Accelerometer-based and self-reported physical activity and sedentary time and their relationships with the P300 in a Go/No-Go task in older adults

Older adults who experience cognitive decline are more likely to have a reduced quality of life. Identifying lifestyle factors that may influence cognitive processing and in turn improve quality of life during older adulthood is an important area of interest. Cognitive function, as measured by the P300 event-related potential (ERP), has been noted to be modified by physical activity; however, no study to date has examined relationships between this neurophysiological measure and physical activity and sedentary time in older adults. Furthermore, there is a gap in understanding as to whether physical activity and sedentary time assessed using self-reported and accelerometer-based methods similarly relate to the P300. This study aimed to assess the P300 during a Go/No-Go task in relation to self-reported and accelerometer-based physical activity and sedentary time in a community sample of 75 older adults. Results indicated that participants engaging in more moderate-to-vigorous physical activity had larger P300 amplitudes across self-reported and accelerometer-based measurements; however, no relationships between sedentary time and P300 amplitude were observed. Notably, accelerometer-based moderate-to-vigorous physical activity explained P300 amplitudes over and above self-reported moderate-to-vigorous physical activity-an effect that remained significant even after accounting for age. Although these results highlight the importance of moderate-to-vigorous physical activity in relation to cognitive function, as measured via the P300 in older adults, a secondary analysis indicated that engaging in lifestyle activity may have similar effects on the P300 as moderate-to-vigorous physical activity. In sum, the present study highlights the role of habitual engagement in physical activity as a possible means for supporting cognitive function during the aging process.

Cumulative lifetime acute stressor exposure interacts with reward responsiveness to predict longitudinal increases in depression severity in adolescence

BACKGROUND

Life stress and blunted reward processing each have been associated with the onset and maintenance of major depressive disorder. However, much of this work has been cross-sectional, conducted in separate lines of inquiry, and focused on recent life stressor exposure, despite the fact that theories of depression posit that stressors can have cumulative effects over the lifespan. To address these limitations, we investigated whether acute and chronic stressors occurring over the lifespan interacted with blunted reward processing to predict increases in depression over time in healthy youth.

METHOD

Participants were 245 adolescent girls aged 8-14 years old (Mage = 12.4, s.d. = 1.8) who were evaluated at baseline and two years later. The reward positivity (RewP), an event-related potential measure of reward responsiveness, was assessed at baseline using the doors task. Cumulative lifetime exposure to acute and chronic stressors was assessed two years later using the Stress and Adversity Inventory for Adolescents (Adolescent STRAIN). Finally, depressive symptoms were assessed at both baseline and follow-up using the Children's Depression Inventory.

RESULTS

As hypothesized, greater lifetime acute stressor exposure predicted increases in depressive symptoms over two years, but only for youth exhibiting a blunted RewP. This interaction, however, was not found for chronic stressors.

CONCLUSIONS

Lifetime acute stressor exposure may be particularly depressogenic for youth exhibiting a blunted RewP. Conversely, a robust RewP may be protective in the presence of greater acute lifetime stressor exposure.

Influences of age and pubertal development on P300 amplitude trajectory across two years in female adolescents

The P300 event-related potential (ERP) has been extensively studied across the human lifespan. However, many studies examining age-related effects are cross-sectional, and few have considered the unique role that pubertal development may have on P300 developmental trajectories. The current study examined whether age, pubertal maturation or their interaction predicted changes in P300 amplitude over two years among 129 females between the ages of 8 and 15 years at baseline. Participants completed a flanker task while EEG was recorded at a baseline and two-year follow-up visit. Both baseline age and increased pubertal development were associated with smaller P300 amplitude at follow-up. However, the influence of age was qualified by an interaction between age and pubertal maturation: among younger girls only, increased pubertal development predicted decreases in P300, whereas decreased pubertal development predicted increases in P300. These data indicate that pubertal timing impacts neurodevelopmental changes in P300 amplitude - such that high versus low pubertal development among 8- to 10-year-old girls predicted differential trajectories of neural activity. In light of links between reduced P300 and mental health disorders, such as depression, future studies might examine whether neurodevelopmental changes influenced by early-onset pubertal development could account for increases in these mental health problems.

Corporal Punishment Is Uniquely Associated With a Greater Neural Response to Errors and Blunted Neural Response to Rewards in Adolescence

BACKGROUND

Although corporal punishment is a common form of punishment with known negative impacts on health and behavior, how such punishment affects neurocognitive systems is relatively unknown.

