Showing papers in "Psychophysiology in 2021"
TL;DR: In this paper, the authors proposed the standardized measurement error (SME), which is a special case of the standard error of measurement and can be applied to virtually any value that is derived from averaged ERP waveforms.
Abstract: Event-related potentials (ERPs) can be very noisy, and yet, there is no widely accepted metric of ERP data quality. Here, we propose a universal measure of data quality for ERP research-the standardized measurement error (SME)-which is a special case of the standard error of measurement. Whereas some existing metrics provide a generic quantification of the noise level, the SME quantifies the data quality (precision) for the specific amplitude or latency value being measured in a given study (e.g., the peak latency of the P3 wave). It can be applied to virtually any value that is derived from averaged ERP waveforms, making it a universal measure of data quality. In addition, the SME quantifies the data quality for each individual participant, making it possible to identify participants with low-quality data and "bad" channels. When appropriately aggregated across individuals, SME values can be used to quantify the combined impact of the single-trial EEG noise and the number of trials being averaged together on the effect size and statistical power in a given experiment. If SME values were regularly included in published articles, researchers could identify the recording and analysis procedures that produce the highest data quality, which could ultimately lead to increased effect sizes and greater replicability across the field.
71 citations
TL;DR: It is suggested that RSFA can be used to separate vascular from neuronal factors, to characterize neurocognitive aging, and recommended for the use of RSFA in the research of aging.
Abstract: Accurate identification of brain function is necessary to understand neurocognitive aging, and thereby promote health and well-being. Many studies of neurocognitive aging have investigated brain function with the blood-oxygen level-dependent (BOLD) signal measured by functional magnetic resonance imaging. However, the BOLD signal is a composite of neural and vascular signals, which are differentially affected by aging. It is, therefore, essential to distinguish the age effects on vascular versus neural function. The BOLD signal variability at rest (known as resting state fluctuation amplitude, RSFA), is a safe, scalable, and robust means to calibrate vascular responsivity, as an alternative to breath-holding and hypercapnia. However, the use of RSFA for normalization of BOLD imaging assumes that age differences in RSFA reflecting only vascular factors, rather than age-related differences in neural function (activity) or neuronal loss (atrophy). Previous studies indicate that two vascular factors, cardiovascular health (CVH) and cerebrovascular function, are insufficient when used alone to fully explain age-related differences in RSFA. It remains possible that their joint consideration is required to fully capture age differences in RSFA. We tested the hypothesis that RSFA no longer varies with age after adjusting for a combination of cardiovascular and cerebrovascular measures. We also tested the hypothesis that RSFA variation with age is not associated with atrophy. We used data from the population-based, lifespan Cam-CAN cohort. After controlling for cardiovascular and cerebrovascular estimates alone, the residual variance in RSFA across individuals was significantly associated with age. However, when controlling for both cardiovascular and cerebrovascular estimates, the variance in RSFA was no longer associated with age. Grey matter volumes did not explain age differences in RSFA, after controlling for CVH. The results were consistent between voxel-level analysis and independent component analysis. Our findings indicate that cardiovascular and cerebrovascular signals are together sufficient predictors of age differences in RSFA. We suggest that RSFA can be used to separate vascular from neuronal factors, to characterize neurocognitive aging. We discuss the implications and make recommendations for the use of RSFA in the research of aging.
45 citations
TL;DR: A framework based on the concept of neurovisceral integration is provided and it is proposed that stress regulation is emotion regulation and studies that have investigated emotion regulation may yield insights into successful stress regulation that helps protect people from age-related decline.
Abstract: Darwin emphasized the intimate relationship between the brain and the heart over 150 years ago. Healthy aging is associated with significant changes in both the brain and the heart. The changes between these, the two most important organs of the body, are linked via the vagus nerve. In this review, we examine the normative changes with aging and the effect that stress may have on how the brain-heart connection changes with age. We provide a framework based on the concept of neurovisceral integration and propose that stress regulation is emotion regulation. As such, studies that have investigated emotion regulation may yield insights into successful stress regulation that helps protect people from age-related decline. In addition, interventions that improve brain health also improve heart health and vice versa. We conclude by noting that significant sex and ethnic differences exist but that future studies are needed to more fully explicate how they may moderate the associations between stress and aging.
34 citations
TL;DR: In this article, a review aimed at detailing how the physiology of the cerebral vascular system changes with age and how these changes lead to differential trajectories of cognitive maintenance or decline, and the methodological implications of age-related changes in the cerebral vasculature for human cognitive neuroscience research.
Abstract: The process of aging includes changes in cellular biology that affect local interactions between cells and their environments and eventually propagate to systemic levels. In the brain, where neurons critically depend on an efficient and dynamic supply of oxygen and glucose, age-related changes in the complex interaction between the brain parenchyma and the cerebrovasculature have effects on health and functioning that negatively impact cognition and play a role in pathology. Thus, cerebrovascular health is considered one of the main mechanisms by which a healthy lifestyle, such as habitual cardiorespiratory exercise and a healthful diet, could lead to improved cognitive outcomes with aging. This review aims at detailing how the physiology of the cerebral vascular system changes with age and how these changes lead to differential trajectories of cognitive maintenance or decline. This provides a framework for generating specific mechanistic hypotheses about the efficacy of proposed interventions and lifestyle covariates that contribute to enhanced cognitive well-being. Finally, we discuss the methodological implications of age-related changes in the cerebral vasculature for human cognitive neuroscience research and propose directions for future experiments aimed at investigating age-related changes in the relationship between physiology and cognitive mechanisms.
