Significant gaps remain in our knowledge of cognitive aging in Hispanic adults, the largest and fastest-growing minority group in the United States (U.S.). Episodic autobiographical memory (EAM), which has well documented age-related differences, has not been directly examined in older U.S. Hispanic adults – a population that is commonly bilingual. This study aimed to examine the effects of Spanish-English bilingualism and aging on EAM among Hispanic adults.

In the present study 100 young and middle-aged/older Hispanic adults (50 English–Spanish bilingual Hispanic participants and 50 monolingual English-speaking Hispanic participants) narrated EAMs in a structured interview. We assessed these narratives for episodic and non-episodic details using an established scoring protocol.

We replicated the commonly observed age-related decrease in episodic detail generation among Hispanic participants, with non-episodic detail not significantly differing between young and older Hispanic participants. Among young Hispanic participants, bilingualism was associated with higher episodic, but not non-episodic, detail generation. This bilingualism advantage for episodic detail, however, was not evident among older Hispanic participants.

These results underscore the complex interplay between bilingualism and age in autobiographical memory for events among Hispanic adults. Our study highlights the importance of including diverse racial/ethnic and linguistic samples in cognitive aging research to better understand how bilingualism and cultural factors influence memory across the lifespan.

We examined cognitive performance in children with complicated mild-severe traumatic brain injury (TBI) versus orthopedic injury (OI) using the National Institutes of Health Toolbox Cognitive Battery (NIH TB-CB).

We recruited children ages 3–18, hospitalized with complicated mild-severe TBI (n = 231) or orthopedic injury (OI, n = 146). Cognition was assessed using the NIH TB-CB at six and twelve months post-injury. We used linear mixed models to assess associations of injury group (TBI versus OI), timepoint (six versus twelve months), and the interaction of injury group and timepoint with NIH TB-CB Total Cognition, Fluid Cognition, and Crystallized Cognition composites, adjusted for sex and socioeconomic status (SES), with Bonferroni correction. We evaluated differences in cognition stratified by injury severity (complicated mild–moderate TBI vs severe TBI) using ANCOVA, adjusting for sex and SES.

Neither injury group nor the interaction of group and timepoint were associated with Total (group: p = 0.50; timepoint*group: p = 0.185), Fluid (group: p = 0.297; timepoint*group: p = 0.842), or Crystallized Cognition (group: p = 0.039; timepoint*group: p = 0.017). However, children with severe TBI performed significantly worse on Fluid and Total Cognition than children with complicated mild–moderate TBI at six months (Fluid: p = 0.004, partial η2 = 0.06, moderate effect, Total: p = 0.012 partial η2 = 0.03, small–moderate effect) and twelve months post-injury (Fluid: p < 0.001, partial η2 = 0.11, moderate–large effect, Total: p = 0.002, partial η2 = 0.06, moderate effect).

The NIH TB-CB detects worse cognitive functioning in children with severe TBI six-twelve months post-injury, largely driven by differences in Fluid Cognition. Our findings suggest the NIH TB-CB may be suitable for monitoring cognition in children with TBI.

Few studies examine the relationship between physical activity, multiple physical fitness domains (cardiorespiratory fitness, strength, speed), and cognition. Our objective was to investigate the association between physical activity and executive function in middle-aged and older adults and examine whether modifiable physical fitness components explain the relationship between physical activity and cognition.

Self-reported moderate-to-vigorous physical activity and objective measures of cardiorespiratory fitness (2-minute walk test), strength (grip strength), speed (4-meter walk test), and executive function were collected from 623 adults within the Human Connectome Project–Aging (ages 36 – 100 years; mean = 59.2 years; 57.8% female). Relative importance metrics, multiple regression, and conditional process analysis were used to examine relationships of age, physical activity, and physical fitness with executive function.

