Towards human circuit analysis, for clinical benefit?

This article in the latest issue of the Journal of Neuroscience is interesting in the sense that they are do human brain stimulation of the hypothalamus, for the treatment of cluster headaches – but they then do positron emission tomography (PET) to examine the downstream neural circuits responsible for the abolition of the perception of headache.

Hypothalamic Deep Brain Stimulation in Positron Emission Tomography

This moves the field of brain stimulation from simple stimulate-and-see-what-happens, towards more of a study of human neural circuitry and how stimulation drives activity in connected locations. It’s possible this will lead, in the future, to better and more focal stimulation protocols, as people figure out what the “circuit-level” phenomena are that correct particular aspects of neural dysfunction. Perhaps someday we will have a map of the “hot spots” where stimulation of a small chunk of matter can modulate a wide degree of neural circuitry for the better.

(Last year, Helen Mayberg and colleagues’ deep-brain-stimulation-and-depression paper got at this issue as well, in which they stimulate the cingulate and (perhaps surprisingly) sent depressed patients into remission, and furthermore changed the activity of frontal structures from the abnormal state, back to a more normal pattern of activity.)

These studies are perhaps setting a good precedent for brain-stimulating neuroclinicians to follow.


Major Journal Calls for Synthesis in Neuroscience

Nature Neuroscience’s editorial board posts a call for a change (doi:10.1038/nn0406-457) in the incentive structure of neuroscience in favor of funding initiatives that foster synthesis.

A quote from the article:

“To shift the emphasis toward quality rather than quantity of scientific results, funding agencies could support specific integrative initiatives, such as large-scale meta-analyses in unresolved areas or experiments to tackle particularly contentious conflicts in the existing literature.”

It goes on:

“Simply having more time to think and interact with colleagues could foster consolidation and conceptual breakthroughs. Unfortunately for many academic researchers, such ruminating might carry the stigma of inactivity or, worse, speculation. However, science is largely a creative process, and the minds of scientists are ultimately its greatest resource. Legitimizing time for creative synthetic thought through funding might be an inexpensive way to shift the current incentive structure.”

This could be the beginning of an important change in the culture of the field.

Combinatorial Structures in Language and Visual Cognition

What gives humans the unique ability to construct novel sentences from the building blocks of language? A recent article in Behavioral and Brain Sciences proposes a “neural blackboard architecture” is capable of just this.

From the article (doi: 10.1017/S0140525X06009022):

“This paper aims to show that neural “blackboard” architectures can provide an adequate theoretical basis for a neural instantiation of combinatorial cognitive structures. […] We also discuss the similarities between the neural blackboard architecture of sentence structure and neural blackboard architectures of combinatorial structures in visual cognition and visual working memory […]”

As with all main articles in Behavioral and Brain Sciences, this one is followed by extensive comment and criticism from colleagues, and finally a reply by the authors. This provides a very deep look at the article and the issues surrounding it.

An older, but freely available, version of the article is available here.

Neural Correlates of Deductive Reasoning

A recent study in the Journal of Cognitive Neuroscience has isolated activation in the brain during a 3-stage model of deductive reasoning.

The study shows that during the ‘premise processing’ stage, there is more activity in occipito-temporal areas. During the ‘integration phase’, anterior prefrontal cortex is more active. During the final ‘valdiation phase’, the find more activity in posterior parietal and prefrontal areas.

AI started working on reasoning early on. Will studies like this lead us to the next advance in building models of reasoning?

Prediction vs. postdiction in self-movement

PLoS Biology: Attenuation of Self-Generated Tactile Sensations Is Predictive, not Postdictive [open access]

I haven’t gotten a chance to fully digest this article (What is the attenuation phenomena that happens when the taps are delayed?), but it seems like a deep result from a relatively simple haptics experiment. Just thought I’d share it with the crowd.

Also, Happy Birthday to fellow Neurodude Bayle! Congrats, man. 🙂

Four-legged Walking Robot Can't Be Kicked Over

New Scientist has the scoop on a state-of-the-art walking robot that navigates uneven terrain, slopes, and significant kicks.

The movie has to be seen to be believed. The robot is called BigDog and it looks like a CGI special effect. But don’t let the film industry desensitize you from the accomplishment here. The robotics engineering required to do this on real terrain is extraordinary. The engineers over at Boston Dynamics really deserve kudos for this.