Dr. Jogeshwar mahanta
174

Meditation May Bolster Brain Activity

Buddhist Meditation May Produce Lasting Changes in the Brain

By Jennifer Warner

Reviewed By Brunilda Nazario, MD

on Wednesday, November 10, 2004

WebMD Medical News

Nov. 10, 2004 -- Meditation may not only produce a calming effect, but new research suggests that the practice of Buddhist meditation may produce lasting changes in the brain.

Researchers found that monks who spent many years in Buddhist meditation training show significantly greater brain activity in areas associated with learning and happiness than those who have never practiced meditation.

The results suggest that long-term mental training, such as Buddhist meditation, may prompt both short and long-term changes in brain activity and function.

Buddhist Meditation May Change the Brain

In the study, which appears in this week's online edition of the Proceedings of the National Academy of Science, researchers compared the brain activity of eight long-time Buddhist monks and 10 healthy students.

The average age of the monks was 49, and each had undergone mental training in meditation for 10,000 to 50,000 hours over the course of 15 to 40 years.

The students' average age was 21. They had no prior experience in meditation and received one week of meditative training before the start of the study.

Both groups were asked to practice compassionate meditation, which does not require concentration on specific things. Instead, the participants are instructed to generate a feeling of love and compassion without drawing attention to a particular object.

Researchers measured brain activity before, during, and after meditation using electroencephalograms.

They found striking differences between the two groups in a type of brain activity called gamma wave activity, which is involved in mental processes including attention, working memory, learning, and conscious perception.

The Buddhist monks had a higher level of this sort of gamma wave activity before they began meditation, and this difference increased dramatically during meditation. In fact, researchers say the extremely high levels of gamma wave activity are the highest ever reported.

The monks also had more activity in areas associated with positive emotions, such as happiness.

Researchers say the fact that the monks had higher levels of this type of brain activity before meditation began suggests that long-term practice of Buddhist or other forms of meditation may alter the brain.

Although age differences may also account for some of the differences found by this study, researchers say that the hours of meditation practice, rather than age, significantly predicted gamma wave activity.

Researchers say more studies are needed to look at whether differences in brain activity are caused by long-term meditation training itself or by individual differences before training.

SOURCE: Lutz, A. Proceedings of the National Academy of Science, online early edition, Nov. 8, 2004

From India, Delhi
Vinisha
1

hi,
A lot of people lately have started realising the importance of meditation. I am undoubtedly one of these people. But getting hold of a good meditation technique and the process of meditation, the requirements etc is something I am blank up on. I have been trying to get hold of a book on meditation but not many people around me seem to know about it. I am a student so the many people are mostly students who dont agree with meditation and some actually ridicule the concept. Anyway, can you tell me of sources where I would find the details on the same? I wanted to start rightaway because my stress levels are increasing day by day and I need to deal with it.
Thanks
Regards,
Vinisha.

From India,
Dr. Jogeshwar mahanta
174

Thank you vinisha for your query. You will get appropriate information you want and also all your doubts will be clarified. Please start with basic of neuropsycholgy. Here is an article.

regards

Brainwaves and EEG

The language of the brain



Definitions

The EEG (electroencephalograph) measures brainwaves of different frequencies within the brain. Electrodes are placed on specific sites on the scalp to detect and record the electrical impulses within the brain.

A frequency is the number of times a wave repeats itself within a second. It can be compared to the frequencies that you tune into on your radio. If any of these frequencies are deficient, excessive, or difficult to access, our mental performance can suffer.

Amplitude represents the power of electrical impulses generated by brain.

Volume or intensity of brain wave activity is measured in microvolts.

The raw EEG has usually been described in terms of frequency bands: Gamma greater than 30(Hz) BETA (13-30Hz), ALPHA (8-12 Hz), THETA (4-8 Hz), and DELTA(less than 4 Hz).



