Brain health in diverse settings: How age, demographics and cognition shape brain function.

Diversity in brain health is influenced by individual differences in demographics and cognition. However, most studies on brain health and diseases have typically controlled for these factors rather than explored their potential to predict brain signals. Here, we assessed the role of individual differences in demographics (age, sex, and education; n = 1298) and cognition (n = 725) as predictors of different metrics usually used in case-control studies. These included power spectrum and aperiodic (1/f slope, knee, offset) metrics, as well as complexity (fractal dimension estimation, permutation entropy, Wiener entropy, spectral structure variability) and connectivity (graph-theoretic mutual information, conditional mutual information, organizational information) from the source space resting-state EEG activity in a diverse sample from the global south and north populations. Brain-phenotype models were computed using EEG metrics reflecting local activity (power spectrum and aperiodic components) and brain dynamics and interactions (complexity and graph-theoretic measures). Electrophysiological brain dynamics were modulated by individual differences despite the varied methods of data acquisition and assessments across multiple centers, indicating that results were unlikely to be accounted for by methodological discrepancies. Variations in brain signals were mainly influenced by age and cognition, while education and sex exhibited less importance. Power spectrum activity and graph-theoretic measures were the most sensitive in capturing individual differences. Older age, poorer cognition, and being male were associated with reduced alpha power, whereas older age and less education were associated with reduced network integration and segregation. Findings suggest that basic individual differences impact core metrics of brain function that are used in standard case-control studies. Considering individual variability and diversity in global settings would contribute to a more tailored understanding of brain function.

Relationship between default mode network and resting-state electroencephalographic alpha rhythms in cognitively unimpaired seniors and patients with dementia due to Alzheimer's disease.

Here we tested the hypothesis of a relationship between the cortical default mode network (DMN) structural integrity and the resting-state electroencephalographic (rsEEG) rhythms in patients with Alzheimer's disease with dementia (ADD). Clinical and instrumental datasets in 45 ADD patients and 40 normal elderly (Nold) persons originated from the PDWAVES Consortium (www.pdwaves.eu). Individual rsEEG delta, theta, alpha, and fixed beta and gamma bands were considered. Freeware platforms served to derive (1) the (gray matter) volume of the DMN, dorsal attention (DAN), and sensorimotor (SMN) cortical networks and (2) the rsEEG cortical eLORETA source activities. We found a significant positive association between the DMN gray matter volume, the rsEEG alpha source activity estimated in the posterior DMN nodes (parietal and posterior cingulate cortex), and the global cognitive status in the Nold and ADD participants. Compared with the Nold, the ADD group showed lower DMN gray matter, lower rsEEG alpha source activity in those nodes, and lower global cognitive status. This effect was not observed in the DAN and SMN. These results suggest that the DMN structural integrity and the rsEEG alpha source activities in the DMN posterior hubs may be related and predict the global cognitive status in ADD and Nold persons.

Resting State Alpha Electroencephalographic Rhythms Are Affected by Sex in Cognitively Unimpaired Seniors and Patients with Alzheimer's Disease and Amnesic Mild Cognitive Impairment: A Retrospective and Exploratory Study.

In the present retrospective and exploratory study, we tested the hypothesis that sex may affect cortical sources of resting state eyes-closed electroencephalographic (rsEEG) rhythms recorded in normal elderly (Nold) seniors and patients with Alzheimer's disease and mild cognitive impairment (ADMCI). Datasets in 69 ADMCI and 57 Nold individuals were taken from an international archive. The rsEEG rhythms were investigated at individual delta, theta, and alpha frequency bands and fixed beta (14-30 Hz) and gamma (30-40 Hz) bands. Each group was stratified into matched females and males. The sex factor affected the magnitude of rsEEG source activities in the Nold seniors. Compared with the males, the females were characterized by greater alpha source activities in all cortical regions. Similarly, the parietal, temporal, and occipital alpha source activities were greater in the ADMCI-females than the males. Notably, the present sex effects did not depend on core genetic (APOE4), neuropathological (Aß42/phospho-tau ratio in the cerebrospinal fluid), structural neurodegenerative and cerebrovascular (MRI) variables characterizing sporadic AD-related processes in ADMCI seniors. These results suggest the sex factor may significantly affect neurophysiological brain neural oscillatory synchronization mechanisms underpinning the generation of dominant rsEEG alpha rhythms to regulate cortical arousal during quiet vigilance.

Food Sovereignty and Health: A Conceptual Framework to Advance Research and Practice.

