developingintelligence | January 13, 2007Recent highlights from the brain blogosphere:
Can crossword puzzles help prevent senile dementia?
The current state of the brain fitness movement: as evaluated by the New York Times.
Spindle neurons evolved very recently - are they also the source of frontal dementia?
A new form of pharmacological brain enhancement - could this technique avoid the long-term risks of excitotoxicity (as might result from extensive use of ampakines?)
What about interrogation neurotechnology? Here's what military's director of psychopharmacology has to say.
Future prospects for interrogation neurotech.
Bird…
developingintelligence | January 12, 2007The cognitive science of hemispheric asymmetry has long been marred by drastic over-simplification. The left/right distinction has been associated with dichotomies like rational vs. emotional, specific vs. holistic, and analytical vs. synthetic. Such differences are much more graded than dichotomous, to the extent that they exist in the first place. So, before reviewing well-established kinds of hemispheric differences, it might be useful to dispel some "lateralization mythology."
First, although the left hemisphere is generally dominant in linguistic tasks, the right hemisphere also has…
developingintelligence | January 11, 2007As enigmatic as prefrontal function seems to be, the anterior portions of prefrontal cortex (aPFC) are even more mysterious. This results partly from the fact that aPFC is particularly difficult to access and study electrophysiologically in nonhuman primates, as Ramnani and Owen note in their 2004 Nature Reviews Neuroscience article, and so detailed neuroanatomical investigations of aPFC have been conducted only recently. The authors report how this work has led to a breakthrough in the understanding of aPFC's computations.
Ramnani and Owen review Brodmann's early analysis of aPFC, also…
developingintelligence | January 10, 2007As described in yesterday's post, many theories have been proposed on the possible functional organization of prefrontal cortex (PFC). Although it's clear that this region plays a large role in human intelligence, it is unclear exactly "how" it does so. Nonetheless at least some general conclusions on prefrontal computation can be made.
A reasonably uncontroversial view is that prefrontal cortex maintains over time representations that integrate sensori-motor with current goal and context information, and that this active maintenance biases processing elsewhere in the cognitive system in…
developingintelligence | January 9, 2007Although much progress has been made since neurologist Richard Restack called the brain one of science's last frontiers, the functions of some brain areas remain mysterious. Foremost among these is prefrontal cortex (PFC), a region that is much reduced in size in most other primates, is among the last areas to develop in human children, and yet is active in almost every cognitive task.
In general, prefrontal cortex is associated with higher-order cognition, such as those processes involved in planning, strategizing, self-monitoring, self-regulation, and more generally, the coordination of…
developingintelligence | January 8, 2007In a few places throughout the second edition of his landmark book, Mark Johnson suggests that the field of developmental cognitive neuroscience has matured from infancy to toddlerhood. This book, then, is a sort of biography, from the field's theoretical ancestry in 17th century debates between "vitalists" and "preformationalists" to current (and in some ways similar) debates between nativists and empiricists. In between, Johnson expertly covers everything from prenatal cortical differentiation to developmental change in the distributions of various neuromodulators, to the development of…
developingintelligence | January 7, 2007Highlights from recent brain blogging:
Top 5 Robots of 2006 - the top 5 that we know about, that is. #1 gives you a taste of the current state of robotics.
Along those lines, this video about a few precautions we should all take.
The Neurophilosopher covers augmented cognition by DARPA, and a recent film commissioned by the same agency "to tell the story of AugCog science and technology, with an eye to how it will mature and be used in the coming decades."
MindHacks provides a history of research bearing on the topic of free will, while MindBlog covers focuses on a essay in the New York…
developingintelligence | January 4, 2007There are many theories of how human behavior came to differ so profoundly from that of even our closest primate relatives - language, recursion, theory of mind, and enhanced working memory are just a few of the "critical components" that have been proposed as enabling human intelligence. A very different perspective, advocated by Tomasello and Carpenter, suggests that it is simply humans' extreme propensity for social interaction that is at the core of the evolution of human intelligence.
In their article, Tomasello and Carpenter focus on four effects of this social tendency, which they…
developingintelligence | January 3, 2007The prefrontal cortex is a major recipient of subcortical dopaminergic projections. Accordingly, almost all of the behavioral tasks that are known to critically depend on the prefrontal cortex are sensitive to dopamine levels. A curious exception is the Self Ordered Pointing task (SOPT), in which subjects must select each of 9 designs by pointing at each one once; after each selection, the locations of the designs are randomized. Therefore, in order to succeed at this task subjects must remember the designs themselves and not the locations to which they pointed.
The dorsolateral…
developingintelligence | January 2, 2007It seem reasonable that evolution might select for adaptive behaviors by increasing the relative size of particular brain regions that support those behaviors; for example, bats might have an enlarged auditory cortex since they navigate with echolocation. To some extent this does happen, but such differences are often apparent only after controlling for a much larger source of variance: changes in brain size that correlate with changes in body size - and the implications of this fact are wide-reaching.
As Barbara Finlay and coauthors wrote in this 2001 Behavioral and Brain Sciences article,…
developingintelligence | December 29, 2006While subjects are generally faster to respond to a stimulus if it is presented at a previously "cued" location, they are paradoxically slower to respond if the spatial "cue" occurred more than 300 ms beforehand. This strange phenomenon is known as inhibition of return (IOR), and is thought to result from the reflexive "suppression" of previously-attended locations in space. IOR can be considered an adaptive characteristic of neural information processing, in that IOR ensures that the environment is being constantly searched for new information.
It turns out that IOR may have other…
developingintelligence | December 28, 2006"Working memory" refers to the cognitive processes involved in temporarily storing & manipulating information. Unsurprisingly, this capacity is correlated with many measures of intelligence, but (somewhat more surprisingly) is also impaired in a variety of neurological disorders, including schizophrenia.
In a recent Psychopharmacology article, Deanna Barch reviewed studies demonstrating drug-induced improvements in working memory with a focus on possible applications for future schizophrenia treatments. What follows is a summary of this excellent article.
To a large extent, the effects…
developingintelligence | December 28, 2006It looks like I'll be joining the bunch here at ScienceBlogs, so I thought I'd introduce myself.
This blog is dedicated to tracking the development of intelligence in both natural and artificial systems. This means looking at intelligence, what it means, and how it emerges over time in humans, monkeys, dolphins, chatbots, and neural network simulations alike.