Binge drinking, sensible drinking, and abstinence after alcohol-related vehicular crashes: the role of intervention versus screening.

Brief interventions have been shown to reduce problem drinking in a variety of populations and settings. The hypothesis for our randomized trial was that individuals injured in alcohol-related crashes who received a more intensive intervention (brief counseling) would have reduced binge drinking as compared to those with a less intensive intervention (simple advice) and controls. Non-alcohol dependent, seriously injured individuals (N = 186) were enrolled in the protocol. At baseline, mean binges/month (b/m) were 5.88 and at 12 months were 2.02 b/m. Although there was no significant difference by condition, at 12 months the brief counseling group had the lowest rate of binge drinking (1.97 b/m). Whether these drinking patterns were a result of the crash, injury, screening for alcohol use, or combination of these factors is difficult to determine.

Validity of self-reported alcohol consumption in nondependent drinkers with unintentional injuries.

BACKGROUND: Self-report has become an anchor for alcohol assessment in the acute and primary care populations. The purpose of the study was to determine the validity of self-reported alcohol consumption after unintentional injuries in hospitalized, nondependent drinkers. METHODS: Non-alcohol-dependent subjects 18 years of age and older with unintentional injuries (n = 209) were enrolled in the study and were interviewed if they had either an admitting blood alcohol concentration (BAC) > or = 10 mg/dl (0.01 g/dl) or a positive screen for a history of problem drinking. The self-reported number of standard drinks, time that drinking commenced, sex, and weight were used to calculate estimated blood alcohol concentration (EBAC), which was then compared to the admission BAC. RESULTS: We had data to calculate the EBAC on 141 of the 209 subjects. Seven men and no women with positive (> or = 10 mg/dl) BAC denied drinking. Of the 134 subjects for whom we had data to calculate EBAC and who acknowledged drinking, mean BAC was 147.06 mg/dl and mean EBAC was 68.66 mg/dl. For women (n = 30), mean BAC was 149.53 mg/dl and mean EBAC was 114.67 mg/dl; for men (n = 104), mean BAC was 146.35 mg/dl and mean EBAC was 55.38 mg/dl. The Spearman's p between laboratory BAC and EBAC was 0.461 (p < 0.001) for all subjects (n = 134), 0.275 (NS) for women (n = 30), and 0.532 (p < 0.001) for men (n = 104). For women and men separately, multiple regression analyses were performed to predict BAC by using weight and reported number of drinks. For women, weight and number of drinks accounted for 3% of the variance in laboratory BAC [r = 0.181, F(2,47) = 0.797,p = NS]. In contrast, for men these same predictors accounted for 34% of the variance [r = 0.585, F(2,135) = 35.203,p < 0.001). CONCLUSIONS: Most nondependent patients with unintentional injury acknowledged drinking before injury. After injury, women and men have different patterns of reporting their drinking, with men more frequently underreporting but reporting more accurately and women more random in their self-reports.

Attribution of injury to alcohol involvement in young adults seriously injured in alcohol-related motor vehicle crashes.

BACKGROUND: Approximately 40% of all traffic fatalities are associated with the use of alcohol. Hospitalization for serious injury after a motor vehicle crash related to use of alcohol may be an opportunity to change drinking behaviors in non-alcohol-dependent drinkers, thereby reducing the risk for future disability and death. OBJECTIVES: To determine the degree to which non-alcohol-dependent adults aged 18 to 45 years with alcohol-related vehicular trauma attributed their injury to use of alcohol. METHODS: During hospitalization, 132 subjects involved in alcohol-related motor vehicle crashes were interviewed. The interviews included the question, "To what extent do you believe your alcohol consumption was responsible for this injury?" Responses were measured on a 7-point scale ranging from 1 (not at all) to 7 (totally). RESULTS: In response to the question about attribution of injury to alcohol, 37.8% of subjects responded "not at all," 24.3 responded "somewhat," and 37.9% responded "mostly" or "totally." Spearman rank correlation between attribution of injury to alcohol involvement and blood alcohol content at admission was r = 0.440 (P < .001). CONCLUSIONS: More than 60% of patients injured in alcohol-related motor vehicle crashes attributed their injury partly or totally to use of alcohol. When alcohol-free, hospitalized patients with higher blood levels of alcohol on admission were more likely than those with lower levels to attribute their injury to alcohol. Hospitalization for a motor vehicle crash related to use of alcohol provides an opportunity for interventions to decrease drinking.