Greater physical fitness was related to better executive function performance (β = 0.28, p < .001). Physical activity was not associated with executive function (β = −0.04, p = .16). There was an indirect relationship between physical activity and executive function through physical fitness (ab = 0.02, 95% CI: 0.004 – 0.04). This association was explained primarily by the indirect association of cardiorespiratory fitness with physical activity and executive function. The indirect association of cardiorespiratory fitness with physical activity and executive function was significant in older study participants (mean (59 years) and + 1 SD (74 years)), but not younger (−1 SD (44 years)), although between-group comparisons were not significant.

These data highlight potential differential associations with cognition when considering physical activity and physical fitness, and the importance of considering multiple domains of physical fitness in relation to physical activity and cognitive performance.

While psychiatric disorders (e.g., depression, anxiety) are well-established predictors of suicidal ideation (SI) in individuals with traumatic brain injury (TBI), the roles of other psychological and cognitive factors remain underexplored. This study examined associations between SI and emotion-processing difficulties, coping strategies, psychological resilience, and cognitive functioning after moderate–severe TBI.

This was a secondary analysis of data from 106 individuals with moderate–severe TBI. SI and emotional distress were assessed using the Inventory of Depression and Anxiety Symptoms and Hospital Anxiety and Depression Scale, respectively. Participants also completed measures of emotional lability and detachment (Comprehensive Assessment of Traits Relevant to Personality Disorders [CAT-PD]), coping (Coping Scale for Adults), psychological resilience (Connor–Davidson Resilience Scale), and cognitive functioning, including subjective (CAT-PD, Brief Rating of Executive Function) and objective measures (Brief Test of Adult Cognition by Telephone). Spearman’s correlations and path models were used to examine psychological and cognitive correlates of SI.

SI was positively associated with emotional lability, emotional detachment, non-productive coping, and self-reported cognitive problems, and negatively associated with resilience. Path models indicated that emotional distress accounted for 76–100% of these associations. Conversely, SI was not significantly associated with adaptive coping or objective cognitive performance.

Emotion-processing difficulties, non-productive coping strategies, low resilience, and self-reported cognitive problems are linked to SI in individuals with moderate–severe TBI, primarily through their associations with emotional distress. Findings underscore the importance of addressing emotional distress, including depression and anxiety, and its underlying contributors in suicide prevention for this population.

This systematic review and meta-analysis aimed to review existing measures of subjective cognition during menopause and to estimate the correlation between subjective and objective cognition in perimenopausal and postmenopausal women.

Eligible studies reported scores for at least one subjective and objective measure of cognition for perimenopausal or postmenopausal women. EMBASE, Medline, and PsycINFO were searched for eligible studies on November 22nd 2024. The risk of bias in individual studies was evaluated using a modified QUADAS-2 form. The results of the review were summarized in narrative form. Studies that reported correlations between subjective and objective cognition were synthesized using a multilevel meta-analysis.

The sample included 5629 participants over 24 studies, including 295 perimenopausal women, 5086 postmenopausal women, and 248 women across mixed peri- and post-menopausal samples. Twelve measures of subjective cognition were used across studies. Six studies were included in the meta-analysis. A small significant correlation was observed between subjective cognition and objective measures of learning efficiency (r = .12; CI = .02 to .23). Correlations across other cognitive domains were non-significant.

Our findings suggest subjective cognition may be associated with performance on measures of learning efficiency, offering a starting point for further research on menopausal brain fog. The present findings highlight the need for a reliable measure of subjective cognitive symptoms associated with menopause. Additionally, a better characterization of the neuropsychological profile of menopausal brain fog is needed to progress research in this field and ultimately improve clinical support for women experiencing these symptoms.

Remote videoconference neuropsychological assessments offer opportunities that remain under-exploited. We aimed to evaluate teleneuropsychology (TeleNP)-suitable oral and digital versions of the Symbol Digit Modalities Task (SDMT) and Trail Making Test (TMT) – widely used measures of speed and attention – by comparing them to their written counterparts.

