EEG Theta/Beta Ratio Neurofeedback Training in Healthy Females.

A growing number of studies suggest that EEG theta/beta ratio (TBR) is inversely related to executive cognitive control. Neurofeedback training aimed at reducing TBR (TBR NFT) might provide a tool to study causality in this relation and might enhance human performance. To investigate whether TBR NFT reduces TBR in healthy participants. Twelve healthy female participants were assigned (single blind) to one of three groups. Groups differed on baseline durations and one group received only sham NFT. TBR NFT consisted of eight or fourteen 25-min sessions. No evidence was found that TBR NFT had any effect on TBR. The current TBR NFT protocol is possibly ineffective. This is in line with a previous study with a different protocol.

Electroencephalography theta/beta ratio covaries with mind wandering and functional connectivity in the executive control network.

The ratio between frontal resting-state electroencephalography (EEG) theta and beta frequency power (theta/beta ratio, TBR) is negatively related to cognitive control. It is unknown which psychological processes during resting state account for this. Increased theta and reduced beta power are observed during mind wandering (MW), and MW is related to decreased connectivity in the executive control network (ECN) and increased connectivity in the default mode network (DMN). The goal of this study was to test if MW-related fluctuations in TBR covary with such functional variation in ECN and DMN connectivity and if this functional variation is related to resting-state TBR. Data were analyzed for 26 participants who performed a 40-min breath-counting task and reported the occurrence of MW episodes while EEG was measured and again during magnetic resonance imaging. Frontal TBR was higher during MW than controlled thought and this was marginally related to resting-state TBR. DMN connectivity was higher and ECN connectivity was lower during MW. Greater ECN connectivity during focus than MW was correlated to lower TBR during focus than MW. These results provide the first evidence of the neural correlates of TBR and its functional dynamics and further establish TBR's usefulness for the study of executive control, in normal and potentially abnormal psychology.

I'm going to fail! Acute cognitive performance anxiety increases threat-interference and impairs WM performance.

Stress can impair cognitive performance, as commonly observed in cognitive performance anxiety (CPA; e.g., test anxiety). Cognitive theories indicate that stress impairs performance by increasing attention to negative thoughts, a phenomenon also known as threat-interference. These theories are mainly supported by findings related to self-report measures of threat-interference or trait anxiety. Our main aim was to test, for the first time in a single study, the hypotheses that acute CPA-related stress negatively affects both working memory (WM) performance and objectively assessed threat-interference during performance. In addition, we aimed to assess the validity of a new stress-induction procedure that was developed to induce acute CPA. Eighty-six females were randomly assigned to a CPA-related stress group (n = 45) or a control group. WM performance and threat-interference were assessed with an n-back task (2-back and 3-back memory loads), using CPA-related words as distracters. The stress group showed higher state anxiety and slower WM performance. Both effects were moderated by trait CPA: the effects were stronger for individuals with higher trait CPA. Finally, trait CPA moderated the effect of stress on threat-interference during higher cognitive load: individuals with higher trait CPA in the stress group showed higher threat-interference. We conclude that acute CPA increases threat-interference and impairs WM performance, especially in vulnerable individuals. The role of threat-interference, cognitive load, and trait anxiety should be taken into account in future research. Finally, our method (combining our stressor and modified n-back task) is effective for studying stress-cognition interactions in CPA.

Frontal EEG theta/beta ratio during mind wandering episodes.

BACKGROUND: In resting-state EEG, the ratio between frontal power in the slow theta frequency band and the fast beta frequency band (the theta/beta ratio, TBR) has previously been negatively related to attentional control. Also, increased theta and reduced beta power were observed during mind wandering (MW) compared to episodes of focused attention. Thus, increased resting-state frontal TBR could be related to MW, suggesting that previously observed relationships between TBR and attentional control could reflect MW episodes increasing the average resting state TBR in people with low attentional control. GOALS: To replicate and extend the previous theta and beta MW effects for frontal TBR recordings and test if MW related changes in frontal TBR are related to attentional control. METHOD: Twenty-six healthy participants performed a 40-minute breath-counting task, after a baseline EEG recording, while EEG was measured and participants indicated MW episodes with button presses. RESULTS: Frontal TBR was significantly higher during MW episodes than during on-task periods. However, no relation between frontal TBR and attentional control was found. CONCLUSIONS: This confirms that frontal TBR varies with MW, which is thought to reflect, among other things, a state of reduced top-down attentional control over thoughts.