The effects of talker familiarity on spoken word identification in younger and older listeners.

The present study was designed to examine age differences in the ability to use voice information acquired intentionally (Experiment 1) or incidentally (Experiment 2) as an aid to spoken word identification. Following both implicit and explicit voice learning, participants were asked to identify novel words spoken either by familiar talkers (ones they had been exposed to in the training phase) or by 4 unfamiliar voices. In both experiments, explicit memory for talkers' voices was significantly lower in older than in young listeners. Despite this age-related decline in voice recognition, however, older adults exhibited equivalent, and in some cases greater, benefit than young listeners from having words spoken by familiar talkers. Implications of the findings for age-related changes in explicit versus implicit memory systems are discussed.

Age differences in backward masking.

The present study was designed to assess the effects of age on the time course of backward masking. In experiment 1, thresholds for detecting a 10-ms, 500-Hz sinusoidal signal were measured as a function of the temporal separation between the signal and a 50-ms broadband masker. Subjects were younger (18-24) and older (over age 65) adults with normal hearing (thresholds less than 20 dB HL) for frequencies of 4 kHz and below. Younger subjects exhibited less overall masking and steeper recovery functions than did the older adults. Masked thresholds for younger participants approached unmasked thresholds for signal-masker delays greater than 6-8 ms. In contrast, older adults exhibited significant masking even at the longest delay tested (20 ms). In experiment 2, signal duration was decreased to 5 ms for a separate group of younger adults. Although overall thresholds were elevated for the shorter signal duration, the slope of the backward masking recovery function was not different from that observed for younger adults in experiment 1. The results suggest that age, independent of hearing loss, affects the temporal course of backward masking.

Perceptual specificity and implicit auditory priming in older and younger adults.

Age differences in perceptual specificity for implicit auditory priming were examined in 3 experiments. All 3 experiments began with a study phase during which participants rated words based on perceptual (shallow encoding) or semantic (deep encoding) attributes. After the study phase, participants were asked to identify filtered versions of repeated and new words (implicit test) and then to make old/new recognition judgments (explicit test). In contrast to earlier findings (D. L. Schacter, B. Church, & D. M. Osowiecki, 1994), older and younger adults were equally sensitive to study-to-test changes in speaking rate (Experiment 1), fundamental frequency (Experiment 2), and voice (Experiment 3). Explicit memory, in contrast, was significantly poorer for older adults but was minimally affected by changes in surface features. Findings from the study are discussed with respect to their implications for establishing the mechanisms mediating perceptual specificity and for their importance in understanding age-related changes in implicit memory.

Inhibitory processes and spoken word recognition in young and older adults: the interaction of lexical competition and semantic context.

Two experiments were conducted to examine the importance of inhibitory abilities and semantic context to spoken word recognition in older and young adults. In Experiment 1, identification scores were obtained in 3 contexts: single words, low-predictability sentences, and high-predictability sentences. Additionally, identification performance was examined as a function of neighborhood density (number of items phonetically similar to a target word). Older adults had greater difficulty than young adults recognizing words with many neighbors (hard words). However, older adults also exhibited greater benefits as a result of adding contextual information. Individual differences in inhibitory abilities contributed significantly to recognition performance for lexically hard words but not for lexically easy words. The roles of inhibitory abilities and linguistic knowledge in explaining age-related impairments in spoken word recognition are discussed.

Foundations of genetics: genetic structure, function, and therapeutics.