Three-hundred and twenty-one Australian Epilepsy Project (AEP) adult participants with seizure disorders completed the written SDMT and TMT in-person. One-hundred and forty-four of these participants also completed the oral SDMT and TMT during a remote videoconference-based assessment while 177 completed a novel, examiner-administered digital SDMT analogous measure named Symbol Decoding and a novel digital TMT remotely via custom videoconference-based software.

Oral SDMT and digital Symbol Decoding strongly correlated with in-person written SDMT (r (133) = .77, p < .001 and r (126) = .76, p < .001, respectively). Oral TMT-B was only moderately associated (r (126) = .52, p < .001) with written TMT-B and, less strongly related to measures of sustained attention and spatial working memory than its written counterpart. Digital TMT better reproduced the written test’s properties with improved association with written TMT-B (r (154) = .71, p < .001).

Oral SDMT and digital Symbol Decoding are strongly correlated with in-person written SDMT. The digital TMT better captures the cognitive demands and performance characteristics of the in-person written form than does oral TMT. Videoconference-integrated digital tasks offer increased standardization and automation in administration and scoring and the potential for rich metadata, making them an attractive area for further development.

Healthy sleep contributes to better cognitive functioning in children. This study sought to investigate the role of pre-injury sleep disturbance as a predictor or moderator of cognitive functioning across 6 months post-injury in children with mild traumatic brain injury (mTBI) or orthopedic injury (OI).

Participants were 143 children with mTBI and 74 with OI, aged 8 – 16 years, prospectively recruited from the Emergency Departments of two children’s hospitals in Ohio, USA. Parents rated their children’s pre-injury sleep retrospectively using the Sleep Disorders Inventory for Students. Children completed the National Institutes of Health (NIH) Toolbox Cognition Battery at 10 days and 3 and 6 months post-injury.

Group differences in both overall performance and reaction time on the Flanker Inhibitory Control and Attention Test varied significantly as a function of the level of pre-injury sleep disturbance as well as time since injury. At the 10 day visit, among children with worse pre-injury sleep, mTBI was associated with slower reaction times relative to OI. Among children with worse pre-injury sleep, those with mTBI improved over time while those with OI did not. Main effects of pre-injury sleep and time since injury were found for several other NIH Toolbox subtests, with poorer performance associated with worse pre-injury sleep and early vs. later timepoints.

These results suggest that pre-existing sleep disturbances and mTBI are jointly associated with poorer executive functioning post-injury. Interventions to improve sleep might help mitigate the effects of mTBI on children’s cognitive functioning.

Research indicates that demographic (e.g., age, education) and sociocultural (e.g., acculturation) factors can impact neuropsychological test performance among ethnoculturally diverse adults. Some studies suggest that greater acculturation to the United States (U.S.) is associated with better neurocognitive functioning, though no meta-analysis to date has examined this relationship. This review provides a comprehensive synthesis of the literature and determines the magnitude of the relationship between acculturation and neuropsychological test performance.

A literature search explored all published articles through January 1, 2024, using three databases (i.e., PubMED/MEDLINE, PsycInfo, PsycNET). Data to calculate study effect sizes (i.e., Fisher’s z) were extracted from in-text results, tables, and figures.

Findings (k = 18 included in quantitative analyses) revealed a small to medium (r = 0.29, partial r = 0.20, p < .01), statistically significant relationship between higher U.S. acculturation and better neuropsychological test performance. Moderation analyses indicated that language of testing emerged as a significant moderator, testing in English yielded larger effect sizes compared to testing in other languages (B = 0.29, p < .05).

Neuropsychological test performance is significantly associated with U.S. acculturation, and results suggest that the magnitude may vary depending on study methodologies and samples (e.g., ethnocultural group, U.S. born vs. immigrant) examined. The current review also provides recommendations for incorporating acculturation assessment into clinical practice and highlights the need to examine the clinical utility of acculturation tools in conjunction with neuropsychological tests to assist in clinical decision-making with ethnoculturally diverse populations.