For example : Our brain uses 13Hz (high alpha or low beta) for "active" intelligence. Often we find individuals who exhibit learning disabilities and attention problems having a deficiency of 13Hz activity in certain brain regions that effects the ability to easily perform sequencing tasks and math calculations.









Brain Wave Frequencies

Delta (0.1 to 3 Hz)

The lowest frequencies are delta. These are less than 4 Hz and occur in deep sleep and in some abnormal processes also during experiences of "empathy state". Delta waves are involved with our ability to integrate and let go. It reflects unconscious mind.

It is the dominant rhythm in infants up to one year of age and it is present in stages 3 and 4 of sleep.

It tends to be the highest in amplitude and the slowest waves. We increase Delta waves in order to decrease our awareness of the physical world. We also access information in our unconscious mind through Delta.

Peak performers decrease Delta waves when high focus and peak performance are required.

However, most individuals diagnosed with Attention Deficit Disorder, naturally increase rather than decrease Delta activity when trying to focus. The inappropriate Delta response often severely restricts the ability to focus and maintain attention. It is as if the brain is locked into a perpetual drowsy state.

Another way to look at Delta is to imagine you are driving in a car and you shift into 1st gear....you're not going to get anywhere very fast. So Delta would represent 1st gear.

Delta (0.1-3 Hz):Distribution: generally broad or diffused may be bilateral, widespread

Subjective feeling states: deep, dreamless sleep, non-REM sleep, trance, unconscious

Associated tasks & behaviors: lethargic, not moving, not attentive

Physiological correlates: not moving, low-level of arousal

Effects of training: can induce drowsiness, trance, deeply relaxed states



Theta (4-8 Hz)

The next brainwave is theta. Theta activity has a frequency of 3.5 to 7.5 Hz and is classed as "slow" activity. It is seen in connection with creativity, intuition, daydreaming, and fantasizing and is a repository for memories, emotions, sensations. Theta waves are strong during internal focus, meditation, prayer, and spiritual awareness. It reflects the state between wakefulness and sleep. Relates to subconscious.

It is abnormal in awake adults but is perfectly normal in children up to 13 years old. It is also normal during sleep. Theta is believed to reflect activity from the limbic system and hippocampal regions. Theta is observed in anxiety, behavioral activation and behavioral inhibition.

When the theta rhythm appears to function normally it mediates and/or promotes adaptive, complex behaviors such as learning and memory. Under unusual emotional circumstances, such as stress or disease states, there may be an imbalance of three major transmitter systems, which results in aberrant behavior.

Back to our car example, Theta would be considered 2nd gear. Not as slow as 1st gear (Delta) but still not very fast.

Distribution: usually regional, may involve many lobes, can be lateralized or diffuse;

Subjective feeling states: intuitive, creative, recall, fantasy, imagery, creative, dreamlike, switching thoughts, drowsy; "oneness", "knowing"

Associated tasks & behaviors: creative, intuitive; but may also be distracted, unfocused

Physiological correlates: healing, integration of mind/body

Effects of Training: if enhanced, can induce drifting, trance-like state. If suppressed, can improve concentration, ability to focus attention



Alpha (8-12 Hz)

Alpha waves are those between 7.5 and 13(Hz). Alpha waves will peak around 10Hz. Good healthy alpha production promotes mental resourcefulness, aids in the ability to mentally coordinate, enhances overall sense of relaxation and fatigue. In this state you can move quickly and efficiently to accomplish whatever task is at hand. When Alpha predominates most people feel at ease and calm. Alpha appears to bridge the conscious to the subconscious.

It is the major rhythm seen in normal relaxed adults - it is present during most of life especially beyond the thirteenth year when it dominates the resting tracing.

Alpha rhythms are reported to be derived from the white matter of the brain. The white matter can be considered the part of the brain that connects all parts with each other.

Alpha is a common state for the brain and occurs whenever a person is alert (it is a marker for alertness and sleep), but not actively processing information. They are strongest over the occipital (back of the head) cortex and also over frontal cortex.

