years ago, its auditory toxicity has been associated with high doses employed in the treatment of chronic inflammatory diseases. Tinnitus, loss of absolute acoustic sensitivity and alterations of perceived sounds are the three auditory alterations described by human subjects after ingestion of large doses of salicylate. They develop over the initials days of treatment but may then level off, fluctuate or decrease, and are reversible within a few days of cessation of treatment. They may also occur within hours of ingestion of an extremely large dose. Individual subjects vary notably as to their susceptibility to salicylate-induced auditory toxicity. Tinnitus may be the first subjective symptom, and is often described as a continuous high pitch sound of mild loudness. The hearing loss is slight to moderate, bilaterally symmetrical and affects all frequencies with often a predominance at the high frequencies. Alterations of perceived sounds include broadening of frequency filtering, alterations in temporal detection, deterioration of speech understanding and hypersensitivity to noise. Behavioral conditioning of animals provides evidence for mild and reversible hearing loss and tinnitus, similar to those observed in humans. Anatomical examinations revealed significant alterations only at outer hair cell lateral membrane. Electrophysiological investigations showed no change in endocochlear resting potential, and small changes in the compound sensory potentials, cochlear microphonic and summating potential, at low acoustic levels. Measures of cochlear mechanical responses to sounds indicated a clear loss of absolute sensitivity and an associated broadening of frequency filtering, both of a magnitude similar to audiometric alterations in humans, but at extremely high salicylate levels. Otoacoustic emissions demonstrated changes in the mechano-sensory functioning of the cochlea in the form of decrease of spontaneous emissions and reduced nonlinearities. In vitro measures of isolated outer hair cells showed reduction of their fast motile responses which are thought to be at the origin of cochlear absolute sensitivity and associated fine filtering. Acoustically evoked neural responses from the eighth nerve to the auditory cortex showed reversible and mild losses of absolute sensitivity and associated broadening of frequency filtering. There is no evidence of a direct alteration of cochlear efferent innervation. Evidence was obtained for decreases in cochlear blood supply under control of autonomous innervation. Spontaneous neural activity of the auditory nerve revealed increases in firings and/or in underlying temporal synchronies. Similar effects were found at the inferior colliculus, mostly at the external nucleus, and at the cortex, mostly at the anterior and less at the secondary auditory cortex but not at the primary auditory cortex. These changes in spontaneous activity might underlie tinnitus as they affect mostly neural elements coding high frequencies, can occur without a loss of sensitivity, are dose dependent, develop progressively, and are reversible. Biochemical cochlear alterations are poorly known. Modifications of oxydative phosphorylation does not seem to occur, involvement of inhibition of prostaglandin synthesis appears controversial but could underlie changes in blood supply. Other biochemical alterations certainly also occur at outer hair cells and at afferent nerve fibers but remain unknown.

Effects of methylphenidate (Ritalin) on auditory performance in children with attention and auditory processing disorders

A double-blind, placebo-controlled study was used to investigate the effects of methylphenidate (Ritalin) on tests of auditory processing in children diagnosed with both Attention Deficit Hyperactivity Disorder (ADHD) and Central Auditory Processing Disorder (CAPD). Thirty-two subjects received three Central Auditory Processing (CAP) tests and the Auditory Continuous Performance Test (ACPT), a measure of attention/impulsivity, at two separate test sessions: once when medicated with Ritalin and once when nonmedicated (placebo). Sixteen subjects were assigned randomly to receive their medication first and 16 to receive the placebo first. A counterbalanced 2 x 2 mixed factorial analysis of variance was conducted for each of the four dependent variables: Staggered Spondaic Word (SSW), Phonemic Synthesis (PS), Speech-in-Noise (SN), and ACPT measures. Analyses revealed that Ritalin did not have a significant effect on any of the three CAP measures. However, ACPT performance was significantly better (p < .000) for the Ritalin versus placebo condition.