Five-Factor Model (FFM) personality traits are associated with cognitive function, however, biological pathways accounting for these relations are not well understood. Here, we examined associations between individual FFM traits (self- and informant-reported) and cognitive function (episodic memory, executive control, and working memory), and the indirect effect of a latent index of cardiometabolic risk (composed of adiposity, glycemic control, blood pressure, blood lipids, and inflammation) in a midlife sample.

Participants included 856 volunteers (M = 44.6 ± 6.9 years, range: 30 – 54; Female 54%; Caucasian 85%) from the Adult Health and Behavior (AHAB) registry. Structural equation models were used to: (1) regress cognitive performance on FFM traits and (2) test indirect effects of cardiometabolic risk. Age, sex, and race were included as covariates in all models.

Lower Neuroticism, higher Openness, and higher Agreeableness were significantly associated with better performance in each cognitive domain, and higher Conscientiousness was associated with better working memory. Associations between these traits and executive control were accounted for by a significant indirect effect of lower cardiometabolic risk, and in component-specific analyses, by indirect effects of adiposity and systemic inflammation.

Overall, FFM personality traits were associated with multiple domains of cognitive performance, which, in the case of executive control, was partially explained by differences in cardiometabolic risk. Future investigations should examine whether these pathways account for longitudinal change in cognition.

The goal of the current study was to study the contribution of source memory, more specifically, a source memory task, on the memory performance measured with a novel virtual reality (VR)-based neuropsychological assessment test, i.e., the Suite Test.

The sample included 676 subjects (49.7% female), aged from 12 to 85 years. The Suite test comprises a 360-degree VR environment designed as a furniture shop. Participants must group specific sets of furniture items (ordered by different families of customers) by clicking on the furniture to be packed, following instructions from a voice-over. All participants were administered the full version of the test, which comprises, among others, an immediate recall task, a source memory task, a short-term delayed recall task, a long-term delayed recall task, and a recognition trial.

Performance on the VR source memory task was associated with recall across age groups, with a stronger contribution in older adults, often enhancing long-term recall. In contrast, younger individuals relied more on immediate and short-term delayed recall, with weaker relationships between source memory and the other types, suggesting that it plays a more secondary role in younger participants.

The Suite Test VR-based test effectively explores source memory contributions across the lifespan. By immersing participants in a dynamic VR environment, it reveals how source memory relates to other memory types, showing age-related differences and offering valuable insights about cognitive changes, as well as about future research implications in the area of memory assessment.

We evaluated performance-based differences in neuropsychological functioning in older adults (age 65+) across the dementia continuum (cognitively intact, mild cognitive impairment, and dementia) according to recent cannabis use (past six months).

A sample of 540 older adults from a well-characterized observational cohort was included for analysis. Participants completed a standardized questionnaire assessing cannabis use in the six months prior to the study visit and completed a comprehensive neuropsychological assessment. We used traditional cross-sectional analyses (multivariate, univariate) alongside causal inference techniques (propensity score matching [PSM]) to evaluate group differences according to recent cannabis use status. We also examined whether cannabis-related problem severity, a risk factor for cannabis use disorder (CUD), was associated with cognitive outcomes among those reporting recent cannabis use.

Approximately 11% of participants reported using cannabis in the prior six months, with the median user consuming cannabis two to four times per month. Participants with recent cannabis use performed similarly across all five domains of neuropsychological functioning compared to those with no cannabis use. Among older adults reporting recent cannabis use, those with elevated risk for CUD demonstrated lower memory performance.

These preliminary results are broadly consistent with other findings indicating that low-frequency cannabis use among older adults, including those along the dementia continuum, is generally well tolerated from a cognitive perspective. However, among older adults who used cannabis, elevated symptoms of CUD may negatively impact memory performance. Future research should explore how variations in cannabis use patterns, individual characteristics, and clinical phenotypes influence cognitive outcomes.

