This study investigated how sensory motor rhythm (SMR, 13-15 Hz) and beta (16-20 Hz) band activity in the brain's EEG is affected by different states of attention. 11 participants completed two attention-demanding tasks - an externally-focused multiple object tracking task and an internally-focused visuospatial memory task - as well as a no-task control condition. EEG was recorded during each condition. Analysis found that both attention tasks reduced EEG power in the SMR, beta, and alpha bands compared to the no-task control. Additionally, the internally-focused task produced higher EEG power than the externally-focused task. These results contradict models suggesting increased SMR and beta reflect improved sustained attention.
Through neurofeedback training, children with ADHD learn to decrease excess theta wave activity in the prefrontal cortex and increase beta wave activity, which helps them better sustain attention and focus. Neurofeedback works by operantly conditioning the brain's EEG patterns over time from an "ADHD" state to one more similar to typically developing children. Studies show neurofeedback can remediate ADHD symptoms by helping children gain control over their thalamocortical brain rhythms and alertness levels through biofeedback of their EEG measurements.
This document discusses studies using neuroimaging techniques like PET, SPECT, and fMRI to study cerebral metabolism, blood flow, and neuroreceptor functioning in schizophrenia. Early studies found abnormalities in frontal lobe activity and the anterior-posterior gradient in patients. Subsequent studies found greater differences between patients and controls when assessing brain activity during cognitive tasks rather than at rest. Tasks probing memory, language, and executive function have revealed impairments in associated brain regions in patients. The relationship between symptoms and metabolism in temporal and basal ganglia regions is still unclear. Neuroleptic-naive and first-episode patients have provided insights with fewer confounding factors.
Challenges of methodological variability in EEGRADHA KUMARI
Discussion about factors affecting variability of EEG results across studies, extended discussion of the article https://sapienlabs.org/challenges-of-methodological-variability-in-eeg/
Investigating the Functional Utility of the Left Parietal ERP Old/New Effect:...Stuart Fairbairns
This study investigated the relationship between the left parietal ERP old/new effect, a neural marker of episodic recollection, and behavioral measures of memory performance across participants. The researchers recorded ERPs from 122 participants during an old/new recognition memory task. Within participants, they replicated previous findings that the magnitude of the left parietal effect increased with manipulations linked to increased recollection. However, they found no correlation between the size of the left parietal effect and behavioral memory performance measures across participants. This suggests that between group differences in the magnitude of the left parietal effect cannot be used to infer differences in recollection.
Mechanisms of white matter changes induced by meditationLoki Stormbringer
Using diffusion tensor imaging, several recent studies have shown that training results in changes in white matter efficiency as measured by fractional anisotropy (FA). In our work, we found that a form of mindfulness meditation, integrative body–mind training (IBMT), improved FA in areas surrounding the anterior cingulate cortex after 4-wk training more than controls given relaxation training. Reductions in radial diffusivity (RD) have been interpreted as improved myelin but reductions in axial diffusivity (AD) involve other mechanisms, such as axonal density. We now report that after 4-wk training with IBMT, both RD and AD decrease accompanied by increased FA, indicating improved efficiency of white matter involves increased myelin as well as other axonal changes. However, 2-wk IBMT reduced AD, but not RD or FA, and improved moods. Our results demonstrate the time-course of white matter neuroplasticity in short-term meditation. This dynamic pattern of white matter change involving the anterior cingulate cortex, a part of the brain network related to self-regulation, could provide a means for intervention to improve or prevent mental disorders.
This document summarizes the neurobiology of obsessive-compulsive disorder (OCD). It discusses the neuroanatomical basis involving regions like the anterior cingulate cortex and orbitofrontal cortex. It outlines the relevant neural pathways like the cortico-striatal-thalamic-cortical loop and their involvement in OCD. The neurochemicals implicated are serotonin, glutamate, and dopamine. Brain imaging studies have shown changes in brain volumes and activity in OCD patients in areas within these circuits.
This study examined patterns of cortical activity using four different EEG testing protocols: an extended 8-minute baseline with alternating eyes open and closed, viewing a 10-minute dyadic social interaction video, and completing a personality survey. The protocols elicited different levels of activity in the alpha band and theta/beta ratio. Specifically, all protocols differed significantly in alpha activity, and the three eyes-open conditions still differed when just compared to each other. This suggests protocol design impacts EEG results and more representative real-world designs should be explored.
Through neurofeedback training, children with ADHD learn to decrease excess theta wave activity in the prefrontal cortex and increase beta wave activity, which helps them better sustain attention and focus. Neurofeedback works by operantly conditioning the brain's EEG patterns over time from an "ADHD" state to one more similar to typically developing children. Studies show neurofeedback can remediate ADHD symptoms by helping children gain control over their thalamocortical brain rhythms and alertness levels through biofeedback of their EEG measurements.
This document discusses studies using neuroimaging techniques like PET, SPECT, and fMRI to study cerebral metabolism, blood flow, and neuroreceptor functioning in schizophrenia. Early studies found abnormalities in frontal lobe activity and the anterior-posterior gradient in patients. Subsequent studies found greater differences between patients and controls when assessing brain activity during cognitive tasks rather than at rest. Tasks probing memory, language, and executive function have revealed impairments in associated brain regions in patients. The relationship between symptoms and metabolism in temporal and basal ganglia regions is still unclear. Neuroleptic-naive and first-episode patients have provided insights with fewer confounding factors.
Challenges of methodological variability in EEGRADHA KUMARI
Discussion about factors affecting variability of EEG results across studies, extended discussion of the article https://sapienlabs.org/challenges-of-methodological-variability-in-eeg/
Investigating the Functional Utility of the Left Parietal ERP Old/New Effect:...Stuart Fairbairns
This study investigated the relationship between the left parietal ERP old/new effect, a neural marker of episodic recollection, and behavioral measures of memory performance across participants. The researchers recorded ERPs from 122 participants during an old/new recognition memory task. Within participants, they replicated previous findings that the magnitude of the left parietal effect increased with manipulations linked to increased recollection. However, they found no correlation between the size of the left parietal effect and behavioral memory performance measures across participants. This suggests that between group differences in the magnitude of the left parietal effect cannot be used to infer differences in recollection.
Mechanisms of white matter changes induced by meditationLoki Stormbringer
Using diffusion tensor imaging, several recent studies have shown that training results in changes in white matter efficiency as measured by fractional anisotropy (FA). In our work, we found that a form of mindfulness meditation, integrative body–mind training (IBMT), improved FA in areas surrounding the anterior cingulate cortex after 4-wk training more than controls given relaxation training. Reductions in radial diffusivity (RD) have been interpreted as improved myelin but reductions in axial diffusivity (AD) involve other mechanisms, such as axonal density. We now report that after 4-wk training with IBMT, both RD and AD decrease accompanied by increased FA, indicating improved efficiency of white matter involves increased myelin as well as other axonal changes. However, 2-wk IBMT reduced AD, but not RD or FA, and improved moods. Our results demonstrate the time-course of white matter neuroplasticity in short-term meditation. This dynamic pattern of white matter change involving the anterior cingulate cortex, a part of the brain network related to self-regulation, could provide a means for intervention to improve or prevent mental disorders.
