From adam to zeus ...through all men and gods.

[Visalakshi Ramani]

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# 61. V. S. Ramachandran.(part #4.)

Phantom limbs.

When an arm or leg is amputated, patients continue to feel vividly the presence of the missing limb as a "phantom limb". Building on earlier work by Ronald Melzack by (McGill University) and Timothy Pons (NIMH), Ramachandran theorized that there was a link between the phenomenon of phantom limbs and neural plasticity in the adult human brain.

In particular, he theorized that the body image maps in the somatosensory cortex are re-mapped after the amputation of a limb. In 1993, working with T.T. Yang who was conducting MEG research at the Scripps Research InstituteRamachandran demonstrated that there had been measurable changes in the somatosensory cortex of several patients who had undergone arm amputations.

Ramachandran theorized that there was a relationship between the cortical reorganization evident in the MEG images and the referred sensations he observed in his subjects. He presented this theory in a paper titled "Perceptual correlates of massive cortical reorganization."

Although Ramachandran was one of the first scientists to emphasize the role of cortical reorganization as the basis for phantom limb sensations, subsequent research has demonstrated that referred sensations are not the perceptual correlate of cortical reorganization after amputation.The question of which neural processes are related to non-painful referred sensations has not been resolved.

Mirror visual feedback

Ramachandran is credited with the invention of the mirror box and the introduction of mirror visual feedback as a treatment for a variety of conditions associated with phantom limb pain, stroke, and regional pain syndrome.

Several research studies using mirror therapy have produced promising results. However, mirror therapy has produced conflicting results in randomized controlled trials and the applications of mirror therapy are still under experimental evaluation.

 

[Visalakshi Ramani]

# 61. V. S. Ramachandran.(part #5.)

Synesthesia

Ramachandran has studied the neural mechanisms of Synesthesia a condition in which stimulation in one sensory modality leads to experiences in a second, unstimulated modality. For example, some people see colors when they hear music!

His initial studies focused on Color Synesthesia, in which viewing black and white letters or numbers (graphemes) on a page evokes the experience of seeing colors.

Ramachandran (with then PhD student, Edward Hubbard) showed that some synesthetes were better able to detect "embedded figures" composed of one letter or number (for example a triangle composed of 2s) on a background of another number (for example 5s).

Based on his previous work on phantom limbs, Ramachandran suggested that synesthesia may arise from a cross-activation between brain regions.

Although the idea of cross-connections dates to some of the earliest work on synesthesia, Ramachandran was the first to give this idea a specific anatomical explanation.

Ramachandran suggested that grapheme-color synesthesia is the result of increased connectivity between brain areas that are responsible for the perceptual recognition of letters and numbers and colors, perhaps due to genetic factors, given that synesthesia is known to run in families.

Consistent with this model, Ramachandran's group found increased activity in the color selective areas in synesthetes compared to non-synesthetes using MRI. They also showed that differences between synesthetes and non-synesthetes begin very quickly after the grapheme is presented

More recently, Ramachandran has also begun investigations of other forms of synesthesia, including number forms and emotion synesthesia.

Recent research in the Netherlands (involving 19 grapheme-color synesthetes) demonstrated that synesthesia can be the result of either direct bottom-up cross-activation from grapheme processing areas or indirectly via higher-order parietal areas.

Tessa van Leeuwen and her colleagues concluded:

To summarize, in this first study of effective connectivity in synesthesia, we established that while the same network of regions is active in different types of synesthesia, individual differences in subjective color experience are determined by altered coupling.
​

Ramachandran has helped to advance public awareness of synesthesia by hosting two meetings of the American Synesthesia Associatiat UCSD in the years 2002 and 2011.

 

[Visalakshi Ramani]

# 61. V. S. Ramachandran.(part #6.)

Mirror neurons

In other people we see ourselves with mirror neurons.
Scientific reason why we see ourselves in others???

Ramachandran is known for advocating the importance of mirror neurons. He has stated that the discovery of mirror neurons is the most important unreported story of the last decade.

Mirror neurons were first reported in a paper published in 1992 by a team of researchers led by Giacomo Rizzolatti at the University of Parma.

Ramachandran has speculated that research into the role of mirror neurons will help explain a variety of human mental capacities ranging from empathy, imitation learning, and the evolution of language.

Ramachandran has also theorized that mirror neurons may be the key to understanding the neurological basis of human self awareness.

Ramchandran has theorized that in addition to motor command mirror neurons, there are mirror neurons that are activated when a person observes someone else being touched.

In 2008 Ramachandran conducted an experiment in which several phantom arm patients reported feeling touch signals on their phantom arms when they observed the arm of a student being touched.