Because of the complexity of Alzheimer’s Disease (AD) clinical presentations across bio-psycho-social domains of functioning, data-reduction approaches, such as latent profile analysis (LPA), can be useful for studying profiles rather than individual symptoms. Previous LPA research has resulted in more precise characterization and understanding of patients, better clarity regarding the probability and rate of disease progression, and an empirical approach to identifying those who might benefit most from early intervention. Whereas previous LPA research has revealed useful cognitive, neuropsychiatric, or functional subtypes of patients with AD, no study has identified patient profiles that span the domains of health and functioning and that also include motor and sensory functioning.

LPA was conducted with data from the Advancing Reliable Measurement in Alzheimer’s Disease and cognitive Aging study. Participants were 209 older adults with amnestic mild cognitive impairment (aMCI) or mild dementia of the Alzheimer’s type (DAT). LPA indicator variables were from the NIH Toolbox® and included cognitive, emotional, social, motor, and sensory domains of functioning.

The data were best modeled with a 4-profile solution. The latent profiles were most differentiated by indices of social and emotional functioning and least differentiated by motor and sensory function.

These multi-domain patient profiles support and extend previous findings on single-domain profiles and highlight the importance of social and emotional factors for understanding patient experiences of aMCI/DAT. Future research should investigate these profiles further to better understand risk and resilience factors, the stability of these profiles over time, and responses to intervention.

To further investigate the “other side of the bell curve” hypothesis, the current study examined the number of low and high scores on a neuropsychological battery: 1) in cognitively unimpaired or impaired older adults, 2) as they relate to biomarkers of Alzheimer’s disease (AD), and 3) as they relate to traditional scores on this battery.

In 68 cognitively unimpaired and 97 cognitively impaired participant, the number of low (i.e., ≤ 16th percentile) and high (i.e., ≥ 75th percentile) scores on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) were calculated, compared between the two groups, and related to biomarkers of AD (i.e., amyloid deposition, hippocampal volumes, ε4 alleles of Apolipoprotein E (APOE)) and RBANS Total score.

In this cognitively diverse sample, low and high scores were common, with approximately 75% having at least one low score and 86% having at least one high score. Unimpaired participants had significantly more high scores and fewer low scores than their impaired counterparts. The number of low scores was significantly related to more amyloid deposition, smaller hippocampal volume, and having one or more copies of the ε4 allele of APOE. The number of high scores was similarly related with these biomarkers. Low/high scores were comparable to traditional scores on the RBANS in identifying cognitively impaired participants.

Support for the “other side of the bell curve” hypothesis was equivocal in these analyses, with both sides of the bell curve appearing to provide relevant information in a cognitively diverse sample.

The Stages of Objective Memory Impairment (SOMI) system, based on the Free and Cued Selective Reminding Test (FCSRT), is a potential marker of subtle cognitive impairment in cognitively normal persons defined by a Clinical Dementia Rating (CDR) = 0. We investigated SOMI’s ability to predict incident cognitive impairment (CDR >0) in combination with demographic features and neuroimaging biomarkers.

Cognitively unimpaired participants (CDR = 0) from the Harvard Aging Brain Study had baseline FCSRT scores, MRI, FDG-PET, and PiB-PET as well as follow-up CDRs for 5 years. Cox proportional hazards models with correction for multiple testing assessed the predictive validity of SOMI and neuroimaging biomarkers for progression (CDR >0). Comprehensive sensitivity analyses examined alternative outcomes and stricter screening criteria.

Participants (N = 231) were 73.7 years (SD = 6.0), 60.2% were female, 29.0% were APOE4 positive, and 54 (23.4%) progressed to CDR >0. At baseline, 67% were SOMI-0, 22% were SOMI-1, 4% were SOMI-2, and 7% were SOMI-3/4. After multiple testing correction, hazard ratios (HRs) using SOMI-0 as reference were: SOMI-1 = 2.06 (CI: 1.09 – 3.88), SOMI-2 = 2.85 (CI: 1.08 – 7.54), and SOMI-3/4 = 3.73 (CI: 1.58 – 8.79, p = 0.016). SOMI-3/4 remained significant across most biomarker models. Entorhinal thickness emerged as the most robust biomarker predictor (HR = 0.57 – 0.65, p ≤ 0.015). Sensitivity analyses confirmed robustness across alternative outcomes and stricter screening criteria.