This document summarizes the neurobiology of obsessive-compulsive disorder (OCD). It discusses the neuroanatomical basis involving regions like the anterior cingulate cortex and orbitofrontal cortex. It outlines the relevant neural pathways like the cortico-striatal-thalamic-cortical loop and their involvement in OCD. The neurochemicals implicated are serotonin, glutamate, and dopamine. Brain imaging studies have shown changes in brain volumes and activity in OCD patients in areas within these circuits.
This study examined patterns of cortical activity using four different EEG testing protocols: an extended 8-minute baseline with alternating eyes open and closed, viewing a 10-minute dyadic social interaction video, and completing a personality survey. The protocols elicited different levels of activity in the alpha band and theta/beta ratio. Specifically, all protocols differed significantly in alpha activity, and the three eyes-open conditions still differed when just compared to each other. This suggests protocol design impacts EEG results and more representative real-world designs should be explored.
Context Dependence Signature, Stimulus Properties and Stimulus Probability as...Carlos Mugruza
This study examined event-related brain potentials (ERPs) in response to an oddball task with four conditions in control and schizophrenic participants. Contrary to previous findings, non-correlation was found between time between novel stimuli and P3a amplitude in controls. Stimulus properties like probability, frequency, amplitude and duration significantly correlated with P300 amplitude, with higher correlations for environmental sounds in schizophrenics. A consistent modulation of mismatch negativity was found for novel stimuli in schizophrenia. Stimulus properties and temporal characteristics are strong predictors of P300 amplitude variability, with group differences relating to implicit memory and contextual processing differences.
This document summarizes current research on EEG neurofeedback applied to seven areas of brain health: attention-deficit hyperactivity disorder (ADHD), addictive disorders, anxiety, cognitive decline, depression, peak performance, and post-traumatic stress disorder (PTSD). For ADHD, two neurofeedback protocols have been shown effective based on meta-analyses and large randomized controlled trials. For addictive disorders, neurofeedback has been shown to reduce addiction severity and craving as an adjunctive treatment. Neurofeedback has also been shown as an efficacious treatment for anxiety disorders. Initial evidence suggests neurofeedback may be promising for improving cognitive function in conditions like mild cognitive impairment. Protocols targeting left-frontal brain asymmetry have shown effectiveness
Kate Toland - Poster Neuro Conference Sept 2015 MKKate Toland
This document describes a study that investigated the effects of neurofeedback training (NFT) on response inhibition. Eighteen healthy participants were randomly assigned to receive NFT targeting theta activity in either the right inferior frontal gyrus (rIFG group) or right angular gyrus (rAG group, control region). Participants completed response inhibition and other executive function tasks before and after five NFT sessions over four weeks. The study found no significant group differences in response inhibition task performance or theta activity after NFT. However, the rIFG group showed improved switching task performance compared to the rAG group.
Positron-emission tomography studies of cross-modality inhibition in selectiv...Dr Brendan O'Sullivan
Published in 1994, this groundbreaking paper featured the research of Professor Per Roland, Professor Ryuta Kawashima (of “Brain Training” fame) and Professor Brendan O’ Sullivan.
This landmark research was the first to prove in human brain imaging studies that visual attention is impaired when we do other attention-competing tasks such as manual tasks such as using mobile phones while driving.
This study investigated the effects of acute alcohol ingestion on electroencephalogram (EEG) power spectra and cross-frequency phase-amplitude coupling (CFPAC) at rest and during a simple subtraction task. The results showed that theta-phase gamma-amplitude coupling at frontal and parietal electrodes was significantly reduced after alcohol ingestion compared to the control condition. This suggests that acute alcohol impairs the synchronized cross-frequency coupling in the brain at rest. The findings indicate that cross-frequency coupling analysis could provide insights into the inhibitory effects of alcohol on cognitive control networks in the brain.
EEG and fNIRS connectivity features were analyzed to assess their ability to differentiate mental workload levels. Connectivity was measured using Pearson correlation and coherence of EEG signals, and correlation of fNIRS oxygenated hemoglobin levels. Results showed that EEG alpha and theta power and the theta/alpha ratio varied significantly with workload. Correlations between frontal-temporal and temporal-occipital fNIRS optodes also differed depending on workload conditions. The Frobenius distance between EEG connectivity matrices could distinguish workload levels and task vs non-task conditions, indicating connectivity features may be useful for mental workload estimation. Further research with more participants is needed to strengthen these preliminary findings.
This thesis examines how attention affects the functional connectivity of the visual cortex using transcranial magnetic stimulation (TMS) and electroencephalography (EEG). Participants performed a covert attention task where they oriented their attention to one of two locations indicated by a central cue arrow. TMS was applied to occipital cortex, parietal cortex, or orthogonally to the scalp 600ms after cue onset. No effects of stimulation site were found on behavior, but the EEG data showed a late interaction between stimulation site and cue direction 340-390ms after the TMS pulse, suggesting a top-down attentional modulation of visual cortex connectivity. Further analyses will investigate this late effect.
Brain research journal regional differences nova Vladimír Krajča
This document analyzes regional differences in neonatal sleep EEG recordings through quantitative analysis. 21 healthy full-term newborns underwent polygraphic recordings including 8-channel EEG during sleep. EEG signals from different brain regions were automatically analyzed and described using 13 variables. Statistical analysis found significant differences between brain regions, with posterior-medial regions exhibiting higher spectral feature values and variability. Differences were also seen between left and right anterior regions. The automatic analysis method was able to detect physiological regional differences in neonatal EEG.
The document summarizes a study that investigated how attention modulates the P1 ERP component. 6 participants completed a spatial cueing task while EEG was recorded. The study found that:
1) P1 amplitude was stronger over electrode sites contralateral to the attended visual field, suggesting attention increases neural sensitivity.
2) P1 onset latency was earlier for attended stimuli, suggesting attention optimizes neural pathways to speed response.
3) Small P1 onset differences between fast and slow reaction times suggest P1 indicates reaction time before response.
Regulation of depression by a new type of brain stimulation in addicted patie...Mrsunny4
Depression is also known as clinical depression and major depressive disorder (MDD). This severe medical illness affects 15 million American adults every year or about 5-8% of the adult population of the US. Women are nearly twice as likely as men to develop major depression.
Psychotherapy the biological dimensionismail sadek
is it real word can affect your brain?
many people say not and don't believe that the psychotherapy change not only our behavior but also it can change the brain structure
Machine learning applications in clinical brain computer interfacingJenny Midwinter
Brain computer interfaces (BCIs) provide alternative communication channels from the brain to external devices for severely disabled individuals and can be used to induce and guide adaptive plasticity for recovery after central nervous system trauma. Clinical BCI effectiveness depends on robust and accurate modeling of the relationship between brain signals and behaviour. Dr. Boulay will give a brief survey of BCI technologies and discuss common BCI paradigms and implementations, with an emphasis on clinical BCI brain signals and machine-learning applications.
* From the Ottawa AI/ML Meetup June 2018.