Molecular genetics provides the basis for understanding patterns of health and disease in people and is part of the scientific foundation on which acute and critical care nurses should build their practice. The human genome, defined as all the genetic information in the cells of humans, provides the blueprint for protein production and cellular function in the body. Alterations in protein production may result in illness or organ malfunction that has a genetic derivation. One therapeutic strategy that holds promise to manage genetic diseases is gene therapy. Gene therapy, or human gene transfer, occurs when scientists or physicians modify the genetic material in cells for therapeutic purposes. Genetic structure, function, and therapeutic reflect the science of the present and future and have profound practice implications for acute and critical care nurses.

Molecular genetics: from bench to bedside.

Diligent work performed at the laboratory bench during the 20th century has resulted in advances in the health care industry and benefits for the patients it serves. Time-saving laboratory techniques such as DNA isolation and polymerase chain reaction (PCR) have helped molecular biologists and geneticists learn more about genes and their function. Information resulting from genetic research is currently used by medical researchers to develop genetic testing, genetic engineering, and gene therapy procedures that will benefit patients with genetic needs. This article provides basic information regarding several of these procedures, including DNA isolation, PCR, gel electrophoresis, and restriction enzyme techniques. In addition, the article explores the experiences of a clinical nurse, who by learning genetic laboratory techniques, developed an appreciation of the nursing implications related to genetic laboratory procedures.

Brief intervention after alcohol-related injuries.

Brief intervention is a clinically-based, cost effective, time efficient intervention designed to counsel nondependent drinkers about strategies to reduce their alcohol consumption. The ultimate goal of brief intervention is to prevent future alcohol-related injury and health problems. This focused and time limited intervention is designed for use by health care providers in their ongoing daily practice. Patients who recently experienced an alcohol-related injury are particularly receptive to brief intervention.

Auditory suppression and frequency selectivity in older and younger adults.

Age differences in auditory suppression were examined by comparing auditory-filter shapes obtained with simultaneous and forward masking at 2 kHz in young and elderly normal-hearing listeners. To compensate for the decay of forward masking, growth of masking functions were used to transform thresholds obtained with a notched-noise masker to the level of a continuous noise band that would give the same threshold values. Although both age groups exhibited smaller equivalent rectangular bandwidths (ERBs) when the filters derived from transformed thresholds were obtained with forward masking, the change from simultaneous to nonsimultaneous masking was significantly greater for young adults. Measures of the low- (Pl) and high- (Pu) frequency sides of the filters for young listeners indicated that the slopes of both sides increased following a change from simultaneous to forward masking but that the high-frequency side exhibited significantly greater sharpening. Filter slopes (both upper and lower) for older adults, in contrast, did not differ between the two masking procedures. The findings from the study are discussed as reflecting possible age differences in auditory suppression. However, it is also noted that conclusions regarding differences between filter shapes derived with simultaneous and forward masking are limited to filter parameters determined with transformed (as described above) thresholds.

Spoken word recognition in individuals with dementia of the Alzheimer's type: changes in talker normalization and lexical discrimination.

Four experiments were conducted to examine the effects of dementia of the Alzheimer's type (DAT) on talker normalization and lexical discrimination. Talker normalization has been proposed as the principal mechanism underlying listeners' ability to maintain perceptual constancy for speech signals. Lexical discrimination refers to the ability to distinguish individual words from phonetically similar items stored in the mental lexicon. Healthy older adults served as controls. Comparisons of controls and very mildly impaired patients with DAT revealed no significant change in either lexical discrimination or talker normalization. In contrast, individuals with more advanced DAT (mildly demented) exhibited significant declines in both abilities. The results are discussed with respect to the possible roles of general slowing and inhibitory declines as factors affecting speech perception in DAT.

Speech perception in older adults: the importance of speech-specific cognitive abilities.

