divendres, 25 de febrer de 2011

"When It Comes To Intelligence, Size Matters" ScienceDaily

A collaborative study led by researchers at the Montreal Neurological Institute (MNI), McGill University has demonstrated a positive link between cognitive ability and cortical thickness in the brains of healthy 6 to 18 year olds. The correlation is evident in regions that integrate information from different parts of the brain.

Areas in the brain where there is an association between general cognitive ability and cortical thickness. (Credit: Montreal Neurological Institute)
The imaging study published this week in a special issue of scientific journal Intelligence is the largest and most comprehensive of its kind with a representative sample of healthy children and adolescents.
This study stems from the NIH MRI Study of Normal Brain Development, for which the MNI was the data coordinating centre. The database contains MRI scans and other data on the structure and function of the developing brains. More than 500 children and adolescents from newborns to 18-year-olds had brain scans multiple times over a period of years as well as intelligence, neuropsychological, verbal, non-verbal and behavioural tests. This information is now contained within the database allowing scientists to study how normal developmental changes in brain anatomy relate to motor and behavioural skills, such as motor coordination and language acquisition. Even higher-order skills like planning, IQ, and organizational skills can be assessed.
Previous studies have shown that intelligence and cognitive ability are correlated with regional brain structure and function. The association between regional cortical thickness and intelligence has been little studied and most previous studies of normal children had a relatively small sample. So with improvements in MRI-based quantification of cortical thickness and a much larger sample, researchers aimed to examine this relationship and to further characterize and identify brain areas where cortical thickness was associated with cognitive performance.
Cortical thickness may in part reflect the amount of complex connections between nerve cells. In other words, thicker cortices are likely to have more complex connections with consequences on cognitive ability. A positive link between cortical thickness and cognitive ability was detected in many areas of the frontal, parietal, temporal and occipital lobes. The regions with the greatest relationship were the 'multi-modal association' areas, where information converges from various regions of the brain for processing.
"A principal finding of this study is that it supports a distributed model of intelligence where multiple areas of the brain are involved with cognitive ability difference instead of the view that there is just one centre or structure important for intelligence differences in the brain," says Dr. Sherif Karama, psychiatrist at the MNI and co-investigator in the study. "Previous studies have shown a link between intelligence differences and individual brain structure or function. This is the first time that a correlation between a general cognitive ability factor and essentially most, if not all, cortical association areas is demonstrated in the same study."
A deeper insight into normal cognitive functioning and abilities is an important first step in the understanding of cognitive decline observed in the elderly as well as in those with various pathologies ranging from multiple sclerosis to schizophrenia, depression and mental retardation. Such an understanding may eventually lead to interventions that may be able to prevent or alleviate the decline or complications in cognitive function.
The project was funded by National Institute of Child Health and Human Development, the National Institute on Drug Abuse, the National Institute of Mental Health, and the National Institute of Neurological Disorders and the Fonds de Recherché en Santé du Quebec (FRSQ).

Source:
McGill University. "When It Comes To Intelligence, Size Matters." 

dimarts, 15 de febrer de 2011

Neurobiology of Violence: Adrian Raine talks (4 talk-playlist)

Neuroethical and Neurolegal Implications // An examination of the brain basis to crime and violence // What we can do to prevent future crime and the neuroethical implications



Adrian Raine
Chair, Department of Criminology, University of Pennsylvania
Richard Perry University Professor, Departments of Criminology, Psychiatry, and Psychology, University of Pennsylvania


"My main area of interest is Neurocriminology – an emerging sub-discipline of Criminology which applies neuroscience techniques to probe the causes and cures of crime. My laboratory focus on risk and protective factors for childhood conduct disorder, reactive and proactive aggression, adult antisocial personality disorder, homicide, and psychopathy. Our clinical neuroscience research program encompasses adults, adolescents, children, and toddlers, and we have interests in both male and female antisocial behavior. Techniques we use in our research include structural and functional brain imaging, autonomic and central nervous system psychophysiology, neuroendocrinology, neuropsychology, and x-ray fluorescence. We take a biosocial perspective to our investigation of antisocial behavior in which our end-goal is to integrate social, psychological, and environmental processes with neurobiological approaches to better understand antisocial behavior. We are also interested in other clinical disorders including schizotypal personality, hyperactivity, oppositional defiant disorder, alcohol and drug abuse, depression, PTSD, and anxiety which are comorbid with antisocial behavior."