This is a paper I wrote for school on brain impairments in attention deficit hyperactivity disorder, with a focus on neuroanatomical differences and connectivity patterns. I reviewed findings from various studies, considered their limitations, and proposed directions for future research.
Dr. Frederick Starr is a psychiatrist and pioneer in the field of neurotechnology. He founded Myneurva to advance neurofeedback treatment. Neurofeedback uses EEG to monitor brain activity and provide feedback to change brainwaves. It has been shown to effectively treat conditions like PTSD, ADHD, anxiety, depression, autism, and more. Dr. Starr's lecture discussed what neurofeedback is, how it works, the research supporting its use for various mental and physical health conditions, and the Starrbase system for remote neurofeedback treatment and diagnosis using QEEG brain mapping and artificial intelligence.
The Impact of Neurodegeneration on Network Connectivity: A Study of Change De...rockbam
This study used magnetoencephalography (MEG) to examine change detection and frontotemporal network connectivity in patients with behavioral variant frontotemporal dementia (bvFTD) compared to healthy older adults. The study found that patients with bvFTD showed normal auditory cortical responses to predictable tones but reduced responses to unpredictable tones, suggesting impaired change detection. Analysis of coherence among frontal, temporal, and parietal sources found reduced left frontotemporal coherence in bvFTD patients in the beta frequency range, as well as reduced frontal interhemispheric coherence and enhanced parietal interhemispheric coherence in the gamma frequency range. These results provide evidence that bvFTD is associated with dysfunctional
Neurofeedback is a type of biofeedback therapy that uses EEG to measure brain waves and teach patients to regulate their brain activity. Studies show neurofeedback can be an effective complementary treatment for addiction when combined with therapies like CBT. It works by training patients over multiple sessions to develop coping skills and process stressors in a calm manner by retraining dysfunctional brain patterns associated with their substance dependence. Research finds neurofeedback improves focus and reduces impulsive behaviors for over 85% of patients, and treatment programs using it have higher success rates and lower relapse.
Mental Strain while Driving on a Driving-Simulator: Potential Effect on Centr...CSCJournals
This document summarizes a study that examined the effects of mental strain while driving in normal and time-constrained conditions using a driving simulator. The study measured magnetoencephalographic (MEG), autonomic nervous system (ANS), and behavioral data. Under time-constrained conditions designed to elicit high strain, participants had longer reaction times when stopping at traffic lights and increased activation in the left dorsolateral prefrontal cortex. Heart rate decreased more before traffic light changes under time constraints, suggesting increased focus on potential changes. A negative correlation was observed between ANS activity and left brain activity. The results have implications for understanding the impacts of mental strain on safety while driving.
This meta-analysis identified three transdiagnostic clusters of hypoactivation across mood and anxiety disorders. The clusters were located in the inferior prefrontal cortex/insula, inferior parietal lobule, and putamen. Differences between disorders were only found in the putamen, where hypoactivation was more prominent in bipolar disorder. Tasks involving cognitive systems made the largest contribution to the hypoactivation clusters. Three additional clusters of hyperactivation were identified in less stringent analyses, located in the anterior cingulate, amygdala/parahippocampal gyrus, and thalamus, with no diagnostic differences. The findings suggest shared abnormalities in regions involved in inhibitory control and salience processing across these disorders.
Following Your Dreams
REM sleep behavior disorder and resulting cognitive decline
Sleep plays an important role in cognitive functioning, notably in learning and
memory. Parasomnias, such as REM Sleep Behavioral disorder (RBD), have been
associated with sleep issues, such as attaining as well as sustaining sleep. As a result of
this deficit, many individuals afflicted with this disorder struggle in remembering as well
as learning. In many cases its idiopathic form (iRBD) may be an early indicator of later,
more severe neurodegenerative disease. Knowing that those afflicted with iRBD may also
be at risk of developing neurodegenerative diseases, the prolonged time frame between
diagnosis of iRBD and the subsequent onset of diseases, such as Parkinson’s, provides an
excellent opportunity for potential treatment (Postuma, Gagnon & Montplaisir, 2011;
Fantini et al. 2011). As research on this topic continues to develop, more recent data has
indicated a significant improvement and normalization of symptoms of RBD with the use
of exogenous, or synthetic, melatonin, which is the hormone found in mammals that is
most associated with sleep. Sleep quality and quantity was also positively affected, thus
patients often retained cognitive capacity that otherwise may have deteriorated (Kunz &
Mahlberg, 2010).
REM sleep behavior disorder is characterized by the loss of muscle atonia that is
present during a normal REM cycle. The demographic most commonly diagnosed with
the disorder is generally males over fifty, although it does not exclude females and
symptoms can also be triggered by anti-depressents, which could include younger
individuals (Postuma, Gagnon & Montplaisir, 2011). REM atonia normally disables
motor or muscle activity during the rapid eye movement stage of the sleep cycle, which is
the stage associated with dreaming. Atonia is generally attributed as one of many
functions associated or regulated by the lower brainstem (Kunz & Mahlberg, 2010). Lack
of atonia, therefore, could be due to malfunction or physical damage to this area. Without
inhibition, the muscles may be active and the sleeping individual is able to move, even
act out their dreams (Fantini et al. 2011). This ability may not only lead to physical harm
to the dreamer, who may injure themselves or others while moving around, but also
presents possible psychological harm as well, since the REM cycle and rest overall is
disturbed. (Kunz & Mahlberg, 2010).
While so much about the roles and purposes of sleep are unclear, many studies
have provided evidence that sleep plays an important role in memory consolidation.
Sleep-dependent memory processing has been investigated via the use of many
behavioral paradigms in humans and other species alike. Although not completely agreed
upon, as any research rarely goes without debate, there is a substantial amount of data
that has indicated a rel ...
This study examined electrodermal activity (EDA) in the hands of male and female college students during rest and reading conditions. The study found:
1) Females had significantly lower EDA on the left hand compared to males for both conditions.
2) Females also had significantly lower EDA for the left hand compared to the right hand for both conditions.
3) On average, EDA was higher for males across both hands and conditions compared to females.
Physiology and chemistry of skin and pigmentation, hairs, scalp, lips and nail, Cleansing cream, Lotions, Face powders, Face packs, Lipsticks, Bath products, soaps and baby product,
Preparation and standardization of the following : Tonic, Bleaches, Dentifrices and Mouth washes & Tooth Pastes, Cosmetics for Nails.
Context Dependence Signature, Stimulus Properties and Stimulus Probability as...Carlos Mugruza
This study examined event-related brain potentials (ERPs) in response to an oddball task with four conditions in control and schizophrenic participants. Contrary to previous findings, non-correlation was found between time between novel stimuli and P3a amplitude in controls. Stimulus properties like probability, frequency, amplitude and duration significantly correlated with P300 amplitude, with higher correlations for environmental sounds in schizophrenics. A consistent modulation of mismatch negativity was found for novel stimuli in schizophrenia. Stimulus properties and temporal characteristics are strong predictors of P300 amplitude variability, with group differences relating to implicit memory and contextual processing differences.