Early and late dot-probe attentional bias to mild and high threat pictures: Relations with EEG theta/beta ratio, self-reported trait attentional control, and trait anxiety.

Frontal EEG theta/beta ratio (TBR; negatively associated with attentional control, or AC) was previously reported to moderate threat-level dependent attentional bias in a pictorial dot-probe task, interacting with trait anxiety. Unexpectedly, this was independent from processing stage (using cue-target delays of 200 and 500 ms) and also not observed for self-reported trait AC. We therefore aimed to replicate these effects of TBR and trait anxiety and to test if effects of early versus late processing stages are evident for shorter cue-target delays. This study also revisited the hypothesis that TBR and self-reported trait AC show similar effects. Fifty-three participants provided measurements of frontal TBR, self-reported trait AC, trait anxiety, and dot-probe task bias for mild and high threat pictures using the same dot-probe task, but this time with 80- and 200-ms cue-target delays. Results indicated that higher TBR predicted more attention to mild than high threat, but this was independent from trait anxiety or delay. Lower self-reported trait AC predicted more attention to mild than high threat, only after 200 ms (also independent of trait anxiety). We conclude that the moderating effect of TBR on threat-level dependent dot-probe task bias was replicated, but not the role of trait anxiety, and this study partially confirms that effects of trait AC are more dominant in later processing.

Acute effects of caffeine on threat-selective attention: moderation by anxiety and EEG theta/beta ratio.

BACKGROUND: Spontaneous EEG theta/beta ratio (TBR) probably marks prefrontal cortical (PFC) executive control, and its regulation of attentional threat-bias. Caffeine at moderate doses may strengthen executive control through increased PFC catecholamine action, dependent on basal PFC function. GOAL: To test if caffeine affects threat-bias, moderated by baseline frontal TBR and trait-anxiety. METHODS: A pictorial emotional Stroop task was used to assess threat-bias in forty female participants in a cross-over, double-blind study after placebo and 200 mg caffeine. RESULTS: At baseline and after placebo, comparable relations were observed for negative pictures: high TBR was related to low threat-bias in low trait-anxious people. Caffeine had opposite effects on threat-bias in low trait-anxious people with low and high TBR. CONCLUSIONS: This further supports TBR as a marker of executive control and highlights the importance of taking baseline executive function into consideration when studying effects of caffeine on executive functions.

Do not look away! Spontaneous frontal EEG theta/beta ratio as a marker for cognitive control over attention to mild and high threat.

BACKGROUND: Low spontaneous EEG theta/beta ratio (TBR) is associated with greater executive control. Their role in regulation of attentional bias for stimuli of different threat-levels is unknown. OBJECTIVES: To provide the first relations between frontal TBR, trait anxiety and attentional bias to mildly and highly threatening stimuli at different processing-stages. METHODS: Seventy-four healthy volunteers completed spontaneous EEG measurement, a self-report trait anxiety questionnaire and a dot-probe task with stimuli of different threat-level and 200 and 500 ms cue-target delays. RESULTS: Participants with high TBR directed attention towards mildly threatening and avoided highly threatening pictures. Moreover, the most resilient participants, (low TBR and low trait anxiety) showed attention towards highly threatening stimuli. There were no effects of delay. CONCLUSIONS: These data confirm that executive control is crucial for the study of threat-related attentional bias and further support the notion that TBR is a marker of cognitive control over emotional information.

Frontal EEG theta/beta ratio as an electrophysiological marker for attentional control and its test-retest reliability.

A robust finding is that resting-state frontal theta/beta ratio (TBR), a spontaneous electroencephalographic (EEG) frequency band parameter, is increased in attention-deficit/hyperactivity disorder. Accumulating evidence suggests that TBR might also provide an objective marker of executive cognitive control (and more specifically attentional control; AC) in healthy adults. The present study aimed to further investigate this conception by assessing EEG frequency band power and AC twice (with a one-week interval) in 41 young female adults. In line with our predictions, the negative association between TBR and trait AC, as measured with an often used self-report measure, was replicated. Results also demonstrated that test-retest reliability of resting-state frontal TBR was very good (r=.93) and, moreover, TBR measured at the first session predicted AC during the second session (r=-.44). These consistent results further reinforce the notion that frontal TBR could be used as a reliable biomarker for prefrontally-mediated executive AC.