METHODS

To address this issue, we examined how corporal punishment affected neural measures of error and reward processing in 149 adolescent boys and girls of ages 11 to 14 years (mean age [SD] = 11.02 [1.16]). Corporal punishment experienced over the lifetime was assessed using the Stress and Adversity Inventory. In addition, participants completed a flankers task and a reward task to measure the error-related negativity and reward positivity, respectively, as well as measures of anxiety and depressive symptoms.

RESULTS

As hypothesized, participants who experienced lifetime corporal punishment reported more anxiety and depressive symptoms. Experiencing corporal punishment was also related to a larger error-related negativity and blunted reward positivity. Importantly, corporal punishment was independently related to a larger error-related negativity and a more blunted reward positivity beyond the impact of harsh parenting and lifetime stressors.

CONCLUSIONS

Corporal punishment appears to potentiate neural response to errors and decrease neural response to rewards, which could increase risk for anxiety and depressive symptoms.

Error-related brain activity in pediatric major depressive disorder: An ERP and time-frequency investigation

BACKGROUND

The error-related negativity (ERN) reflects individual differences in error monitoring. However, findings on the ERN in adult and adolescent depression have been inconsistent. Analyzing electroencephalographic (EEG) data in both the time- and time-frequency domain can be useful to better quantify neural response to errors. The present study aimed at examining electrocortical measures of error monitoring in early adolescents with and without depression.

METHOD

EEG activity was collected during an arrowhead version of the flanker task in 29 (25 females) early adolescents with depression and 34 without MDD (29 females).

RESULTS

The depression group showed reduced ERN amplitude, reduced error-related theta power and increased error-related beta power compared to the control group. When all variables that related to MDD diagnosis were considered simultaneously, both theta and beta power, but not the ERN, were independently related to an increased likelihood of being diagnosed with depression.

CONCLUSIONS

By examining both time-domain and separate time-frequency measures, the present study provided novel evidence on error monitoring alterations in youth depression, suggesting that depression during adolescence may be characterized by reduced error monitoring (i.e., reduced ERN and error-related theta) and post-error inhibition (i.e., greater error-related beta power). These results support that time-frequency measures might be better suited for examining error-related neural activity in MDD relative to time-domain measures.

Depression reduces neural correlates of reward salience with increasing effort over the course of the progressive ratio task

BACKGROUND

Depressive disorders have been associated with altered effort-cost decision making (ECDM) in behavioral investigations, such as a decreased willingness to expend effort for reward attainment. However, little is known about neural mechanisms implicated in altered ECDM.

METHODS

The study investigates neural correlates of reward attainment during a progressive ratio task in participants with a current depressive disorder (n = 65) and never-depressed healthy individuals (n = 44). On each trial, participants completed an increasing number of button presses to attain a fixed monetary reward, indicated by an auditory reward signal. Participants could decide to quit the task anytime (breakpoint). EEG was recorded during the task and P300 amplitudes were examined in response to the auditory signal of reward attainment.

RESULTS

There was no difference in breakpoint, as both groups completed comparable numbers of button presses. In contrast, results from mixed-effects models of trial-level ERP responses indicated depression-related effects on P300 amplitudes over the course of the task. Generally, the reward-locked P300 increased with ascending effort expenditure; however, compared to healthy participants, individuals with current depression were characterized by an attenuated trajectory of the reward-locked P300, pointing towards decreased reactivity to reward attainment with increasing effort.

LIMITATIONS

Sample size and reward magnitude were possibly not large enough to detect differences in breakpoint.

CONCLUSIONS

The results of the current study demonstrate that the investigation of reward-related P300 trajectory may represent an informative novel addition to the progressive ratio task, which could help shed light on depression-related alterations in motivation and ECDM.

Emotion regulation and the late positive potential (LPP) in older adults

Emotion regulation (ER) processes in older adults may be important for successful aging. Neural correlates of ER processes have been examined using event-related brain potentials (ERPs), such as the late-positive potential (LPP) during cognitive reappraisal paradigms. The current study sought to extend this research by examining the LPP from an ER task in a sample of 47 community-dwelling older adults between the ages of 60 and 84 years, scoring either high on emotional well-being (as measured by habitual ER use and resiliency; high WB group, n = 20) or low on emotional well-being (as measured by habitual ER use, resiliency, and depression; low WB group, n = 27). Participants viewed unpleasant and neutral images and were instructed to simply react to the images or reappraise their emotional response. Both pre- and post-instruction LPP amplitudes were scored, in addition to self-reported ratings of negative emotion collected during the task. We found greater LPP amplitude to emotionally salient compared to neutral stimuli, reduced LPP amplitude following instructions to reappraise emotional response to stimuli across groups, and a blunted LPP overall for individuals with higher depressive symptoms. Additionally, we demonstrated that older adults with low emotional well-being were less successful at reappraisal according to self-reported ratings of negative emotion, although this was not reflected in the LPP. Collectively, these data suggest that laboratory-based ER tasks might be used to understand abnormal ER use-though the LPP may be more sensitive to depression than individual differences in ER ability.

