Resting-state EEG data before and after cognitive activity across the adult lifespan and a 5-year follow-up.

This dataset consists of 64-channels resting-state EEG recordings of 608 participants aged between 20 and 70 years, 61.8% female, as well as follow-up measurements after approximately 5 years of 208 participants, starting 2021. The EEG was measured for three minutes with eyes open and eyes closed before and after a 2-hour block of cognitive experimental tasks. The data set is part of the Dortmund Vital Study, a prospective study on the determinants of healthy cognitive aging. The dataset can be used for (1) analyzing cross-sectional resting-state EEG of healthy individuals across the adult life span; (2) generating normalization data sets for comparison of resting-state EEG data of patients with clinically relevant disorders; (3) studying effects of performing cognitive tasks on resting-state EEG and age; (4) exploring intra-individual changes in resting-state EEG and effects of task performance over a time period of about 5 years. The data are provided in Brain Imaging Data Structure (BIDS) format and are available on OpenNeuro.

The neural basis of attentional selection in goal-directed memory retrieval.

Goal-directed memory reactivation involves retrieving the most relevant information for the current behavioral goal. Previous research has linked this process to activations in the fronto-parietal network, but the underlying neurocognitive mechanism remains poorly understood. The current electroencephalogram (EEG) study explores attentional selection as a possible mechanism supporting goal-directed retrieval. We designed a long-term memory experiment containing three phases. First, participants learned associations between objects and two screen locations. In a following phase, we changed the relevance of some locations (selective cue condition) to simulate goal-directed retrieval. We also introduced a control condition, in which the original associations remained unchanged (neutral cue condition). Behavior performance measured during the final retrieval phase revealed faster and more confident responses in the selective vs. neutral condition. At the EEG level, we found significant differences in decoding accuracy, with above-chance effects in the selective cue condition but not in the neutral cue condition. Additionally, we observed a stronger posterior contralateral negativity and lateralized alpha power in the selective cue condition. Overall, these results suggest that attentional selection enhances task-relevant information accessibility, emphasizing its role in goal-directed memory retrieval.

The effect of performance contingent reward prospects flexibly adapts to more versus less specific task goals.

In some situations, for example, when we expect to gain a reward in case of good performance, goal-driven top-down attention is particularly strong. Little is known about the task specificity of such increases of top-down attention due to environmental factors. To understand to what extent performance-contingent reward prospects can result in specific and unspecific changes in cognitive processing, we here investigate reward effects under different levels of task specification. Thirty-two participants performed a visual or an auditory discrimination task cued by two consecutive visual stimuli: First, a reward cue indicated if good performance was rewarded. Second, a task cue announced either which of the two tasks would follow (precise cue) or that both tasks would follow equally likely (imprecise cue). Reward and task cue preciseness both significantly improved performance. Moreover, the response time difference between precisely and imprecisely cued trials was significantly stronger in rewarded than in unrewarded trials. These effects were reflected in event-related potential (ERP) slow wave amplitudes: Reward and preciseness both significantly enhanced the contingent negative variation (CNV) prior to the task stimulus. In an early CNV time interval, both factors also showed an interaction. A negative slow wave prior to the task cue was also significantly enhanced for rewarded trials. This effect correlated with the reward difference in response times. These results indicate that reward prospects trigger task-specific changes in preparatory top-down attention which can flexibly adapt over time and across different task requirements. This highlights that a reward-induced increase of cognitive control can occur on different specificity levels.

Phenotyping in clinical laterality research: a comparison of commonly used methods to determine mixed-handedness and ambidexterity.

