Effects of Age and Acute Moderate Alcohol Administration on Neurophysiology During Simulated Driving

How do drunk-driving events escalate into drunk-driving crashes? An empirical analysis of Beijing from a spatiotemporal perspective

Drunk-driving events often escalate into drunk-driving crashes, however, the contributing factors of this progression remain elusive. To mitigate the likelihood of crashes stemming from drunk-driving events, this paper introduces the notion of 'the severity of drunk-driving event' and examines the complex relationship between the severity and its contributing factors, considering spatiotemporal heterogeneity. The study utilizes a Geographically and Temporally Weighted Binary Logistic Regression (GTWBLR) model to conduct spatiotemporal analysis based on police-reported drunk-driving events in Beijing, China. The results show that most factors passed the non-stationary test, indicating their effects on the severity of drunk-driving event vary significantly across different spatial and temporal domains. Notably, during non-workday, drunk-driving events in northeast of Beijing are more likely to escalate into crashes. Furthermore, severe weather during winter in the northwest of Beijing is associated with high risk of drunk-driving crashes. Based on these insights, the authorities can strengthen drunk-driving checks in the northeast region of Beijing, particularly during non-workdays. And it is crucial to promptly clear accumulated snow on the roads during severe winter weather to improve road safety. These insights and recommendations are highly valuable for reducing the risk of drunk-driving crashes.

WOMEN'S USE OF ALCOHOL: NEUROBIOBEHAVIORAL CONCOMITANTS AND CONSEQUENCES

In this narrative review, we draw from historical and contemporary literature to explore the impact of alcohol consumption on brain and behavior among women. We examine three domains: 1) the impact of alcohol use disorder (AUD) on neurobiobehavioral outcomes, 2) its impact on social cognition/emotion processing, and 3) alcohol's acute effects in older women. There is compelling evidence of alcohol-related compromise in neuropsychological function, neural activation, and brain structure. Investigations of social cognition and alcohol effects in older women represent emerging areas of study. Initial analyses suggest that women with AUD show significant deficits in emotion processing, a finding also observed in older women who have consumed a moderate dose of alcohol. Critically, despite the long-recognized need for programmatic interrogation of alcohol's effect in women, studies with sufficient numbers of women for meaningful analysis represent a small proportion of the literature, constraining interpretation and generalization.

Aging in nucleus accumbens and its impact on alcohol use disorders

Ethanol is one of the most widely consumed drugs in the world and prolonged excessive ethanol intake might lead to alcohol use disorders (AUDs), which are characterized by neuroadaptations in different brain regions, such as in the reward circuitry. In addition, the global population is aging, and it appears that they are increasing their ethanol consumption. Although research involving the effects of alcohol in aging subjects is limited, differential effects have been described. For example, studies in human subjects show that older adults perform worse in tests assessing working memory, attention, and cognition as compared to younger adults. Interestingly, in the field of the neurobiological basis of ethanol actions, there is a significant dichotomy between what we know about the effects of ethanol on neurochemical targets in young animals and how it might affect them in the aging brain. To be able to understand the distinct effects of ethanol in the aging brain, the following questions need to be answered: (1) How does physiological aging impact the function of an ethanol-relevant region (e.g., the nucleus accumbens)? and (2) How does ethanol affect these neurobiological systems in the aged brain? This review discusses the available data to try to understand how aging affects the nucleus accumbens (nAc) and its neurochemical response to alcohol. The data show that there is little information on the effects of ethanol in aged mice and rats, and that many studies had considered 2-3-month-old mice as adults, which needs to be reconsidered since more recent literature defines 6 months as young adults and >18 months as an older mouse. Considering the actual relevance of an aged worldwide population and that this segment is drinking more frequently, it appears at least reasonable to explore how ethanol affects the brain in adult and aged models.

Acute Tolerance to the Analgesic Effects of Alcohol

OBJECTIVE

The goal of this study was to determine whether the acute analgesic effects of alcohol intake are moderated by acute alcohol tolerance, characterized by differing subjective and neurobehavioral effects of a given blood alcohol concentration (BAC) depending on whether BAC is rising or falling.