Alpha has been linked to extroversion (introverts show less), creativity (creative subjects show alpha when listening and coming to a solution for creative problems), and mental work.

When your alpha is with in normal ranges we tend to also experience good moods, see the world truthfully, and have a sense of calmness. Alpha is one of the brain's most important frequency to learn and use information taught in the classroom and on the job.

You can increase alpha by closing your eyes or deep breathing or decrease alpha by thinking or calculating.

Alpha-Theta training can create an increase in sensation, abstract thinking and self-control.

In our car scenario, Alpha would represent neutral or idle. Alpha allows us to shift easily from one task to another.

Distribution: regional, usually involves entire lobe; strong occipital w/eyes closed

Subjective feeling states: relaxed, not agitated, but not drowsy; tranquil, conscious

Associated tasks & behaviors: meditation, no action

Physiological correlates: relaxed, healing

Effects of Training: can produce relaxation

Sub band low alpha: 8-10: inner-awareness of self, mind/body integration, balance

Sub band high alpha: 10-12: centering, healing, mind/body connection



Beta (above 12 Hz)

Beta activity is 'fast' activity. It has a frequency of 14 and greater Hz. It reflects desynchronized active brain tissue. It is usually seen on both sides in symmetrical distribution and is most evident frontally. It may be absent or reduced in areas of cortical damage.

It is generally regarded as a normal rhythm and is the dominant rhythm in those who are alert or anxious or who have their eyes open.

It is the state that most of brain is in when we have our eyes open and are listening and thinking during analytical problem solving, judgment, decision making, processing information about the world around us.

Beta would represent overdrive or hyperdrive in our car scenario.

The beta band has a relatively large range, and has been divided into low, midrange and high.

Low Beta (12-15 Hz), formerly "SMR":

Distribution: localized by side and by lobe (frontal, occipital, etc)

Subjective feeling states: relaxed yet focused, integrated

Associated tasks & behaviors: low SMR can reflect "ADD", lack of focused attention

Physiological correlates: is inhibited by motion; restraining body may increase SMR

Effects of Training: increasing SMR can produce relaxed focus, improved attentive abilities,

Midrange Beta (15-18 Hz)

Distribution: localized, over various areas. May be focused on one electrode.

Subjective feeling states: thinking, aware of self & surroundings

Associated tasks & behaviors: mental activity

Physiological correlates: alert, active, but not agitated

Effects of Training: can increase mental ability, focus, alertness, IQ

High Beta (above 18 Hz):

Distribution: localized, may be very focused.

Subjective feeling states: alertness, agitation

Associated tasks & behaviors: mental activity, e.g. math, planning, etc.

Physiological correlates: general activation of mind & body functions.

Effects of Training: can induce alertness, but may also produce agitation, etc.

Gamma (above 36 Hz)

Gamma is measured between 36 ­ 44 (Hz) and is the only frequency group found in every part of the brain. When the brain needs to simultaneously process information from different areas, its hypothesized that the 40Hz activity consolidates the required areas for simultaneous processing. A good memory is associated with well-regulated and efficient 40Hz activity, whereas a 40Hz deficiency creates learning disabilities.

Gamma (40 Hz):

Distribution: very localized

Subjective feeling states: thinking; integrated thoughts

Associated tasks & behaviors: high-level information processing, "binding"

Physiological correlates: associated with information-rich task processing

Effects of Training: not known



Source-Cross Roads Institute

From India, Delhi
MINDSKILLS
13

Hello Vinisha

I think I can help you. I have been meditating for several years now ( not regularly ) and I also teach meditation, de-stressing skills etc.

Do not look for books and trainers at this stage. What you, and most people, need is meditation for joy and not for any major therauptic benefits.

Different people have different theories of meditation. If anyone tells you that unless you strictly follow a particular technique closely it may harm you, just disregard that person.