dilluns, 14 de febrer de 2011

Redes 83: Las decisiones son inconscientes





¿Somos libres cuando decidimos? ¿Qué margen tiene el libre albedrío ahora que la neurociencia desvela cada vez más el gran poder del inconsciente?
Ya hay máquinas para ver cómo decide el cerebro y los primeros resultados muestran que, antes de entrar en la conciencia, muchas decisiones ya están tomadas por complejas redes cerebrales.

Desde Berlín, John-Dylan Haynes nos habla hoy en Redes de sus experimentos para descifrar la actividad cerebral que se esconde detrás de nuestros estados mentales.

dissabte, 5 de febrer de 2011

"Brain Story" attempts to answer the question “What is my mind and who am I?” We talk to philosophers, clinicians, neurosurgeons and their patients to discover quite what a finely balanced and complex machine the brain is (subtitulado)




Why do we think and feel as we do? For years man has sought to understand the workings of the mind. Now, with advances in modern-day technology and developments in neuroscience, a whole new world of brain research is opening up.

Understanding our minds is becoming a reality. Guided by top neuroscientist Susan Greenfield, Brain Story attempts to answer the question “What is my mind and who am I?” We talk to philosophers, clinicians, neurosurgeons and their patients to discover quite what a finely balanced and complex machine the brain is.

Watch the full documentary now

Susan Greenfield explains why she believes all aspects of human experience will eventually be explained in terms of the physical processes of the brain. The story of how we have gradually come to understand the astonishing complexity of the brain is revealed, from the earliest crude studies of the effects of brain injury, through to the latest insights from direct stimulation of specific areas in patients undergoing brain surgery whilst wide awake. Is it possible that our most spiritual feelings are merely the result of electrical activity in the temporal lobe?

I. All in the Mind
Where do emotions come from? Why do they feel so different from thoughts? Susan Greenfield looks at some of the old attempts to explain emotion in terms of brain areas and explains why she believes the answer must lie in the biochemistry of the brain – all the hundreds of chemical neurotransmitters which bathe the nerves.

II. In the Heat of the Moment
The illusion of vision. It feels as though we open our eyes and just see what’s out there, but the more we learn about the brain’s visual system, the further it seems this is from the truth. Patients who can’t see movement or recognize faces, reveal the tricks and short cuts the brain uses to construct an illusion of reality. Is the brain making up so much of what we think we’re seeing that vision is really just dreaming with your eyes open?

III. The Mind’s Eye
What is it about brains that has put us in charge of the planet? Were have humans’ unique linguistic abilities come from? Are there special structures in our brains which no other animals possess? Or is it possible that our sophisticated rich cultures are merely the result of having larger brains? Susan Greenfield explains why she believes we are truly just big-brained chimps.

IV. First Among Equals
The changes in the brain during the growth and development of a baby into an adult are explored. Susan Greenfield looks at how little of the fine structure of our brains is predetermined at birth, how the connections between nerves are constantly changing in response to what we encounter in the outside world. She explains her view that learning, memory and even the process of becoming a unique individual, should all be seen as a restless brain adapting minute by minute to the environment it encounters. Life is about how the world leaves its mark on us.

V. Growing the Mind
How do our brains generate consciousness? We take it for granted that the brain makes being alive feel the way it does, but there’s no reason why it should.The brain is made of the same biological ingredients as the rest of the body, and yet somehow it manages to generate the indescribable phenomenon of consciousness. Consciousness is far more than just being able to imagine; it’s a whole extra dimension. Susan Greenfield explains why she believes that the existence of a private world of experiences and feelings, is actually more extraordinary than the fact that living things evolved at all. She explores how we are finally taking the first steps towards understanding this tantalising paradox, and the implications for our view of ourselves as something more than complex machines.

VI. The Final Mystery