33 citations
TL;DR: How psychophysiological measures can help elucidate emotional processes that underlie the pathophysiology of MDD as part of an integrated and contextualized approach is emphasized.
Abstract: Major depressive disorder (MDD) is characterized by pervasive mood disturbance as well as deficits in emotional processing, reactivity, and regulation. There is accumulating evidence that MDD is characterized by emotional patterns consistent with environmental disengagement, as reflected in attenuated positive and negative emotional reactivity, consistent with Emotion Context Insensitivity (ECI) theory. However, MDD individuals vary considerably in the extent to which they exhibit specific alterations in patterns of emotional responding. Emotions are complex, multicomponent processes that invoke responses across multiple functional domains and levels of analysis, including subjective experience, behavior, autonomic regulation, cognition, and neural processing. In this article, I review the current state of the literature on emotional responding and MDD from the lens of ECI. I focus on the importance of assessing emotional indices from multiple levels of analysis across development and contexts. I also discuss methodological and measurement issues that may contribute to inconsistent findings. In particular, I emphasize how psychophysiological measures can help elucidate emotional processes that underlie the pathophysiology of MDD as part of an integrated and contextualized approach.
33 citations
TL;DR: It is concluded that emotional mimicry only occurs when the expresser and observer share the intention to affiliate, and this supports the three social functions proposed here: Affiliation, Emotional understanding, and Social regulation.
Abstract: The goal of this manuscript is to provide support for the notion that emotional mimicry is a social act. For this, I will provide a brief overview of recent developments in the domain of emotional mimicry research. I will present the mimicry in social context model of mimicry and evidence for four predictions that set this theory apart. Specifically, based on a review of the literature on emotional mimicry, I conclude that we do not mimic the specific muscle movements we observe, but rather we mimic what we infer from these movements. Furthermore, emotional mimicry only occurs when the expresser and observer share the intention to affiliate. Hence, we are less likely to mimic strangers and do not mimic people we do not like. Interactions in which affiliative mimicry occurs are perceived as more positive, but interactions in which mimicry is antagonistic as more negative. This supports the three social functions proposed here: Affiliation, Emotional understanding, and Social regulation.
32 citations
TL;DR: In this article, a living Bayesian random effects meta-analysis was performed to synthesize the current evidence concerning the effects of transcutaneous auricular vagus nerve stimulation on vagally mediated heart rate variability (vmHRV), a candidate biomarker that has, so far, received most attention in the field.
Abstract: Non-invasive brain stimulation techniques, such as transcutaneous auricular vagus nerve stimulation (taVNS), have considerable potential for clinical use. Beneficial effects of taVNS have been demonstrated on symptoms in patients with mental or neurological disorders as well as transdiagnostic dimensions, including mood and motivation. However, since taVNS research is still an emerging field, the underlying neurophysiological processes are not yet fully understood, and the replicability of findings on biomarkers of taVNS effects has been questioned. The objective of this analysis was to synthesize the current evidence concerning the effects of taVNS on vagally mediated heart rate variability (vmHRV), a candidate biomarker that has, so far, received most attention in the field. We performed a living Bayesian random effects meta-analysis. To keep the synthesis of evidence transparent and up to date as new studies are being published, we developed a Shiny web app that regularly incorporates new results and enables users to modify study selection criteria to evaluate the robustness of the inference across potential confounds. Our analysis focuses on 16 single-blind studies comparing taVNS versus sham in healthy participants. The meta-analysis provides strong evidence for the null hypothesis (g = 0.014, CIshortest = [-0.103, 0.132], BF01 = 24.678), indicating that acute taVNS does not alter vmHRV compared to sham. To conclude, there is no support for the hypothesis that vmHRV is a robust biomarker for acute taVNS. By increasing transparency and timeliness, the concept of living meta-analyses can lead to transformational benefits in emerging fields such as non-invasive brain stimulation.
26 citations
TL;DR: This article provided formulas from classical test theory and generalizability theory for estimating the internal consistency of subtraction-based and residualized difference scores, and applied these formulas to error-related negativity (ERN) and reward positivity (RewP) difference scores.
Abstract: In studies of event-related brain potentials (ERPs), difference scores between conditions in a task are frequently used to isolate neural activity for use as a dependent or independent variable. Adequate score reliability is a prerequisite for studies examining relationships between ERPs and external correlates, but there is no extensive treatment on the suitability of the various available approaches to estimating difference score reliability that focus on ERP research. In the present study, we provide formulas from classical test theory and generalizability theory for estimating the internal consistency of subtraction-based and residualized difference scores. These formulas are then applied to error-related negativity (ERN) and reward positivity (RewP) difference scores from the same sample of 117 participants. Analyses demonstrate that ERN difference scores can be reliable, which supports their use in studies of individual differences. However, RewP difference scores yielded poor reliability due to the high correlation between the constituent reward and non-reward ERPs. Findings emphasize that difference score reliability largely depends on the internal consistency of constituent scores and the correlation between those scores. Furthermore, generalizability theory yields more suitable estimates of internal consistency for subtraction-based difference scores than classical test theory. We conclude that ERP difference scores can show adequate reliability and be useful for isolating neural activity in studies of individual differences.