In my concept, meditation is being like a tube light and not a focussed beam. What I mean is that you should let your mind reamain diffused rather than concentrated.

Twice a day, sit down quietly. Sit on a chair or on floor. Just keep your spine stright. Be comfortable. Use a cushion etc. Talk to yourself silently that you are about to meditate and shall try not to let your attention latch on to any thought at all. Tell yourself that the technique you will use is simply to let your mind loose. Loosen your body, limb by limb. After spending about 2 minutes in this, close your eyes loosely.

Now do nothing. I mean mentally. Whenever your mind starts latching on to any thought, shake it off. Become diffused like a tubelight. If after some minutes you realize that the mind has got stuck in the groove of any specific thought, do not get annoyed with yourself.Laught it off and move on to reamaining menatally diffused. If someone disturbs you in this duration ( avoid such a possibility though), laugh it off and resume.

Particularly, do not assess your performance - Am I

doing it right? If it does happen unconsciously, laugh it off---.

At times, you MAY move your attention to your breath. Feel how the breath comes in and goes out. Become aware of the sensation bit do not verbalise. Also, do not start contolling the breath in any manner.

After about 12-15 minutes ( use an alarm etc), loosen up again. Open your eyes and slowly get up.

If you do this, twice a day for about 20 days, you will learn the correct technique yourself. Your body will teach you. Just sit down for 15 minutes twice a day, for 20 days and it is done.

After this, you can buy some book. Many are available. If you ask me, I can guide you thereafter.

Just get on. It is much easier than people make it out to be. People just do not start. Once they do, they are surprised at how easy the whole thing is. Just stick on for the first fortnight.

Best

From India, Mumbai
Vinisha
1

Hello,
Thanks for both the articles. Both were indeed useful.
Sir Alok, I dont think you remember me. I had taken your help a month or two ago on my project of Assessment Centres & Development Centres. I took a couple of Telephone Interviews for the same. Have been wanting to call you for a while. Thanks to you, my project was a great success.
Thanks a lot.
Regards,
Vinisha.

From India,
Dr. Jogeshwar mahanta
174

Dear mindskills,

Namaskar.

Happy to find a meditator. Trust, the discussion in this thread will be lively thanks to you.

To me meditation is focusing attention upon something. To voluntarise the involuntary psychophysiological processes one is to learn to increse and decrease alertness. That is altering the states of consciousness. As alertness rises voluntarily, the voltage behind brain waves and their frequency go up, sympathetic division of the autonomic nervous system becomes more and more active and every cell of the body gets toned up. Conversely when alertness is lowered down voltage and frequency go down, parasympathetic division of the autonomic nervous system takes up and the body assumes approximates homeostasis.

To illustrate let me speak about Galvanic skin response(GSR).GSR monitor will show your degree of registance to elcric conductance in kilo ohms. What is your initial resistance and how much you can raise speaks about your ability to resist stress. Normally I find people at the range of 0 to 500 kilo ohm resistence by Medicaid systems(Chandigarh) equipment. Whereas my basal level of resistance starts at about 600 kilo ohms and rises beyond 2000 kilo ohms. This is not necessarily in calm and quite set up but I demonostrate it in claas room seeing also. Higher resistence is correlated with low voltage brain waves.

regards

regards

From India, Delhi
Noel
Dear Vinisha,

I too have been doing meditation, both type as suggested by Mindskill and Dr. Jogeshwar. Like the saying goes, there is more than one way to skin a cat. There are many styles of meditation and you will need to find one that you are most comfortable with and the only way to know is to try them out.

I started out with the focus meditation as mentioned by Dr. Jogeshwar. I start of by imagining a white cross. As I breath (deep diaphragm breathing). As I breath I imagine maintaining the cross in the middle of my mind's eye and continue holding the image there.

Then later I was introduced to the relaxing method. Where I let go of everything and at the same time being aware of everything that is going on, Mindskill describe it beautifully. So its like floating in a space of thoughts and you are aware of every thought.