This document summarizes current research on EEG neurofeedback applied to seven areas of brain health: attention-deficit hyperactivity disorder (ADHD), addictive disorders, anxiety, cognitive decline, depression, peak performance, and post-traumatic stress disorder (PTSD). For ADHD, two neurofeedback protocols have been shown effective based on meta-analyses and large randomized controlled trials. For addictive disorders, neurofeedback has been shown to reduce addiction severity and craving as an adjunctive treatment. Neurofeedback has also been shown as an efficacious treatment for anxiety disorders. Initial evidence suggests neurofeedback may be promising for improving cognitive function in conditions like mild cognitive impairment. Protocols targeting left-frontal brain asymmetry have shown effectiveness
Kate Toland - Poster Neuro Conference Sept 2015 MKKate Toland
This document describes a study that investigated the effects of neurofeedback training (NFT) on response inhibition. Eighteen healthy participants were randomly assigned to receive NFT targeting theta activity in either the right inferior frontal gyrus (rIFG group) or right angular gyrus (rAG group, control region). Participants completed response inhibition and other executive function tasks before and after five NFT sessions over four weeks. The study found no significant group differences in response inhibition task performance or theta activity after NFT. However, the rIFG group showed improved switching task performance compared to the rAG group.
Positron-emission tomography studies of cross-modality inhibition in selectiv...Dr Brendan O'Sullivan
Published in 1994, this groundbreaking paper featured the research of Professor Per Roland, Professor Ryuta Kawashima (of “Brain Training” fame) and Professor Brendan O’ Sullivan.
This landmark research was the first to prove in human brain imaging studies that visual attention is impaired when we do other attention-competing tasks such as manual tasks such as using mobile phones while driving.
This study investigated the effects of acute alcohol ingestion on electroencephalogram (EEG) power spectra and cross-frequency phase-amplitude coupling (CFPAC) at rest and during a simple subtraction task. The results showed that theta-phase gamma-amplitude coupling at frontal and parietal electrodes was significantly reduced after alcohol ingestion compared to the control condition. This suggests that acute alcohol impairs the synchronized cross-frequency coupling in the brain at rest. The findings indicate that cross-frequency coupling analysis could provide insights into the inhibitory effects of alcohol on cognitive control networks in the brain.
EEG and fNIRS connectivity features were analyzed to assess their ability to differentiate mental workload levels. Connectivity was measured using Pearson correlation and coherence of EEG signals, and correlation of fNIRS oxygenated hemoglobin levels. Results showed that EEG alpha and theta power and the theta/alpha ratio varied significantly with workload. Correlations between frontal-temporal and temporal-occipital fNIRS optodes also differed depending on workload conditions. The Frobenius distance between EEG connectivity matrices could distinguish workload levels and task vs non-task conditions, indicating connectivity features may be useful for mental workload estimation. Further research with more participants is needed to strengthen these preliminary findings.
This thesis examines how attention affects the functional connectivity of the visual cortex using transcranial magnetic stimulation (TMS) and electroencephalography (EEG). Participants performed a covert attention task where they oriented their attention to one of two locations indicated by a central cue arrow. TMS was applied to occipital cortex, parietal cortex, or orthogonally to the scalp 600ms after cue onset. No effects of stimulation site were found on behavior, but the EEG data showed a late interaction between stimulation site and cue direction 340-390ms after the TMS pulse, suggesting a top-down attentional modulation of visual cortex connectivity. Further analyses will investigate this late effect.
Brain research journal regional differences nova Vladimír Krajča
This document analyzes regional differences in neonatal sleep EEG recordings through quantitative analysis. 21 healthy full-term newborns underwent polygraphic recordings including 8-channel EEG during sleep. EEG signals from different brain regions were automatically analyzed and described using 13 variables. Statistical analysis found significant differences between brain regions, with posterior-medial regions exhibiting higher spectral feature values and variability. Differences were also seen between left and right anterior regions. The automatic analysis method was able to detect physiological regional differences in neonatal EEG.
The document summarizes a study that investigated how attention modulates the P1 ERP component. 6 participants completed a spatial cueing task while EEG was recorded. The study found that:
1) P1 amplitude was stronger over electrode sites contralateral to the attended visual field, suggesting attention increases neural sensitivity.
2) P1 onset latency was earlier for attended stimuli, suggesting attention optimizes neural pathways to speed response.
3) Small P1 onset differences between fast and slow reaction times suggest P1 indicates reaction time before response.
Regulation of depression by a new type of brain stimulation in addicted patie...Mrsunny4
Depression is also known as clinical depression and major depressive disorder (MDD). This severe medical illness affects 15 million American adults every year or about 5-8% of the adult population of the US. Women are nearly twice as likely as men to develop major depression.
Psychotherapy the biological dimensionismail sadek
is it real word can affect your brain?
many people say not and don't believe that the psychotherapy change not only our behavior but also it can change the brain structure
Machine learning applications in clinical brain computer interfacingJenny Midwinter
Brain computer interfaces (BCIs) provide alternative communication channels from the brain to external devices for severely disabled individuals and can be used to induce and guide adaptive plasticity for recovery after central nervous system trauma. Clinical BCI effectiveness depends on robust and accurate modeling of the relationship between brain signals and behaviour. Dr. Boulay will give a brief survey of BCI technologies and discuss common BCI paradigms and implementations, with an emphasis on clinical BCI brain signals and machine-learning applications.
* From the Ottawa AI/ML Meetup June 2018.
This is a paper I wrote for school on brain impairments in attention deficit hyperactivity disorder, with a focus on neuroanatomical differences and connectivity patterns. I reviewed findings from various studies, considered their limitations, and proposed directions for future research.
Dr. Frederick Starr is a psychiatrist and pioneer in the field of neurotechnology. He founded Myneurva to advance neurofeedback treatment. Neurofeedback uses EEG to monitor brain activity and provide feedback to change brainwaves. It has been shown to effectively treat conditions like PTSD, ADHD, anxiety, depression, autism, and more. Dr. Starr's lecture discussed what neurofeedback is, how it works, the research supporting its use for various mental and physical health conditions, and the Starrbase system for remote neurofeedback treatment and diagnosis using QEEG brain mapping and artificial intelligence.
The Impact of Neurodegeneration on Network Connectivity: A Study of Change De...rockbam
This study used magnetoencephalography (MEG) to examine change detection and frontotemporal network connectivity in patients with behavioral variant frontotemporal dementia (bvFTD) compared to healthy older adults. The study found that patients with bvFTD showed normal auditory cortical responses to predictable tones but reduced responses to unpredictable tones, suggesting impaired change detection. Analysis of coherence among frontal, temporal, and parietal sources found reduced left frontotemporal coherence in bvFTD patients in the beta frequency range, as well as reduced frontal interhemispheric coherence and enhanced parietal interhemispheric coherence in the gamma frequency range. These results provide evidence that bvFTD is associated with dysfunctional
Neurofeedback is a type of biofeedback therapy that uses EEG to measure brain waves and teach patients to regulate their brain activity. Studies show neurofeedback can be an effective complementary treatment for addiction when combined with therapies like CBT. It works by training patients over multiple sessions to develop coping skills and process stressors in a calm manner by retraining dysfunctional brain patterns associated with their substance dependence. Research finds neurofeedback improves focus and reduces impulsive behaviors for over 85% of patients, and treatment programs using it have higher success rates and lower relapse.