Mineralocorticoid receptor haplotype moderates the effects of oral contraceptives and menstrual cycle on emotional information processing.

RATIONALE: The processing of emotional information is affected by menstrual cycle phase and by the use of oral contraceptives (OCs). The stress hormone cortisol is known to affect emotional information processing via the limbic mineralocorticoid receptor (MR). OBJECTIVES: We investigated in an exploratory study whether the MR-genotype moderates the effect of both OC-use and menstrual cycle phase on emotional cognition. METHODS: Healthy premenopausal volunteers (n=93) of West-European descent completed a battery of emotional cognition tests. Forty-nine participants were OC users and 44 naturally cycling, 21 of whom were tested in the early follicular (EF) and 23 in the mid-luteal (ML) phase of the menstrual cycle. RESULTS: In MR-haplotype 1/3 carriers, ML women gambled more than EF women when their risk to lose was relatively small. In MR-haplotype 2, ML women gambled more than EF women, regardless of their odds of winning. OC-users with MR-haplotype 1/3 recognised fewer facial expressions than ML women with MR-haplotype 1/3. CONCLUSION: MR-haplotype 1/3 carriers may be more sensitive to the influence of their female hormonal status. MR-haplotype 2 carriers showed more risky decision-making. As this may reflect optimistic expectations, this finding may support previous observations in female carriers of MR-haplotype 2 in a naturalistic cohort study.

Attentional bias modification in Dutch veterans with posttraumatic stress disorder--a case series with a personalized treatment version.

Beneficial effects of attentional bias modification have been claimed for a number of anxiety disorders, but study results are variable. A recent trial in patients with posttraumatic stress disorder (PTSD) showed no therapeutic effects. The use of personally relevant and verbal stimuli might increase the efficacy of attentional bias modification. In an A-B case series design, we hypothesized that individualized attentional bias modification would lead to reduction of attentional bias and a decrease in PTSD symptoms. Six Dutch male war veterans (mean age 39.33 years) who had developed PTSD after peacekeeping missions underwent the treatment. No therapeutic effects were observed. Inter- and intraindividual attentional bias scores varied widely and did not respond to attentional bias modification as hypothesized. This study provides no evidence that individualized attentional bias modification is an effective treatment for PTSD.

EEG theta/beta ratio as a potential biomarker for attentional control and resilience against deleterious effects of stress on attention.

Anxious stress compromises cognitive executive performance. This occurs, for instance, in cognitive performance anxiety (CPA), in which anxiety about one's cognitive performance causes that performance to actually deteriorate (e.g., test anxiety). This is thought to result from a prefrontal cortically (PFC) mediated failure of top-down attentional control over stress-induced automatic processing of threat-related information. In addition, stress-induced increased catecholamine influx into the PFC may directly compromise attentional function. Previous research has suggested that the ratio between resting state electroencephalographic (EEG) low- and high-frequency power (the theta/beta ratio) is related to trait attentional control, which might moderate these effects of stress on attentional function. The goals of the present study were to test the novel prediction that theta/beta ratio moderates the deleterious effects of CPA-like anxious stress on state attentional control and to replicate a previous finding that the theta/beta ratio is related to self-reported trait attentional control. After recording of baseline frontal EEG signals, 77 participants performed a stress induction or a control procedure. Trait attentional control was assessed with the Attentional Control Scale, whereas stress-induced changes in attentional control and anxiety were measured with self-report visual analogue scales. The hypothesized moderating influence of theta/beta ratio on the effects of stress on state attentional control was confirmed. Theta/beta ratio explained 28% of the variance in stress-induced deterioration of self-reported attentional control. The negative relationship between theta/beta ratio and trait attentional control was replicated (r = -.33). The theta/beta ratio reflects, likely prefrontally mediated, attentional control, and should be a useful biomarker for the study of CPA and other anxiety-cognition interactions.

The 5-HTTLPR polymorphism, early and recent life stress, and cognitive endophenotypes of depression.