SOMI stages predict progression to incident cognitive impairment with SOMI-3/4 maintaining significance after rigorous multiple testing correction. Entorhinal thickness provides the strongest biomarker enhancement to prediction models. SOMI demonstrates substantial incremental predictive value beyond standard demographic and biomarker predictors.

Acquired Brain Injury (ABI) is a leading cause of childhood disability, yet educators report a gap in knowledge about supporting students with ABI when they return to school. We tested our TeachABI professional development module to examine how it impacted educators’ ABI knowledge and self-efficacy for supporting students with ABI.

Fifty educators filled out questionnaires about their knowledge and self-efficacy at three time points: pre-module, post-module, and 60 days post-module. Score differences were examined across time.

Participants’ ABI knowledge, subjective knowledge of the module learning objectives, and self-efficacy increased from pre- to post-module, and these gains were maintained at 60 days.

This suggests that TeachABI is a tool for better equipping educators to support students with ABI.

Cognitive intra-individual variability (IIV) is a neuropsychological marker reflecting divergent performance across cognitive domains. In this brief communication, we examined whether clinical severity, apolipoprotein E (APOE) ε4 carriers, and higher polygenic risk were associated with higher cognitive IIV, and whether higher polygenic risk and cognitive IIV synergistically influence clinical severity.

This large study involved up to 24,248 participants (mean age = 72) from the National Alzheimer’s Coordinating Center (NACC) and multiple regression controlling for age, sex, and education was used to analyze the data.

We found that disease severity (B = 0.055, SE = 0.001, P < 0.001), APOE ε4 carriers (B = 0.02, SE = 0.003, P < 0.001), and higher polygenic risk (B = 0.02, SE = 0.004, P < 0.001) were associated with higher cognitive IIV. Polygenic risk and cognitive IIV also interacted to influence clinical severity, beyond APOE ε4 (B = 0.11, SE = 0.05, P = 0.02), such that individuals with high polygenic risk and cognitive IIV had the greatest clinical severity.

Heightened polygenic risk and increased cross-domain cognitive variation are implicated in dementia and may impact clinical decline in tandem.

This study examined three neurocognitive patterns or “clinical pearls” historically viewed as evidence for executive dysfunction in Parkinson disease (PD): 1) letter < category fluency; 2) word list < story delayed recall; 3) word list delayed recall < recognition. The association between intraindividual magnitudes of each neuropsychological pattern and individual performance on traditional executive function tests was examined.

A clinical sample of 772 individuals with PD underwent neuropsychological testing including tests of verbal fluency, word list/story recall, recognition memory, and executive function. Raw scores were demographically normed (Heaton) and converted to z-scores for group-level analyses.

Letter fluency performance was worse than category fluency (d = −0.12), with 28% of participants showing a discrepancy of ≥ −1.0 SD. Delayed recall of a list was markedly poorer than story recall (d = −0.86), with 52% of the sample exhibiting ≥ −1.0 SD deficits. Lastly, delayed free recall was worse than recognition memory (d = −0.25), with 24% showing a discrepancy of ≥ −1.0 SD. These patterns did not consistently correlate with executive function scores. The word list < story recall pattern was more common in earlier than later PD stages and durations.

Among the three pearls, the most pronounced was stronger memory performance on story recall than word lists, observed in more than half the sample. Only ¼ the participants exhibited all three neurocognitive patterns simultaneously. The variability in patterns across individuals highlights the heterogeneity of cognitive impairment in PD and suggests that intra-individual comparisons may offer a more nuanced insight into cognitive functioning.