An increased prevalence of mixed-handedness has been reported in several neurodevelopmental and psychiatric disorders. Unfortunately, there is high between-study variability in the definition of mixed-handedness, leading to a major methodological problem in clinical laterality research and endangering replicability and comparability of research findings. Adding to this challenge is the fact that sometimes researchers use the concepts of mixed-handedness and ambidexterity interchangeably. Therefore, having a consensus on how to determine mixed-handedness and how to distinguish it from ambidexterity is crucial for clinical laterality research. To this end, hand preference and hand performance data from more than 600 participants from the Dortmund Vital Study (Trial registration: ClinicalTrials.gov NCT05155397), a population-based study in Germany, was analyzed to ascertain an optimal classification to determine mixed-handedness and ambidexterity. Using a combination of latent class analyses, effect size determination, and comparisons with the existing literature, we establish that an LQ cut-off criterion of +/-60 for mixed-handedness is optimal for future clinical laterality studies. Moreover, we show that mixed-handedness and ambidexterity are not identical and that the terms should not be used interchangeably. We further highlight the need for a consensus on how to mathematically determine ambidexterity as results of existing categorization schemes largely differ.Trial registration: ClinicalTrials.gov NCT05155397; https://clinicaltrials.gov/ct2/show/NCT05155397.

Stress from early life to adulthood: Is there a protective role of cognitive control?

Early life events can have long-lasting effects that may impact the quality of life into adulthood. The link between childhood adversities and adult mental and physical health is well documented, however, the underlying mechanisms remain poorly understood. Executive functions are assumed to be a key factor in successfully dealing with cognitive-emotional challenges thereby contributing to stress resilience and mental health across the lifespan. Here, we examined whether cognitive control moderates the link between early life adversity and depression. Data was available from a sample of 424 participants aged 20-70 years (Clinicaltrials.gov: NCT05155397). They performed in the Stroop task and behavior as well as frontal theta power were recorded. Negative childhood experiences were assessed with the Childhood Trauma Questionnaire (CTQ), chronic stress was measured with the Trier Inventory for Chronic Stress (TICS) and depression symptoms with Beck's Depression Inventory (BDI). The CTQ predicted symptoms of chronic stress and depression. Regression models pointed to the TICS as a crucial mediator in the relationship between CTQ and BDI. However, parameters of cognitive control demonstrated a rather weak effect as moderators. These results indicate that chronic stress is an important mediator linking childhood trauma to depression but suggest only a limited role for cognitive control.

Triggered by your heart: Effects of cardioafferent traffic and stress on automatic responses in a Simon task.

Variations in cardioafferent traffic are relayed to the brain via arterial baroreceptors and have been shown to modulate perceptual processing. However, less is known about the cognitive-behavioral consequences of these effects and their role during stress. Here, we investigated in how far automatic responses during the Simon task were modulated by exposure to a laboratory stressor and the different phases of the cardiac cycle. In this study, 30 participants performed three blocks of a combined horizontal and vertical Simon task, which is characterized by either sensorimotor or cognitive response conflicts, respectively. Before each block, subjects were exposed to both the cold pressor test (CPT) and a control condition according to a within-subjects design. Target stimuli were presented during either systole or diastole. Behavioral and EEG-correlates of task processing were assessed along with subjective, cardiovascular, and endocrine measures of stress. The stress induction was successful yielding significant increases in all these measures compared to control. Moreover, we found the expected Simon effects: in incompatible compared to compatible trials performance was decreased and LRP latency as well as anterior N2 area increased. Importantly, accuracy was improved in compatible but reduced in incompatible trials during systole vs. diastole but only in the horizontal Simon condition. Stress dampened N2 area, however, no interactions with cardiac cycle were evident. These results indicate a faciliatory effect of cardioafferent traffic on automated sensorimotor processes.

Be prepared for interruptions: EEG correlates of anticipation when dealing with task interruptions and the role of aging.

Dealing with task interruptions requires the flexible use of working memory and attentional control mechanisms, which are prone to age-related changes. We investigated effects of age on dealing with task interruptions and potential advantages of anticipating an interruption using EEG and a retrospective cueing (retro-cue) paradigm. Thirty-two young (18-30 years) and 28 older (55-70 years) participants performed a visual working memory task, where they had to report the orientation of a target following a retro-cue. Within blocks of 10 trials, they were always, never, or randomly interrupted with an arithmetic task before the onset of the retro-cue. The interruption-induced decline in primary task performance was more pronounced in older participants, while only these benefited from anticipation. The EEG analysis revealed reduced theta and alpha/beta response to the retro-cue following interruptions, especially for the older participants. In both groups, anticipated interruptions were associated with increased theta and alpha/beta power prior and during the interruption, and stronger beta suppression to the retro-cue. The results indicate that interruptions impede the refocusing of attention on the task-relevant representation of the primary task, especially in older people, while anticipation facilitates preparation for the interruption task and resumption of the primary task.

