7 Apr 2010

Direct recording shows brain signal active even in dreamless sleep

Neuroscientists at Washington University School of Medicine in St. Louis have taken one of the first direct looks at one of the human brain's most fundamental "foundations": a brain signal that never switches off and may support many cognitive functions. The results, appearing online this week in the Proceedings of the National Academy of Sciences, are an important step forward for efforts to outline what neuroscientists call the functional architecture of the brain. Better understanding of this architecture will aid efforts to treat brain injury and mental disorders.

6 Apr 2010

Are Vision and Consciousness Intimately Related?

In my article on brain waves and consciousness I looked at some research associating gamma wave activity with consciousness. This is, however, a controversial area in that other researchers have found that such gamma activity is also correlated with eye movements known as saccades: these are the small eye movements that the brain edits out so that we do not perceive the world as a blur as we switch focus. So, are brain gamma waves merely a byproduct of saccadic movements or are they correlated with consciousness or, potentially, both?

You can follow the relevant articles and the subsequent discussions at Neuron. Also an article Developing Intelligence blog.

Are Vision and Consciousness Intimately Related?

Image: Phosphene artistic depiction (detail) from Wikimedia.

28 Mar 2010



The European Society for the Study of Science And Theology (ESSSAT)
& The Science Religion Forum (SRF)
present the
XIIIth European Conference on Science and Theology, Edinburgh, UK,
April 7-11, 2010

Transient Induced Gamma-Band Response in EEG as a Manifestation of Miniature Saccades

The induced gamma-band EEG response (iGBR) recorded on the scalp is widely assumed to reflect synchronous neural oscillation associated with object representation, attention, memory, and consciousness. The most commonly reported EEG iGBR is a broadband transient increase in power at the gamma range not, vert, similar200–300 ms following stimulus onset. A conspicuous feature of this iGBR is the trial-to-trial poststimulus latency variability, which has been insufficiently addressed. Here, we show, using single-trial analysis of concomitant EEG and eye tracking, that this iGBR is tightly time locked to the onset of involuntary miniature eye movements and reflects a saccadic “spike potential.” The time course of the iGBR is related to an increase in the rate of saccades following a period of poststimulus saccadic inhibition. Thus, whereas neuronal gamma-band oscillations were shown conclusively with other methods, the broadband transient iGBR recorded by scalp EEG reflects properties of miniature saccade dynamics rather than neuronal oscillations.

Transient Induced Gamma-Band Response in EEG as a Manifestation of Miniature Saccades

The above link to the article also has links to the exchanges that followed about whether gamma waves as recorded by EEG are intimately linked to consciousness or results of electrical signals from microsaccades, or possibly both.

17 Mar 2010

Center for Investigating Healthy Minds

Welcome to the Center for Investigating Healthy Minds

I know, this sounds like a New Age flake factory... but it isn't.

Located within the Waisman Center at the University of Wisconsin-Madison, we are a research Center dedicated to creating a world in which healthy qualities of mind flourish. The Center for Investigating Healthy Minds, through hard-nosed basic and translational scientific research, will help to pave the way toward more widespread incorporation of methods and practices to nourish positive qualities of mind throughout society. The work and research of this Center are at the forefront of the scientific and scholarly communities, and have led to the development of a new hybrid discipline – contemplative neuroscience. In a global era where individuals, communities and the world are reconnecting with the pursuit of happiness, well-being and contentment and seeking innovative and mindful solutions to achieve it, the Center offers facts about interventions and methods grounded both in research and the wisdom of contemplative traditions.

They even have Einstein sounding like Gautama Buddha.

"A human being is part of the whole, called by us 'universe,' a part limited in time and space. He experiences himself, his thoughts and feelings, as something separate from the rest -- a kind of optical delusion of consciousness. This delusion is a kind of prison for us, restricting us to our personal desires and to affection for a few persons nearest to us. Our task must be to free ourselves from this prison by widening our circle of compassion to embrace all living creatures and the whole of nature in its beauty."
- Albert Einstein, 1921

The director, Richard Davidson, has already done research on the brainwaves of Tibetan monks in meditation, so will be interesting to see what they do next.

16 Mar 2010

Is This How Brain Waves And Neurons Create Consciousness?

This is a controversial issue, but some light is starting to be shone in this direction. Many neuroscientists assume that the electric fields generated by neurons are too weak to have any effect on their neighbours. However, recent research (Radman et al., 2007) has shown that weak electric fields (<5 V/m) within a broad spectrum of operating brain frequencies affect the firing properties of individual neurons. The researchers show that the nonlinear properties of an individual neuron can 'amplify' the effects of such small fields, effectively 'resonating' with the extracellular field. [...]