Post-stroke neurocognitive disorders are highly prevalent, yet screening tools that are fit for culturally diverse populations are scarce. This study evaluates the impact of cultural differences on the Oxford Cognitive Screen (OCS), a stroke-specific screening tool.

To evaluate cultural differences, we compared two populations with varying degrees of cultural diversity and Western, Educated, Industrialized, Rich and Democratic (WEIRD) characteristics. We adapted the Dutch OCS for Suriname through a multi-stage process. Using Bayesian hierarchical regression analysis, we compared 264 Surinamese participants, assessed with the adapted Dutch OCS, with 247 Belgian participants, assessed with the Dutch OCS, while controlling for age and education. We further investigated whether the associations of age and education with performance were comparable between the two populations.

Our findings revealed minimal differences in OCS performance between the Belgian and Surinamese populations. Both populations showed similar age-related decline and education-related improvement across all subtests, except for Picture naming, where the age-related decline was more pronounced in the Belgian population.

These findings suggest that with minimal adaptation, the OCS is a viable tool for screening post-stroke neurocognitive disorders in culturally diverse populations.

Impairments in social interaction are common symptoms of dementia and necessitate the use of validated neuropsychological instruments to measure social cognition. We aim to investigate the Hinting Task – Dutch version (HT-NL), which measures the ability to infer intentions behind indirect speech to assess Theory of Mind, in dementia.

Sixty-six patients with dementia, of whom 22 had behavioral variant frontotemporal dementia (bvFTD), 21 had primary progressive aphasia, and 23 had Alzheimer’s disease (AD), and 99 healthy control participants were included. We examined the HT-NL’s psychometric properties, including internal consistency, between-group differences using analyses of covariance with Bonferroni-adjusted post hoc comparisons, discriminative ability and concurrent validity using the area under the receiver operating characteristic curve (AUC), and construct validity using Spearman rank correlations with other cognitive tests.

Internal consistency was acceptable (Cronbach’s α = 0.74). All patient groups scored lower on the HT-NL than the control group. Patients with bvFTD scored lower than patients with AD dementia. The HT-NL showed excellent discriminative ability (AUC = 0.83), comparable to a test of emotion recognition (ΔAUC = 0.03, p = .67). The HT-NL correlated significantly with a test for emotion recognition (r = .45), and with measures of memory and language (r = [.31, .40]), but not with measures of information processing speed, executive functioning, or working memory (r = [.00, .17]). Preliminary normative data are provided.

The HT-NL is a psychometrically sound and valid instrument and is useful for identifying Theory of Mind impairments in patients with dementia.

Recent functional magnetic resonance imaging (fMRI) studies have shown that interpersonal synchronization of brain activity can be measured between people sharing similar emotional, narrative, or attentional states. There is evidence that odors can modulate the activity of brain regions involved in memory, emotion and social cognition, suggesting a link between shared olfactory experiences and synchronized brain activity in social contexts.

We used fMRI to investigate the effects of a positively-valenced odor on inter-subject correlation (ISC) of brain activity in healthy volunteers watching movies. While being inside an MRI scanner, participants (N = 20) watched short movie clips to induce either positive (happiness, tenderness) or negative (sadness, fear) emotions. Two movie clips were presented for each emotional category. Participants were scanned in two separate randomized sessions, once while watching the movie clips in the presence of an odor, and once without.

When all emotional categories were combined, the odor condition showed significantly higher ISC compared to the control condition in bilateral superior temporal gyri (STG), right middle temporal gyrus, left calcarine, and lingual gyrus. When splitting the movies according to valence, odor-induced increases in ISC were stronger for the negative movies. For the negative movies, ISC in the supramarginal gyrus and STG was larger in the second compared to first movie clips, indicating a time-by odor interaction.

These findings show that odor increases ISC and that its effects depend on emotional valence. Our results further emphasize the critical role of the STG in odor-based social communication.