Settler colonialism disrupted traditional Indigenous foodways and practices and created high rates of diet-related disease among Indigenous peoples. Food sovereignty, the rights of Indigenous peoples to determine their own food systems, is a culturally centered movement rooted in traditional Indigenous knowledge. This approach directly intervenes upon systems-level barriers to health, making it an important strategy for health equity. While food sovereignty initiatives can be found within many Indigenous communities, the conceptual linkages between food sovereignty and health have not been well documented within the public health literature. We present a practice-informed conceptual framework developed as part of the Center for Indigenous Innovation and Health Equity (CIIHE) initiative, a community-academic partnership with the goal of strengthening Indigenous food systems and practices to promote health and well-being. The framework emphasizes connectedness, including the transmission of knowledge across generations and the restoration of relational responsibilities, as central to Indigenous concepts of health and wellness.

Food Systems, Food Sovereignty, and Health: Conference Shares Linkages to Support Indigenous Community Health.

The Center for Indigenous Innovation and Health Equity (CIIHE) at Oklahoma State University Center for Health Sciences (OSU-CHS) is a community-academic partnership with Indigenous peoples from Alaska, Hawai'i, and Oklahoma. The CIIHE supports communities to strengthen traditional food practices and food sovereignty and evaluate the impact of those efforts on health. In February 2022, the CIIHE sponsored and hosted a virtual conference to better understand how food sovereignty initiatives can improve health. More than 600 participants gathered to hear the latest research and practice in the areas of public health and agriculture, nutrition, community-based and Indigenous knowledge, and health economics. Community-led food sovereignty initiatives being implemented as part of the CIIHE were featured along with other Indigenous initiatives in urban, rural, and reservation communities. A survey was administered to conference participants to assess food sovereignty topics and priorities for future research. In this Practice Note, we describe innovative community-led initiatives presented as part of the conference and recommendations for action emerging from qualitative and quantitative data collected from conference participants.

Abnormalities of Cortical Sources of Resting State Alpha Electroencephalographic Rhythms are Related to Education Attainment in Cognitively Unimpaired Seniors and Patients with Alzheimer's Disease and Amnesic Mild Cognitive Impairment.

In normal old (Nold) and Alzheimer's disease (AD) persons, a high cognitive reserve (CR) makes them more resistant and resilient to brain neuropathology and neurodegeneration. Here, we tested whether these effects may affect neurophysiological oscillatory mechanisms generating dominant resting state electroencephalographic (rsEEG) alpha rhythms in Nold and patients with mild cognitive impairment (MCI) due to AD (ADMCI). Data in 60 Nold and 70 ADMCI participants, stratified in higher (Edu+) and lower (Edu-) educational attainment subgroups, were available in an Italian-Turkish archive. The subgroups were matched for age, gender, and education. RsEEG cortical sources were estimated by eLORETA freeware. As compared to the Nold-Edu- subgroup, the Nold-Edu+ subgroup showed greater alpha source activations topographically widespread. On the contrary, in relation to the ADMCI-Edu- subgroup, the ADMCI-Edu+ subgroup displayed lower alpha source activations topographically widespread. Furthermore, the 2 ADMCI subgroups had matched cerebrospinal AD diagnostic biomarkers, brain gray-white matter measures, and neuropsychological scores. The current findings suggest that a high CR may be related to changes in rsEEG alpha rhythms in Nold and ADMCI persons. These changes may underlie neuroprotective effects in Nold seniors and subtend functional compensatory mechanisms unrelated to brain structure alterations in ADMCI patients.

Measures of resting state EEG rhythms for clinical trials in Alzheimer's disease: Recommendations of an expert panel.

The Electrophysiology Professional Interest Area (EPIA) and Global Brain Consortium endorsed recommendations on candidate electroencephalography (EEG) measures for Alzheimer's disease (AD) clinical trials. The Panel reviewed the field literature. As most consistent findings, AD patients with mild cognitive impairment and dementia showed abnormalities in peak frequency, power, and "interrelatedness" at posterior alpha (8-12 Hz) and widespread delta (< 4 Hz) and theta (4-8 Hz) rhythms in relation to disease progression and interventions. The following consensus statements were subscribed: (1) Standardization of instructions to patients, resting state EEG (rsEEG) recording methods, and selection of artifact-free rsEEG periods are needed; (2) power density and "interrelatedness" rsEEG measures (e.g., directed transfer function, phase lag index, linear lagged connectivity, etc.) at delta, theta, and alpha frequency bands may be use for stratification of AD patients and monitoring of disease progression and intervention; and (3) international multisectoral initiatives are mandatory for regulatory purposes.