An individualized, sensitive frequency range for early detection of ototoxicity

OBJECTIVE

The aim of this study was to identify auditory frequencies at which serial threshold testing would provide the greatest sensitivity for early detection of ototoxicity. The overall objective is to develop a more time-efficient ototoxicity monitoring protocol.

DESIGN

Threshold data were analyzed from 370 hospitalized patients treated with aminoglycoside antibiotics (AMGs) or cisplatin (CDDP) who received serial auditory monitoring before, during, and after treatment at conventional (0.25 to 8 kHz) and high (9 to 20 kHz) frequencies.

RESULTS

For patients showing hearing changes due to ototoxicity, a frequency range was identified for its apparent high sensitivity to initial ototoxicity. This sensitive range is identified according to an individual's hearing threshold configuration, and is, therefore, unique for each patient. The range consists of five frequencies, generally separated by 1/6 octave, e.g., 8, 9, 10, 11.2, and 12.5 kHz. To determine frequencies and combinations of frequencies that were most often involved in ototoxicity detection, threshold data in the sensitive range were analyzed in detail. This analysis suggests that patients receiving treatment with AMG or CDDP can be monitored for hearing thresholds at only five frequencies, resulting in an 84% detection rate for AMG and 94% for CDDP compared with monitoring at all conventional and high frequencies.

CONCLUSIONS

This comprehensive analysis supports earlier observations that a sensitive, limited frequency range exists in which serial threshold monitoring will provide early warning of ototoxicity before effects in the speech frequency range. This finding is now being evaluated in a prospective investigation.

Hearing results of intratympanic steroid treatment of endolymphatic hydrops

OBJECTIVES/HYPOTHESIS

This study evaluated the effectiveness of a single application of steroids to the open middle ear in improving short-term hearing in patients with Meniere's disease and cochlear hydrops.

STUDY DESIGN

Retrospective study in which each patient's pretreatment hearing served as the control compared with posttreatment hearing.

METHODS

Patients were treated with a single application of dexamethasone, 8 mg, in hyaluronan. Following tympanotomy and lysis of round window adhesions, steroids were placed in the round window niche with absorbable gelatin sponge and the remainder of the middle ear was then filled with the steroid solution. Systemic steroids were not administered. Audiograms were performed within 1 month before surgery and at least 1 month after surgery.

RESULTS

Between September 1996 and July 1997, 21 ears in 19 patients underwent intratympanic steroid treatment. The criterion for hearing change was a 10-dB or greater change in pure-tone average (PTA), or a 15% change in speech discrimination score (SDS). Of the 15 ears meeting inclusion criteria for this study, five (33%) demonstrated hearing improvement and three (20%) demonstrated hearing deterioration. Maximum improvement was a 38-dB improvement in PTA and a 32% improvement in SDS.

CONCLUSION

A single application of intratympanic dexamethasone/hyaluronan solution directly to the round window did not produce dramatic short-term hearing improvement in patients with endolymphatic hydrops. Although the theoretical basis for intratympanic steroid treatment of endolymphatic hydrops is appealing, we urge close evaluation of the results of specific protocols of intratympanic steroid administration before widespread utilization of this treatment. The choice of steroid, route of administration, frequency of application, and need for simultaneous systemic administration require standardization to adequately assess the efficacy of this treatment.

Intratympanic gentamicin treatment for Meniere's disease

OBJECTIVES

The purpose of this study was to evaluate the safety and efficacy of a modified intratympanic gentamicin technique in patients with intractable unilateral or bilateral Meniere's disease.

METHODS

A retrospective review of 25 consecutive patients who underwent gentamicin treatment for Meniere's disease was conducted between 1992 and 1996. Two separate delivery systems were used during this study, with the last 13 subjects undergoing placement of the new system (flanged polyethylene tubing).

RESULTS

Follow-up averaged 23 months. Absence of vertigo spells was reported in 88%, and substantial control was achieved in 12%. Four of five patients with bilateral disease achieved complete control. Results for the two delivery systems were not significantly different. Absence of ice-water caloric response was seen in 75% (15 of 20) patients. Clinically significant sensorineural hearing loss occurred in 5 (20%) of 25 ears. Nonserviceable hearing developed in only two (8%) patients.