A randomized trial of aerobic exercise for major depression: examining neural indicators of reward and cognitive control as predictors and treatment targets

BACKGROUND

Aerobic exercise has demonstrated antidepressant efficacy among adults with major depression. There is a poor understanding of the neural mechanisms associated with these effects. Deficits in reward processing and cognitive control may be two candidate targets and predictors of treatment outcome to exercise in depression.

METHODS

Sixty-six young adults aged 20.23 years (s.d. = 2.39) with major depression were randomized to 8 weeks of moderate-intensity aerobic exercise (n = 35) or light stretching (n = 31). Depressive symptoms were assessed across the intervention to track symptom reduction. Reward processing [reward positivity (RewP)] and cognitive control [error-related negativity (ERN)] were assessed before and after the intervention using event-related brain potentials.

RESULTS

Compared to stretching, aerobic exercise resulted in greater symptom reduction (gs = 0.66). Aerobic exercise had no impact on the RewP (gav = 0.08) or ERN (gav = 0.21). In the aerobic exercise group, individuals with a larger pre-treatment RewP [odds ratio (OR) = 1.45] and increased baseline depressive symptom severity (OR = 1.18) were more likely to respond to an aerobic exercise program. Pre-treatment ERN did not predict response (OR = 0.74).

CONCLUSIONS

Aerobic exercise is effective in alleviating depressive symptoms in adults with major depression, particularly for those with increased depressive symptom severity and a larger RewP at baseline. Although aerobic exercise did not modify the RewP or ERN, there is preliminary support for the utility of the RewP in predicting who is most likely to respond to exercise as a treatment for depression.

Appearance Concerns are Uniquely Associated with LPP Amplitude to Pictures of Oneself

A number of psychiatric disorders, including body dysmorphic disorder (BDD), anorexia nervosa, bulimia nervosa, and social anxiety disorder, are characterized by heightened appearance concerns and increased cognitive and perceptual biases toward one’s own physical appearance. In the present study, we examined individual differences in self-reported appearance anxiety and symptoms of BDD in relation to the late positive potential (LPP)—an index of stimulus significance—in response to pictures of oneself, strangers and objects among 83 female college students. The results indicated that the LPP was larger for pictures of oneself compared to pictures of strangers and objects. Further, the Yale–Brown Obsessive-Compulsive Scale Modified for Body Dysmorphic Disorder and Appearance Anxiety Inventory scales both related to an increased LPP to pictures of oneself but not to strangers or objects. The findings suggest that the LPP elicited by pictures of oneself may function as a neural marker of appearance concerns, which could be leveraged to study the development and maintenance of a range of psychiatric disorders characterized by increased appearance concerns.

Neural responses to reward and pleasant pictures prospectively predict remission from depression

Reduced neural responses to reward and pleasant stimuli-indicators of anhedonia and reduced emotional reactivity, respectively-have been reported among individuals with depressive disorders. The current study examined whether these neural measures could prospectively predict the course of depression among a community-based sample of 83 participants diagnosed with a depressive disorder. At initial assessment, participants performed both a guessing task to elicit the reward positivity (RewP) and a picture viewing paradigm with neutral and pleasant pictures to measure the late positive potential (LPP)-both event-related brain potentials (ERPs) independently related to diagnosis of depression. After approximately 9 months, 53 of those participants returned to the lab for a clinical assessment of current symptoms and course of disorder during the follow-up period. We found a more intact (i.e., larger) RewP and LPP at baseline among participants who achieved an episode of full remission from depression at any point during the follow-up period. In multiple logistic regression models, the RewP and LPP were both independent predictors of remission status; moreover, the RewP, but not the LPP, remained a significant predictor after accounting for other clinical variables that predicted remission. These data provide initial evidence for the clinical utility of ERPs from reward and picture viewing tasks within depressed individuals to predict disease course prospectively, which could be further leveraged to improve intervention approaches and parse the heterogeneity of depression. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The impact of a single session of aerobic exercise on positive emotional reactivity in depression: Insight into individual differences from the late positive potential