OBJECTIVE: To provide a critical evaluation of studies examining the contribution of changes in language-specific cognitive abilities to the speech perception difficulties of older adults. DESIGN: A review of the literature on aging and speech perception. CONCLUSIONS: The research considered in the present review suggests that age-related changes in absolute sensitivity is the principal factor affecting older listeners' speech perception in quiet. However, under less favorable listening conditions, changes in a number of speech-specific cognitive abilities can also affect spoken language processing in older people. Clinically, these findings suggest that hearing aids, which have been the traditional treatment for improving speech perception in older adults, are likely to offer considerable benefit in quiet listening situations because the amplification they provide can serve to compensate for age-related hearing losses. However, such devices may be less beneficial in more natural environments, (e.g., noisy backgrounds, multiple talkers, reverberant rooms) because they are less effective for improving speech perception difficulties that result from age-related cognitive declines. It is suggested that an integrative approach to designing test batteries that can assess both sensory and cognitive abilities needed for processing spoken language offers the most promising approach for developing therapeutic interventions to improve speech perception in older adults.

Some considerations in evaluating spoken word recognition by normal-hearing, noise-masked normal-hearing, and cochlear implant listeners. I: The effects of response format.

OBJECTIVE: The purpose of the present studies was to assess the validity of using closed-set response formats to measure two cognitive processes essential for recognizing spoken words---perceptual normalization (the ability to accommodate acoustic-phonetic variability) and lexical discrimination (the ability to isolate words in the mental lexicon). In addition, the experiments were designed to examine the effects of response format on evaluation of these two abilities in normal-hearing (NH), noise-masked normal-hearing (NMNH), and cochlear implant (CI) subject populations. DESIGN: The speech recognition performance of NH, NMNH, and CI listeners was measured using both open- and closed-set response formats under a number of experimental conditions. To assess talker normalization abilities, identification scores for words produced by a single talker were compared with recognition performance for items produced by multiple talkers. To examine lexical discrimination, performance for words that are phonetically similar to many other words (hard words) was compared with scores for items with few phonetically similar competitors (easy words). RESULTS: Open-set word identification for all subjects was significantly poorer when stimuli were produced in lists with multiple talkers compared with conditions in which all of the words were spoken by a single talker. Open-set word recognition also was better for lexically easy compared with lexically hard words. Closed-set tests, in contrast, failed to reveal the effects of either talker variability or lexical difficulty even when the response alternatives provided were systematically selected to maximize confusability with target items. CONCLUSIONS: These findings suggest that, although closed-set tests may provide important information for clinical assessment of speech perception, they may not adequately evaluate a number of cognitive processes that are necessary for recognizing spoken words. The parallel results obtained across all subject groups indicate that NH, NMNH, and CI listeners engage similar perceptual operations to identify spoken words. Implications of these findings for the design of new test batteries that can provide comprehensive evaluations of the individual capacities needed for processing spoken language are discussed.

Stimulus variability and spoken word recognition. II. The effects of age and hearing impairment.

Three experiments were conducted to investigate the effects of variations in talker characteristics, speaking rate, and overall amplitude on perceptual identification in normal-hearing young (NHY), normal-hearing elderly (NHE), and hearing-impaired elderly (HIE) listeners. The three dimensions were selected because variations in voice characteristics and speaking rate affect features of speech signals that are important for word recognition while overall amplitude changes do not alter stimulus parameters that have direct effects on phonetic identification. Thus, the studies were designed to examine how variations in both phonetically relevant and irrelevant stimulus dimensions affect speech processing in a number of different populations. Age differences, as indicated by greater effects of variability for the NHE compared with the NHY listeners, were observed for mixed-talker and mixed-amplitude word lists. Effects of age-related hearing impairment, as indicated by reduced scores for the HIE compared with the NHE group, were observed for variations in speaking rate and talker characteristics. Considered together, the findings suggest that age-related changes in perceptual normalization and selective attention may contribute to the reduced speech understanding that is often reported for older adults.