Mental Strain while Driving on a Driving-Simulator: Potential Effect on Centr...CSCJournals
This document summarizes a study that examined the effects of mental strain while driving in normal and time-constrained conditions using a driving simulator. The study measured magnetoencephalographic (MEG), autonomic nervous system (ANS), and behavioral data. Under time-constrained conditions designed to elicit high strain, participants had longer reaction times when stopping at traffic lights and increased activation in the left dorsolateral prefrontal cortex. Heart rate decreased more before traffic light changes under time constraints, suggesting increased focus on potential changes. A negative correlation was observed between ANS activity and left brain activity. The results have implications for understanding the impacts of mental strain on safety while driving.
This meta-analysis identified three transdiagnostic clusters of hypoactivation across mood and anxiety disorders. The clusters were located in the inferior prefrontal cortex/insula, inferior parietal lobule, and putamen. Differences between disorders were only found in the putamen, where hypoactivation was more prominent in bipolar disorder. Tasks involving cognitive systems made the largest contribution to the hypoactivation clusters. Three additional clusters of hyperactivation were identified in less stringent analyses, located in the anterior cingulate, amygdala/parahippocampal gyrus, and thalamus, with no diagnostic differences. The findings suggest shared abnormalities in regions involved in inhibitory control and salience processing across these disorders.
Following Your Dreams
REM sleep behavior disorder and resulting cognitive decline
Sleep plays an important role in cognitive functioning, notably in learning and
memory. Parasomnias, such as REM Sleep Behavioral disorder (RBD), have been
associated with sleep issues, such as attaining as well as sustaining sleep. As a result of
this deficit, many individuals afflicted with this disorder struggle in remembering as well
as learning. In many cases its idiopathic form (iRBD) may be an early indicator of later,
more severe neurodegenerative disease. Knowing that those afflicted with iRBD may also
be at risk of developing neurodegenerative diseases, the prolonged time frame between
diagnosis of iRBD and the subsequent onset of diseases, such as Parkinson’s, provides an
excellent opportunity for potential treatment (Postuma, Gagnon & Montplaisir, 2011;
Fantini et al. 2011). As research on this topic continues to develop, more recent data has
indicated a significant improvement and normalization of symptoms of RBD with the use
of exogenous, or synthetic, melatonin, which is the hormone found in mammals that is
most associated with sleep. Sleep quality and quantity was also positively affected, thus
patients often retained cognitive capacity that otherwise may have deteriorated (Kunz &
Mahlberg, 2010).
REM sleep behavior disorder is characterized by the loss of muscle atonia that is
present during a normal REM cycle. The demographic most commonly diagnosed with
the disorder is generally males over fifty, although it does not exclude females and
symptoms can also be triggered by anti-depressents, which could include younger
individuals (Postuma, Gagnon & Montplaisir, 2011). REM atonia normally disables
motor or muscle activity during the rapid eye movement stage of the sleep cycle, which is
the stage associated with dreaming. Atonia is generally attributed as one of many
functions associated or regulated by the lower brainstem (Kunz & Mahlberg, 2010). Lack
of atonia, therefore, could be due to malfunction or physical damage to this area. Without
inhibition, the muscles may be active and the sleeping individual is able to move, even
act out their dreams (Fantini et al. 2011). This ability may not only lead to physical harm
to the dreamer, who may injure themselves or others while moving around, but also
presents possible psychological harm as well, since the REM cycle and rest overall is
disturbed. (Kunz & Mahlberg, 2010).
While so much about the roles and purposes of sleep are unclear, many studies
have provided evidence that sleep plays an important role in memory consolidation.
Sleep-dependent memory processing has been investigated via the use of many
behavioral paradigms in humans and other species alike. Although not completely agreed
upon, as any research rarely goes without debate, there is a substantial amount of data
that has indicated a rel ...
This study examined electrodermal activity (EDA) in the hands of male and female college students during rest and reading conditions. The study found:
1) Females had significantly lower EDA on the left hand compared to males for both conditions.
2) Females also had significantly lower EDA for the left hand compared to the right hand for both conditions.
3) On average, EDA was higher for males across both hands and conditions compared to females.
Similar to Vachon-Presseau_Achim_Benoit-Lajoie2009_DirectionofSMRandBetaChange.doc (20)
Physiology and chemistry of skin and pigmentation, hairs, scalp, lips and nail, Cleansing cream, Lotions, Face powders, Face packs, Lipsticks, Bath products, soaps and baby product,
Preparation and standardization of the following : Tonic, Bleaches, Dentifrices and Mouth washes & Tooth Pastes, Cosmetics for Nails.
The simplified electron and muon model, Oscillating Spacetime: The Foundation...RitikBhardwaj56
Discover the Simplified Electron and Muon Model: A New Wave-Based Approach to Understanding Particles delves into a groundbreaking theory that presents electrons and muons as rotating soliton waves within oscillating spacetime. Geared towards students, researchers, and science buffs, this book breaks down complex ideas into simple explanations. It covers topics such as electron waves, temporal dynamics, and the implications of this model on particle physics. With clear illustrations and easy-to-follow explanations, readers will gain a new outlook on the universe's fundamental nature.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
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Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
हिंदी वर्णमाला पीपीटी, hindi alphabet PPT presentation, hindi varnamala PPT, Hindi Varnamala pdf, हिंदी स्वर, हिंदी व्यंजन, sikhiye hindi varnmala, dr. mulla adam ali, hindi language and literature, hindi alphabet with drawing, hindi alphabet pdf, hindi varnamala for childrens, hindi language, hindi varnamala practice for kids, https://www.drmullaadamali.com
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
1. Direction of SMR and beta change: Journal of Neurotherapy, 2009, 13: 22-29 1
Running head: DIRECTION OF SMR AND BETA CHANGE
Direction of SMR and Beta Change with Attention in Adults.
Etienne Vachon-Presseau
Institut Universitaire de Gériatrie de Montréal, Université de Montréal, Montréal
André Achim and Aimée Benoit-Lajoie
Université du Québec à Montréal, Montréal
2. Direction of SMR and beta change: Journal of Neurotherapy, 2009, 13: 22-29 2
Abstract
The aim of the present study was to clarify the interpretation of SMR (13-15 Hz) and beta
(16-20 Hz) changes with respect to attention states. For this purpose, EEG was recorded from
11 subjects during: 1) a multiple object tracking task (MOT), which required externally
directed attention, 2) the retention phase of a visuo-spatial memory task (VSM), which
required internally directed attention and avoidance of sensory distraction, and 3) the waiting
intervals between trials, which constituted a no-task-imposed control condition. The 2 active
tasks were consecutively presented at 2 difficulty levels (i.e. easy and hard). Two analyses of
variance were conducted on EEG log spectral amplitudes in the alpha (8-12 Hz), SMR and
beta bands from F3, F4, C3, C4 and P3, P4. The first analysis compared the MOT to the
VSM by difficulty levels and revealed a significant task effect (p<0.0005) but no effect of
difficulty. The results showed that externally directed attention (MOT) resulted in lower
values than internally directed attention (VSM) in all three bands. The second analysis
averaged the difficulty levels together and added the no-task-imposed reference condition.
