Under this category you can find Human Brain related topics. Latest advances in neuroscience are closely followed and research results can be used as feedback for our machine consciousness models.
Scientists at the Massachusetts General Hospital have combined a normally inactive lidocaine derivative with capsaicin, the ‘heat’-generating ingredient in chili peppers, to produce pain-specific local anesthesia. When injected into rats, this combination completely blocked pain without interfering with either motor function or sensitivity to non-painful stimuli.
This technique could revolutionize pain management, as it specifically targets pain-sensing neurons. Current local anesthetics block all neurons, not just pain-sensing ones, and produce dramatic side effects such as temporary paralysis and complete numbness. [1]
This means that using this drug you are still aware of touch while you are unaware of pain. A lot new applications could result if the new method is validated in humans (hopefully in 2 or 3 years).
As reposrted in Nature [2], rats given an injection of the anaesthetic were able to tolerate more heat than usual, while moving around normally. Then, they tried injecting the anesthetic near the sciatic nerve of the rats and pricked their paws with nylon probes. The animals seemed to ignore the painful prick, but continued to move normally and responded to other stimuli.
Researcher Professor Clifford Woolf, of Harvard Medical School and Massachusetts General Hospital in Boston in the US, said: 'We're optimistic that this method will eventually be applied to humans and change our experience during procedures ranging from knee surgery to tooth extractions.
'Eventually this method could completely transform surgical and post-surgical analgesia, allowing patients to remain fully alert without experiencing pain or paralysis. 'In fact, the possibilities seem endless. I could even imagine using this method to treat itch, as itch-sensitive neurons fall into the same group as pain-sensing ones.'
In time, it may be possible to package it in pill form, rather than giving it as an injection. There are, however, several hurdles to be crossed before the technique can be tested on human patients. Scientists will have to find a way of removing the temporary burning sensation associated with the use of capsaicin, as well as prolonging the pain-relieving effect of the drug.
[2] Nature, Oct. 4, 2007 “Inihibition of nociceptors by TRPV1-mediated entry of impermeant sodium channel blockers” Alexander M. Binshtok (1), Bruce P. Bean (2), and Clifford J. Woolf (1)
Although classical AI approaches have usually neglected the emotional dimension, it is becoming a key part of many of the current artificial cognitive architectures. The neurobiological study of emotions during the last decades has offered new insight. The analysis of patients that have lost part of their brains, and the use of brain imaging techniques, give scientists many significant clues about how our emotional brain works.
In the book “Descartes’ Error: Emotion, Reason, and the Human Brain” by neurologist Antonio R. Damasio [1], the argument is made that emotion and reason are quite dependent upon one another. The famous case of Phineas Cage, whose frontal lobes were damaged in an accident, is explored in this book. Phineas P. Gage (1823-1860) suffered a brain injury at work when a tamping iron accidentally passed through his skull (see picture).
Gage’s case is said to be the first clinical proof of the role of the frontal lobe in personality and social interaction. Actually, after Gage suffered the accident, his friends said that he was no longer the same - he became a very unsociable person. The following is an excerpt from Harlow – Cage’s doctor (1968):
Gage was fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom), manifesting but little deference for his fellows, impatient of restraint or advice when it conflicts with his desires, at times pertinaciously obstinate, yet capricious and vacillating, devising many plans of future operations, which are no sooner arranged than they are abandoned in turn for others appearing more feasible. A child in his intellectual capacity and manifestations, he has the animal passions of a strong man. Previous to his injury, although untrained in the schools, he possessed a well-balanced mind, and was looked upon by those who knew him as a shrewd, smart businessman, very energetic and persistent in executing all his plans of operation. In this regard his mind was radically changed, so decidedly that his friends and acquaintances said he was 'no longer Gage. [2]
Damasio proposed a theory called somatic marker hypothesis, which suggests a link between the fontal lobes, emotion, and decision making. Since Cage’s case, Antonio Damasio, Marc Hauser and colleagues have studies six more cases with damage in the ventromedial prefrontal cortex (VMPC), one of the social motional nodes of the brain. They have concluded that this damage increases utilitarian moral judgements [3]. Here, the term utilitarian comes form utilitarism, and and refers to moral judgements or dilemmas where there is a conflict between aggregate welfare and highly emotionally aversive behaviors (for instance, having to sacrifice one person's life to save a number of other lives).