METHOD

Twenty-nine healthy drinkers (20 women) completed two laboratory sessions in which they consumed a study beverage: active alcohol (target BAC= .08 g/dl) and placebo. Acute alcohol tolerance was assessed by examining the main and interactive effects of beverage condition and assessment limb (ascending vs. descending) on quantitative sensory testing measures collected using slowly ramping heat stimuli and perceived relief ratings at comparable breath alcohol concentrations on the ascending and descending limbs.

RESULTS

BAC limb moderated the effect of condition on pain threshold, such that the threshold was significantly elevated in the alcohol condition on the ascending limb. The alcohol condition produced greater ratings of perceived pain relief than the placebo condition, and pain relief ratings were greater on the ascending versus descending limb of the BAC curve. Alcohol intake did not significantly affect pain tolerance or aftersensation ratings on either BAC limb.

CONCLUSIONS

This study provides initial experimental evidence that alcohol's analgesic and pain-relieving effects are subject to acute tolerance following acute alcohol intake. These findings suggest that self-medicating pain via alcohol intake may be associated with high-risk drinking topography, increasing the risk for alcohol-related consequences. Further research is needed to determine if these effects extend to the context of clinical and chronic pain.

Acute Tolerance to the Analgesic Effects of Alcohol

OBJECTIVE

The goal of this study was to determine whether the acute analgesic effects of alcohol intake are moderated by acute alcohol tolerance, characterized by differing subjective and neurobehavioral effects of a given blood alcohol concentration (BAC) depending on whether BAC is rising or falling.

METHOD

Twenty-nine healthy drinkers (20 women) completed two laboratory sessions in which they consumed a study beverage: active alcohol (target BAC= .08 g/dl) and placebo. Acute alcohol tolerance was assessed by examining the main and interactive effects of beverage condition and assessment limb (ascending vs. descending) on quantitative sensory testing measures collected using slowly ramping heat stimuli and perceived relief ratings at comparable breath alcohol concentrations on the ascending and descending limbs.

RESULTS

BAC limb moderated the effect of condition on pain threshold, such that the threshold was significantly elevated in the alcohol condition on the ascending limb. The alcohol condition produced greater ratings of perceived pain relief than the placebo condition, and pain relief ratings were greater on the ascending versus descending limb of the BAC curve. Alcohol intake did not significantly affect pain tolerance or aftersensation ratings on either BAC limb.

CONCLUSIONS

This study provides initial experimental evidence that alcohol's analgesic and pain-relieving effects are subject to acute tolerance following acute alcohol intake. These findings suggest that self-medicating pain via alcohol intake may be associated with high-risk drinking topography, increasing the risk for alcohol-related consequences. Further research is needed to determine if these effects extend to the context of clinical and chronic pain.

Acute ethanol administration produces larger spatial and nonspatial memory impairments in 29-33 month old rats compared to adult and 18-24 month old rats

The average age of the population in many countries is continuing to increase. Older people continue to consume alcohol, often in a binge like fashion. Previous research has demonstrated that older human subjects and aged animal subjects have an increased sensitivity to the effects of ethanol on a variety of behaviors. However, it has yet to be determined if acute ethanol exposure impairs spatial and/or nonspatial memory to a greater extent in aged rats compared to adult rats. In the current studies we trained male rats ranging in age from young adult (2 months of age) to aged rats (29-33 months of age) in the standard nonspatial task followed by the standard spatial task in the Morris water maze. Only animals deemed "cognitively-spared", that is aged animals that learn as well as young animals, were administered one of two doses of moderate ethanol and had their memory tested 30 min later. Acute ethanol administration produced similar performance impairments in spatial and nonspatial memory in all cognitively-spared animals except for the 29-33 month old animals which showed a significantly greater cognitive impairment in both tasks. In addition, blood ethanol levels were similar across all ages. The present work adds to the growing literature on the selective effects of acute ethanol exposure in aged animals.

Effects of Age and Acute Moderate Alcohol Consumption on Electrophysiological Indices of Attention

OBJECTIVE

Despite increased attention to risks and benefits associated with moderate drinking lifestyles among aging adults, relatively few empirical studies focus on acute alcohol effects in older drinkers. Using electroencephalographic indices of early attention modulation (P1 and N1) and later stimulus processing (P3), we investigated whether acute alcohol consumption at socially relevant doses differentially influences neurocognitive performance in older, relative to younger, moderate drinkers.

