Frontal EEG Activity Research Articles

Intrusive and withdrawn depressed mothers and their infants

This review of the literature on two different interaction styles of depressed mothers, intrusive and withdrawn, shows that withdrawn versus intrusive mothers typically have an EEG pattern that is associated with negative affect (i.e., greater relative right frontal EEG activation) as well as lower levels of the activating neurotransmitter, dopamine. These profiles also occur in their newborn infants. These prenatal effects together with the less stimulating interactive behavior of their withdrawn mothers might explain why infants of withdrawn mothers are less exploratory and have lower scores than infants of intrusive mothers on the Bayley Mental scale at one year. Interventions have been differentially tailored for intrusive and withdrawn mothers, such as interaction coaching which has been designed to decrease the behaviors of intrusive mothers (imitation) or increase the behaviors of withdrawn mothers (attention-getting). Similarly, different types of music have been tried as mood inductions for the different interaction style mothers. Although immediate positive effects have been noted, more intensive, long-term interventions may be needed to alter these negative interaction behaviors.

Individual differences in anterior EEG asymmetry between high and low defensive individuals during a rumination/distraction task

The current study examined how reactions to a negative mood manipulation and a rumination/distraction task differed between high defensive (HD) and low defensive (LD) individuals. At baseline, high defensive participants exhibited significantly greater relative left frontal EEG activity than low defensive participants. HD also exhibited greater relative left anterior activity during both the negative mood induction and during the rumination/distraction task, regardless of group assignment. Contrary to predictions, there were no differences in self-reported mood between HD and LD in either the rumination or distraction group. A significant interaction was found between gender and group, indicating that anterior alpha asymmetry patterns differed for men and women during the rumination/distraction task.

Comparison of a New Bispectral Index (BIS) Algorithm to Modified Observer's Assessment of Alertness/Sedation (MOAA/S) Scale in Moderate Sedation (MS)

Background: Assessment of sedation levels in endoscopy is crucial for patient safety. Sedation assessment is currently guided by indirect measures: vital signs, direct observation, and subjective sedation assessment like the MOAA/S scale. BIS monitoring is a mathematical evaluation of frontal cortex EEG activity used to improve general anesthetic titration and patient recovery. Current BIS algorithms do not differentiate various levels of MS. Aim: To compare the new BIS monitoring algorithm (BIS Revision 4.1) to MOAA/S scale for MS during elective endoscopy. Methods: 80 pts (43M/37F, mean age 61 yrs) were studied using a balanced cohort of procedures (20-EGD; 20-Colon; 20-ERCP; 20-EUS). IV MS (meperidine/midazolam) was administered. BIS levels and MOAA/S scores were recorded q 3 min. BIS level (0-100; 0=flatline EEG to 100=fully awake) and MOAA/S score (1-5; 1=unresponsive to shaking to 5=coherent). The mean BIS level and MOAA/S score were compared. Results: Levels of sedation achieved: 54 pts (67.5%) deep sedation and 26 pts (32.5%) mild to moderate sedation. The correlation coefficient between BIS level and MOAA/S score was 0.66 (p < 0.01; Graph). The new BIS algorithm had excellent correlation to mild/moderate sedation levels (MOAA/S 2-5; p < 0.001) but failed to discriminate between moderate/deep sedation levels (MOAA/S 1-2; p = 0.75). Conclusions: (1)Deep sedation occurs frequently during elective endoscopy. (2)The new BIS algorithm is successful in discriminating levels of mild/moderate sedation, but is no more effective than direct observation (MOAA/S score) at distinguishing between moderate/deep levels of sedation. Clinical implication: Since a large percentage of patients experience deep sedation during elective endoscopy, the new BIS algorithm needs to be refined to differentiate deeper levels of sedation.