The researchers are thus fully aware of the importance of their findings in that they provide a framework within which others can develop neuro-therapies, as well as for researchers looking at the effects of environmental electromagnetic radiation. Add to that the not insignificant contribution to how the brain really functions! So much so that an open letter is appended to the research paper by David M. Alexander, RIKEN Brain Science Institute, Japan. "As reported by Massimini et al. (2004), slow-wave sleep EEG has been shown to take the form of a global spatio-temporal wave. Such waves are able to act as an 'external' source of electric fields to individual minicolumns in the cortex. There is now sufficient evidence to outline the case that large-scale electrical field dynamics do indeed play a causal role in brain activity, and to propose confirmatory experiments." The letter is also interesting in that it lists other papers that add weight to the Radman experiments, one paper going all the way back to 1984. Alexander sounds like a converted skeptic as he also quotes:"our [Radman et al.] results challenge the common view that extracellular slow potential oscillations represent mere epiphenomena without physiological significance per se."

Is This How Brain Waves And Neurons Create Consciousness?

Spike Timing Amplifies the Effect of Electric Fields on Neurons: Implications for Endogenous Field Effects

Despite compelling phenomenological evidence that small electric fields (<5 mV/mm) can affect brain function, a quantitative and experimentally verified theory is currently lacking. Here we demonstrate a novel mechanism by which the nonlinear properties of single neurons "amplify" the effect of small electric fields: when concurrent to suprathreshold synaptic input, small electric fields can have significant effects on spike timing.

For low-frequency fields, our theory predicts a linear dependency of spike timing changes on field strength. For high-frequency fields (relative to the synaptic input), the theory predicts coherent firing, with mean firing phase and coherence each increasing monotonically with field strength. Importantly, in both cases, the effects of fields on spike timing are amplified with decreasing synaptic input slope and increased cell susceptibility (millivolt membrane polarization per field amplitude).

We confirmed these predictions experimentally using CA1 hippocampal neurons in vitro exposed to static (direct current) and oscillating (alternating current) uniform electric fields. In addition, we develop a robust method to quantify cell susceptibility using spike timing. Our results provide a precise mechanism for a functional role of endogenous field oscillations (e.g., gamma) in brain function and introduce a framework for considering the effects of environmental fields and design of low-intensity therapeutic neurostimulation technologies.

14 Mar 2010


Recent developments in the field of electromagnetic dosimetry have produced high resolution anatomically correct man and animal models from medical imaging data for use in numerical simulation exercises. The level of details is such that over 30 tissue types can be identified. The application of such models require that dielectric properties be allocated to the various tissues at all the frequencies to which the model is exposed. There is, as yet, no consensus on the dielectric data. This project is geared towards this objective. The following has been achieved in the period covered by this report:

    * Three experimental techniques were used to measure the dielectric properties of tissue in the frequency range 10 Hz to 20 GHz. Over 20 tissue types were measured over the full frequency range and over 10 others measured down to 1 MHz only.
    * Internal consistency between the three sets of data was demonstrated in the overlapping frequency regions. When measurements are made on the same sample throughout, the agreement between data sets is particularly good.
    * A comprehensive survey of dielectric data published over more than 45 years has been carried out and presented for comparison purposes. The data obtained in the course of this study fall well within the vast body of literature data where available and bridges the gaps within it.
    * To facilitate the incorporation of the dielectric data in numerical solutions, their frequency dependence was modelled to a spectrum characterised by 4 dispersion regions. This model was successfully applied to the new experimental data.
    * Finally, the conductivity of tissues below 100 Hz was estimated from the recent measurements mitigated by data from the literature and used to estimate the conductivity of the whole body and of various body parts.

The work is briefly described in this report, the data are presented in graphical and tabular format in Appendices A to D.


The vast majority of the data is not from in vivo sources, but rather from dead flesh, hence fairly useless in terms of the biological interactions with emf and any resonance properties.


Electromagnetic hypersensitivity: a systematic review of provocation studies.

Electromagnetic hypersensitivity: a systematic review of provocation studies.

Mobile Phones Research Unit, Division of Psychological Medicine, Institute of Psychiatry and Guy's, King's and St. Thomas' School of Medicine, King's College London, UK. g.rubin@iop.kcl.ac.uk
OBJECTIVES: The objectives of this study were to assess whether people who report hypersensitivity to weak electromagnetic fields (EMFs) are better at detecting EMF under blind or double-blind conditions than nonhypersensitive individuals, and to test whether they respond to the presence of EMF with increased symptom reporting. METHODS: An extensive systematic search was used to identify relevant blind or double-blind provocation studies. This involved searching numerous literature databases and conference proceedings, and examining the citations of reviews and included studies. The results of relevant studies were tabulated and metaanalyses were used to compare the proportions of "hypersensitive" and control participants able to discriminate active from sham EMF exposures. RESULTS: Thirty-one experiments testing 725 "electromagnetically hypersensitive" participants were identified. Twenty-four of these found no evidence to support the existence of a biophysical hypersensitivity, whereas 7 reported some supporting evidence. For 2 of these 7, the same research groups subsequently tried and failed to replicate their findings. In 3 more, the positive results appear to be statistical artefacts. The final 2 studies gave mutually incompatible results. Our metaanalyses found no evidence of an improved ability to detect EMF in "hypersensitive" participants. CONCLUSIONS: The symptoms described by "electromagnetic hypersensitivity" sufferers can be severe and are sometimes disabling. However, it has proved difficult to show under blind conditions that exposure to EMF can trigger these symptoms. This suggests that "electromagnetic hypersensitivity" is unrelated to the presence of EMF, although more research into this phenomenon is required.