CONCLUSIONS

Our results support the previously reported efficacy and relative safety of gentamicin infusion therapy for intractable Meniere's disease. Polyethylene tubing may be more advantageous than T-tube delivery because of anatomic concerns in certain patients.

Quinine reduces the dynamic range of the human auditory system

The aim of the study was to evaluate and quantify quinine-induced changes in the human auditory dynamic range, as a model for cochlear hearing loss. Six otologically normal volunteers (21-40 years old) received quinine hydrochloride (15 mg/kg body weight) in two identical oral doses and one intravenous infusion. Refined hearing tests were performed monaurally at threshold, at moderate hearing levels and at high hearing levels. Quinine induced a maximal pure-tone threshold shift of 23 dB (1000-2000 Hz). The increase in the psychoacoustical click threshold agreed with an increase in the detection threshold of click-evoked otoacoustic emissions. The change in the stimulus-response relationship of the emissions reflected recruitment. The self-attained most comfortable speech level and the acoustic stapedius reflex thresholds were not affected by quinine administration. Quinine is a useful model substance for reversibly inducing complete loudness recruitment in humans as it acts specifically on some parts of the hearing function. Its mechanism of action on the molecular level is likely to reveal further information on the physiology of hearing.

Androgen-behavior correlations in hypogonadal men and eugonadal men. I. Mood and response to auditory sexual stimuli

Mood and response to auditory sexual stimuli were assessed in 33 hypogonadal men receiving testosterone (T) replacement therapy, 10 eugonadal men receiving T in a male contraceptive clinical trial, and 19 eugonadal men not administered T. Prior to and after 6 weeks of hormone administration, men completed a mood questionnaire, rated sexual arousal to and sexual enjoyment of auditory sexual stimuli, and performed a dichotic listening task measuring selective attention for sexual stimuli. Mood questionnaire results suggest that T has positive effects on mood in hypogonadal men when hormone levels are well below the normal male range of values, but does not have any effects on mood when hormone levels are within or above the normal range. However, increased sexual arousal and sexual enjoyment were associated with T administration regardless of gonadal status. Eugonadal men administered T also increased in the bias to attend to sexual stimuli. In contrast, the comparison group of eugonadal men not administered T showed no mood or sexual behavior changes across the two test sessions. These data support a positive relationship between T and sexual interest, sexual arousal, and sexual enjoyment in men.

Patterns of language dominance in focal left and right hemisphere epilepsies: relation to MRI findings, EEG, sex, and age at onset of epilepsy

The present study evaluates results of language testing during intracarotid amobarbital procedures in 167 patients with either left (LHE, n = 81) or right hemisphere epilepsies (RHE, n = 86). In both groups there was a high rate of deviance from complete left hemisphere dominance of 24 and 31%, respectively. Whilst complete right hemisphere or incomplete left hemisphere language dominance were the prominent atypical patterns in LHE, RHE was associated with either bilateral dominance or incomplete left dominance. In LHE, atypical language dominance was frequently associated with an extratemporal localization of lesions or epileptic foci. The age at onset of epilepsy and the degree of right hemisphere language dominance correlated significantly in LHE but not in RHE. Finally, atypical dominance in LHE but not in RHE was associated with poorer language and nonlanguage functions, the latter being negatively correlated with the degree of right hemisphere language dominance. Conclusions are: (1) The data contradict the assumption of equipotentiality and favor the supposition of a predetermined left hemisphere superiority in language processing. (2) Atypical language dominance in LHE can largely be explained in terms of a plasticity dependent language shift as a consequence of early left hemisphere epilepsies and lesions. (3) Atypical dominance patterns in RHE appear to reflect the prevalence of genetically determined variants and the possibility of a language transfer from the right to the left hemisphere.