Currently I am practicing a vocal form of meditation, I understand it as kotatama (a japanese word). A vocalisation of A, O, Aum and E, O, I. This I find the most peaceful and my personal favourate.

The benefits of meditation is astounding.

Hope it will help give you a bit more information.

Regards

Noel Liew

From Malaysia, Johor Bahru
MINDSKILLS
13

Dear Dr Mahanta
It is evident that you have good knowledge of the subject and the focussing method is working well for you. For me, the diffusion method works well. I do not even mind if it is called Relaxation Response, rather than meditation.
In your earlier mail, you too spoke of loving compassion type of meditation where it is required NOT to concentrate. Many people get a headache in the concentration method.
The beginers should be encouraged to just sit for 15 minutes, twice a day, calming their thoughts. This is a welcome way to get them initiated. Thereafter, they may explore further.
I believe the concentration method helps to reduce the diverse mind-chatters to one unified one - which can then be conviniently dropped!
My teacher used to say, "Do not nurture the mind: drop it." When I told him that I seem to be losing track of consciousness at times, he told me, ' Isn't that what you aiming for? Don't be afraid to let go. "
Best

From India, Mumbai
umalme
12

Hello All,
Good discussion on meditation and relaxation technique.
Dr Mahanta,
Would i please mention some meditation technique for the people who are depresion prone and have mental illness history.
I could help furter some body.

From India, Delhi
Dr. Jogeshwar mahanta
174

Namskar to all of you.

Trust, you all have enjoyed dusserah well. I am very happy to find Noel ji and umalme ji here. I shall be responding to your replies. But before that I like you to read the following article.Umalme ji is most welcome to post whatever you desire. But I am thinking why none of you have asked me why I have named the thread as "heaven of kranti".

regards.

Extraordinary States

Gamma

HyperGamma

Lambda

Epsilon

New evidence has emerged of brainwave states above the highest recognized brainwave frequencies of Beta (30 Hz). Higher-than Beta frequencies are called Gamma. These Gamma brainwaves resonate around 40 Hz and are associated with the brain function which holographically synthesizes all the bits of individual data from various areas of the brain and fuses them all together in a higher perspective.

Gamma is a 'newer' brainwave only because it is difficult to get instrumentation to accurately measure it. It is thought the Gamma is the harmonizing frequency - for example when you are observing an object, its colour, size, texture etc are all perceived and processed by different parts of the brain, it is thought that Gamma allows for unification of all the different information.

This brainwave activity is associated with states of self awareness, higher levels of insight and information, psychic abilities and out of body experiences. This new region of brain activity and states of consciousness associated with it is called EPSILON.

Theta and gamma rhythms also interact helping the brain to package information into coherent images, thought and memories.

EEG researchers are noticing extremely high brainwave frequencies above Gamma, at up to 100 Hz. Totally opposite speed brainwave frequencies - some at 100 Hz and others at less than 0.5 Hz - have exactly the same states of consciousness associated with them. These high-range brain frequency states are named HyperGamma. Later information showed new evidence of frequencies even higher than this, at almost 200 Hz.named: Lambda brainwave frequencies and states of consciousness.

These HyperGamma, Lambda and Epsilon frequencies, are linked together in a circular relationship -where if you looked with a magnifying glass at an extremely slow Epsilon brain frequency, you would see hidden within it a modulation frequency of 100 - 200 Hz. If you stand back far enough from an extremely fast 200 Hz brainwave frequency, you would see that is it riding on the crest of a slow motion modulating wave of Epsilon.

This Epsilon state of consciousness (the state Yogi's go into when they achieve "suspended animation") is where western medical doctors can perceive no heart beat, respiration or pulse. HyperGamma and Lambda states of consciousness are the states associated with the ability of certain sects of Tibetan monks who can mediate in the Himalayan mountains in sub-zero temperatures with scanty clothing and melt the snow all around them.