Treatment Efficacy and Safety Related to the Use of Propofol vs. Conventional Sedation in the Performance of Colonoscopy: A Meta-Analysis of Published Randomized Controlled Trials

Background: Assessment of sedation levels in endoscopy is crucial for patient safety. Sedation assessment is currently guided by indirect measures: vital signs, direct observation, and subjective sedation assessment like the MOAA/S scale. BIS monitoring is a mathematical evaluation of frontal cortex EEG activity used to improve general anesthetic titration andpatient recovery. Current BIS algorithms do not differentiate various levels of MS. Aim: To compare the new BIS monitoring algorithm (BIS Revision 4.1) to MOAA/S scale for MS during elective endoscopy. Methods: 80 pts (43M/37F,mean age 61 yrs)were studied using a balanced cohort of procedures (20-EGD; 20-Colon; 20-ERCP; 20-EUS). IV MS (meperidine/midazolam) was administered. BIS levels and MOAA/S scores were recorded q 3 min. BIS level (0-100; 0=flatline EEG to 100=fully awake) and MOAA/S score (1-5; 1=unresponsive to shaking to5=coherent). ThemeanBIS level andMOAA/S score were compared. Results: Levels of sedation achieved: 54 pts (67.5%) deep sedation and 26 pts (32.5%) mild to moderate sedation. The correlation coefficient between BIS level and MOAA/S score was 0.66 (p < 0.01; Graph). The new BIS algorithm had excellent correlation tomild/moderate sedation levels (MOAA/S 2-5; p<0.001) but failed to discriminate betweenmoderate/deep sedation levels (MOAA/S 1-2; p= 0.75). Conclusions: (1)Deep sedation occurs frequently during elective endoscopy. (2)The new BIS algorithm is successful in discriminating levels of mild/moderate sedation, but is no more effective than direct observation (MOAA/S score) at distinguishing between moderate/deep levels of sedation. Clinical implication: Since a largepercentageofpatients experiencedeep sedationduringelective endoscopy, the new BIS algorithm needs to be refined to differentiate deeper levels of sedation. Treatment Efficacy and Safety Related to the Use of Propofol vs. Conventional Sedation in the Performance of Colonoscopy: A Meta-Analysis of Published Randomized Controlled Trials Neena S. Abraham, Maitreyi Raman, Kara Thompson Background and Aim: There is increasing interest in the use of propofol during the performance of colonoscopy. Our aim was to quantitatively evaluate the efficacy and safety of propofol as compared to conventional sedation in theperformance of routine colonoscopy. Methods: All randomized controlled trials evaluating propofol in colonoscopy, publishedas fullmanuscripts,were identifiedusing a standardized search and data abstraction policy. Comparisons between propofol and conventional sedationweremade in the areas of efficacy (pain control, patient satisfaction, recovery time) and risks (hypoxia, hypotension). A single combined estimate of treatment efficacy (ORwith 95%CI) was generated using a fixed effect model or random effects model if appropriate. When estimates could not be aggregated mathematically, a narrative systematic review was performed. Results: Eight studies were identified, however, twowere excluded for lack of control comparator. Aggregation of outcomes was impossible in all six studies due to lack of comparable outcome, failure to report a measure of variability or inability to dichotomize results. Recovery time post colonoscopy was substantially reduced using propofol when compared with conventional sedation (OR 18.25; 95% CI: 12.37 to 24.13). Hypoxic events occurred less frequently in the propofol arm, although this was not statistically significant (OR= 0.72; 95%CI: 0.72 to 2.37). Hypotension occurred less frequently using propofol, however, the heterogeneity in examination of this variablewas toogreat, rendering the result inconclusive. Pain and satisfaction were qualitatively reviewed due to heterogeneity in outcomes assessment andwere found equivalent or superior using propofol. Conclusions: There are a limited number of randomised controlled trials reporting on efficacy and safety of propofol during colonoscopy. Among the six published placebo controlled studies, there is a suggestion that propofol is superior to conventional sedationwith respect to recovery time, hypoxia, hypotension, pain control and patient satisfaction. The evidence for improved patient pain control and satisfaction is qualitative. Future studies require standardized assessment of these outcomes to allow quantitative aggregation of results. As more centers utilize propofol for routine colonoscopy, the cost-efficacy of reduced recovery time may become apparent.