The results again showed a significant task effect that did not interact with site, hemisphere
or, more importantly, band. Post hoc tests revealed that both MOT and VSM produced
significantly smaller means than the no-task-imposed condition. This pattern of log-
amplitude means and the lack of task interaction with any other factor indicate that task
induced attention reduces EEG power in the same proportion across the 3 bands and the 6
channels studied. These results contradict a frequent interpretation concerning the
relationship between the brain’s aptitude to increase low beta in neurofeedback programs and
improved sustain attention capacities.
3. Direction of SMR and beta change: Journal of Neurotherapy, 2009, 13: 22-29 3
Direction of SMR and Beta Change with Attention in Adults.
Neurofeedback programs for ADHD involve behavioural training sessions designed to
modulate the EEG spectral contents. The aim is typically to reduce excess theta EEG activity
(5-7 Hz) and to increase sensory-motor rhythm (SMR, 12-15 Hz) or low beta activity (16-20
Hz) (Monastra, Monastra, & George 2002). These targeted changes are based on QEEG
observations and are often assumed to directly correspond to increased control over attention
and hyperactivity. In sharp contrast to this literature, event related studies generally present
activation as reduced amplitude over both alpha and beta bands (Pfurtscheller, & Lopes da
Silva, 1999). Since experimental data linking EEG fluctuations to increased attention are
scarce, it remains possible that such event related responses have no parallel in general
attention states. The motivation for the present study was to better identify the type of
modulation of SMR (13-15 Hz) and beta band (16-20 Hz) during sustained attention states,
especially compared to a situation in which no task is imposed. This purpose is meant to
contribute to our models of how neurofeedback may improve attention.
A few studies support the association of increase SMR with increased attention
capacity. For instance, Egner & Gruzelier (1994) observed that SMR enhancement training
improved performance in both visual and auditory attention tests. Moreover, SMR can be
interpreted as a sensory-motor idling rhythm equivalent to occipital alpha that indirectly
facilitates visuo-spatial attention. Indeed, Cooper, Croft, Dominey, Burgess, & Gruzelier,
(1983) have observed alpha enhancement when attention benefits from an active inhibition of
all visual inputs or of selected parts of the visual field. Correspondingly, learning to increase
SMR in ADHD could simply be learning to inhibit the sensory-motor system, i.e. mastering
how to get calm. Thus, whether increased SMR directly comes from increased activity in an
4. Direction of SMR and beta change: Journal of Neurotherapy, 2009, 13: 22-29 4
attention network or from sensory-motor disengagement that facilitates attention is still
debatable.
In a similar fashion, increased beta (15-20 Hz) amplitude prescribed for ADHD is
typically meant to directly support attention and alleviate symptoms of inattentiveness
(Egner, & Gruzelier, 2004). Indeed, ADHD medication has been reported to increase frontal
beta in responders in a manner positively correlated with improvement in a continuous
performance test (Loo, Hopfer, Teale, & Reite, 2004). Nevertheless, the relationship of beta
enhancement with improved attention remains uncertain since decreasing EEG amplitude
over this range of frequencies is sometimes prescribed to increase concentration in high-level
executives (Cowan, 1998). The rational supporting these opposite prescriptions for increased
attention capacity could be simultaneously correct if beta was associated with good attention
in opposite directions in children and in adults. This paradox could also be overcome with an
alternate view, in which increased beta might represent inhibition or disengagement of a
system that hinders attention rather than directly reflect a better attention state. Hence, better
attentional capacities could be an indirect effect of reduced background processing reflected
in increased beta. Although high beta (above 20 Hz) seems to characterise rumination in
depression (Demos, 2005), the low beta band could represent an idling state, akin to the
neighbouring alpha and SMR bands.
Ray and Cole (1985) have approached the relationship between EEG and attention
differently. They presented evidence that alpha activity reflects attention demands (external
versus internal attention) while beta activity rather reflects emotional and cognitive
processing. They contrasted several ‘external’ and ‘internal’ tasks, in which attention must
respectively be paid to the external environment or directed to internally held information
while resisting distraction from external stimuli (e.g. during mental arithmetic). Internal
tasks, which they called ‘rejection tasks’, were characterised by larger amplitude relative to
5. Direction of SMR and beta change: Journal of Neurotherapy, 2009, 13: 22-29 5
the external tasks (which they called ‘intake tasks’), in both parietal lobes, for each 4 Hz-
wide band from 8 to 20 Hz. Moreover, all these bands had more energy in the right (R)
hemisphere than in the left (L). Finally, their results indicated significant interaction of
attention demand (external versus internal) with hemisphere. These interactions are however
questionable, since the analyses were carried on EEG power, rather than on its logarithm,
such that even strictly proportional reduction could appear as significant interaction. For
instance, the 16-20 Hz band R-L difference was 29 units for internal and 37 units for external,
but the corresponding (R-L)/(R+L) ratio were respectively 0.130 and 0.135, indicating that
the hemisphere differences were nearly proportional to the means. The increased alpha and
beta amplitudes observed during the external tasks relative to the internal task are consistent
with the active inhibition hypothesis. From a strictly logical point of view, it remains possible
that increased alpha reflects sensory input inhibition while increased beta (sought in
neurofeedback programs) would reflects increased processing involvement on internally held
information.
While this paradigm revealed locus of attention to be an important alpha and beta
band modulator, the Ray and Cole study lacked a neutral control group to help interpreting
the difference between the attention demanding internal and external situations. The object of
the present study is to clarify the relationship of SMR and low beta with attention in normal
adults by revisiting the external-internal paradigm with the addition of a neutral no-task-
imposed condition. This constitutes a preliminary step to clarify the function of increasing
beta through neurofeedback in children with ADHD.
The main hypothesis of the present study is based on the event related studies and
proposes that alpha, SMR, and low beta are reduced in amplitude when one of its supporting
systems is engaged. Since the attention tasks used do not specifically require sensory motor
inhibition, we expected that any spectral difference with the control no-task-imposed
6. Direction of SMR and beta change: Journal of Neurotherapy, 2009, 13: 22-29 6
condition would consist in amplitude reduction. In line with Ray and Cole (1985), we
hypothesised that the internal task would show larger amplitude than the external task in any
affected band. In addition to our main hypothesis (reduced EEG amplitude for the external
task relative to the internal task), we also expected both experimental tasks to show reduced
EEG amplitude compared to the control no-task-imposed condition.
Method
Participants
The present study was approved by the ethics committee of the Department of
Psychology of Université du Québec à Montréal. Twelve undergraduate students (aged
between 22 and 30 years old) were recruited, signed informed consent, and received 25 $
after their participation in the EEG recording session. Data from one participant had to be
excluded because of technical problems.