23 citations
Heidelberg University1, University of Bern2, University of Ulm3, University of Oslo4, Karolinska Institutet5, Stockholm University6, Oslo University Hospital7, University of Rochester Medical Center8, University of Regensburg9, University of Parma10, Brighton and Sussex Medical School11, University of Minnesota12, Public Health Research Institute13, Humboldt University of Berlin14, Max Planck Society15, University of Pittsburgh16, Monash University17, Louisiana State University18, Northeastern University19, University of Bergen20, Free University of Berlin21, Virginia Tech22, University of Greifswald23, King's College London24, University College London25, Stockholm County Council26, University of Southern California27, University of Sussex28, University of Kiel29, Haukeland University Hospital30, Sapienza University of Rome31, Kochi University of Technology32, University of Reading33, University of Oxford34, University of California, Irvine35, Boston University36, University of Melbourne37, University of Potsdam38, Southwest University39
TL;DR: Results suggest a decline in HRV as well as CT with increasing age and reveal an important association between CT and cardiac parasympathetic activity with implications for healthy aging and longevity that should be studied further in longitudinal research.
Abstract: Understanding the association between autonomic nervous system [ANS] function and brain morphology across the lifespan provides important insights into neurovisceral mechanisms underlying health and disease. Resting-state ANS activity, indexed by measures of heart rate [HR] and its variability [HRV] has been associated with brain morphology, particularly cortical thickness [CT]. While findings have been mixed regarding the anatomical distribution and direction of the associations, these inconsistencies may be due to sex and age differences in HR/HRV and CT. Previous studies have been limited by small sample sizes, which impede the assessment of sex differences and aging effects on the association between ANS function and CT. To overcome these limitations, 20 groups worldwide contributed data collected under similar protocols of CT assessment and HR/HRV recording to be pooled in a mega-analysis (N = 1,218 (50.5% female), mean age 36.7 years (range: 12-87)). Findings suggest a decline in HRV as well as CT with increasing age. CT, particularly in the orbitofrontal cortex, explained additional variance in HRV, beyond the effects of aging. This pattern of results may suggest that the decline in HRV with increasing age is related to a decline in orbitofrontal CT. These effects were independent of sex and specific to HRV; with no significant association between CT and HR. Greater CT across the adult lifespan may be vital for the maintenance of healthy cardiac regulation via the ANS-or greater cardiac vagal activity as indirectly reflected in HRV may slow brain atrophy. Findings reveal an important association between CT and cardiac parasympathetic activity with implications for healthy aging and longevity that should be studied further in longitudinal research.
23 citations
TL;DR: In this article, eye-based features have been used to measure mental fatigue and explore the relation of eyebased features to mental fatigue, including saccades as the most promising category, with saccade mean and peak velocity providing quick access to cognitive states within 30 min of fatiguing activity.
Abstract: Mental fatigue measurement techniques utilize one or a combination of the cognitive, affective, and behavioral responses of the body. Eye-tracking and electrooculography, which are used to compute eye-based features, have gained momentum with increases in accuracy and robustness of the lightweight equipment emerging in the markets and can be used for objective and continuous assessment of mental fatigue. The main goal of this systematic review was to summarize the various eye-based features that have been used to measure mental fatigue and explore the relation of eye-based features to mental fatigue. The review process, following the preferred reporting items for systematic reviews and meta-analyses, used the electronic databases Web of Science, Scopus, ACM digital library, IEEE Xplore, and PubMed. Of the 1,385 retrieved documents, 34 studies met the inclusion criteria, resulting in 21 useful eye-based features. Categorizing these into eight groups revealed saccades as the most promising category, with saccade mean and peak velocity providing quick access to the cognitive states within 30 min of fatiguing activity. Complex brain networks involving sympathetic and parasympathetic nervous systems control the relation of mental fatigue to tonic pupil size and have the potential to indicate mental fatigue in controlled experimental conditions. Other categories, like blinks, are derived from the field of sleep research and should be used with caution. Several limitations emerged in the analysis, including varied experimental methods, use of dim lighting during the experiment (that could possibly also induce sleepiness), and use of unclear data analysis techniques, thereby complicating comparisons between studies.
22 citations
TL;DR: In this article, the authors examined whether initial P300 amplitude prospectively predicted changes in depressive symptoms among a community sample of 58 adults (mean age = 38.86 years old, 81% female) with a current depressive disorder.
Abstract: Neurocognitive impairments commonly observed in depressive disorders are thought to be reflected in reduced P300 amplitudes. To date, depression-related P300 amplitude reduction has mostly been demonstrated cross-sectionally, while its clinical implication for the course of depression remains largely unclear. Moreover, the relationship between P300 and specific clinical characteristics of depression is uncertain. To shed light on the functional significance of the P300 in depression, we examined whether initial P300 amplitude prospectively predicted changes in depressive symptoms among a community sample of 58 adults (mean age = 38.86 years old, 81% female) with a current depressive disorder. This sample was assessed at two-time points, separated by approximately nine months (range = 6.6-15.9). At the initial visit, participants completed clinical interviews, self-report measures, and a flanker task, while EEG was recorded to derive P300 amplitude. At the follow-up visit, participants again completed the same clinical interviews and self-report measures. Results indicated that a reduced P300 amplitude at the initial visit was associated with higher total depressive symptoms at follow-up, even after controlling for initial depressive symptoms. These data indicate the potential clinical utility for the P300 as a neural marker of disease course among adults with a current depressive disorder. Future research may target P300 in interventions to determine whether depression-related outcomes can be improved.