MASSAGE THERAPY OF MODERATE AND LIGHT PRESSURE AND VIBRATOR EFFECTS ON EEG AND HEART RATE

Three types of commonly used massage therapy techniques were assessed in a sample of 36 healthy adults, randomly assigned to: (1) moderate massage, (2) light massage, or (3) vibratory stimulation group (n = 12 per group). Changes in anxiety and stress were assessed, and EEG and EKG were recorded. Anxiety scores decreased for all groups, but the moderate pressure massage group reported the greatest decrease in stress. The moderate massage group also experienced a decrease in heart rate and EEG changes including an increase in delta and a decrease in alpha and beta activity, suggesting a relaxation response. Finally, this group showed increased positive affect, as indicated by a shift toward left frontal EEG activation. The light massage group showed increased arousal, as indicated by decreased delta and increased deta activity and increased heart rate. The vibratory stimulation group also showed increased arousal, as indicated by increased heart rate and increased theta, alpha, and beta activity

Binaural Beat Induced Theta EEG Activity and Hypnotic Susceptibility: Contradictory Results and Technical Considerations

The present study offered a constructive replication of an earlier study which demonstrated significant increases in theta EEG activity following theta binaural beat (TBB) entrainment training and significant increases in hypnotic susceptibility. This study improved upon the earlier small-sample, multiple-baseline investigation by employing a larger sample, by utilizing a double-blind, repeated-measures group experimental design, by investigating only low and moderate susceptible participants, and by providing 4 hours of binaural beat training. With these design improvements, results were not supportive of the specific efficacy of the theta binaural beat training employed in this study in either increasing frontal theta EEG activity or in increasing hypnotic susceptibility. Statistical power analyses indicated the theta binaural beat training to be a very low power phenomenon on theta EEG activity. Furthermore, we found no significant relationship between frontal theta power and hypnotizability, although the more hypnotizable participants showed significantly greater increases in hypnotizability than the less hypnotizables. Results are discussed within the context of participant selection and classification factors, technical considerations in the presentation of TBB training, and theta blocking.

Depressed mothers who are “good interaction” partners versus those who are withdrawn or intrusive

The interactions of 3-month-old infants and their depressed mothers were classified as intrusive, withdrawn or good interactions. Analyses of retrospective data suggested that all depressed groups scored higher on depression (CES-D) and anxiety (STAI) scales and had similarly elevated cortisol, norepinephrine and epinephrine during pregnancy. The depressed mothers and their newborns also had greater relative right frontal EEG activation. Despite these group similarities, the infants of the “good interaction” mothers did not show high amounts of indeterminate sleep and they received better scores on the Brazelton scale. The more organized behaviors of these newborns may have contributed to the better interaction ratings of the “good interaction” depressed mothers.

Pregnancy anxiety and comorbid depression and anger: effects on the fetus and neonate.

One hundred sixty-six women were classified as experiencing high or low anxiety during the second trimester of pregnancy. The high anxiety women also had high scores on depression and anger scales. In a follow-up across pregnancy, the fetuses of the high anxiety women were noted to be more active and to experience growth delays. The high anxiety mothers' high prenatal norepinephrine and low dopamine levels were followed by their neonates having low dopamine and serotonin levels. The high anxiety mothers' newborns also had greater relative right frontal EEG activation and lower vagal tone. Finally, the newborns of high anxiety mothers spent more time in deep sleep and less time in quiet and active alert states and showed more state changes and less optimal performance on the Brazelton Neonatal Behavior Assessment Scale (motor maturity, autonomic stability and withdrawal). These data highlight the need for prenatal intervention for elevated anxiety symptoms during pregnancy.