Understanding Perceptions of Nonsuicidal Self-Injury: Descriptive and Injunctive Norms.

Nonsuicidal self-injury (NSSI) is a major public health concern. Web-based personalized feedback interventions (PFIs) may be a cost-effective and efficient way to treat NSSI. In order to develop a PFI, it is imperative to assess descriptive and injunctive norms. The current study examines descriptive and injunctive norms of NSSI within college students and adults in the community, comparing how perceived norms may differ for those who do or do not engage in NSSI. Study 1 calculated percentages of NSSI behavior within the student sample. Study 2 then examined perceived descriptive and injunctive norms between those with and without history of NSSI in both samples. Study 1 indicated that 19% of undergraduate students had histories of NSSI. Additionally, there was a general tendency to overestimate the percentage of people who engage in NSSI and the number of times a typical person engages in NSSI. Finally, those who engaged in NSSI believed that most people do not understand why individuals engage in NSSI; comparatively, the majority of people without history of NSSI still indicated that they understand why others would engage in NSSI. These research findings may be utilized in a PFI to reduce shame and NSSI behavior.

Electronic cigarette use and sleep health in young adults.

Poor sleep health is associated with numerous health concerns, and sleep problems are exacerbated by cigarette smoking. Although rates of traditional tobacco use are declining, rates of electronic cigarette (e-cigarette) use are comparatively high and growing. Given that nicotine is a primary mechanism by which smoking negatively impacts sleep health, e-cigarette use may also be linked to poor sleep health; however, no research has investigated this association. Participants were 1,664 college students, 40.9% of whom reported ever trying or currently using an e-cigarette. Questionnaires assessed demographic information, sleep health and e-cigarette use status and patterns. All measures were completed remotely via a secure online survey. Analysis of covariance was used to compare the sleep health of daily/non-daily e-cigarette users to (a) non-users and (b) users of combustible cigarettes. Gender and drinks per week were included as covariates in analyses. Current combustible and e-cigarette users reported significantly more sleep difficulties than never users. Users of e-cigarettes reported greater use of sleep medication than combustible cigarette users. Similar to combustible cigarette smoking, e-cigarette use (vs. non-use) was associated with worse sleep health, even among non-daily e-cigarette users. These findings may indicate a need for assessment of and education on the role of e-cigarette use in sleep health among individuals who report experimentation with or current use of e-cigarettes. Future research should examine these relationships prospectively.

Chronic BACE-1 Inhibitor Administration in TASTPM Mice (APP KM670/671NL and PSEN1 M146V Mutation): An EEG Study.

OBJECTIVE: In this exploratory study, we tested whether electroencephalographic (EEG) rhythms may reflect the effects of a chronic administration (4 weeks) of an anti-amyloid ß-site amyloid precursor protein (APP) cleaving enzyme 1 inhibitor (BACE-1; ER-901356; Eisai Co., Ltd., Tokyo, Japan) in TASTPM (double mutation in APP KM670/671NL and PSEN1 M146V) producing Alzheimer's disease (AD) amyloid neuropathology as compared to wild type (WT) mice. METHODS: Ongoing EEG rhythms were recorded from a bipolar frontoparietal and two monopolar frontomedial (prelimbic) and hippocampal channels in 11 WT Vehicle, 10 WT BACE-1, 10 TASTPM Vehicle, and 11 TASTPM BACE-1 mice (males; aged 8/9 months old at the beginning of treatment). Normalized EEG power (density) was compared between the first day (Day 0) and after 4 weeks (Week 4) of the BACE-1 inhibitor (10 mg/Kg) or vehicle administration in the 4 mouse groups. Frequency and magnitude of individual EEG delta and theta frequency peaks (IDF and ITF) were considered during animal conditions of behaviorally passive and active wakefulness. Cognitive status was not tested. RESULTS: Compared with the WT group, the TASTPM group generally showed a significantly lower reactivity in frontoparietal ITF power during the active over the passive condition (p < 0.05). Notably, there was no other statistically significant effect (e.g., additional electrodes, recording time, and BACE-1 inhibitor). CONCLUSIONS: The above EEG biomarkers reflected differences between the WT and TASTPM groups, but no BACE-1 inhibitor effect. The results suggest an enhanced experimental design with the use of younger mice, longer drug administrations, an effective control drug, and neuropathological amyloid markers.