TL;DR: Reference results and an investigation of methodological considerations for the ERP (reward positivity) and frequency (delta and theta power) correlates of feedback evaluation with a large sample size are provided and selected methodological recommendations for standardization of future research are concluded.
Abstract: Human learning, at least in part, appears to be dependent on the evaluation of how outcomes of our actions align with our expectations. Over the past 23 years, electroencephalography (EEG) has been used to probe the neural signatures of feedback processing. Seminal work demonstrated a difference in the human event-related potential (ERP) dependent on whether people were processing correct or incorrect feedback. Since then, these feedback evoked ERPs have been associated with reinforcement learning and conflict monitoring, tied to subsequent behavioral adaptations, and shown to be sensitive to a wide range of factors (e.g., Parkinson's disease). Recently, research has turned to frequency decomposition techniques to examine how changes in the EEG power spectra are related to underlying learning mechanisms. Although the literature on the neural correlates of feedback processing is vast, there are still methodological discrepancies and differences in results across studies. Here, we provide reference results and an investigation of methodological considerations for the ERP (reward positivity) and frequency (delta and theta power) correlates of feedback evaluation with a large sample size. Specifically, participants (n = 500) performed a two-armed bandit task while we recorded EEG. Our findings provide key information about the data characteristics and relationships that exist between the neural signatures of feedback evaluation. Additionally, we conclude with selected methodological recommendations for standardization of future research. All data and scripts are freely provided to facilitate open science.
TL;DR: The authors found that salient distractors in visual search are actively suppressed by the fact that these objects elicit PD components believed to be associated with inhibition, which is inconsistent with the serial scanning hypothesis and supports the idea that the PD reflects signal suppression.
Abstract: The hypothesis that salient distractors in visual search are actively suppressed is supported by the fact that these objects elicit PD components believed to be associated with inhibition. This account was challenged by Kerzel and Burra (2020), who found that a PD to lateral colour singleton distractors was followed by a contralateral negativity, which they interpreted as an N2pc indicative of attentional capture. As this would be at odds with successful distractor suppression, they proposed an alternative lateral-first serial scanning hypothesis, which assumes that the PD might actually be an N2pc elicited when a lateral context item is selected. We tested this hypothesis by measuring lateralized ERP components to search displays with two lateral and two vertical midline items, including a colour singleton and a shape-defined target. Colour singletons triggered PD components not only in blocks where attention was unfocused because target location was unpredictable, but critically also in blocks where targets only appeared on the midline and participants had no reason to attend to lateral items. This is inconsistent with the serial scanning hypothesis and supports the idea that the PD reflects signal suppression. PD components to singleton distractors were followed by a contralateral negativity, which we interpreted as a second PD elicited by non-salient distractors on the opposite side. Our sequential inhibition account reconciles conflicting results of recent studies and emphasizes the role of inhibitory processes during attentional target selection in visual search.
TL;DR: In this paper, the authors conducted a qualitative analysis of the literature and identified optimal frequencies as NFT targets for specifically improving executive functions, and concluded that more rigorous NFT studies are required in order to overcome the methodological weaknesses that they encountered in their qualitative analysis.
Abstract: Electroencephalographic (EEG)-neurofeedback training (NFT) is a promising technique that supports individuals in learning to modulate their brain activity to obtain cognitive and behavioral improvements. EEG-NFT is gaining increasing attention for its potential "peak performance" applications on healthy individuals. However, evidence for clear cognitive performance enhancements with healthy adults is still lacking. In particular, whether EEG-NFT represents an effective technique for enhancing healthy adults' executive functions is still controversial. Therefore, the main objective of this systematic review is to assess whether the existing EEG-NFT studies targeting executive functions have provided reliable evidence for NFT effectiveness. To this end, we conducted a qualitative analysis of the literature since the limited number of retrieved studies did not allow us meta-analytical comparisons. Moreover, a second aim was to identify optimal frequencies as NFT targets for specifically improving executive functions. Overall, our systematic review provides promising evidence for NFT effectiveness in boosting healthy adults' executive functions. However, more rigorous NFT studies are required in order to overcome the methodological weaknesses that we encountered in our qualitative analysis.
TL;DR: The multifaceted effects of aging and the contributions of age-related pathologies on structural and functional integrity of the cerebral microcirculation as they has been investigated in animal models of aging are discussed.
Abstract: The present and future research efforts in cognitive neuroscience and psychophysiology rely on the measurement, understanding, and interpretation of blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to effectively investigate brain function. Aging and age-associated pathophysiological processes change the structural and functional integrity of the cerebrovasculature which can significantly alter how the BOLD signal is recorded and interpreted. In order to gain an improved understanding of the benefits, drawbacks, and methodological implications for BOLD fMRI in the context of cognitive neuroscience, it is crucial to understand the cellular and molecular mechanism of age-related vascular pathologies. This review discusses the multifaceted effects of aging and the contributions of age-related pathologies on structural and functional integrity of the cerebral microcirculation as they has been investigated in animal models of aging, including age-related alterations in neurovascular coupling responses, cellular and molecular mechanisms involved in microvascular damage, vascular rarefaction, blood-brain barrier disruption, senescence, humoral deficiencies as they relate to, and potentially introduce confounding factors in the interpretation of BOLD fMRI.