Relative right versus left frontal EEG in neonates.

Although infants have been noted to have greater relative right or left frontal EEG as early as the neonatal period, other ways in which these newborns differ have not been reported. In this study, 48 newborns were divided on the basis of greater relative right versus greater relative left frontal EEG to determine whether these groups differed in other ways at the neonatal period including behavior, physiology, and biochemistry. We also were interested in whether these EEG patterns were related to any prenatal maternal variables including mood states (depression, anxiety, anger) and biochemistry as well as fetal activity. The greater relative right frontal EEG newborns had mothers with lower prenatal and postnatal serotonin and higher postnatal cortisol levels. The mothers of the greater relative right frontal EEG newborns also had greater relative right frontal EEG activation and lower vagal tone. The greater relative right frontal EEG newborns themselves had elevated cortisol levels, showed a greater number of state changes during sleep/wake behavior observations, and performed less optimally on the Brazelton Neonatal Behavior Assessment (T. B. Brazelton, 1973) including the habituation, motor, range of state, excitability, and depressive symptoms scales. These data suggest that greater relative right frontal EEG newborns may be at greater risk for developmental problems than those with greater relative left frontal EEG activation. In addition, a discriminant function analysis correctly classified 67% of the newborns' EEGs by prenatal maternal variables, suggesting that these might be used to target pregnant women for prenatal intervention.

Right Frontal EEG and Pregnancy/Neonatal Outcomes

Fifty-two pregnant women recruited during their second trimester were given EEGs and divided into greater relative right and left frontal EEG activation groups. The greater relative right frontal EEG women had lower dopamine levels during their second trimester and lower dopamine and higher cortisol levels during the neonatal period. The newborns of the right frontal EEG mothers also showed greater relative right frontal EEG, had lower dopamine and serotonin levels, spent more time in indeterminate sleep and had inferior Brazelton scores. A discriminant function analysis based on the mothers' prenatal depression scores and biochemical measures correctly classified 74% of the women as greater relative right or left frontal EEG group members.

EEG ASYMMETRY RESPONSES TO LAVENDER AND ROSEMARY AROMAS IN ADULTS AND INFANTS

Frontal EEG asymmetry shifting from baseline was examined in adults and infants exposed to lavender and rosemary by reanalyzing previously published data, using techniques different from those utilized in the original two studies. Results from Study 1 on 39 adults revealed significant EEG shifting in the lavender group, with greater relative left frontal EEG activation (associated with greater approach behavior and less depressed affect). The participants in the two aroma groups were further grouped by those with greater baseline, relative to left frontal EEG activation, versus those with a greater baseline, relative to right frontal activation. Collapsing across aroma groups, those with greater baseline, relative to right frontal activation, shifted left during the aroma. Those with greater baseline relative to left frontal activation did not change. In the rosemary group, those with greater baseline relative to right frontal EEG activation shifted left during the aroma, while those with greater baselines relative to left frontal EEG activation shifted right. In the lavender group, those with greater baselines relative to right frontal baseline EEG activation shifted left, but those with greater baselines relative to left baseline did not shift. Study 2 on 27 full-term newborns revealed no significant shifts in asymmetry in either aroma group. However, when the aroma groups were collapsed, the right frontal EEG group exhibited significant shifting relative to left frontal EEG activation. This finding was similar to the adult findings, suggesting that either lavender or rosemary may induce left frontal EEG shifting in adults and infants who show greater baselines relative to right frontal EEG activation.

Prenatal anger effects on the fetus and neonate

One hundred and sixty-six women were classified as experiencing high or low anger during the second trimester of pregnancy. The high-anger women also had high scores on depression and anxiety scales. In a follow-up across pregnancy, the fetuses of the high-anger women were noted to be more active and to experience growth delays. The high-anger mothers' high prenatal cortisol and adrenaline and low dopamine and serotonin levels were mimicked by their neonates' high cortisol and low dopamine levels. The high-anger mothers and infants were also similar on their relative right frontal EEG activation and their low vagal tone. Finally, the newborns of high-anger mothers had disorganised sleep patterns (greater indeterminate sleep and more state changes) and less optimal performance on the Brazelton Neonatal Behavior Assessment Scale (orientation, motor maturity and depression). These data highlight the need for prenatal intervention for elevated angry mood during pregnancy.