Experimental design and procedure
Two tasks were designed to share the same visual and response interface and were
presented at two levels of difficulty (easy and hard). The first experimental condition
consisted in a multiple object tracking task (MOT), in which the subjects visually tracked
designated targets among moving stimuli. The second experimental condition was a visuo-
spatial memory task (VSM), in which the subjects had to keep in mind the spatial positions of
the stimuli designated as targets. The conditions differed in that the stimuli moved randomly
in one condition and temporarily disappeared in the other. Although both tasks recruit the
subjects’ attention toward the spatial location of targets, the MOT and VSM are respectively
‘external’ and ‘internal’ tasks, or ‘intake’ and ‘rejection’ tasks in the sense of Ray and Cole
(1985). Indeed, the MOT commands an intense external focus since the subjects have to
simultaneously follow selected moving objects on the computer screen, while on the other
7. Direction of SMR and beta change: Journal of Neurotherapy, 2009, 13: 22-29 7
hand, the VSM task, during the period of stimulus disappearance, requires avoidance of
distraction and focuses on the internal representation of the positions to remember.
The MOT trial’s procedure consisted of several steps. First, the subject’s EEG was
recorded during a six seconds period preceding the onset of each trial while the display
screen was blank. These EEG data were used as a control condition in which no specific task
demand was imposed on the subjects. Six to twelve identical blue small squares (1 cm2
) then
appeared on the white screen of the monitor. Half of them blinked during two seconds, which
defined them as the targets. All objects then moved haphazardly for 10 to 30 seconds (during
which the EEG was collected for this condition). After the stimuli stopped moving, subjects
were required to identify the targets with the mouse. If the participants lost track of some of
the targets, they were asked to click outside the experimental frame rather than guess. Finally,
feedback on the trial was provided as the proportion of correctly identified targets along with
the display of the correct positions.
In order to assess whether the tasks’ difficulty was an important predictor of EEG
fluctuations, the MOT was presented at two levels of difficulty (i.e. easy and hard). These
difficulty levels were produced by manipulating: the number of objects, the speed of
movement, the predictability of direction change of individual dots, the task duration, and the
size of the frame inside which the objects moved.
The VSM trial’s procedure consisted of similar steps. The EEG was recorded during a
six seconds period preceding the onset of the task while the screen was blank. Between six
and sixteen small squares, identical to those in the MOT condition, then appeared on the
screen at random positions. A cross was inscribed inside half of the squares to define them as
the targets. The subjects were given unlimited time to observe and memorize the targets’
locations. At their signal (mouse click), all the squares disappeared for a period of 10, 15 or
30 seconds (during which the EEG was collected for this condition). After all the squares
8. Direction of SMR and beta change: Journal of Neurotherapy, 2009, 13: 22-29 8
reappeared at their initial positions, the subjects were required to click with the mouse on
those previously defined as targets. As in the MOT task, participants were asked to click
outside the stimulus zone rather than simply guess. Finally, feedback on performance was
given as the trial success rate along with the illustration of the correct positions.
The VSM task was also presented at two difficulty levels, produced by manipulating:
the number of objects, the size of the frame inside which object were presented and the
duration of the retention period.
All subjects were exposed to both tasks at both difficulty levels. The experimentation
contained a total of 48 trials, presented in alternating blocks of 12 of the same type and
difficulty level. The starting task was counterbalanced across subjects, but the two easy levels
always preceded the two harder ones.
Electrophysiological recording and data preparation
The EEG was recorded through a 128 channel BioSemi ActiveTwo system with
linked ears reference. The electrodes of interest were those corresponding to the international
10/20 system positions frequently used in neurofeedback: F3, F4, C3, C4, along with the P3
and P4 sites used by Ray and Cole (1985). The EEG signal was filtered with a 0.1 to 45 Hz
band pass and then digitized at 256 Hz. The EEG analyses were conducted only on data
acquired during the 6 s blank screen stage separating the trials (no-task-imposed) or during
the movement or retention intervals of the two tasks.
Trials with behavioural errors were excluded from analysis, as the error could reflect
lack of attention, but the waiting period that preceded them was retained for the no-task-
impose condition. All EEG epochs retained for analysis (MOT, VSM and control no-task-
imposed) were broken into non overlapping 1 s segments which were inspected visually,
blind to condition, and rejected if they contained an artefact. Each retained EEG segment was
windowed (raised half cosine on 0.1 s at both ends) and Fourier transformed. The individual
9. Direction of SMR and beta change: Journal of Neurotherapy, 2009, 13: 22-29 9
spectra within each condition were averaged in the amplitude domain within subject. The
resulting average amplitude spectra were then transformed to their base-10 logarithmic values
for statistical analyses. The choice of these different units for averaging was based on ranking
the mean spectrum among the individual spectra contributing to the mean. This was
successively done for amplitude, power, and log power. The form of data for which the mean
ranked closest to 50% (the median) across the frequency bands from 1 to 25 Hz was retained.
This resulted in applying a logarithmic transform to the averaged amplitude within each
subject and condition. The log amplitudes of the various 1-Hz wide bands within the alpha
(8-12 Hz), SMR (13-15 Hz) and low beta (16-20 Hz) bands were averaged together as a final
step before statistical analysis of log spectral amplitudes.
Statistical analyses
Statistical testing was done with repeated measure analysis of variance (ANOVA),
using SPSS MANOVA and by applying the Geisser & Greenhouse correction for effects with
more than two levels; in those cases, the degrees of freedom reported are the reduced ones. A
first ANOVA, ignoring the waiting condition, implemented the completely within-subject
design: 2 Tasks x 2 Difficulty levels x 3 Bands (i.e. alpha, SMR, low beta) x 2 Hemispheres x
3 Sites (i.e. frontal, central, parietal). Such five factor analysis yields 31 statistical tests. The
effects of Band, Hemisphere or Site without interaction with Task or Difficulty are not
relevant to the purpose of the present study. Their presence, however, increases the risk of a
type I error since any interaction of Task or Difficulty with Band, Hemisphere or Site would
justify concluding in a Task or Difficulty effect. Consequently, a Bonferroni correction was
applied, which set the per-test significance level to 0.05/8 = 0.00625. Significant effects not
involving Task or Difficulty are reported but were not further explored into simple effects or
pair wise differences.
10. Direction of SMR and beta change: Journal of Neurotherapy, 2009, 13: 22-29 10
Since the first analysis showed no effect of difficulty, the easy and hard conditions
could be averaged together within task for the purpose of a second ANOVA, which included
the no-task-imposed control as a third level for the Task factor. This analysis (without the
Difficulty level) tested 15 different effects, from which only the 8 involving the Task factor
were directly relevant to this study. For the same reason as for the first ANOVA, the per-test
significant level was set at 0.05/4 = 0.0125. The comparison of the no-task-imposed
condition with each of the other two tasks was a priori justified and the critical level for these
contrasts was set at the usual 0.05 per test.
Results
Behavioural results
The success rates for the easy conditions were 96.3% of MOT trials and 98.2% of
VSM trials. The success rates for the harder conditions were 68.5% of MOT trials and 71.3%
of VSM trials.
EEG results
Figure 1 illustrates the means for the five experimental conditions over the six
channels of interest. Given the lack of interaction involving band (see below) and the greater
interest for the SMR and beta band (because neurofeedback in ADHD targets these more than
alpha), the alpha band was omitted to simplify the figure.