Serial recovery of language during the intracarotid amobarbital procedure

There is considerable variability among epilepsy centers in the methods and interpretations of the intracarotid amobarbital procedure. Prominent among these differences is the determination of language representation and assessment of language functions. Some centers rely on speech arrest following amobarbital injection as a marker for language representation, whereas other centers examine verbal output for the presence of aphasic errors. The present study assessed the pattern of language recovery following amobarbital injection in epilepsy patients who were candidates for temporal lobectomy. Language recovery from dominant hemisphere injection (left or right) followed a stereotypical progression, with 71.8% of patients showing return of vocalization followed by return of naming and comprehension. Repetition deficits with paraphasic errors persisted the longest (mean = 12'30"), with a conduction aphasia persisting after the acute global aphasia resolved. Although two patients interpreted as left hemisphere language dominant were mute following right hemisphere injection, all language functions were intact immediately upon resumption of vocalization and they showed no other signs of aphasia such as paraphasias or anomia. Possible explanations for serial language recovery and persistent conduction aphasia are discussed. These findings have significant implications for the determination of cerebral language dominance.

Information processing during general anesthesia: evidence for unconscious memory

Memory for words presented during general anesthesia was studied in two experiments. In Experiment 1, surgical patients (n = 80) undergoing elective procedures under general anesthesia were presented shortly before and during surgery with words via headphones. At the earliest convenient time after surgery (within 5 h) and 24 h later, memory was tested by asking patients to complete auditorily presented word stems with the first word that came to mind and to leave out words they remembered having heard earlier (exclusion task). Moreover, patients were requested to perform a "yes/no" forced-choice recognition task to assess recognition memory for both the pre- and intraoperative words. Memory for the material presented during anesthesia was demonstrated immediately after surgery and 24 h later by means of both tasks. In a second similar experiment (n = 80), the results were replicated. These findings show that anesthetized patients can process information that was presented intraoperatively.

Auditory event-related potentials, auditory digit span, and clinical symptoms in chronic schizophrenic men on neuroleptic medication

The aim of this study was to test predictions based on Grossberg's theories of overarousal in neural networks as related to schizophrenic symptomatology. We predicted that symptoms of blunted affect and volition would be associated with reduced P300 amplitude, while impaired attention and short-term memory and symptoms of disorganization would be associated with increased N200 and P300 latency. Event-related potentials, elicited by auditory stimuli, were recorded in 20 chronic schizophrenic men on neuroleptic medication and an age- and sex-matched control group of 20 normal volunteers. The amplitude and latency values of the N200 and P300 waves at the vertex (Cz) were compared with clinical ratings (the Scale for the Assessment of Positive Symptoms and the Scale for the Assessment of Negative Symptoms) and with neuropsychological test scores by means of Spearman rank correlation coefficient. The patients showed a reduced P300 amplitude and an increased N200 latency. No correlation was found between the P300 amplitude and the symptom scores. The N200 latency was negatively correlated with auditory digit span and positively correlated with high global scores for attentional impairment, alogia, and positive formal thought disorder. Our initial predictions are partly confirmed by the apparent association between increased N200 latency and symptoms of disorganization.

Auditory sustained attention in schizophrenia: a comparison of the Continuous Performance Test and the Pigache Attention Task

An auditory version of the Continuous Performance Test (CPT) was compared with the Pigache Attention Task (PAT) to evaluate relative sensitivities in schizophrenia. Digits spoken seamlessly for 5 min required a button-press response to each of 50 targets. Diotic and dichotic event rates were 1/s for the CPT and 0.5/s and 2/s for the PAT. 'Correct' responses were restricted to the interstimulus interval (CPT) or to longer intervals (PAT). This study demonstrated that the CPT method of scoring is invalid since significant numbers of late responses counted as both omission and commission errors. The CPT was significantly easier than the PAT, which provided a more appropriate range of difficulty. The PAT again discriminated between healthy subjects and schizophrenic patients.