EEG during different emotions in 10-month-old infants of depressed mothers

EEG activity of 10-month-old infants of depressed and non-depressed mothers was compared during stimuli designed to produce happy and sad responses. During a baseline recording and during their happy facial expressions, infants of depressed mothers showed greater relative right frontal EEG asymmetry compared to infants of non-depressed mothers. The greater relative right frontal EEG asymmetry was also noted during a play interaction with their mothers. Infants of depressed mothers also showed more negative and less positive expressions. These findings are discussed in relation to the theory that frontal EEG activity may be a biological marker for symptoms associated with depression.

Enhanced frontal cortex activation in rats by convergent amygdaloid and noxious sensory signals.

The modulation of frontal cortical EEG activation to noxious somatosensory (tail pressure) and olfactory (acetone) stimulation by the basal amygdala was examined in urethane-anesthetized rats. Mild tail pressure produced no EEG activation, while acetone (sniffed by freely breathing rats or drawn across the olfactory epithelium in tracheotomized rats) produced a moderate suppression of large-amplitude synchronized EEG patterns. Concurrent, low-intensity 100 Hz stimulation of the basal amygdala permitted EEG activation to tail pressure to occur, and strongly enhanced olfactory-induced cortical activation. These results indicate that excitation of the basal amygdala potentiates frontal cortical responsiveness to aversive sensory events. This may provide a mechanism to facilitate cortical excitability and processing by amygdaloid neuronal activity.

Frontal brain electrical activity (EEG) distinguishes valence and intensity of musical emotions

Using recent regional brain activation/emotion models as a theoretical framework, we examined whether the pattern of regional EEG activity distinguished emotions induced by musical excerpts which were known to vary in affective valence (i.e., positive vs. negative) and intensity (i.e., intense vs. calm) in a group of undergraduates. We found that the pattern of asymmetrical frontal EEG activity distinguished valence of the musical excerpts. Subjects exhibited greater relative left frontal EEG activity to joy and happy musical excerpts and greater relative right frontal EEG activity to fear and sad musical excerpts. We also found that, although the pattern of frontal EEG asymmetry did not distinguish the intensity of the emotions, the pattern of overall frontal EEG activity did, with the amount of frontal activity decreasing from fear to joy to happy to sad excerpts. These data appear to be the first to distinguish valence and intensity of musical emotions on frontal electrocortical measures.

Frontal brain electrical activity (EEG) distinguishes valence and intensity of musical emotions

Using recent regional brain activation/emotion models as a theoretical framework, we examined whether the pattern of regional EEG activity distinguished emotions induced by musical excerpts which were known to vary in affective valence (i.e., positive vs. negative) and intensity (i.e., intense vs. calm) in a group of undergraduates. We found that the pattern of asymmetrical frontal EEG activity distinguished valence of the musical excerpts. Subjects exhibited greater relative left frontal EEG activity to joy and happy musical excerpts and greater relative right frontal EEG activity to fear and sad musical excerpts. We also found that, although the pattern of frontal EEG asymmetry did not distinguish the intensity of the emotions, the pattern of overall frontal EEG activity did, with the amount of frontal activity decreasing from fear to joy to happy to sad excerpts. These data appear to be the first to distinguish valence and intensity of musical emotions on frontal electrocortical measures.

Dynamics of frontal EEG activity, sleepiness and body temperature under high and low sleep pressure.