In a 2009 discussion of this theory Ramachandran and Althschuler called these mirror neurons "touch mirror neurons."

 

[Visalakshi Ramani]

Ref # 501.

Illusions such as this mirror trick can help to reduce pain in phantom limbs.

Used to alleviate amputees of phantom-limb pain.

 

[Visalakshi Ramani]

# 61. V. S. Ramachandran.(part #7.)

Awards and honors

Ramachandran was elected to a visiting fellowship at All Souls College (1998 to1999)

In addition he was a Hilgard visiting professor at Stanford University in 2005. He has received honorary doctorates from Connecticut College (2001) and the Indian Institute of Technology, Madras (2004).

Ramachandran received in 2004, the annual award of Ramon y Cajal from the International Neuropsychiatry Society. He was awarded the Ariens Kaappers medal from the Royal Netherlands Academy of Sciences for his contribution to Neuroscience in 1999.

He shared the 2005 Henry Dale Prize with Michael Brady of Oxford, and, as part of the award was elected an honorary life member of the Royal institution for "outstanding research of an interdisciplinary nature".

In 2007, the President of India conferred on him the Padma Bhushan award, third highest civilian award and honorific title in India.

In 2008, he was listed as number 50 in the Top 100 Public Intellectuals Poll.

Books authored

• Phantoms in the Brain: Probing the Mysteries of the Human Mind, coauthor Sandra Blakeslee, 1998.
  
• The Encyclopedia of the Human Brain (editor-in-chief)
• The Emerging Mind, 2003,
  
• A Brief Tour of Human Consciousness: From Impostor Poodles to Purple Numbers, 2005, (paperback edition)
  
• The tell-Tale Brain: A neuroscientist's Quest for what makes us human 2010.
  

Ramachandran has presented numerous plenary lectures around the world.

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[Visalakshi Ramani]

Conclusion:

When I started this thread I hoped the that others will contribute to it in their own way. :bump2:

But every time I was made to keep on posting as no one else wished to post anything.

I leave this thread open for future contributions by the learned members of the Forum about the people who have impressed them.ray2:

My own contribution to this thread ends here! :wave:

In case I come across any unusual or weird person, I can still write about him in the Think about it column!

 

[Brahmanyan]

Conclusion:

When I started this thread I hoped the that others will contribute to it in their own way. :bump2:

But every time I was made to keep on posting as no one else wished to post anything.

I leave this thread open for future contributions by the learned members of the Forum about the people who have impressed them.ray2:

My own contribution to this thread ends here! :wave:

In case I come across any unusual or weird person, I can still write about him in the Think about it column!

Dear Mrs. Visalakshi Ramani,

You have concluded the series with Dr.V.S.Ramachandran, Eminent Neuroscientist about whom I have referred to in one of my earlier posts. I have read some of his lectures like The Emerging Mind, The Artful Brain and heard his talks to The Indian Express Editor-in-Chief Shekhar Gupta on NDTV 24x7’s Walk the Talk programme about his path-breaking research into the human brain and the human mind. Since the subjects dealt in them are of highly scientific nature I could understand very little from them.

The subjects you have selected under this thread are of serious one. It needs time and effort to gather information and presentation, which very few people can afford to within their busy schedule.
What you have contributed to the Tamil Brahmins Forum is highly valuable.

Wishing you all the best,
Warm Regards,
Brahmanyan,
Bangalore.

 

[Visalakshi Ramani]

dear Sir,

Actually many people have worked round the clock and collected all the details about the people who were being featured here.

Wikipedia, The free encyclopedia is doing yeoman service to the spread of knowledge and information.

i am only making the long and heavy articles, lighter, easier to read, to understand and to assimilate. :typing:

I am like the farmer who enjoys the honey collected by the industrious bees (without killing them) with his friends (of the forum). I will try to keep the thread alive with occasional posts.

My trip to USA with my husband has finally taken shape today.

We will leave for Chennai on 10th July. We will fly to Denver on 17h July.

We will be with our younger son for a month or more and go to our elder son's place before their college reopens.

Our return trip is on 10th December from Denver.

I do not know how much time I will be able to get write fresh posts and type them. So I will try my level best to present the daily Tamil poems
(Kanda Puranam) and the thread Think It Over.

During the latest trip I was able to create my blogs with the help of my younger daughter in law Rupa Raman from Bangalore

I can always stay up late at night and finish my posts.

Let us see how things develop. But surely I will be around frequenting the forum as many times as possible. :roll:

with warm regards,
Visalakshi Ramani.