Comparing auditory distance perception in real and virtual environments and the role of the loudness cue: A study based on event-related potentials.

The perception of the distance to a sound source is relevant in many everyday situations, not only in real spaces, but also in virtual reality (VR) environments. Where real rooms often reach their limits, VR offers far-reaching possibilities to simulate a wide range of acoustic scenarios. However, in virtual room acoustics a plausible reproduction of distance-related cues can be challenging. In the present study, we compared the detection of changes of the distance to a sound source and its neurocognitive correlates in a real and a virtual reverberant environment, using an active auditory oddball paradigm and EEG measures. The main goal was to test whether the experiments in the virtual and real environments produced equivalent behavioral and EEG results. Three loudspeakers were placed at ego-centric distances of 2 m (near), 4 m (center), and 8 m (far) in front of the participants (N = 20), each 66 cm below their ear level. Sequences of 500 ms noise stimuli were presented either from the center position (standards, 80 % of trials) or from the near or far position (targets, 10 % each). The participants had to indicate a target position via a joystick response ("near" or "far"). Sounds were emitted either by real loudspeakers in the real environment or rendered and played back for the corresponding positions via headphones in the virtual environment. In addition, within both environments, loudness of the auditory stimuli was either unaltered (natural loudness) or the loudness cue was manipulated, so that all three loudspeakers were perceived equally loud at the listener's position (matched loudness). The EEG analysis focused on the mismatch negativity (MMN), P3a, and P3b as correlates of deviance detection, attentional orientation, and context-updating/stimulus evaluation, respectively. Overall, behavioral data showed that detection of the target positions was reduced within the virtual environment, and especially when loudness was matched. Except for slight latency shifts in the virtual environment, EEG analysis indicated comparable patterns within both environments and independent of loudness settings. Thus, while the neurocognitive processing of changes in distance appears to be similar in virtual and real spaces, a proper representation of loudness appears to be crucial to achieve a good task performance in virtual acoustic environments.

Chronic Toxoplasma gondii Infection Modulates Hearing Ability across the Adult Life Span.

While several studies have shown associations between hearing disorders and congenital toxoplasmosis, the present study investigated the impact of chronic, latent Toxoplasma gondii (T. gondii) infection on hearing loss. We used a regression analysis to explore whether latent T. gondii infection modulates changes in hearing thresholds over an age range from 20 to 70 years. We analyzed audiometric data of 162 T. gondii IgG-positive and 430 T. gondii-negative participants, collected in the Dortmund Vital Study (DVS, ClinicalTrials.gov Identifier: NCT05155397), a prospective study on healthy cognitive aging. The regression analysis indicated that latent toxoplasmosis was associated with an accelerated development in hearing loss over the observed age range. Hearing loss was less frequent in IgG-positive than in IgG-negative participants up to the age of about 40 for a low (0.125-1 kHz)-frequency range. For high (2-8 kHz) frequencies, this pattern reversed for ages above 65 years. We discuss these findings on hearing function in the context of a recently proposed model, suggesting that latent toxoplasmosis can differentially affect brain functions across a lifespan.

Normative Intercorrelations Between EEG Microstate Characteristics.

EEG microstates are brief, recurring periods of stable brain activity that reflect the activation of large-scale neural networks. The temporal characteristics of these microstates, including their average duration, number of occurrences, and percentage contribution have been shown to serve as biomarkers of mental and neurological disorders. However, little is known about how microstate characteristics of prototypical network types relate to each other. Normative intercorrelations among these parameters are necessary to help researchers better understand the functions and interactions of underlying networks, interpret and relate results, and generate new hypotheses. Here, we present a systematic analysis of intercorrelations between EEG microstate characteristics in a large sample representative of western working populations (n = 583). Notably, we find that microstate duration is a general characteristic that varies across microstate types. Further, microstate A and B show mutual reinforcement, indicating a relationship between auditory and visual sensory processing at rest. Microstate C appears to play a special role, as it is associated with longer durations of all other microstate types and increased global field power, suggesting a relationship of these parameters with the anterior default mode network. All findings could be confirmed using independent EEG recordings from a retest-session (n = 542).