The structural organization of the mental lexicon and its contribution to age-related declines in spoken-word recognition.

Three experiments were conducted within the framework of the Neighborhood Activation Model of spoken-word recognition to study how the structural organization of the mental lexicon may contribute to age-related declines in spoken-language processing. Experiment 1 showed that the number and frequency of words that are phonetically similar to a target word had differential effects on perceptual identification in older and younger adults, with older adults being particularly disadvantaged in identifying hard words (words phonetically similar to many other high-frequency words). Experiment 2 showed that age-related deficits in the ability to identify hard words remained under conditions in which performance for a set of easy words (items phonetically similar to relatively few other low-frequency words) was the same for older and younger adults. In Experiment 3, reducing the resources available for identification by changing from single to multiple talkers reduced word recognition more among older than younger adults. Diminished cognitive resources, impaired inhibitory control, and increased general slowing are discussed as explanations for the results.

Modeling formant frequency discrimination of female vowels.

The present investigations were designed to establish the features of vowel spectra that mediate formant frequency discrimination. Thresholds for detecting frequency shifts in the first and second formants of two steady-state vowels were initially measured for conditions in which the amplitudes of all harmonics varied in accordance with a model of cascade formant synthesis. In this model, changes in formant frequency produce level variations in components adjacent to the altered formant as well as in harmonics spectrally remote from the shifted resonant frequency. Discrimination thresholds determined with the cascade synthesis procedure were then compared to difference limens (DLs) obtained when the number of harmonics exhibiting level changes was limited to the frequency region surrounding the altered formant. Results indicated that amplitude variations could be restricted to one to three components near the shifted formant before significant increases in formant frequency DLs were observed. In a second experiment, harmonics remote from the shifted formant were removed from the stimuli. In most cases, thresholds for these reduced-harmonic complexes were not significantly different from those obtained with full-spectrum vowels. Preliminary evaluation of an excitation-pattern model of formant frequency discrimination indicated that such a model can provide good accounts of the thresholds obtained in the present experiments once the salient regions of the vowel spectra have been identified. Implications of these findings for understanding the mechanism mediating vowel perception are discussed.

Effects of stimulus variability on perception and representation of spoken words in memory.

A series of experiments was conducted to investigate the effects of stimulus variability on the memory representations for spoken words. A serial recall task was used to study the effects of changes in speaking rate, talker variability, and overall amplitude on the initial encoding, rehearsal, and recall of lists of spoken words. Interstimulus interval (ISI) was manipulated to determine the time course and nature of processing. The results indicated that at short ISIs, variations in both talker and speaking rate imposed a processing cost that was reflected in poorer serial recall for the primary portion of word lists. At longer ISIs, however, variation in talker characteristics resulted in improved recall in initial list positions, whereas variation in speaking rate had no effect on recall performance. Amplitude variability had no effect on serial recall across all ISIs. Taken together, these results suggest that encoding of stimulus dimensions such as talker characteristics, speaking rate, and overall amplitude may be the result of distinct perceptual operations. The effects of these sources of stimulus variability in speech are discussed with regard to perceptual saliency, processing demands, and memory representation for spoken words.

New directions for assessing speech perception in persons with sensory aids.

This study examined the influence of stimulus variability and lexical difficulty on the speech perception performance of adults who used either multichannel cochlear implants or conventional hearing aids. The effects of stimulus variability were examined by comparing word identification in single-talker versus multiple-talker conditions. Lexical effects were assessed by comparing recognition of "easy" words (ie, words that occur frequently and have few phonemically similar words, or neighbors) with "hard" words (ie, words with the opposite lexical characteristics). Word recognition performance was assessed in either closed- or open-set response formats. The results demonstrated that both stimulus variability and lexical difficulty influenced word recognition performance. Identification scores were poorer in the multiple-talker than in the single-talker conditions. Also, scores for lexically "easy" items were better than those for "hard" items. The effects of stimulus variability were not evident when a closed-set response format was employed.