The association between posterior resting-state EEG alpha rhythms and functional MRI connectivity in older adults with subjective memory complaint.

Resting-state eyes-closed electroencephalographic (rsEEG) alpha rhythms are dominant in posterior cortical areas in healthy adults and are abnormal in subjective memory complaint (SMC) persons with Alzheimer's disease amyloidosis. This exploratory study in 161 SMC participants tested the relationships between those rhythms and seed-based resting-state functional magnetic resonance imaging (rs-fMRI) connectivity between thalamus and visual cortical networks as a function of brain amyloid burden, revealed by positron emission tomography and cognitive reserve, measured by educational attainment. The SMC participants were divided into 4 groups according to 2 factors: Education (Edu+ and Edu-) and Amyloid burden (Amy+ and Amy-). There was a statistical interaction (p < 0.05) between the two factors, and the subgroup analysis using estimated marginal means showed a positive association between the mentioned rs-fMRI connectivity and the posterior rsEEG alpha rhythms in the SMC participants with low brain amyloidosis and high CR (Amy-/Edu+). These results suggest that in SMC persons, early Alzheimer's disease amyloidosis may contrast the beneficial effects of cognitive reserve on neurophysiological oscillatory mechanisms at alpha frequencies and connectivity between the thalamus and visual cortical networks.

Resting state electroencephalographic alpha rhythms are sensitive to Alzheimer's disease mild cognitive impairment progression at a 6-month follow-up.

Are posterior resting-state electroencephalographic (rsEEG) alpha rhythms sensitive to the Alzheimer's disease mild cognitive impairment (ADMCI) progression at a 6-month follow-up? Clinical, cerebrospinal, neuroimaging, and rsEEG datasets in 52 ADMCI and 60 Healthy old seniors (equivalent groups for demographic features) were available from an international archive (www.pdwaves.eu). The ADMCI patients were arbitrarily divided into two groups: REACTIVE and UNREACTIVE, based on the reduction (reactivity) in the posterior rsEEG alpha eLORETA source activities from the eyes-closed to eyes-open condition at ≥ -10% and -10%, respectively. 75% of the ADMCI patients were REACTIVE. Compared to the UNREACTIVE group, the REACTIVE group showed (1) less abnormal posterior rsEEG source activity during the eyes-closed condition and (2) a decrease in that activity at the 6-month follow-up. These effects could not be explained by neuroimaging and neuropsychological biomarkers of AD. Such a biomarker might reflect abnormalities in cortical arousal in quiet wakefulness to be used for clinical studies in ADMCI patients using 6-month follow-ups.

Short-term mating orientation as a predictor of alcohol use and risky sexual behavior.

OBJECTIVES: Sexual Strategies Theory suggests people fall on a continuum between having short-term mating orientation (STMO) and long-term mating orientation. One way STMO individuals signal mating goals is via risky drinking. The current study therefore aims to investigate drinks per week (DPW) as a mediator between STMO and risky sexual behavior (RSB), with gender as a moderator between STMO and DPW. PARTICIPANTS: Undergraduate students (N = 300) from a Midwestern university during Fall 2019. METHOD: Participants completed questionnaires assessing STMO, DPW, and RSB frequency. RESULTS: A moderated-mediation model indicated DPW significantly mediated the relationship between STMO and RSB. Positive associations were found among all three variables. Gender was not a moderator between STMO and DPW. CONCLUSIONS: Mating orientation was a correlate of alcohol use and RSB for women and men, contributing to the literature identifying STMO as an indicator of those in need of substance use and RSB intervention.

Cortical sources of electroencephalographic alpha rhythms related to the anticipation and experience of mirror visual feedback-induced illusion of finger movements.

Mirror visual feedback (MVF) technique consists in placing a mirror in a person's body midline to induce the illusion of bilateral synchronous movements of the limbs during actual unilateral movements. A recent electroencephalographical (EEG) study demonstrated that MVF-induced illusion was related to the event-related desynchronization (ERD) of alpha (8-12 Hz) rhythms (cortical activation) at the central and parietal scalp electrodes ipsilateral to the unilateral right finger movements. In the present study, we re-analyzed those data to localize the cortical sources of alpha ERD during the anticipation and experience of the MVF-induced illusion of index finger movements. To this aim, the exact Low-Resolution Brain Electromagnetic Tomography freeware was used for the estimation of the cortical sources of the alpha ERD. Results showed that as compared to the condition without MVF, the MVF condition was characterized by greater (p < .01, uncorrected) alpha ERD sources in right frontopolar areas during the anticipation of the MVF-induced illusion of left movements. The MVF condition was also characterized by greater (p < .05, corrected) alpha ERD sources in right premotor, primary somatomotor, and posterior inferior parietal areas during both the anticipation and experience of that MVF-induced illusion. These findings suggest that the MVF-induced illusory experience of left finger movements may be due to dynamic changes in alpha ERD in associative, premotor, somatomotor, and visuomotor frontal-parietal areas located in the hemisphere contralateral to the mirrored motor acts.

