Just a minute meditation: Rapid voluntary conscious state shifts in long term meditators

Meditation induces a modified state of consciousness that remains under voluntary control. Can meditators rapidly and reversibly bring about mental state changes on demand? To check, we carried out 128 channel EEG recordings on Brahma Kumaris Rajayoga meditators (36 long term: median 14240 h meditation; 25 short term: 1095 h) and controls (25) while they tried to switch every minute between rest and meditation states in different conditions (eyes open and closed; before and after an engaging task). Long term meditators robustly shifted states with enhanced theta power (4–8 Hz) during meditation. Short term meditators had limited ability to shift between states and showed increased lower alpha power (8–10 Hz) during eyes closed meditation only when pre and post task data were combined. Controls could not shift states. Thus trained beginners can reliably meditate but it takes long term practice to exercise more refined control over meditative states.     

Intra- and interindividual differences in lateralized cognitive performance and asymmetrical EEG activity in the frontal cortex

The study shows that changes in relative verbal vs. figural working memory and fluency performance from one session to a second session two to 3 weeks apart covary with spontaneously occurring changes of cortical asymmetry in the lateral frontal and central cortex, measured by electroencephalography (EEG) in resting conditions before the execution of tasks. That is, it was examined whether the current state of cortical asymmetry predicts verbal vs. figural performance. The findings complete the circle from studies showing correlations between changes of EEG asymmetry in the lateral frontal cortex and changes of mood to studies showing correlations between changes of mood and changes of relative verbal vs. figural working memory and fluency performance. The study suggests that state-dependent changes of lateralized cortical activity may underlie certain cognitive-emotional interactions observed in previous studies, and supports the assumption of reciprocal influences of specific emotional and specific cognitive processes.     

Typical performance measures of emotion regulation and emotion perception and frontal EEG asymmetry in an emotional contagion paradigm

In order to replicate and extend previous observations of validity of the self-reported habitual regulation of one’s affect and the perception of other people’s emotions, prefrontal electroencephalographic (EEG) asymmetry was recorded during and after social-emotional stimulation. After stimulation with other people’s vocal expression of anxiety, individuals with lower scores on emotion regulation did not show recovery of asymmetry changes but even increased changes in the direction that had been adopted during the stimulation. Whether this was to the right or to the left depended on their scores on emotion perception. Participants high on perception showed the expected changes to the right during the anxiety stimulation (indicating increased withdrawal motivation) and to the left during the cheerfulness stimulation (indicating increased approach motivation), whereas individuals low on perception showed the opposite pattern. During the anxiety stimulation, participants low on perception only showed the unexpected change to the left if they were also low on regulation. Individual differences in regulation did not play a role when participants were confronted with other people’s laughter. The findings demonstrate the validity of the self-report measures by using EEG measures, and moreover support the usefulness of differentiated and process-oriented approaches in the field of trait emotional intelligence.     

Frontal brain electrical activity (EEG) and heart rate in response to affective infant-directed (ID) speech in 9-month-old infants

Many studies have shown that infants prefer infant-directed (ID) speech to adult-directed (AD) speech. ID speech functions to aid language learning, obtain and/or maintain an infant's attention, and create emotional communication between the infant and caregiver. We examined psychophysiological responses to ID speech that varied in affective content (i.e., love/comfort, surprise, fear) in a group of typically developing 9-month-old infants. Regional EEG and heart rate were collected continuously during stimulus presentation. We found the pattern of overall frontal EEG power was linearly related to affective intensity of the ID speech, such that EEG power was greatest in response to fear, than surprise than love/comfort; this linear pattern was specific to the frontal region. We also noted that heart rate decelerated to ID speech independent of affective content. As well, infants who were reported by their mothers as temperamentally distressed tended to exhibit greater relative right frontal EEG activity during baseline and in response to affective ID speech, consistent with previous work with visual stimuli and extending it to the auditory modality. Findings are discussed in terms of how increases in frontal EEG power in response to different affective intensity may reflect the cognitive aspects of emotional processing across sensory domains in infancy.     

EMG scanning: Normative data

Surface EMG was recorded from both right and left aspects of 18 muscle groups for the purpose of establishing a data base of normative EMG levels. A scanning electrode permitted easy and rapid EMG measurement from 52 male and 51 female college students, both sitting and standing. Several a posteriori analyses of variance revealed sex differences in the masseter, occipital, posterior cervical, upper trapezius, latissimus dorsi, and anterior tibialis. Similarly, there were side differences for the anterior temporalis, occipitalis, splenius capitus, trapezius, paraspinalis, and soleus. The analyses also revealed interactions among sex, position, and side for various measures on the trapezius. The data show that females tend to muscle brace more than males in the upper extremities. The study provides data for normative comparisons and helps to plan and interpret future EMG studies.     

A portable biofeedback device for autonomic responses

The design of a versatile and programmable transducer amplifier device with analogue display for self-monitoring of autonomic responses is described. The design features low cost, portability, and flexibility across direct-current transducer options (e.g., photoplethysmograph or thermistor). The device can be used for the visual or auditory display of continuous blood volume pulse or temperature measures where the relative amplitude or pulse rate is of concern. Auditory or visual biofeedback may be provided via the choice of a stacked bar-graph display or piezoelectric buzzer. A common circuit design to allow programming options for the estimation of heart rate, inter-beat interval, or pulse duration is provided.     

Relative alpha desynchronization and synchronization during perception of music

Relative desynchronization (ERD) and synchronization (ERS) of the 8–10 Hz and 10–12 Hz alpha freqency bands elicited by music were studied in ten musically untrained right-handed subjects. The subjects listened to two five-minute musical excerpts representing two different musical genres, popular and classical, presented both foward and backward. ERD/ERS of the two alpha frequency bands was examined during the first four minutes of stimulus presentation using one-minute time windows. The results demonstrated that both the 8–10 Hz and the 10–12Hz frequency band exhibited reactivity to musical stimuli. The responses of the 8–10Hz and 10–12 Hz alpha frequency bands were dissimilar, dymanic and dependent on both time and stimulation type. The dynamics of these changes over time may explain some discrepancies in earlier EEG studies during listening to music.     

书面语言的提前学习对幼儿脑电α波的影响

本研究以脑电α波为分析指标探讨提前学习书面语言对幼儿大脑皮层相应区域发育的促进作用。结果表明对学龄前幼儿提前进行书面语言学习可以使幼儿脑电α波超前发展,本结果提示提前进行书面语言学习对幼儿大脑皮层相应脑区的发育与成熟有促进作用。     

Neurofeedback and the Brain

Neurofeedback is an emerging neuroscience-based clinical application, and understanding the underlying principles of neurofeedback allows the therapist to provide referrals or treatment, and provides clients with a framework for understanding the process. The brain's electrical patterns are a form of behavior, modifiable through “operant conditioning,” with the excessive brain frequencies reduced, and those with a deficit are increased. The learning curve for EEG has been described (Hardt, 1975).