Fast, gamma rhythms range from 30 to 100 Hz, and may vary in frequency during a response. The 20-100 Hz range we consider here overlaps the beta band (15 to 30 Hz), but we will ignore the finer points of EEG classification here. The natural history and functional roles of synchronous gamma oscillations have been reviewed recently [5,10,12,22]. Below is a potted history.

Gamma rhythms occur in humans and other mammals following sensory stimuli. They often occur in brief runs in these responses. "Induced rhythms" at 50-60 Hz were first described in olfactory bulb by Adrian [1]. They have since been found in: olfactory [4], visual [3a,3b,6-8,11,22], auditory [13,16], somatosensory [2] and motor cortex [17,19,21]. Gamma oscillations also occur in the hippocampus [3,24], where the link with external sensory stimuli is less direct, but may still exist in the multimodal inputs it receives from higher order sensory cortices. Hippocampal gamma tends to occur during the theta (4-12 Hz) EEG that is a prominent feature of the hippocampus in vivo [3,23], especially during exploration.

In Man the auditory response includes brief "40 Hz transient responses" [18,25], which increase when the subject pays attention and which disappear with loss of consciousness during anaesthesia [14]. Repetitive auditory stimulation at ~40 Hz generates a large "40 Hz steady state response" [9]. MEG recordings in Man suggest that gamma rhythms can be very widespread [20], both during waking and dream states. Other MEG measurements in Man suggest that gamma rhythms may be organised to sweep across the whole brain, perhaps providing "temporal binding .... into a single cognitive experience" [15].

Bibliography 1 Adrian, E.D. The electrical activity of the mammalian olfactory bulb, Electroencephalogr. Clin. Neurophysiol. 2 (1950) 377-388.

2 Bouyer, J.J., Montaron, M.F., Vahnee, J.M., Albert, M.P. and Rougeul, A. Anatomical localization of cortical beta rhythms in cat, Neuroscience, 22 (1987) 863-869.

3 Bragin, A., Jand¢, G., N dasdy, Z., Hetke, J., Wise, K. and Buzs ki, G. Gamma (40-100 Hz) oscillation in the hippocampus of the behaving rat, J. Neurosci. 15 (1995) 47-60.

3a Eckhorn, R., Bauer, R., Jordan, W., Brosch, M., Kruse, W., Munk, M. and Reitboeck, H.J. Coherent oscillations: a mechanism of feature linking in the visual cortex? Multiple electrode and correlation analyses in the cat, Biol. Cybern. 60 (1988) 121-130.

3b Eckhorn, R., Reitboeck, H.J., Arndt, M. and Dicke, P. Feature linking via synchronization among distributed assemblies: simulations of results from cat visual cortex, Neural Comput. 2 (1990) 293-307.

4 Eeckman, F.H. and Freeman, W.J. Correlations between unit firing and EEG in the rat olfactory system, Brain Res. 528 (1990) 238-244.

5 Engel, A.K., K”nig, P., Kreiter, A.K., Schillen, T.B. and Singer, W. Temporal coding in the visual cortex: New vistas on integration in the nervous system, Trends Neurosci. 15 (1992) 218-226.

6 Engel, A.K., K”nig, P., Kreiter, A.K. and Singer, W. Interhemispheric synchronization of oscillatory neuronal responses in cat visual cortex, Science, 252 (1991) 1177-1179.

7 Engel, A.K., K”nig, P. and Singer, W. Direct physiological evidence for scene segmentation by temporal coding, Proc. Natl. Acad. Sci. USA, 88 (1991) 9136-9140.

8 Freeman, W.J. and van Dijk, B.W. Spatial patterns of visual cortical fast EEG during conditioned reflex in a rhesus monkey, Brain Res. 422 (1987) 267-276.

9 Galambos, R., Makeig, S. and Talmachoff, P.J. A 40-Hz auditory potential recorded from the human scalp, Proc. Natl. Acad. Sci. USA, 78 (1981) 2643-2647.

