Frontal Eeg Asymmetry Research Papers (original) (raw)
Recent years have seen an explosion of interest in using neural oscillations to characterize the mechanisms supporting cognition and emotion. Oftentimes, oscillatory activity is indexed by mean power density in predefined frequency bands.... more
Recent years have seen an explosion of interest in using neural oscillations to characterize the mechanisms supporting cognition and emotion. Oftentimes, oscillatory activity is indexed by mean power density in predefined frequency bands. Some investigators use broad bands originally defined by prominent surface features of the spectrum. Others rely on narrower bands originally defined by spectral factor analysis (SFA). Presently, the robustness and sensitivity of these competing band definitions remains unclear. Here, a Monte Carlo-based SFA strategy was used to decompose the tonic (“resting” or “spontaneous”) electroencephalogram (EEG) into five bands: delta (1–5 Hz), alpha-low (6–9 Hz), alpha-high (10–11 Hz), beta (12–19 Hz), and gamma (N21 Hz). This pattern was consistent across SFA methods, artifact correction/rejection procedures, scalp regions, and samples. Subsequent analyses revealed that SFA failed to deliver enhanced sensitivity; narrow alpha sub-bands proved no more sensitive than the classical broadband to individual differences in temperament or mean differences in task-induced activation. Other analyses suggested that residual ocular and muscular artifact was the dominant source of activity during quiescence in the delta and gamma bands. This was observed following threshold-based artifact rejection or independent component analysis (ICA)- based artifact correction, indicating that such procedures do not necessarily confer adequate protection. Collectively, these findings highlight the limitations of several commonly used EEG procedures and underscore the necessity of routinely performing exploratory data analyses, particularly data visualization, prior to hypothesis testing. They also suggest the potential benefits of using techniques other than SFA for interrogating high-dimensional EEG datasets in the frequency or time–frequency (event-related spectral perturbation, event-related synchronization/desynchronization) domains. KEY WORDS: principal components analysis (PCA); exploratory factor analysis (EFA); blind source separation (BSS); resting neural activity; resting EEG; frontal alpha asymmetry; frontal EEG asymmetry.
Background: It is unclear why children with autism spectrum disorders (ASD) tend to be inattentive to, or even avoid eye contact. The goal of this study was to investigate affective-motivational brain responses to direct gaze in children... more
Background: It is unclear why children with autism spectrum disorders (ASD) tend to be inattentive to, or even avoid eye contact. The goal of this study was to investigate affective-motivational brain responses to direct gaze in children with ASD. To this end, we combined two measurements: skin conductance responses (SCR), a robust arousal measure, and asymmetry in frontal electroencephalography (EEG) activity which is associated with motivational approach and avoidance tendencies. We also explored whether degree of eye openness and face familiarity modulated these responses. Methods: Skin conductance responses and frontal EEG activity were recorded from 14 children with ASD and 15 typically developing children whilst they looked at familiar and unfamiliar faces with eyes shut, normally open or wide-open. Stimuli were presented in such a way that they appeared to be looming towards the children. Results: In typically developing children, there were no significant differences in S...
Individuals show marked variation in their responses to threat. Such individual differences in behavioral inhibition play a profound role in mental and physical well-being. Behavioral inhibition is thought to reflect variation in the... more
Individuals show marked variation in their responses to threat. Such individual differences in behavioral inhibition play a profound role in mental and physical well-being. Behavioral inhibition is thought to reflect variation in the sensitivity of a distributed neural system responsible for generating anxiety and organizing defensive responses to threat and punishment. Although progress has been made in identifying the key constituents of this behavioral inhibition system in humans, the involvement of dorsolateral prefrontal cortex (DLPFC) remains unclear. Here, we acquired self-reported Behavioral Inhibition System Sensitivity scores and high-resolution electroencephalography from a large sample (n= 51). Using the enhanced spatial resolution afforded by source modeling techniques, we show that individuals with greater tonic (resting) activity in right-posterior DLPFC rate themselves as more behaviorally inhibited. This observation provides novel support for recent conceptualizations of behavioral inhibition and clues to the mechanisms that might underlie variation in threat-induced negative affect.
Aggression correlates with relatively greater left than right frontal electroencephalographic activity (inverse of EEG alpha power). The present experiment extends this research by manipulating frontal asymmetry and examining its effect... more
Aggression correlates with relatively greater left than right frontal electroencephalographic activity (inverse of EEG alpha power). The present experiment extends this research by manipulating frontal asymmetry and examining its effect on aggression. Participants were assigned to increase left frontal activation or increase right frontal activation by contracting their contralateral hand. They then received insulting feedback and played a game in which they could aggress toward the person who insulted them. Right-hand contractions caused greater left than right central and frontal activation and aggression as compared to left-hand contractions.Within the right-hand contraction condition, greater relative left frontal activity was associated with greater aggression. Descriptors: Frontal asymmetry, Aggression, Approach motivation
The hopelessness theory of depression proposes that individuals with a depressogenic cognitive style are more likely to become hopeless and experience depression following negative life events. Although the neurophysiological... more
The hopelessness theory of depression proposes that individuals with a depressogenic cognitive style are more likely to become hopeless and experience depression following negative life events. Although the neurophysiological underpinnings of cognitive style remain speculative, research indicates that decreased relative left frontal brain electrical activity holds promise as a trait-like marker of depression. This begs the question: Do measures of depressogenic cognitive style and resting frontal brain asymmetry index a common vulnerability? The present study provides preliminary support for this hypothesis. At baseline assessment, increased cognitive vulnerability to depression was associated with decreased relative left frontal brain activity at rest in individuals with no prior history of, or current, depression. Following baseline assessment, participants were followed prospectively an average of 3 years with structured diagnostic interviews at 4-month intervals. Both cognitive vulnerability and asymmetric frontal cortical activity prospectively predicted onset of first depressive episode in separate univariate analyses. Furthermore, multivariate analyses indicated that cognitive vulnerability and frontal asymmetry represented shared, rather than independent, predictors of first depression onset.
An extensive literature shows that greater left, relative to right, frontal cortical activity (LFA) is involved in approach-motivated affective states and reflects stable individual differences in approach motivation. However, relatively... more
An extensive literature shows that greater left, relative to right, frontal cortical activity (LFA) is involved in approach-motivated affective states and reflects stable individual differences in approach motivation. However, relatively few studies have linked LFA to behavioral indices of approach motivation. In this study, we examine the relation between LFA and effort expenditure for reward, a behavioral index of approach motivation. LFA was calculated for 51 right-handed participants (55% female) using power spectral analysis of electroencephalogram recorded at rest. Participants also
completed the effort expenditure for rewards task (EEfRT), which presents a series of trials requiring a choice between a low-reward low-effort task and a high-reward high-effort task. We found that individuals with greater resting LFA were more willing to expend greater effort in the pursuit of larger
rewards, particularly when reward delivery was less likely. Our findings offer a more nuanced understanding of the motivational significance of LFA, in terms of processes that mitigate the effort- and uncertainty-related costs of pursuing rewarding goals.