TL;DR: Evidence is shown that sympathetic and renal influences known to increase blood pressure also impact brain integrity, and stress, cardiovascular reactions to stress, and diet/obesity may provide a starting point for defining the independent and interacting effects of aging and increasing blood pressure on the brain.
Abstract: The majority of individuals over an age of 60 have hypertension. Elevated blood pressure and older age are associated with very similar changes in brain structure and function. We review the parallel brain changes associated with increasing age and blood pressure. This review focuses on joint associations of aging and elevated blood pressure with neuropsychological function, regional cerebral blood flow responses to cognitive and metabolic challenges, white matter disruptions, grey matter volume, cortical thinning, and neurovascular coupling. Treatment of hypertension ameliorates many of these changes but fails to reverse them. Treatment of hypertension itself appears more successful with better initial brain function. We show evidence that sympathetic and renal influences known to increase blood pressure also impact brain integrity. Possible central mechanisms contributing to the course of hypertension and aging are then suggested. An emphasis is placed on psychologically relevant factors: stress, cardiovascular reactions to stress, and diet/obesity. The contribution of some of these factors to biological aging remains unclear and may provide a starting point for defining the independent and interacting effects of aging and increasing blood pressure on the brain.
TL;DR: In this paper, the authors investigated the time course of and neural oscillation underlying the WF effect in handwritten production and found that WF modulated the evoked and induced theta-band (4-8 Hz) neural oscillations in the time window of around 36-240 and 244-472 ms, respectively.
Abstract: It has been widely documented that word frequency (WF) modulates language processing in various input and output modalities. WF effect has also been reported in the domain of written production; however, how WF affects written production is a controversial issue. The present study attempts to investigate the time course of and neural oscillation underlying the WF effect in handwritten production. Participants were asked to handwrite pictures names of high versus low WF, while concurrently recording EEG. EEG trials were extracted time-locked to picture onsets and then submitted to event-related potential analysis and time-frequency analysis. WF affected ERPs in the time windows of around 98-160 and 282-360 ms after picture onsets. More importantly, WF modulated the evoked and induced theta-band (4-8 Hz) neural oscillations in the time window of around 36-240 and 244-472 ms, respectively. Considering the time course of language production and the role of theta-band oscillation in long-term memory retrieval, we suggest that the two stages of the WF effect, respectively, reflect conceptual preparation and retrieval of orthographic word-forms in written production.
TL;DR: In this paper, the authors used a case-by-case approach to determine the emotional modulation of the early posterior negativity (EPN) and late positive potential (LPP) at the level of individual case.
Abstract: Stimuli encountered in the environment are continuously evaluated according to their affective stimulus significance. Numerous event-related potential studies have shown that the early posterior negativity (EPN) and the late positive potential (LPP) are larger for pictures high in emotional arousal compared to low arousing images. Here, we used a case-by-case approach to determine the emotional modulation of the EPN and LPP at the level of the individual case. We probed the effect in three studies regarding behavior systems of predator fear, disease avoidance, and sexual reproduction. In each study, high and low arousing pictures from the respective behavior system were presented and event-related brain potentials measured. At the group level, previous findings regarding an enhanced EPN and LPP for high compared to low arousing stimuli were replicated. Novel findings were observed when analyzing each case individually. The majority of participants showed significantly larger EPN and LPP amplitudes to pictures showing threatening compared to harmless animals (15 and 16 out of 16 tests, respectively), images of disease and mutilation compared to neutral people (15 and 17 out of 18 tests, respectively), and high-arousing erotic compared to romantic pictures (17 and 17 out of 17 tests, respectively). Further analyses exploring the tradeoff between specificity and sensitivity suggest reliance on picture categories of sexual reproduction and disease avoidance. Overall, the present findings demonstrate that the case-by-case approach can be useful for revealing a general principle of emotional stimulus processing common-to-all. Implications for the reproducibility of the findings and biomarker development are discussed.
TL;DR: The data suggest that the effect of task difficulty on the experience of tiredness from listening may go undetected using the traditional approach of collecting a single data point at the end of a listening block.
Abstract: Effort during listening is commonly measured using the task-evoked pupil response (TEPR); a pupillometric marker of physiological arousal. However, studies to date report no association between TEPR and perceived effort. One possible reason for this is the way in which self-report effort measures are typically administered, namely as a single data point collected at the end of a testing session. Another possible reason is that TEPR might relate more closely to the experience of tiredness from listening than to effort per se. To examine these possibilities, we conducted two preregistered experiments that recorded subjective ratings of effort and tiredness from listening at multiple time points and examined their covariance with TEPR over the course of listening tasks varying in levels of acoustic and attentional demand. In both experiments, we showed a within-subject association between TEPR and tiredness from listening, but no association between TEPR and effort. The data also suggest that the effect of task difficulty on the experience of tiredness from listening may go undetected using the traditional approach of collecting a single data point at the end of a listening block. Finally, this study demonstrates the utility of a novel correlation analysis technique ("rmcorr"), which can be used to overcome statistical power constraints commonly found in the literature. Teasing apart the subjective and physiological mechanisms that underpin effortful listening is a crucial step toward addressing these difficulties in older and/or hearing-impaired individuals.