Adult ADHD: it is old and new at the same time - what is it?

Even though the number of studies aiming to improve comprehension of ADHD pathology has increased in recent years, there still is an urgent need for more effective studies, particularly in understanding adult ADHD, both at preclinical and clinical levels, due to the increasing evidence that adult ADHD is highly distinct and a different entity from childhood ADHD. This review paper outlines the symptoms, diagnostics, and neurobiological mechanisms of ADHD, with emphasis on how adult ADHD could be different from childhood-onset. Data show a difference in the environmental, genetic, epigenetic, and brain structural changes, when combined, could greatly impact the behavioral presentations and the severity of ADHD in adults. Furthermore, a crucial aspect in the quest to fully understand this disorder could be through longitudinal analysis. In this way, we will determine if and how the pathology and pharmacology of ADHD change with age. This goal could revolutionize our understanding of the disorder and address the weaknesses in the current clinical classification systems, improving the characterization and validity of ADHD diagnosis, specifically those in adults.

On the Reliability of the EEG Microstate Approach.

EEG microstates represent functional brain networks observable in resting EEG recordings that remain stable for 40-120ms before rapidly switching into another network. It is assumed that microstate characteristics (i.e., durations, occurrences, percentage coverage, and transitions) may serve as neural markers of mental and neurological disorders and psychosocial traits. However, robust data on their retest-reliability are needed to provide the basis for this assumption. Furthermore, researchers currently use different methodological approaches that need to be compared regarding their consistency and suitability to produce reliable results. Based on an extensive dataset largely representative of western societies (2 days with two resting EEG measures each; day one: n = 583; day two: n = 542) we found good to excellent short-term retest-reliability of microstate durations, occurrences, and coverages (average ICCs = 0.874-0.920). There was good overall long-term retest-reliability of these microstate characteristics (average ICCs = 0.671-0.852), even when the interval between measures was longer than half a year, supporting the longstanding notion that microstate durations, occurrences, and coverages represent stable neural traits. Findings were robust across different EEG systems (64 vs. 30 electrodes), recording lengths (3 vs. 2 min), and cognitive states (before vs. after experiment). However, we found poor retest-reliability of transitions. There was good to excellent consistency of microstate characteristics across clustering procedures (except for transitions), and both procedures produced reliable results. Grand-mean fitting yielded more reliable results compared to individual fitting. Overall, these findings provide robust evidence for the reliability of the microstate approach.

Blink-related EEG activity measures cognitive load during proactive and reactive driving.

Assessing drivers' cognitive load is crucial for driving safety in challenging situations. This research employed the occurrence of drivers' natural eye blinks as cues in continuously recorded EEG data to assess the cognitive workload while reactive or proactive driving. Twenty-eight participants performed either a lane-keeping task with varying levels of crosswind (reactive) or curve road (proactive). The blink event-related potentials (bERPs) and spectral perturbations (bERSPs) were analyzed to assess cognitive load variations. The study found that task load during reactive driving did not significantly impact bERPs or bERSPs, possibly due to enduring alertness for vehicle control. The proactive driving revealed significant differences in the occipital N1 component with task load, indicating the necessity to adapt the attentional resources allocation based on road demands. Also, increased steering complexity led to decreased frontal N2, parietal P3, occipital P2 amplitudes, and alpha power, requiring more cognitive resources for processing relevant information. Interestingly, the proactive and reactive driving scenarios demonstrated a significant interaction at the parietal P2 and occipital N1 for three difficulty levels. The study reveals that EEG measures related to natural eye blink behavior provide insights into the effect of cognitive load on different driving tasks, with implications for driver safety.

From Immunosenescence to Aging Types-Establishing Reference Intervals for Immune Age Biomarkers by Centile Estimation.