Bromocriptine treatment of nonfluent aphasia

Using a double-blind, placebo-controlled, crossover design, we studied the effect of bromocriptine (15 mg daily) in 20 men with chronic nonfluent aphasia. The study was conducted over a 28-week period in two phases. In phase I, the patients received either bromocriptine or placebo; in phase II the treatments were crossed over. We evaluated each patient's language and nonverbal cognitive skills at the beginning and end of each phase and 6 weeks after completion of phase II. When compared with placebo treatment, bromocriptine did not significantly improve the patient's speech fluency, language content, overall degree of aphasia severity, or nonverbal cognitive abilities. Based on these results, bromocriptine is not recommended as monotherapy for the treatment of chronic nonfluent aphasia.

Implicit memory for stimuli presented during inhalation anesthesia in children

During general inhalation anesthesia, neutral phrases including either the color blue or yellow combined with one of two objects, ball or kite, were repeatedly presented to 36 children undergoing eye surgery. Postoperative testing with a coloring and two-choice task was performed to detect preferences for the colors and objects presented under anesthesia. No preference attributable to implicit memory could be demonstrated, and there was no explicit recollection of intraoperative events. Memory of intraoperative events occurring during inhalation anesthesia was not demonstrated with the present methodology in young children.

Language comprehension in schizophrenia: trait or state indicator?

Language comprehension, measured by the Luria-Nebraska Relational Concepts Factor Scale, was evaluated twice in 15 male DSM-III-R schizophrenic patients during a controlled double-blind haloperidol maintenance (without anticholinergics) and placebo replacement protocol. Fifteen male normal controls were tested once. Patients and controls were matched on age and education. Language comprehension was significantly reduced in patients under both pharmacologic conditions, as compared with controls. Patients' comprehension accuracy did not differ significantly between neuroleptic-treatment and placebo replacement conditions. Patients' comprehension accuracy was independent of positive symptoms, anxiety-depression, measures of clinical course, and CSF and plasma monoamines. Comprehension accuracy was also not associated with patients' educational level or WAIS-R measures of their intellectual and short-term memory functioning. Patients' comprehension performance was significantly associated only with the negative symptom anhedonia-asociality during haloperidol maintenance. Thus, language comprehension in schizophrenic patients was independent of changes in pharmacologic treatment and the positive symptoms of psychosis. Results suggest language comprehension may represent a stable or trait characteristic in schizophrenia.

Auditory cerebral lateralization following cross-gender hormone therapy

In this study, 10 men, 10 women, and 13 genetic male transsexuals, all of them righthanded, were tested on two verbal (CV and nonsense polysyllables) and two nonverbal (melodies and triple tone [3T]) dichotic tasks to investigate relations between hormone therapy and auditory cerebral specialization for speech and non speech stimuli in adults. At time of testing, all transsexuals had been made under hormonal treatment for at least one year and eight had had corrective surgery. ANOVA results showed a right ear advantage and similar pattern of performance for the three groups in the treatment of speech. In nonverbal tasks, interactions revealed a left ear advantage in the processing of melodies and 3T for men only: women and transsexuals exhibited similar performance in both nonverbal tasks. In accord with generalization from the animal literature, cautious interpretation of the data is some possible hormonal involvement, in adults, in the modulation of right hemispheric cognitive processing.

Distraction does not impair memory during intoxication: support for the attention-allocation model

OBJECTIVE

This study was developed to offer direct support for the Josephs and Steele attention-allocation model. The model suggests that alcohol consumption limits attentional resources to the most salient environmental cue.

METHOD

Forty men participated in a study designed to test the model using measures of memory and attention during ethanol intoxication. Twenty completed memory tests in the presence of a background distractor and 20 completed the tests without a distractor, in two sessions: once while intoxicated (80 mg/dl BAC) and once while sober.

RESULTS

A significant Distraction x Intoxication interaction indicated that ethanol-related differences in recall occurred only in the absence of distraction. Distraction impaired subjects only when they were sober.

CONCLUSIONS

Results support the Josephs and Steele attention-allocation model. Findings are discussed in broad terms of an individual's cognitive capabilities when intoxicated and in terms of risk for later alcoholism.