METHOD

Younger (25-35 years; n = 97) and older (55-70 years; n = 87) healthy drinkers were randomly assigned to receive one of three alcohol doses (placebo, .04 g/dl, or .065 g/dl target breath alcohol concentrations). Repeated-measures analysis of variance examined the effects of age, alcohol dose concentration, and their potential interaction on P1/P3 amplitudes and N1 latency during completion of a directed attend/ignore task.

RESULTS

Age-specific effects on P1 amplitudes varied by instruction set, with alcohol-associated decreases in amplitude among older drinkers in response to task-relevant stimuli and increases to irrelevant stimuli, F(2, 141) = 2.70, p = .07, ηp2 = .04. In contrast, N1 analyses demonstrated alcohol-related latency reductions among older, relative to younger, adults, F(2, 83) = 3.42, p = .04. Although no Age × Alcohol interactions were detected for P3, main effects indicated dose-dependent amplitude reductions for relevant stimuli, F(2, 144) = 5.73, p < .01, ηp2 = .08.

CONCLUSIONS

Our results underscore the impact of acute moderate alcohol consumption on attentional functioning, highlighting age-dependent sensitivity in electrophysiological indices of early attentional processing. Given the import of attentional functioning to quality of life and increases in drinking among a rapidly expanding aging population, these findings have broad public health relevance.

Clarifying the neurobehavioral sequelae of moderate drinking lifestyles and acute alcohol effects with aging

Epidemiological estimates indicate not only an increase in the proportion of older adults, but also an increase in those who continue moderate alcohol consumption. Substantial literatures have attempted to characterize health benefits/risks of moderate drinking lifestyles. Not uncommonly, reports address outcomes in a single outcome, such as cardiovascular function or cognitive decline, rather than providing a broader overview of systems. In this narrative review, retaining focus on neurobiological considerations, we summarize key findings regarding moderate drinking and three health domains, cardiovascular health, Type 2 diabetes (T2D), and cognition. Interestingly, few investigators have studied bouts of low/moderate doses of alcohol consumption, a pattern consistent with moderate drinking lifestyles. Here, we address both moderate drinking as a lifestyle and as an acute event. Review of health-related correlates illustrates continuing inconsistencies. Although substantive reductions in risk for cardiovascular and T2D events are reported, robust conclusions remain elusive. Similarly, whereas moderate drinking is often associated with enhanced cognition and lower dementia risk, few benefits are noted in rates of decline or alterations in brain structure. The effect of sex/gender varies across health domains and by consumption levels. For example, women appear to differentially benefit from alcohol use in terms of T2D, but experience greater risk when considering aspects of cardiovascular function. Finally, we observe that socially relevant alcohol doses do not consistently impair performance in older adults. Rather, older drinkers demonstrate divergent, but not necessarily detrimental, patterns in neural activation and some behavioral measures relative to younger drinkers. Taken together, the epidemiological and laboratory studies reinforce the need for greater attention to key individual differences and for the conduct of systematic studies sensitive to age-related shifts in neurobiological systems.

I can't drink what I used to: The interaction between ethanol and the aging brain

The population of most countries is increasing and the United Nations predicts that by the year 2050 those over the age of 60 years old will increase from 900 million individuals to approximately 2.1 billion individuals (United Nations, 2015). The increase in the number of older individuals will place a strain on many national health care systems making it important to investigate behaviors in the aged that may negatively impact general health in this demographic. Recent work has shown that older adults consume alcohol, often at levels that exceed the legal limit of intoxication. Unfortunately, consumption of high levels of ethanol in the older population is associated with many health consequences and may negatively impact the brain. Given ethical constraints found in many biomedical studies, animal models are needed to investigate the possible negative impact of high ethanol use in aged populations. However, few studies have investigated the effect of ethanol exposure in aged animals compared to ethanol exposure in younger animals and consequently the impact of ethanol in the aged population is not well understood. The current review summarizes initial work establishing the impact of ethanol in aged animals. The reviewed research studies support the working hypothesis that ethanol exposure produces significantly greater effects in aged animals compared to younger animals on many, if not all, behavioral tasks. In addition, the review proposes several initial, promising avenues of research to explore the neurobiological mechanisms that underly greater effects on ethanol-induced ataxia, cognition and sleep time. It is hoped that this effort will not only lead to a better understanding of behaviors impacted by ethanol in aged animals, but also improve the understanding brain mechanisms of the reported increased sensitivity to ethanol in the aged population.