According to Raymond J. Dolan, Patients with medial prefrontal lesions often display irresponsible behavior, despite being intellectually unimpaired. But similar lesions occurring in early childhood can also prevent the acquisition of factual knowledge about accepted standards of moral behavior. [4]
[1] Antonio R. Damasio (1995) Descartes' Error: Emotion, Reason, and the Human Brain [2] Harlow, J.M. (1868). "Recovery from a Passage of an Iron Bar through the Head". Publications of the Massachusetts Medical Society 2: 327-347. [3] Michael Koenigs, Liane Young, Ralph Adolphs, Daniel Tranel, Fiery Cushman, Marc Hauser & Antonio Damasio. Nature 446, 908-911 (19 April 2007). [4] Raymond J. Dolan. On the neurology of morals. Nature Neuroscience 2, 927 - 929 (1999).
This is a filmed lecture of Christof Koch, neuroscientist famous for his contributions to the quest for understanding the underlying mechanisms of consciousness. He has been working jointly with Francis Crick researching on the visual perception and specifcally attention and consciousness neurological mechanisms.
The video is provided by the University of California - Berkeley. The graduate council lectures series. Foersters Lectures on the inmortality of the soul. Lecture's title is 'The Quest for Consciousness: A Neurological Approach", and is conducted by Christof Koch, Professor of Cognitive and Behavioral Biology from the California Institute of Technology.
This is a link to an online course on neuroanatomy (written in Spanish) by Pontificia Universidad Católica de Chile. Anatomy Department - Medicine School.
These pages are property of the Anatomy Department of the Medicine School of Catholic University of Chile, and are available as support material for students of Neuroanatomy course included in the medicine grade.
Human brain weight is about 2% of body weight. However, its energy consumption is 20%. Thanks to brain imaging techniques (like fMRI and PET) scientists can see the changing metabolism and brain blood streams, which mean energy consumption as explained by Marcus E. Raichle from Washington University [1]. According to Raichle, only between 0,5% and 1% of the energy is used to bear with external world. 60% to 80% of the energy is dedicated to maintain the connection between neurons. Therefore, the creation of new neuronal routes is the main energy consumption mechanism.
Other source of energy consumption could be the constant prediction processes present in the brain. Human brain is often defined as a prediction machine, as it collects information and experiences from the past and tries to prepare and anticipate the immediate future.
[1] The Brain's Dark Energy. Marcus E. Raichle. Science 24 November 2006: Vol. 314. no. 5803, pp. 1249 - 1250. DOI: 10.1126/science. 1134405
Santiago Ramón y Cajal (May 1, 1852 - Octiber 17, 1934) was awarded the Nobel Prize in 1906 (jointly with Camillo Golgi). This Spanish scientist is considered one of the founders of neuroscience. Ramón y Cajal was very prolific in histologic studies of the central nervous system. His most salient work is included in [1] (Spanish) and [2] (English).
[1] Ramón y Cajal S. Estudios sobre la degeneración y regeneración de sistema nervioso. 2 vols. Madrid: N. Moya, 1913–14.
[2] S. Ramón y Cajal, Studies on the degeneration and regeneration of the nervous system, 2 vols, Oxford University Press, Oxford (1928).
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Gage’s case is said to be the first clinical proof of the role of the frontal lobe in personality and social interaction. Actually, after Gage suffered the accident, his friends said that he was no longer the same - he became a very unsociable person. The following is an excerpt from Harlow – Cage’s doctor (1968):
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