10 Gray, C.M. Synchronous oscillations in neuronal systems: mechanisms and function, J. Comput. Neurosci. 1 (1994) 11-38.

11 Gray, C.M., K”nig, P., Engel, A.K. and Singer, W. Oscillatory responses in cat visual cortex exhibit inter-columnar synchronization which reflects global stimulus properties, Nature, 338 (1989) 334-337.

12 Jefferys, J.G.R., Traub, R.D. and Whittington, M.A. Neuronal networks for induced "40 Hz" rhythms, Trends Neurosci. 19 (1996) 202-208.

13 Keller, I., Madler, C., Schwender, D. and Poppel, E. Analysis of oscillatory components in perioperative AEP-recordings: a nonparametric procedure for frequency measurement, Clin. Electroencephalogr. 21 (1990) 88-92.

14 Kulli, J. and Koch, C. Does anesthesia cause loss of consciousness, Trends Neurosci. 14 (1991) 6-10.

15 Llin s, R. and Ribary, U. Coherent 40-Hz oscillation characterizes dream state in humans, Proc. Natl. Acad. Sci. USA, 90 (1993) 2078-2081.

16 Madler, C., Keller, I., Schwender, D. and Poppel, E. Sensory information processing during general anaesthesia: effect of isoflurane on auditory evoked neuronal oscillations, Br. J. Anaesth. 66 (1991) 81-87.

17 Murthy, V.N. and Fetz, E.E. Coherent 25- to 35-Hz oscillations in the sensorimotor cortex of awake behaving monkeys, Proc. Natl. Acad. Sci. USA, 89 (1992) 5670-5674.

18 Pantev, C., Makeig, S., Hoke, M., Galambos, R., Hampson, S. and Gallen, C. Human auditory evoked gamma-band magnetic fields, Proc. Natl. Acad. Sci. USA, 88 (1991) 8996-9000.

19 Pfurtscheller, G., Flotzinger, D. and Neuper, C. Differentiation between finger, toe and tongue movement in man based on 40 Hz EEG, Electroencephalogr. Clin. Neurophysiol. 90 (1994) 456-460.

20 Ribary, U., Ioannides, A.A., Singh, K.D., Hasson, R., Bolton, J.P.R., Lado, F., Mogilner, A. and Llin s, R. Magnetic field tomography of coherent thalamocortical 40-Hz oscillations in humans, Proc. Natl. Acad. Sci. USA, 88 (1991) 11037-11041.

21 Sanes, J.N. and Donoghue, J.P. Oscillations in local field potentials of the primate motor cortex during voluntary movement, Proc. Natl. Acad. Sci. USA, 90 (1993) 4470-4474.

22 Singer, W. and Gray, C.M. Visual feature integration and the temporal correlation hypothesis, Annu. Rev. Neurosci. 18 (1995) 555-586.

23 Soltesz, I. and Deschˆnes, M. Low- and high-frequency membrane potential oscillations during theta activity in CA1 and CA3 pyramidal neurons of the rat hippocampus under ketamine-xylazine anesthesia, J. Neurophysiol. 70 (1993) 97-116.

24 Stumpf, C. The fast component in the electrical activity of rabbit's hippocampus, Electroencephalogr. Clin. Neurophysiol. 18 (1965) 477-486.

25 Tiitinen, H., Sinkkonen, J., Reinikainen, K., Alho, K., Lavikainen, J. and Naatanen, R. Selective attention enhances the auditory 40-Hz transient response in humans, Nature, 364 (1993) 59-60.

From India, Delhi
Community Support and Knowledge-base on business, career and organisational prospects and issues - Register and Log In to CiteHR and post your query, download formats and be part of a fostered community of professionals.






Contact Us Privacy Policy Disclaimer Terms Of Service

All rights reserved @ 2024 CiteHR ®

All Copyright And Trademarks in Posts Held By Respective Owners.