Studies associating interactions of 5-HTTLPR and life adversities with depression have yielded equivocal results. Studying endophenotypes may constitute a more powerful approach. In the current study, it was assessed whether interactions of 5-HTTLPR with childhood emotional abuse (CEA) and recent negative life events (RNLE) affect possible cognitive endophenotypes of depression, namely, attention-allocation bias and the ability to recognise others' mind states in 215 young adults of North-West European descent. The ability to classify others' negative mind states was found to be increased with increasing RNLE in carriers of low-expressing Serotonin Transporter Linked Polymorphic Region (5-HTTLPR) alleles. Carriers of two low-expressing alleles also preferentially oriented attention towards negative information. Gene-environment interactions were not observed for attention allocation bias. No effects involving CEA were observed. These results suggest that low-expressing 5-HTTLPR alleles may confer increased risk for depression through enhanced recognition of negative facial expressions following RNLE.

Attentional bias and attentional control in Posttraumatic Stress Disorder.

Extensive evidence exists for an association between attentional bias (AB; attentional vigilance or avoidance) and anxiety. Recent studies in healthy participants suggest that attentional control (AC) may facilitate inhibition of automatic attentional processes associated with anxiety. To investigate relationships among AC, trauma-related AB, symptom severity and trait anxiety in patients with Posttraumatic Stress Disorder (PTSD), participants (N = 91) completed self-report measures of AC, posttraumatic stress symptoms (PTSS) and trait anxiety. AB was measured with a pictorial version of the Dot Probe Test. AC moderated the relationship between PTSS and AB (threat avoidance). Patients high in PTSS and low in AC showed attentional avoidance. No association between PTSS and AB in patients with medium or high levels of AC was found. A similar pattern of results was observed for the relationship between trait anxiety, AC and AB. These results suggest that a low ability to control attention is a risk factor for AB in PTSD. This first clinical study corroborates the accumulating evidence from analog studies that individual differences in top-down attentional control are of considerable importance in the expression of AB in anxious psychopathology.

A multiple case series analysis of six variants of attentional bias modification for depression.

Background. Attention bias modification (ABM) is a new treatment for affective disorders. A meta-analysis of ABM for anxiety disorders showed that the effect size may be large but the number of studies is low. The working mechanism is still unclear, and little is known about the optimal treatment parameters. ABM for depression is much less studied. A few studies claimed positive effects but the sample sizes are low. Furthermore, the treatment parameters varied widely and differed from the anxiety literature. Aim. To select the most promising version of ABM for depression for further evaluation in clinical trials. Methods. Multiple case series design. We tested six versions of ABM that varied on stimulus duration and training direction. Thirty students with mild to moderate symptoms of depression underwent four sessions of ABM. Change of attentional bias was measured during each session. Generalization of treatment effects and the role of awareness of receiving training were also investigated. Results. None of the investigated versions of ABM had a consistent effect on attentional bias. Changes of attentional bias in individual participants the effects did not generalize to untrained stimuli. Conclusion. It is unlikely that any of these ABM versions will have a specific effect on symptoms in controlled studies.

Enhanced orienting of attention in response to emotional gaze cues after oxytocin administration in healthy young men.

BACKGROUND: Oxytocin is known to enhance recognition of emotional expressions and may increase attention to the eye region. Therefore, we investigated whether oxytocin administration would lead to increased orienting of attention in response to gaze cues of emotional faces. METHODS: In a randomized placebo-controlled double-blind crossover study 20 healthy males received 24 IU of oxytocin or placebo. Thirty-five minutes after administration they performed a gaze cueing task with happy, fearful and neutral faces. Stress levels were measured throughout the study. RESULTS: Oxytocin did not affect stress levels during the study, but significantly increased gaze cueing scores for happy and fearful expressions compared to placebo. No effects were found for neutral expressions. Trait anxiety or depression did not moderate the effect. CONCLUSIONS: Oxytocin increases orienting of attention in response to emotional gaze cues, both for happy and fearful expressions. Replication is needed in female and clinical populations. Effects of oxytocin on early, automatic processing levels should be studied in relation to previously found pro-social and behavioral effects of oxytocin.

Attentional bias modification in posttraumatic stress disorder: a randomized controlled trial.

BACKGROUND: Attentional bias modification (ABM) is a new treatment for anxiety disorders. Three randomized controlled clinical trials have shown positive effects of ABM in social anxiety disorder and generalized anxiety disorder. This study investigated the efficacy of ABM in outpatients with chronic posttraumatic stress disorder (PTSD). METHODS: Randomized controlled double-blind trial (n = 102). ABM and control treatment consisted of eight 20-min sessions over the course of 3 weeks. Symptoms and attentional bias were assessed before and after treatment and at 3-week follow-up. RESULTS: ABM and the control treatment were equally effective in reducing the symptoms of PTSD. The effect sizes of the improvement (from before to after treatment) were 0.66 for ABM and 0.46 for the control treatment, which is comparable to the effect sizes of pill-placebos in pharmacotherapy trials of chronic PTSD. Both treatments did not affect attentional bias. The acceptability and tolerability of ABM was moderate. CONCLUSIONS: This version of ABM is not an effective treatment of PTSD.