TL;DR: In this article, the authors examined the impact of manipulating exhalation to inhalation ratio (E:I) on heart rate variability without altering the intrinsic breathing rate of healthy individuals.
Abstract: Heart rate variability (HRV) is a well-established surrogate of cardiac and emotional health that reflects the balance between sympathetic and parasympathetic activity of the autonomic nervous system. We examined the impact of manipulating exhalation to inhalation ratio (E:I) on HRV, without altering the intrinsic breathing rate of healthy individuals. We hypothesized that a longer exhalation relative to inhalation (E:I > 1) would shift HRV metrics in a direction consistent with increased parasympathetic activity. Twenty-eight individuals (16 young [6M, age = 21-28];12 older adults [6M, age = 66-80]) completed a task during which they paced breathing according to their intrinsic respiratory rate, but altered onset of exhalation and inhalation according to 1:1 sound cue (equal exhalation and inhalation duration) or 2:1 cue (exhalation twice as long as inhalation). Paced 1:1 breathing followed these task conditions to examine residual effects. Estimates of actual E:I ratio based on thoracic movement were 1.08(0.16) for 1:1 task and 1.33(0.20) for 2:1 task, which were significantly different from one another. HRV metrics derived from electrocardiogram included root mean square of the successive differences between normal heartbeats (RMSSD) and high-frequency (HF) HRV. Analyses of HRV metrics by block showed that RMSSD and HF-HRV were higher in the 2:1 task condition compared to 1:1. Time series analysis showed that HF-HRV increased after the end of the 2:1 task block and remained elevated for four minutes. These findings suggest that longer duration of exhalation relative to inhalation, without altering breathing rate, acutely increased RMSSD and HF-HRV, consistent with enhancement of cardiac vagal tone.
TL;DR: This study is the first to examine changes in heart rate and vagally mediated HR variability, as assessed by Respiratory Sinus Arrythmia (RSA), after a longer duration of nature exposure, and demonstrated a significant decrease in RSA and a significant increase in HR during the trip compared to before or after the trip.
Abstract: Stress Recovery Theory (SRT) suggests that time spent in nature reduces stress. While many studies have examined changes in stress physiology after exposure to nature imagery, nature virtual reality, or nature walks, this study is the first to examine changes in heart rate (HR) and vagally mediated HR variability, as assessed by Respiratory Sinus Arrythmia (RSA), after a longer duration of nature exposure. Consistent with SRT, we hypothesized that immersion in nature would promote stress recovery, as indexed by an increase in RSA and a decrease in HR. We also predicted that exposure to nature would improve self-reported mood. We used a within-subjects design (N = 67) to assess changes in peripheral physiology before, during, and after a 5-day nature trip. Results demonstrated a significant decrease in RSA and a significant increase in HR during the trip compared to before or after the trip, suggesting that immersion in nature is associated with a shift toward parasympathetic withdrawal and possible sympathetic activation. These results were contrary to our hypotheses and may suggest increased attentional intake or presence of emotions associated with an increase in sympathetic activation. We also found an improvement in self-reported measures of mood during the trip compared to before or after the trip, confirming our hypotheses and replicating previous research. Implications of this study are discussed in the context of SRT.
Istanbul Medipol University1, Maastricht University2, Huntington Medical Research Institutes3, University of Chieti-Pescara4, Sapienza University of Rome5, Alzheimer's Association6, Trinity College, Dublin7, University of Toronto8, Centre for Addiction and Mental Health9, Vertex Pharmaceuticals10, Dokuz Eylül University11
TL;DR: Delta and theta phase-locked EROs during oddball tasks may be useful neurophysiological biomarkers of cognitive systems at work in heuristic and intervention clinical trials performed in AD patients, but more research is needed regarding their potential role for other dementias.
Abstract: Cerebrospinal and structural-molecular neuroimaging in-vivo biomarkers are recommended for diagnostic purposes in Alzheimer's disease (AD) and other dementias; however, they do not explain the effects of AD neuropathology on neurophysiological mechanisms underpinning cognitive processes. Here, an Expert Panel from the Electrophysiology Professional Interest Area of the Alzheimer's Association reviewed the field literature and reached consensus on the event-related electroencephalographic oscillations (EROs) that show consistent abnormalities in patients with significant cognitive deficits due to Alzheimer's, Parkinson's (PD), Lewy body (LBD), and cerebrovascular diseases. Converging evidence from oddball paradigms showed that, as compared to cognitively unimpaired (CU) older adults, AD patients had lower amplitude in widespread delta (>4 Hz) and theta (4-7 Hz) phase-locked EROs as a function of disease severity. Similar effects were also observed in PD, LBD, and/or cerebrovascular cognitive impairment patients. Non-phase-locked alpha (8-12 Hz) and beta (13-30 Hz) oscillations were abnormally reduced (event-related desynchronization, ERD) in AD patients relative to CU. However, studies on patients with other dementias remain lacking. Delta and theta phase-locked EROs during oddball tasks may be useful neurophysiological biomarkers of cognitive systems at work in heuristic and intervention clinical trials performed in AD patients, but more research is needed regarding their potential role for other dementias.
TL;DR: It is demonstrated that weight-related reductions in cerebral blood flow can be modified by 10% weight loss over the course of 12 months and that interventions involving exercise exposure may provide unique effects on cerebralBlood flow compared to interventions involving only diet.