Read original paper online.

25 Feb 2010

Selflessness, core of all major world religions, has neuropsychological connection

All spiritual experiences are based in the brain. That statement is truer than ever before, according to a University of Missouri neuropsychologist. An MU study has data to support a neuropsychological model that proposes spiritual experiences associated with selflessness are related to decreased activity in the right parietal lobe of the brain. The study is one of the first to use individuals with traumatic brain injury to determine this connection. Researchers say the implication of this connection means people in many disciplines, including peace studies, health care or religion can learn different ways to attain selflessness, to experience transcendence, and to help themselves and others. This study, along with other recent neuroradiological studies of Buddhist meditators and Francescan nuns, suggests that all individuals, regardless of cultural background or religion, experience the same neuropsychological functions during spiritual experiences, such as transcendence. Transcendence, feelings of universal unity and decreased sense of self, is a core tenet of all major religions. Meditation and prayer are the primary vehicles by which such spiritual transcendence is achieved.

"The brain functions in a certain way during spiritual experiences," said Brick Johnstone, professor of health psychology in the MU School of Health Professions. "We studied people with brain injury and found that people with injuries to the right parietal lobe of the brain reported higher levels of spiritual experiences, such as transcendence."

This link is important, Johnstone said, because it means selflessness can be learned by decreasing activity in that part of the brain. He suggests this can be done through conscious effort, such as meditation or prayer. People with these selfless spiritual experiences also are more psychologically healthy, especially if they have positive beliefs that there is a God or higher power who loves them, Johnstone said.

"This research also addresses questions regarding the impact of neurologic versus cultural factors on spiritual experience," Johnstone said. "The ability to connect with things beyond the self, such as transcendent experiences, seems to occur for people who minimize right parietal functioning. This can be attained through cultural practices, such as intense meditation or prayer or because of a brain injury that impairs the functioning of the right parietal lobe. Either way, our study suggests that 'selflessness' is a neuropsychological foundation of spiritual experiences."

The research was funded by the MU Center on Religion and the Professions. The study – "Support for a neuropsychological model of spirituality in persons with traumatic brain injury" – was published in the peer-reviewed journal Zygon.

"Our research focused on the personal experience of spiritual transcendence and does not in any way minimize the importance of religion or personal beliefs, nor does it suggest that spiritual experience are related only to neuropsychological activity in the brain," Johnstone said. "It is important to note that individuals experience their God or higher power in many different ways, but that all people from all religions and beliefs appear to experience these connections in a similar way."

24 Feb 2010

Selective brain damage modulates human spirituality

New research provides fascinating insight into brain changes that might underlie alterations in spiritual and religious attitudes. The study, published by Cell Press in the February 11 issue of the journal Neuron, explores the neural basis of spirituality by studying patients before and after surgery to remove a brain tumor. Although it is well established that all behaviors and experiences, spiritual or otherwise, must originate in the brain, true empirical exploration of the neural underpinnings of spirituality has been challenging. However, recent advances in neuroscience have started to make the complex mental processes associated with religion and spirituality more accessible.

"Neuroimaging studies have linked activity within a large network in the brain that connects the frontal, parietal, and temporal cortexes with spiritual experiences, but information on the causative link between such a network and spirituality is lacking," explains lead study author, Dr. Cosimo Urgesi from the University of Udine in Italy.

Dr. Urgesi and colleagues were interested in making a direct link between brain activity and spirituality. They focused specifically on the personality trait called self-transcendence (ST), which is thought to be a measure of spiritual feeling, thinking, and behaviors in humans. ST reflects a decreased sense of self and an ability to identify one's self as an integral part of the universe as a whole.

The researchers combined analysis of ST scores obtained from brain tumor patients before and after they had surgery to remove their tumor, with advanced techniques for mapping the exact location of the brain lesions after surgery. "This approach allowed us to explore the possible changes of ST induced by specific brain lesions and the causative role played by frontal, temporal, and parietal structures in supporting interindividual differences in ST," says researcher Dr. Franco Fabbro from the University of Udine.

The group found that selective damage to the left and right posterior parietal regions induced a specific increase in ST. "Our symptom-lesion mapping study is the first demonstration of a causative link between brain functioning and ST," offers Dr. Urgesi. "Damage to posterior parietal areas induced unusually fast changes of a stable personality dimension related to transcendental self-referential awareness. Thus, dysfunctional parietal neural activity may underpin altered spiritual and religious attitudes and behaviors."

These results may even lead to new strategies for treating some forms of mental illness. "If a stable personality trait like ST can undergo fast changes as a consequence of brain lesions, it would indicate that at least some personality dimensions may be modified by influencing neural activity in specific areas," suggests Dr. Salvatore M. Aglioti from Sapienza University of Rome. "Perhaps novel approaches aimed at modulating neural activity might ultimately pave the way to new treatments of personality disorders."
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