The effects of a visual search attentional bias modification paradigm on attentional bias in dysphoric individuals.

BACKGROUND AND OBJECTIVES: Attentional Bias Modification (ABM) may constitute a new type of treatment for affective disorders. ABM refers to computerized training programs that have been developed based on laboratory findings in experimental psychology. Meta-analyses have reported moderate effect sizes in anxiety disorders. Two small studies have also claimed an effect in dysphoria. Furthermore, a series of studies in individuals with low self-esteem has shown that they benefit from a single session of an ABM variant based on a visual search task. The current study tested the working mechanism of visual search ABM in dysphoria. METHODS: Forty dysphoric individuals engaged in a single session of ABM training or control training. Attentional bias for positive and negative facial expressions was assessed pre- and post training. Positive and negative mood states were assessed throughout the procedure. RESULTS: Attentional training had no effect on attentional bias. Positive and negative mood states were not differentially affected by training condition. LIMITATIONS: Small treatment effects may have gone undetected and there are some methodological differences with prior research. CONCLUSION: We found no evidence that engaging in a single session of a visual search ABM modifies attentional biases for happy, sad or disgusted facial expressions.

In the eye of the beholder: reduced threat-bias and increased gaze-imitation towards reward in relation to trait anger.

The gaze of a fearful face silently signals a potential threat's location, while the happy-gaze communicates the location of impending reward. Imitating such gaze-shifts is an automatic form of social interaction that promotes survival of individual and group. Evidence from gaze-cueing studies suggests that covert allocation of attention to another individual's gaze-direction is facilitated when threat is communicated and further enhanced by trait anxiety. We used novel eye-tracking techniques to assess whether dynamic fearful and happy facial expressions actually facilitate automatic gaze-imitation. We show that this actual gaze-imitation effect is stronger when threat is signaled, but not further enhanced by trait anxiety. Instead, trait anger predicts facilitated gaze-imitation to reward, and to reward compared to threat. These results agree with an increasing body of evidence on trait anger sensitivity to reward.

Emotional Stroop interference for threatening words is related to reduced EEG δ-ß coupling and low attentional control.

Previously, electroencephalographic (EEG) delta-beta coupling (positive correlation between power in the fast beta and slow delta frequency bands) has been related to affective processing. For instance, differences in delta-beta coupling have been observed between people in a psychological stress condition and controls. We previously reported relationships between attentional threat processing and delta-beta coupling and individual differences in attentional control. The present study extended and replicated these findings in a large mixed gender sample (N=80). Results demonstrated that emotional Stroop task interference for threatening words was related to self-reported attentional inhibition capacity and frontal delta-beta coupling. There was no clear gender difference for delta-beta coupling (only a non-significant trend) and the relationship between delta-beta coupling and attentional threat-processing was not affected by gender. These results replicate and extend an earlier finding concerning delta-beta coupling and cognitive affect regulation and further clarify relationships between delta-beta coupling, attentional control, and threat-processing.

Cortisol acutely reduces selective attention for erotic words in healthy young men.

Psychological stress prompts activity of the hypothalamic-pituitary-adrenal (HPA) axis resulting in increased release of cortisol. Long-term HPA aberrations have been observed for stress-related affective disorders but research into acute effects of cortisol on affect-regulation has only recently begun. Previous studies reported that exogenous cortisol acutely attenuated automatic attentional processing of task-irrelevant threatening information. This has been taken to suggest that cortisol may have acute anxiolytic properties, possibly through facilitating inhibition of threatening information. However, the role of cortisol in attentional inhibition of non-threatening arousing stimuli remained unclear. Therefore acute effects of 40 mg cortisol on performance of a masked and unmasked emotional Stroop task (EST) were assessed. Results for only the unmasked task demonstrated EST interference (interpreted as increased automatic attention) for erotic stimuli which was abolished by cortisol administration. This implies that effects of cortisol may not be restricted to attenuation of specifically anxiogenic information processing, as previously suggested.