Abstract: Overweight and obesity may damage the cerebrovascular architecture, resulting in a significant reduction in cerebral blood flow. To date, there have been few randomized clinical trials (RCT) examining whether obesity-related reductions in cerebral blood flow could be modified by weight loss. Further, it is unknown whether the behavioral intervention strategy for weight loss (i.e., diet alone or diet combined with exercise) differentially influences cerebral blood flow in adults with overweight or obesity. The primary aim of this study was to determine whether a 12-month RCT of exercise and diet increases cerebral blood flow in 125 midlife (Mean age ± SD = 44.63 ± 8.36 years) adults with overweight and obesity. Further, we evaluated whether weight loss via diet combined with aerobic exercise has an added effect on changes in cerebral blood flow compared to weight loss via diet alone and whether there were regionally specific effects of the type of behavioral intervention on cerebral blood flow patterns. Consistent with our predictions, a 12-month diet and exercise program resulting in 10% weight loss increased cerebral blood flow. These effects were widespread and extended throughout frontal, parietal, and subcortical regions. Further, there was some regional specificity of effects for both diet-only and diet combined with exercise. Our results demonstrate that weight-related reductions in cerebral blood flow can be modified by 10% weight loss over the course of 12 months and that interventions involving exercise exposure may provide unique effects on cerebral blood flow compared to interventions involving only diet.
TL;DR: In this article, the effects of mindfulness-based interventions on state mindfulness, perceived stress, and indicators of sympathetic-nervous-system (saliva alpha-amylase, sAA) and hypothalamic-pituitary-adrenalaxis(saliva cortisol, sCort) activation in daily life through an ecological momentary assessment approach were examined.
Abstract: A large body of literature has shown the effectiveness of mindfulness-based interventions (MBI) on stress-reduction. However, little is known about their effects on psychobiological stress-markers in daily life through an ecological momentary assessment approach. Our study examines the effects of MBI on state mindfulness, perceived stress, and indicators of sympathetic-nervous-system (saliva alpha-amylase, sAA) and hypothalamic-pituitary-adrenal-axis (saliva cortisol, sCort) activation in daily life. Twenty-eight individuals participated in a three-month MBI (IG) and were compared to 46 controls (CG). An ecological momentary assessment (EMA) was used to assess mindfulness, stress, sAA and sCort at six measurements per day on two days each before and after the MBI. Multilevel-modeling was used to analyze the data on a moment-to-moment and averaged day-level. The IG showed decreased sAA levels (AUCg) from pre to post, while the CG showed increases. Furthermore, diurnal decreases in sCort (AUCi) were pronounced in the IG compared to the CG. On a momentary basis, mindfulness was associated with lower stress and sAA levels, but not sCort. As such, we show that MBI can reduce sympathetic and to a lesser extent hypothalamic-pituitary-adrenal activation in daily life. Increased mindfulness can momentarily decrease stress and stress-related autonomic activation with implications for health. Our results emphasize the importance of brief interventions that can be easily integrated into everyday life.
TL;DR: In this article, the authors conducted an fMRI-study with 75 healthy participants who completed three tasks: imitation, empathy, and theory of mind, and found common activation in inferior frontal gyrus, inferior parietal cortex, fusiform gyrus and posterior superior temporal sulcus.
Abstract: According to the theory of embodied simulation, mirror neurons (MN) in our brain's motor system are the neuronal basis of all social-cognitive processes. The assumption of such a mirroring process in humans could be supported by results showing that within one person the same region is involved in different social cognition tasks. We conducted an fMRI-study with 75 healthy participants who completed three tasks: imitation, empathy, and theory of mind. We analyzed the data using group conjunction analyses and individual shared voxel counts. Across tasks, across and within participants, we find common activation in inferior frontal gyrus, inferior parietal cortex, fusiform gyrus, posterior superior temporal sulcus, and amygdala. Our results provide evidence for a shared neural basis for different social-cognitive processes, indicating that interpersonal understanding might occur by embodied simulation.
TL;DR: In this article, the authors systematically assess the research using event-related potentials (ERPs) as outcome measures in ABM protocols and explore the extent to which the ERPs modified by ABM represent earlier or later stages of information processing.
Abstract: Attention bias modification (ABM) was initially developed with the goal of reducing attentional bias to threat-and subsequently anxious symptoms-in individuals with heightened anxiety. Although controversial, ABM appears to be generally effective in achieving this goal. Yet, the primary outcome measure of ABM (i.e., the reaction time-based differences score) has poor reliability and temporal resolution, which limits the inferences that can be drawn. In contrast, event-related potentials (ERPs) have superior reliability as well as temporal resolution and may therefore be better outcome measures of ABM. In this review, I systematically assess the research using ERPs as outcome measures in ABM protocols. I focus on the extent to which the ERPs modified by ABM represent earlier or later stages of information processing. In addition, I explore the extent to which ABM produces near and/or far transfer of learning effects on ERP measures. The reviewed literature suggests that ERPs are promising outcome measures of ABM. ABM modulates the effects of affective stimuli on posterior visually evoked ERPs (i.e., P1) as well as ERPs at anterior electrodes (i.e., P2, N2, and ERN). Based on the state of the field, several directions for future research are identified.
TL;DR: This paper found a negative correlation between trait boredom proneness and power in the alpha and theta bands during the resting state and higher levels of task-induced boredom were associated with reduced amplitudes for the P3 and error-related negativity event-related potentials.