Depression has been characterized by a broad disengagement from the environment, as reflected by dampened positive and negative emotional reactivity. Research has shown that acute exercise may enhance positive emotional reactivity in healthy adults. It is unknown whether it can alter positive emotional reactivity in depression. In the present study, positive emotional reactivity was assessed using the late positive potential (LPP) event-related potential before and after 30 min of moderate-intensity aerobic exercise in 43 adults with current or a lifetime history of depression (Mage = 32.74 years; Min/Max = 18/59) and 18 never-depressed healthy adults (Mage = 37.94 years; Min/Max = 21/61). Acute exercise increased the LPP for healthy adults; the LPP did not change among those with current or a lifetime history of depression. A secondary aim was to identify moderators of change in positive emotional reactivity among subgroups of adults with current depression. Compared to adults with impaired mood reactivity, those with intact mood reactivity had a pre-to-post increase in the LPP. The current study provides preliminary support for the LPP as a neural indicator of exercise efficacy and highlights individual differences in response to acute exercise in depression.

Ventral striatal activation during reward differs between major depression with and without impaired mood reactivity

BACKGROUND

Recent efforts to classify subtypes of major depressive disorder marked by different psychophysiological indicators have identified blunted reward-related brain activation in gambling tasks as a characteristic linked specifically to depressed participants with impaired mood reactivity.

METHODS

The current study compared individuals diagnosed with current depressive disorder (n = 26) with healthy controls (n = 24) regarding brain responses to gain and loss trials in an fMRI version of the "Doors" choice-feedback task. Study aims were to examine reward-related brain activation in relation to depression, depressive subtypes, and course of depression.

RESULTS

Across the sample, participants showed a significant response to gain versus loss in left and right ventral striatum as well as medial and left lateral prefrontal cortex. Relative to controls, participants with current depression were characterized by blunted reactivity in left ventral striatum. Furthermore, activation in the left ventral striatum differentiated subgroups of depression with and without impaired mood reactivity. Finally, left striatal hypoactivation to reward predicted remission when controlling for current depressive symptomatology, albeit at a trend level.

CONCLUSIONS

Blunted reward-related activation in the left ventral striatum might be useful as a marker for depression subtype and may have the potential to predict future course of depression.

A reduced P300 prospectively predicts increased depressive severity in adults with clinical depression

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.

Acute aerobic exercise increases respiratory sinus arrythmia reactivity and recovery to a sad film among individuals at risk for depression

Cardiac vagal control (CVC), as indexed by abnormalities in resting, reactivity, and recovery levels of respiratory sinus arrythmia (RSA), has been proposed as an index of impaired self-regulatory capacity in depression. Aerobic exercise has been shown to improve positive and negative affective responses and influence autonomic function; however, it is unknown whether exercise impacts RSA reactivity and subsequent recovery to emotional challenges among individuals at risk for depression. The present study aimed to determine the effects of moderate-intensity aerobic exercise on RSA reactivity and recovery to a sad film. Using a within-subjects design, 47 individuals with variable symptoms of depression completed a 30-min session of exercise and a sedentary control condition on separate days prior to viewing a sad film. On the control day, individuals with elevated depressive symptom severity displayed less vagal withdrawal to the sad film and exhibited impaired post-film RSA recovery. Following exercise, individuals with elevated depressive symptom severity demonstrated a higher degree of vagal withdrawal to the sad film and subsequent post-film recovery that matched individuals with lower depressive symptom severity. These findings suggest that a single session aerobic exercise may be an effective approach to increase emotional and self-regulatory capacity among individual at risk for, or currently experiencing, depression.

MAP training: combining meditation and aerobic exercise reduces depression and rumination while enhancing synchronized brain activity

Mental and physical (MAP) training is a novel clinical intervention that combines mental training through meditation and physical training through aerobic exercise. The intervention was translated from neuroscientific studies indicating that MAP training increases neurogenesis in the adult brain. Each session consisted of 30 min of focused-attention (FA) meditation and 30 min of moderate-intensity aerobic exercise. Fifty-two participants completed the 8-week intervention, which consisted of two sessions per week. Following the intervention, individuals with major depressive disorder (MDD; n=22) reported significantly less depressive symptoms and ruminative thoughts. Typical healthy individuals (n=30) also reported less depressive symptoms at follow-up. Behavioral and event-related potential indices of cognitive control were collected at baseline and follow-up during a modified flanker task. Following MAP training, N2 and P3 component amplitudes increased relative to baseline, especially among individuals with MDD. These data indicate enhanced neural responses during the detection and resolution of conflicting stimuli. Although previous research has supported the individual beneficial effects of aerobic exercise and meditation for depression, these findings indicate that a combination of the two may be particularly effective in increasing cognitive control processes and decreasing ruminative thought patterns.