Displacement imposition scale assesses reactions of cigarette and e-cigarette users impacted by a campus-wide smoking ban.

OBJECTIVE: The present study developed a measure assessing the emotional responses, "Displacement Imposition," of cigarette and e-cigarette users on a college campus with a smoking/vaping ban. It also examined the relationship between Displacement Imposition and readiness to quit smoking/vaping, and how this relationship differed between cigarette and e-cigarette users. PARTICIPANTS: Participants (N = 297) were from a large, Midwestern university. METHODS: Participants completed online questionnaires assessing demographics, cigarette and e-cigarette use, Displacement Imposition, and readiness to quit. RESULTS: All six Displacement Imposition items loaded onto a single factor. A significant interaction emerged between Displacement Imposition and product use in predicting readiness to quit. At high levels of Displacement Imposition, cigarette users were less ready to quit than e-cigarette users. CONCLUSIONS: Findings suggest restrictions imposed on cigarette and e-cigarette users were associated with reduced readiness to quit. Findings inform tobacco control policies as tobacco denormalization may increase the burden placed on tobacco users.

An Updated Narrative Review on the Role of Alcohol Among Indigenous Communities.

Purpose of Review: The role of alcohol varies considerably among Indigenous Peoples and is the backdrop of persistent stereotypes despite decades of research. This paper provides an updated narrative review on the alcohol literature among Indigenous communities, highlighting recent studies published since 2017. Recent Findings: We examined published literature involving alcohol use rates, including abstinence; risk and protective factors; treatment; and recovery, as well as future directions for alcohol prevention and intervention efforts with Indigenous communities. Summary: Evidence-based alcohol use prevention, intervention, and recovery strategies with Indigenous communities are outlined. Recommendations are provided for researchers, health providers, and public policy advocates to address and better understand alcohol use, treatment, prevention, and recovery among Indigenous Peoples. Specific recommendations include using community-based participatory research strategies and harm reduction approaches to prevent and treat alcohol use problems with Indigenous communities. Future research is needed to elucidate mechanisms of resilience and recovery from Alcohol Use Disorder and possible shifts in perceptions of alcohol use for Indigenous Peoples.

What a Single Electroencephalographic (EEG) Channel Can Tell us About Alzheimer's Disease Patients With Mild Cognitive Impairment.

Abnormalities in cortical sources of resting-state eyes closed electroencephalographic (rsEEG) rhythms recorded by hospital settings (10-20 montage) with 19 scalp electrodes characterized Alzheimer's disease (AD) from preclinical to dementia stages. An intriguing rsEEG application is the monitoring and evaluation of AD progression in large populations with few electrodes in low-cost devices. Here we evaluated whether the above-mentioned abnormalities can be observed from fewer scalp electrodes in patients with mild cognitive impairment due to AD (ADMCI). Clinical and rsEEG data acquired in hospital settings (10-20 montage) from 75 ADMCI participants and 70 age-, education-, and sex-matched normal elderly controls (Nold) were available in an Italian-Turkish archive (PDWAVES Consortium; www.pdwaves.eu). Standard spectral fast fourier transform (FFT) analysis of rsEEG data for individual delta, theta, and alpha frequency bands was computed from 6 monopolar scalp electrodes to derive bipolar C3-P3, C4-P4, P3-O1, and P4-O2 markers. The ADMCI group showed increased delta and decreased alpha power density at the C3-P3, C4-P4, P3-O1, and P4-O2 bipolar channels compared to the Nold group. Increased theta power density for ADMCI patients was observed only at the C3-P3 bipolar channel. Best classification accuracy between the ADMCI and Nold individuals reached 81% (area under the receiver operating characteristic curve) using Alpha2/Theta power density computed at the C3-P3 bipolar channel. Standard rsEEG power density computed from six posterior bipolar channels characterized ADMCI status. These results may pave the way toward diffuse clinical applications in health monitoring of dementia using low-cost EEG systems with a strict number of electrodes in lower- and middle-income countries.