Abstract: Boredom, the unfulfilled desire to be engaged in a satisfying mental activity, is an aversive state characterized by poor self-regulation. There is ample evidence that both state and trait boredom are associated with failures of attention in both experimental and everyday settings. The neural correlates of boredom, however, remain underexplored. We recorded electroencephalographic signal from 83 participants during a resting state and while performing a go/no-go task. We found a negative correlation between trait boredom proneness and power in the alpha and theta bands during the resting state. Furthermore, higher levels of task-induced boredom were associated with reduced amplitudes for the P3 and error-related negativity event-related potentials. Increased commission error rates were also associated with higher levels of task-induced boredom. We conclude that state and trait boredom are associated with inadequate engagement of attentional resources.
TL;DR: This paper investigated the effects of trait anxiety on ERP differences between fearful and neutral faces across three different tasks and found that high trait anxiety was associated with smaller EPN differences between neutral faces and fearful faces during perceptual discrimination task.
Abstract: Fearful facial expressions are prioritized across different stages of information processing as reflected by early, mid-latency, and late components of event-related brain potentials (ERP). Trait anxiety has been proposed to modulate these responses, but it is yet unclear how such modulations depend on feature-based attention. In this preregistered study (N = 80), we investigated the effects of trait anxiety on ERP differences between fearful and neutral faces across three different tasks. Participants had to discriminate either the orientation of lines overlaid onto the faces, the gender of the face, or the emotional expression, thus increasing attention to emotionally relevant facial features across the tasks. Fearful versus neutral faces elicited increased P1 and N170 amplitudes across tasks and potentiated amplitudes when attention was directed to faces (early posterior negativity [EPN]) or the expression (EPN and late positive potential). Higher trait anxiety was related to smaller EPN differences between fearful and neutral faces during the perceptual discrimination task. This early relationship suggests reduced instead of amplified processing of fearful faces for high trait anxious participants under perceptual distraction.
TL;DR: Overall, among the four tested deep breathing techniques, loaded breathing was associated with enhanced cardiovascular effects and pursed-lips breathing with better emotional responses, while also enhancing cardiovascular effects (albeit less than loaded breathing).
Abstract: Deep breathing exercises are commonly used for several health conditions including pain and hypertension. Various techniques are available to practice deep breathing, whereas possible differential psychophysiological effects have not been investigated. We compared four deep breathing techniques and examined outcomes in blood pressure variability, respiratory sinus arrhythmia, baroreflex function, and emotional state. Healthy adult volunteers performed pursed-lips breathing, left and right unilateral nostril breathing, and deep breathing with an inspiratory threshold load (loaded breathing), all at a frequency of 0.1 Hz (i.e., controlled breathing) and for three minutes each. Results showed that blood pressure variability was higher during loaded breathing versus other conditions and higher during pursed-lips breathing versus left and right unilateral nostril breathing. Respiratory sinus arrhythmia was higher during loaded breathing versus other conditions and higher during pursed-lips breathing versus left unilateral nostril breathing. The effect of breathing condition on respiratory sinus arrhythmia was mediated by alterations in blood pressure variability. There was no difference between the breathing conditions in baroreflex sensitivity or effectiveness. Participants rated pursed-lips breathing as more calming and pleasant and with more sense of control (vs. other conditions). Overall, among the four tested deep breathing techniques, loaded breathing was associated with enhanced cardiovascular effects and pursed-lips breathing with better emotional responses, while also enhancing cardiovascular effects (albeit less than loaded breathing). These findings can be informative in applying deep breathing techniques as self-management interventions for health conditions, in which baroreceptors stimulation and autonomic and emotional modulations can be beneficial, such as pain and hypertension.
TL;DR: In this paper, the authors analyzed cou-ple´s cardiac synchrony as measured by heart rate and heart rate variability (HRV) and found evidence for negative (anti-phase) synchrony of couple´s HRV and positive (inphase) synchronization of HR.
Abstract: The degree to which romantic partners’ autonomic responses are coordinated, represented by their pattern of physiological synchrony, seems to capture important aspects of the reciprocal influence and co-regulation between spouses. In this study, we analyzed cou-ple´s cardiac synchrony as measured by heart rate (HR) and heart rate variability (HRV). A sample of twenty-seven couples (N = 54) performed a structured interaction task in the lab where they discussed positive and negative aspects of the relationship. During the interaction, their cardiac measures (HR and HRV) were recorded using the Biopac Sys-tem. Additional assessment, prior to the lab interaction task, included self-report measures of empathy (Interpersonal Reactivity Index and Interpersonal Reactivity Index for Couples) and relationship satisfaction (Revised Dyadic Adjustment Scale). Synchrony computation was based on the windowed cross-correlation of both partner´s HR and HRV time series. In order to control for random synchrony, surrogate controls were cre-ated using segment-wise shuffling. Our results confirmed the presence of cardiac syn-chrony during the couple´s interaction when compared to surrogate testing. Specifically, we found evidence for negative (anti-phase) synchrony of couple´s HRV and positive (in-phase) synchrony of HR. Further, both HRV and HR synchronies were associated with several dimensions of self-report data. This study suggests that cardiac synchrony, partic-ularly the direction of the co-variation in the partners´ physiological time series, may have an important relational meaning in the context of marital interactions