Immunological aging type definition requires establishing reference intervals from the distribution of immunosenescence biomarkers conditional on age. For 1605 individuals (18-97 years), we determined the comprehensive immune age index IMMAX from flow-cytometry-based blood cell sub-populations and identified age-specific centiles by fitting generalized additive models for location, scale, and shape. The centiles were uncorrelated with age and facilitated the categorization of individuals as immunologically slow or fast aging types. Using its 50th percentile as a reference, we rescaled the IMMAX to equivalent years of life (EYOL) and computed the immunological age gap as the difference between EYOL and chronological age. Applied to preliminary baseline and follow-up measurements from 53 participants of the Dortmund Vital Study (Clinical-Trials.gov Identifier: NCT05155397), the averaged changes in the IMMAX and EYOL conformed to the 5-year follow-up period, whereas no significant changes occurred concerning IMMAX centiles and age gap. This suggested that the participants immunologically adapted to aging and kept their relative positions within the cohort. Sex was non-significant. Methodical comparisons indicated that future confirmatory analyses with the completed follow-up examinations could rely on percentile curves estimated by simple linear quantile regression, while the selection of the immunosenescence biomarker will greatly influence the outcome, with IMMAX representing the preferable choice.

Effects of cognitive and stress management training in middle-aged and older industrial workers in different socioeconomic settings: a randomized controlled study.

Introduction: The demographic change requires longer working lifetime. However, fear of job loss may lead to chronic stress whereas aging and unchallenging work may accelerate cognitive decline and early retirement. Long-time repetitive work led to impairments of cognitive functions in middle-aged and older employees, as demonstrated in a previous study conducted in a large car manufacturer. In the present study, a training concept was implemented to enhance the cognitive and emotional competence of these employees. Methods: A first group of employees received a trainer-guided cognitive training only, whereas a wait list control group received a cognitive training and stress management training. This design was applied in two independent samples separated by one year either during or after a socioeconomically tense situation of the factory. Results: In sample 1, with a tense occupational situation, the cognitive training effects occurred with a delay of three months. In contrast, in sample 2, with less critical socioeconomic situation, the training effects occurred immediately and persisted three months later. Stress management training showed reduction of subjectively and objectively measured stress level. Discussion: The results indicate that effects of cognitive interventions are diminished under chronic stress which can be reduced after a short stress management training. This leads also to enhanced attention and memory in daily life. In contrast, in Sample 2 with less chronic stress, effects of cognitive training were stronger and persisted at least three months later, whereas stress management training had less impact. This suggests that cognitive learning in occupational settings is only efficient at lower stress levels.

Decoding Eye Blink and Related EEG Activity in Realistic Working Environments.

Accurately evaluating cognitive load during work-related tasks in complex real-world environments is challenging, leading researchers to investigate the use of eye blinking as a fundamental pacing mechanism for segmenting EEG data and understanding the neural mechanisms associated with cognitive workload. Yet, little is known about the temporal dynamics of eye blinks and related visual processing in relation to the representation of task-specific information. Therefore, we analyzed EEG responses from two experiments involving simulated driving (re-active and pro-active) with three levels of task load for each, as well as operating a steam engine (active vs. passive), to decode the temporal dynamics of eye blink activity and the subsequent neural activity that follows blinking. As a result, we successfully decoded the binary representation of difficulty levels for pro-active driving using multivariate pattern analysis. However, the decoding level varied for different re-active driving conditions, which could be attributed to the required level of alertness. Furthermore, our study revealed that it was possible to decode both driving types as well as steam engine operating conditions, with the most significant decoding activity observed approximately 200 ms after a blink. Additionally, our findings suggest that eye blinks have considerable potential for decoding various cognitive states that may not be discernible through neural activity, particularly near the peak of the blink. The findings demonstrate the potential of blink-related measures alongside EEG data to decode cognitive states during complex tasks, with implications for improving evaluations of cognitive and behavioral states during tasks, such as driving and operating machinery.

Cognitive aging at work and in daily life-a narrative review on challenges due to age-related changes in central cognitive functions.