Patients with Alzheimer's disease dementia show partially preserved parietal 'hubs' modeled from resting-state alpha electroencephalographic rhythms.

Introduction: Graph theory models a network by its nodes (the fundamental unit by which graphs are formed) and connections. 'Degree' hubs reflect node centrality (the connection rate), while 'connector' hubs are those linked to several clusters of nodes (mainly long-range connections). Methods: Here, we compared hubs modeled from measures of interdependencies of between-electrode resting-state eyes-closed electroencephalography (rsEEG) rhythms in normal elderly (Nold) and Alzheimer's disease dementia (ADD) participants. At least 5 min of rsEEG was recorded and analyzed. As ADD is considered a 'network disease' and is typically associated with abnormal rsEEG delta (<4 Hz) and alpha rhythms (8-12 Hz) over associative posterior areas, we tested the hypothesis of abnormal posterior hubs from measures of interdependencies of rsEEG rhythms from delta to gamma bands (2-40 Hz) using eLORETA bivariate and multivariate-directional techniques in ADD participants versus Nold participants. Three different definitions of 'connector' hub were used. Results: Convergent results showed that in both the Nold and ADD groups there were significant parietal 'degree' and 'connector' hubs derived from alpha rhythms. These hubs had a prominent outward 'directionality' in the two groups, but that 'directionality' was lower in ADD participants than in Nold participants. Discussion: In conclusion, independent methodologies and hub definitions suggest that ADD patients may be characterized by low outward 'directionality' of partially preserved parietal 'degree' and 'connector' hubs derived from rsEEG alpha rhythms.

Resting state EEG rhythms in different stages of chronic kidney disease with mild cognitive impairment.

Here, we tested that standard eyes-closed resting-state electroencephalographic (rsEEG) rhythms may characterize patients with mild cognitive impairment due to chronic kidney disease at stages 3-4 (CKDMCI-3&4) in relation to CKDMCI patients under hemodialysis (CKDMCI-H) and mild cognitive impairment (MCI) patients with cerebrovascular disease (CVMCI). Clinical and rsEEG data in 22 CKDMCI-3&4, 15 CKDMCI-H, 18 CVMCI, and 30 matched healthy control (HC) participants were available in a national archive. Spectral rsEEG power density was calculated from delta to gamma frequency bands at scalp electrodes. Results showed that (1) all MCI groups over the HC group showed decreased occipital rsEEG alpha power density; (2) compared to the HC and CVMCI groups, the 2 CKDMCI groups had higher rsEEG delta-theta power density; and (3) the CKDMCI-3&4 group showed the lowest parietal rsEEG alpha power density. The present rsEEG measures may be useful to monitor the impact of circulating uremic toxins on brain regulation of cortical arousal for quiet vigilance in CKDMCI patients.

Social norms of alcohol use among American Indian/Alaska Native college students.

OBJECTIVE: Research on misperceived descriptive and injunctive drinking norms, or normative perceptions of frequency, quantity, and acceptability of drinking, has rarely been extended to American Indian/Alaska Native (AI/AN) college student populations. Ethnic identity, or strength of one's ties to their AI/AN culture, has been hypothesized as a protective factor against problematic alcohol use. As a step toward informing culturally appropriate and gender-specific norms-based interventions for AI/AN students, this study examined differences between perceived and actual descriptive and injunctive drinking norm reference groups (e.g., AI/AN males/females, "typical" males/females), and investigated ethnic identity as a moderator between perceived and actual drinking norms. METHOD: AI/AN college students (N = 356) completed an online survey assessing drinking patterns, descriptive norms, injunctive norms, and ethnic identity. RESULTS: Compared to actual drinking levels, participants overestimated all gender-specific descriptive norm groups and all gender-specific injunctive norm groups except for AI/AN males. Participants estimated lower drinking levels for AI/AN-specific groups than non-AI/AN groups. Descriptive AI/AN male and best male friend norms significantly predicted drinking for men while only best female friend norms predicted drinking for women. Injunctive typical male norms significantly predicted drinking for men, and no injunctive norms predicted drinking for women. Finally, ethnic identity was unrelated to drinking and did not significantly moderate the relation between perceived and actual drinking. CONCLUSIONS: Current findings may inform norms-based alcohol use interventions, as AI/AN-specific reference groups may have a significant impact on drinking among men, but not women. Future culturally relevant alcohol use intervention research for AI/AN young adults is warranted. (PsycInfo Database Record (c) 2022 APA, all rights reserved).