The first ANOVA (Task x Difficulty x Band x Hemisphere x Site) showed five
significant effects out of the 31 tested. Among the effects of interest, i.e. those involving Task
or Difficulty, only the main Task effect was significant (F(1,10)=33.84, p<0.0005). The main
Difficulty effect was clearly absent (F(1,10)=0.39, p=0.547) as well as any interaction effects
involving Difficulty.
Of the effects involving neither Task nor Difficulty, all three main effects were
significant (Band: F(1.6,16)=33.34, p<0.0005; Hemisphere: F(1,10)=177.68, p<0.0005; Site:
11. Direction of SMR and beta change: Journal of Neurotherapy, 2009, 13: 22-29 11
F(1.59,15.9)=492.82, p<0.0005), as was the Hemisphere by Site interaction
(F(1.79,17.9)=74.14, p<0.0005).
For the Task effects, the means were 0.959 (±0.027 s.e.m.) for MOT and 1.027
(±0.024) for VSM. For the Band effect, the means were 1.136 (±0.036) for alpha, 0.991
(±0.036) for SMR and 0.853 (±0.022) for beta. The Hemisphere and Site means are reported
through their interaction; for frontal, central and parietal respectively, the means were 1.123
(±0.023), 0.925 (±0.028) and 0.713 (±0.025) for the left hemisphere and 1.162 (±0.025),
1.070 (±0.032) and 0.968 (±0.029) for the right hemisphere. This interaction thus indicates
that hemisphere difference grows from front to back (0.038, 0.145 and 0.255 respectively).
Since the measures were in log units, these R-L differences are also the logarithm of the R/L
amplitude ratio.
The real interest of the present study lies in the comparison with the condition in
which no task was imposed on the participants. Since the initial ANOVA indicated that the
two difficulty levels were too similar to be reflected differently in the EEG spectra, the data
could be averaged across difficulty levels for a second analysis involving the control no-task-
imposed condition. There is little surprise that all significant effects of the first ANOVA are
still present after adding a third Task level; (Task: F(1.37,13.7)=20.12, p<0.0005; Band:
F(1.55,15.5)=30.00, p<0.0005; Hemisphere: F(1,10)=179.41, p<0.0005; Site:
F(1.59,15.9)=522.98, p<0.0005; with the only significant interaction being that of
Hemisphere by Site: F(1.72,17.2)=97.63, p<0.0005). More importantly, as shown in figure 1,
the results of this second analysis revealed that the mean for the control no-task-imposed
condition (1.067 (±0.036)) significantly differed from each of the active tasks
(F(1,10)=24.18, p=0.001 for the MOT and F(1,10)=5.82, p=0.036 for VSM).
12. Direction of SMR and beta change: Journal of Neurotherapy, 2009, 13: 22-29 12
Discussion
The main conclusion from this study is that the involvement in a task requiring
attention in young adults causes a reduction in EEG spectral amplitude compared to a
condition in which they simply wait for the upcoming trial. As indicated by the lack of
interactions, this effect is essentially the same for all three bands across all six recording
channels analysed. Thus, in line with the general principle that brain activation tends to
desynchronise neuronal activity, the results of the present study reveal that the signature of
increased attention is a reduction of alpha, SMR and beta amplitudes. Therefore, the beta
band effect turns out to be opposite to what is often interpreted as the reason why
renormalizing low beta (increasing it) through neurofeedback is beneficial for ADHD. This,
however, does not mean that such target should be abandoned. The present data rather
challenge the rationale underlying the success of the treatment.
Adding the neutral control condition brings an interesting complement to interpret the
results of Ray and Cole (1985). Firstly, our results replicate their hemisphere effect, with
larger amplitudes observed for the right than for the left hemisphere for all bands from 8 to
20 Hz. Secondly, since a multiplicative (i.e. proportionality) model is more appropriate than
an additive model to explore EEG amplitudes variations over space, the present results
confirm our speculation that the Ray and Cole (1985) Task x Hemisphere effects might be
illusory. Indeed, their results were not replicated in the present analyses that embedded a
multiplicative model implemented through logarithmic transformations. Thirdly, while the
original data suggested that internal tasks produce increased amplitudes relative to external
tasks, we found that the comparison with the no-task-imposed condition rather indicates that
it is more appropriate to see this as lesser desynchronisation. The lack of interaction of the
Task factor with band or with topography leads us to consider that the MOT external task just
requires more intense concentration and discredits the hypothesis of an extra motor inhibition
13. Direction of SMR and beta change: Journal of Neurotherapy, 2009, 13: 22-29 13
during the VSM rejection task. Indeed, we did not find any sign of difference between tasks
exclusive to the SMR band or to the central recording sites, which would have suggested a
motor inhibition component. This interpretation is therefore consistent with a general
decrease in EEG amplitude while performing a cognitive effort (i.e., steadily increasing
desynchronisation from no-task-imposed to VSM to MOT).
Since the influence of the cognitive effort required to perform the tasks is an
important modulator of EEG patterns, the lack of effect regarding the Difficulty factor may
seem surprising. While some studies did find a significant effect of difficulty level on EEG
patterns (e.g., Sterman & Mann, 1995), Babiloni et al. (2004) illustrated that the prominent
factor for EEG desynchronisation is the nature of the cognitive effort rather than its difficulty.
They observed that even their easiest task (i.e. the retention of a single item) desynchronised
the EEG spectra in the theta and alpha bands. The results of the present study revealed a
similar effect, extended to low beta frequencies, in which performing the task correctly over
95% of the time desynchronised the EEG as much as the harder task (around 70% of correct
answers). This does not mean, however, that still more challenging difficulty levels would not
further desynchronise the EEG.
Finally, a Difficulty by Band interaction could have been considered significant if no
correction had been applied for the number of tests (F(1.85, 18.5)=3.74, p=0.046). The means
would then show that increasing difficulty level enhanced alpha by 0.013, but decreased
SMR and low beta by 0.006 and 0.007 log units respectively. Although the effect likely
constitutes a type I error, its trend would be consistent with extra attention effort reducing
SMR and beta rather than increasing their amplitude.
The present study is just a preliminary step in resolving the apparent paradox that
attention capacity would be enhanced through neurofeedback by increasing beta in children
with ADHD and by decreasing it in adults without ADHD. Although the present results only
14. Direction of SMR and beta change: Journal of Neurotherapy, 2009, 13: 22-29 14
characterise the latter population, a reasonable doubt should be raised that the association
between increasing 16-20 Hz beta in children with ADHD and improving their attention
capacity in daily life may not be as direct as previously suspected. As suggested earlier, one
way to sustain increased beta is possibly to learn to tame an intrusive system that interferes
with good management of attention capacities. According to that assumption, the lower part
of the beta band should be considered as the idling rhythm of an internal system that would
be over activated in ADHD. Such a system might be related to the profusion of distracting
thoughts that intrude normal activity in the life of the child.
Identifying experimental conditions to test this hypothesis is a challenging task.
Meanwhile, ongoing studies have been undertaken to explore whether comparable results
could be obtained in children with and without ADHD. Should the present EEG data pattern
replicate with children, a revised interpretation of the beneficial effect of increasing beta
through neurofeedback would become unavoidable.