Demographic change is leading to an increasing proportion of older employees in the labor market. At the same time, work activities are becoming more and more complex and require a high degree of flexibility, adaptability, and cognitive performance. Cognitive control mechanism, which is subject to age-related changes and is important in numerous everyday and work activities, plays a special role. Executive functions with its core functions updating, shifting, and inhibition comprises cognitive control mechanisms that serve to plan, coordinate, and achieve higher-level goals especially in inexperienced and conflicting actions. In this review, influences of age-related changes in cognitive control are demonstrated with reference to work and real-life activities, in which the selection of an information or response in the presence of competing but task-irrelevant stimuli or responses is particularly required. These activities comprise the understanding of spoken language under difficult listening conditions, dual-task walking, car driving in critical traffic situations, and coping with work interruptions. Mechanisms for compensating age-related limitations in cognitive control and their neurophysiological correlates are discussed with a focus on EEG measures. The examples illustrate how to access influences of age and cognitive control on and in everyday and work activities, focusing on its functional role for the work ability and well-being of older people.

Tracking drivers' minds: Continuous evaluation of mental load and cognitive processing in a realistic driving simulator scenario by means of the EEG.

Driving safety strongly depends on the driver's mental states and attention to the driving situation. Previous studies demonstrate a clear relationship between EEG measures and mental states, such as alertness and drowsiness, but often only map their mental state for a longer period of time. In this driving simulation study, we exploit the high temporal resolution of the EEG to capture fine-grained modulations in cognitive processes occurring before and after eye activity in the form of saccades, fixations, and eye blinks. A total of 15 subjects drove through an approximately 50-km course consisting of highway, country road, and urban passages. Based on the ratio of brain oscillatory alpha and theta activity, the total distance was classified into 10-m-long sections with low, medium, and high task loads. Blink-evoked and fixation-evoked event-related potentials, spectral perturbations, and lateralizations were analyzed as neuro-cognitive correlates of cognition and attention. Depending on EEG-based estimation of task load, these measures showed distinct patterns associated with driving behavior parameters such as speed and steering acceleration and represent a temporally highly resolved image of specific cognitive processes during driving. In future applications, combinations of these EEG measures could form the basis for driver warning systems which increase overall driving safety by considering rapid fluctuations in driver's attention and mental states.

Does physical fitness affect cognitive functions differently across adulthood? An advantage of being older.

Introduction: There is a large interindividual variability in cognitive functioning with increasing age due to biological and lifestyle factors. One of the most important lifestyle factors is the level of physical fitness (PF). The link between PF and brain activity is widely accepted but the specificity of cognitive functions affected by physical fitness across the adult lifespan is less understood. The present study aims to clarify whether PF is basically related to cognition and general intelligence in healthy adults, and whether higher levels of PF are associated with better performance in the same or different cognitive functions at different ages. Methods: A sample of 490 participants (20-70 years) was analyzed to examine this relationship. Later, the sample was split half into the young to middle-aged group (YM; 20-45 years; n = 254), and the middleaged to older group (MO; 46-70 years; n = 236). PF was measured by a quotient of maximum power in a bicycle ergometry test PWC-130 divided by body weight (W/kg), which was supported by a self-reported level of PF. Cognitive performance was evaluated by standardized neuropsychological test batteries. Results: Regression models showed a relationship between PF and general intelligence (g-factor) and its subcomponents extracted using structural equation modeling (SEM) in the entire sample. This association was moderated by age, which also moderated some specific cognitive domains such as attention, logical reasoning, and interference processing. After splitting the sample into two age groups, a significant relationship was found between cognitive status, as assessed by the Mini Mental State Examination (MMSE), and PF in both age groups. However, apart from cognitive failures in daily life (CFQ), no other association between PF and specific cognitive functions was found in the YM group. In contrast, several positive associations were observed in the MO group, such as with selective attention, verbal memory, working memory, logical reasoning, and interference processing. Discussion: These findings show that middle-aged to older adults benefit more from PF than younger to middle-aged adults. The results are discussed in terms of the neurobiological mechanisms underlying the cognitive effects of PF across the lifespan. Clinical trial registration: https://clinicaltrials.gov/ct2/show/NCT05155397, identifier NCT05155397.