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The ethics of using brain-boosting drugs
Corie Lok
Wednesday, 19 December 2007 18:46 UTC
There’s a new forum discussion topic here on Nature Network you might be interested in.
It’s about whether healthy and sick individuals should take drugs to enhance cognition, memory, etc. The discussion stems from a commentary published in this week’s Nature by two Cambridge University researchers.
Have a look and post your comments there.
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Sorry, I apologize for writing Ari instead of Avi.
I don´t know whether the following may be helpful: I´ve read your claim for a paradigm shift and for a new way to think about mental orders.
I do not believe that ADD will be apparent at the neural network level but I hypothesize that this assumption applies to mental disorders like agnosia. -
Dear Elisabeth:
As I understand your explanation, “functional” people are those who jump from the stimulus to a (subjectively defined) goal, without representing the means to achieve it. “Predicative” people are those who analyse the stimulus (e.g. Kanisza illusory triangle) and report their representation of it, only relating it to a goal if they are asked to make such a connection.
In the current paradigm of executive functions in cognitive neuroscience, “functional” people are at risk of being classified as having a prefrontal function disorder.
Maybe in a different context (e.g. in the future of our own society) the “functional” behavior turns out to be adaptive, but at this moment they constitute a problem for the educational system. Possibly the whole system is built on sand. However, for those (like me) who work in this context, “functional” students are often “disfunctional” in the sense that they do not play the game we would like them to play.
Possibly this kind of behavioral tendency is based on prefrontal neural network properties, as proposed by Avi. Experimental data on this regard would be helpful.Best,
Alfredo
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Dear Alfredo,
Alfredo: However, for those (like me) who work in this context, “functional” students are often “disfunctional” in the sense that they do not play the game we would like them to play.
Elisabeth: This description will fit.:-)
For experimental data see:
Mölle,M., Schwank, I., Marshall, L., Klöhn, A.,& Born, J.(2000): Dimensional complexitiy and power spectral measures of the EEG during functional versus predicative problem solving. Brain & Cognition, Vol.22 No.3, 547-563Schwank, I.: Analysis of Eye-Movement During Functional versus Predicative Problem Solving. 2nd Conference of the European Society for Research in Mathematics Education 24th – 27th Feb. 2001, Marinske Lazne
http://www.ikm.uni-osnabrueck.de/mitglieder/schwank/schwank_e/schwank_e.htmlBest regards,
Elisabeth -
News about Ritalin and Prefrontal Function.
From ScienceDaily
Thanks to Malcolm Dean for forwarding it to me.
AlfredoUniversity of Wisconsin-Madison (2008, June 25). How Ritalin Works In
Brain To Boost Cognition, Focus Attention.ScienceDaily (June 25, 2008) — Stimulant medications such as Ritalin
have been prescribed for decades to treat attention deficit
hyperactivity disorder (ADHD), and their popularity as “cognition
enhancers” has recently surged among the healthy, as well. What’s now
starting to catch up is knowledge of what these drugs actually do in
the brain. In a paper publishing online this week in Biological
Psychiatry, University of Wisconsin-Madison psychology researchers
David Devilbiss and Craig Berridge report that Ritalin fine-tunes the
functioning of neurons in the prefrontal cortex (PFC) – a brain region
involved in attention, decision-making and impulse control – while
having few effects outside it.Because of the potential for addiction and abuse, controversy has
swirled for years around the use of stimulants to treat ADHD,
especially in children. By helping pinpoint Ritalin’s action in the
brain, the study should give drug developers a better road map to
follow as they search for safer alternatives. At the same time, the
results support the idea that today’s ADHD drugs may be safer than
people think, says Berridge. Mounting behavioral and neurochemical
evidence suggests that clinically relevant doses of Ritalin primarily
target the PFC, without affecting brain centers linked to over-arousal
and addiction. In other words, Ritalin at low doses doesn’t appear to
act like a stimulant at all.“It’s the higher doses of these drugs that are normally associated
with their effects as stimulants, those that increase locomotor
activity, impair cognition and target neurotransmitters all over the
brain,” says Berridge. “These lower doses are diametrically opposed to
that. Instead, they help the PFC better do what it’s supposed to do.”A behavioral disorder marked by hyperactivity, impulsivity and the
inability to concentrate, ADHD has been treated for more than a
half-century with Ritalin, Adderall and other stimulant drugs. New
reports also indicate these meds have lately been embraced by healthy
Americans of all ages as a means to boost mental performance.Yet, despite their prevalence, we know remarkably little about how
these drugs work, especially at lower doses that have been proven
clinically to calm behavior and focus attention in ADHD patients, says
Berridge. In 2006, his team reported that therapeutic doses of Ritalin
boosted neurotransmitter levels primarily in the PFC, suggesting a
selective targeting of this region of the brain. Since then, he and
Devilbiss have focused on how Ritalin acts on PFC neurons to enhance
cognition.To answer this, the pair studied PFC neurons in rats under a variety
of Ritalin doses, including one that improved the animals’ performance
in a working memory task of the type that ADHD patients have trouble
completing. Using a sophisticated new system for monitoring many
neurons at once through a set of microelectrodes, the scientists
observed both the random, spontaneous firings of PFC neurons and their
response to stimulation of an important pathway into the PFC, the
hippocampus.Much like tiny microphones, the electrodes record a pop every time a
neuron fires, Devilbiss explains. Analyzing the complex patterns of
“voices” that emerge is challenging but also powerful, because it
allows study of neurons on many levels.“Similar to listening to a choir, you can understand the music by
listening to individual voices,” says Devilbiss, “or you can listen to
the interplay between the voices of the ensemble and how the different
voices combine.”When they listened to individual PFC neurons, the scientists found
that while cognition-enhancing doses of Ritalin had little effect on
spontaneous activity, the neurons’ sensitivity to signals coming from
the hippocampus increased dramatically. Under higher, stimulatory
doses, on the other hand, PFC neurons stopped responding to incoming
information.“This suggests that the therapeutic effects of Ritalin likely stem
from this fine-tuning of PFC sensitivity,” says Berridge. “You’re
improving the ability of these neurons to respond to behaviorally
relevant signals, and that translates into better cognition, attention
and working memory.” Higher doses associated with drug abuse and
cognitive impairment, in contrast, impair functioning of the PFC.More intriguing still were the results that came from tuning into the
entire chorus of neurons at once. When groups of neurons were already
“singing” together strongly, Ritalin reinforced this coordinated
activity. At the same time, the drug weakened activity that wasn’t
well coordinated to begin with. All of this suggests that Ritalin
strengthens dominant and important signals within the PFC, while
lessening weaker signals that may act as distractors, says Berridge.“These results show a new level of action for cognition-enhancing
doses of Ritalin that couldn’t have been predicted from single neuron
analyses,” he says. “So, if you’re searching for drugs that might
replace Ritalin, this is one effect you could potentially look for.”He and Devilbiss also hope the research will help unravel an even
deeper mystery: exactly how neurons encode complex behavior and
cognition.“Most studies look at how something that impairs cognition affects PFC
neurons. But to really understand how neurons encode cognitive
function, you want to see what neurons do when cognition is improved,”
says Berridge. “So this work sets the stage for examining the
interplay among PFC neurons, higher cognition, and the action of
therapeutic drugs.”The work was funded by the National Institute on Drug Abuse, the
National Institute of Mental Health and the UW-Madison Discovery Seed
Grant Program.
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