Drinking patterns and adherence to "low-risk" guidelines among community-residing older adults

BACKGROUND

Older adults constitute a rapidly expanding proportion of the U.S.

POPULATION

Contemporary studies note the increasing prevalence of alcohol consumption in this group. Thus, understanding alcohol effects, consumption patterns, and associated risks in aging populations constitute critical areas of study with increasing public health relevance.

METHODS

Participants (n = 643; 292 women; ages 21-70) were community residing adult volunteers. Primary measures of interest included four patterns of alcohol consumption (average [oz./day]; typical quantity [oz./occasion]; frequency [% drinking days]; and maximal quantity [oz.]). Regression analyses explored associations between these measures, age, and relevant covariates. Subsequent between-group analyses investigated differences between two groups of older adults and a comparator group of younger adults, their adherance to "low-risk" guidelines, and whether alcohol-associated risks differed by age and adherence pattern.

RESULTS

Average consumption did not vary by age or differ between age groups. In contrast, markedly higher frequencies and lower quantities of consumption were observed with increasing age. These differences persisted across adherence categories and were evident even in the oldest age group. Exceeding "low-risk" guidelines was associated with greater risk for alcohol-related problems among the older groups.

CONCLUSIONS

These results emphasize the utility of considering underlying constituent patterns of consumption in older drinkers. Findings highlight difficulties in identifying problem drinking among older adults and contribute to the few characterizations of "risky" drinking patterns in this group. Taken together, our data contribute to literatures of import for the design and enhancement of screening, prevention, and education initiatives directed toward aging adults.

Effects of acute alcohol and driving complexity in older and younger adults

RATIONALE

Our previous work demonstrated differential neurobehavioral effects of low-dose alcohol consumption on older and younger adults in a driving simulator. However, the ability to enhance or suppress a response in such context has yet to be examined.

OBJECTIVES

The current study contrasted older and younger drivers' responses to specific stimuli (i.e., relevant, irrelevant) in scenarios of differing complexity following low-dose acute alcohol administration.

METHODS

Healthy older (55-70) and younger (25-35) adults completed two driving scenarios (i.e., country and metropolis) both before and after consuming beverages targeted to reach peak BrACs of 0.00, 0.04, or 0.065%. Throughout the simulation, participants encountered relevant stimuli (e.g., pedestrians walking into the street) and irrelevant stimuli (e.g., pedestrians walking parallel). Peak deceleration, range of steering, and distance until brake application were assessed within a 450-ft window preceding each stimulus.

RESULTS

Following low-dose alcohol consumption, older adults shifted from a strategy using both deceleration and steering to relying solely on deceleration in responding to relevant stimuli in the country. Older adults under both low and moderate alcohol conditions displayed an inability to withhold responses to irrelevant stimuli in the metropolis.

CONCLUSION

These findings are consistent with our prior work showing differential effects of low-dose alcohol on older, relative to younger, adults. The interactive effects of age and alcohol, however, depend on stimulus type and environmental complexity. Continued investigation of neurobehavioral mechanisms in ecologically valid paradigms is necessary for understanding the implications of the combined impairing effects of alcohol and older age.

A study of at-fault older drivers in light-vehicle crashes in Singapore

A number of studies on motor vehicle crashes have suggested that older drivers are more likely to be at-fault compared to younger drivers. The objective of this paper is to identify factors that contribute to older drivers (aged 65 and above) being at fault in light vehicle crashes in Singapore. Based on 3 years of crash data, the calibrated binary logit model shows that older drivers are more likely to be at fault during peak periods and festive seasons between November to February, as well as at gore areas of expressways, intersections. Curb lanes of multi-lane roads and single-lane roads are also found to increase the odds of older drivers being at fault. Furthermore, older drivers appear to have more problems on roads with wet surfaces and speed limits of 60 km/h and 70 km/h. In the light of an aging population in Singapore, it is imperative that more targeted countermeasures be taken from multiple perspectives to lower such risks.