The impact of sleep deprivation (high sleep pressure) vs sleep satiation (low sleep pressure) on waking EEG dynamics, subjective sleepiness and core body temperature (CBT) was investigated in 10 young volunteers in a 40 h controlled constant posture protocol. The differential sleep pressure induced frequency-specific changes in the waking EEG from 1-7 Hz and 21-25 Hz. Frontal low EEG activity (FLA, 1-7 Hz) during sleep deprivation exhibited a prominent increase as time awake progressed, which could be significantly attenuated by sleep satiation attained with intermittent naps. Subjective sleepiness exhibited a prominent circadian regulation during sleep satiation, with virtually no homeostatic modulation. These extremely different sleep pressure conditions were not reflected in significant changes of the CBT rhythm. The data demonstrate that changes in FLA during wakefulness are to a large extent determined by the sleep-wake dependent process with little circadian modulation, and reflect differential levels of sleep pressure in the awake subject.

Extraversion–introversion and 8–13 Hz waves in frontal cortical regions

Abstract The study examined a possible relationship between electrical activity recorded from the scalp and personality, especially extraversion–introversion, in a sample of 50 male and female volunteers. EEG activity was recorded from 19 electrodes while subjects opened and closed their eyes on instruction. The participants completed Cattell’s 16 Personality Factor questionnaire and from those results, second-order personality traits (extraversion–introversion, low anxiety–high anxiety, tough poise–tender mindedness, and subduedness–independence) were calculated. An association was only found between the extraversion–introversion and frontal EEG activity in the 8–13 Hz range. Results also showed that extraverts were at least 3 times more likely to have larger amplitude activity in this range. No significant associations were found in posterior regions of the brain.

Frontal electrocortical and cardiovascular reactivity during happiness and anger

The present study investigated electrocortical and cardiovascular reactivity during positive and negative emotion, and examined the relation of asymmetric frontal lobe activation to cardiovascular responses. Participants were 30 healthy, right-handed university students (mean age, 23.9; 60% female; 76% Caucasian). Electroencephalographic (EEG), blood pressure (BP), and heart rate (HR) responses were assessed while subjects engaged in laboratory tasks (personally-relevant recall tasks and film clips) designed to elicit happiness or anger. Happiness-inducing tasks evoked more prominent left than right frontal EEG activation, and greater left frontal EEG activation than anger-inducing tasks. However, anger-inducing tasks were, on average, associated with comparable left and right frontal EEG activation. Irrespective of emotional valence, cardiovascular activation was more pronounced during personally-relevant recall tasks than during the viewing of film clips. During anger recall, both greater left frontal EEG response ( r=−0.46, P<0.02) and greater right frontal EEG response ( r=−0.45, P<0.02) were correlated significantly with increased HR reactivity during the task. In addition, a right lateralized frontal EEG response during anger-inducing tasks was associated with greater concomitant systolic BP ( P<0.03) and diastolic BP ( P<0.008) reactivity. Exploratory analyses also indicated that men who displayed a left lateralized frontal EEG response during happiness-inducing tasks showed the greatest concomitant systolic BP and HR reactivity ( P's<0.03). These findings suggest that asymmetric frontal EEG responses to emotional arousal may elicit different patterns of cardiovascular reactivity in healthy adults.

Anterior electroencephalographic asymmetry changes in elderly women in response to a pleasant and an unpleasant odor

Greater left than right frontal EEG activation has been associated with increased positive and/or decreased negative affect, whereas greater right than left frontal activation has been associated with the opposite pattern. Substantial research has documented the trait properties of asymmetry, as well as responses to pleasant and unpleasant stimuli. The present study examined changes in anterior alpha asymmetries in response to pleasant (vanilla), unpleasant (valerian), and neutral (water) odors. As predicted, vanilla produced relative left frontal activation compared to valerian and water. Frontal asymmetry did not differ in response to valerian compared to water. The results are consistent with the hypothesis that the left frontal region of the brain is involved in positive/approach-related emotion, and extend previous results into the olfactory realm.