Chris Chatham
developingintelligence
Posts by this author
November 21, 2011
Stimulating the brain with high frequency electrical noise can supersede the beneficial effects observed from transcranial direct current stimulation, either anodal or cathodal (as well as those observed from sham stimulation), in perceptual learning, as newly reported by Fertonani, Pirully &…
November 18, 2011
In their wonderful Neuroimage article, Braun & Mattia present a comprehensive introduction to the possible neuronal implementations and cognitive sequelae of a particular dynamical phenomenon: the attractor state. In another excellent paper, just recently out in Frontiers, Itskov, Hansel and…
November 17, 2011
If you ever said to yourself, "I wonder whether the human mid- and posterior ventrolateral prefrontal cortex has a homologue in the monkey, and what features of its cytoarchitecture or subcortical connectivity may differentiate it from other regions of PFC" then this post is for you.
Otherwise,…
November 16, 2011
Suppose - rather reasonably - that soups which taste like garlic have garlic in them. You observe two people eating soup; one of them says to the other, "There is no garlic in this soup." Do you think it's likely that the soup taste like garlic?
If you said yes, then congratulations! You've just…
November 8, 2011
Last month's Frontiers in Psychology contains a fascinating study by Dambacher, HuÌbner, and Schlösser in which the authors demonstrate that the promise of financial reward can actually reduce performance when rewards are given for high accuracy. Counterintuitively, performance (characterized as…
September 12, 2011
Owing to the low signal-to-noise ratio of functional magnetic resonance imaging, it is difficult to get a good estimate of neural activity elicited by task novelty: by the time one has collected enough trials for a good estimate, the task is no longer novel! However, a recent J Neurosci paper from…
September 12, 2011
How do we detect important items in our environment? This crucial capacity has received less attention than one might think, and a number of extremely basic issues remain to be explored. For example, it has long been known that target probability has profound effects on the recruitment of the…
October 27, 2010
A really excellent PBS CBC (thanks m5) documentary on the surprising cognitive abilities of crows:
Watch the full episode. See more Nature.
See also how crows might be trained to do something a little more lucrative:
This latter video tells a great story, but as John Hawkes has pointed out,…
September 24, 2010
Sometimes, ground-breaking studies don't get the attention they deserve - even from experts in the field. One great example of this is an elegant study by Nieuwenhuis et al. from CABN in 2003; in it, they conclusively demonstrate why a particular event-related potential - the negative-going…
September 15, 2010
In last week's Science, Dosenbach et al describe a set of sophisticated machine learning techniques they've used to predict age from the way that hemodynamics correlate both within and across various functional networks in the brain. As described over at the BungeLab Blog, and at Neuroskeptic, the…
September 14, 2010
With our introduction to paired pulse transcranial magnetic stimulation (ppTMS) out of the way, we now turn to a 2010 PNAS paper by Neubert, Mars, Buch, Olivier & Rushworth in which conditioning TMS is applied to the right inferior frontal gyrus (rIFG) as well as the pre-supplementary motor…
September 14, 2010
Yesterday's introduction to paired-pulse transcranial magnetic stimulation elicited an insightful comment from reader "Kix":
As you mention, TMS can be used in order to disrupt or to read out some areas of the brain. I don't see why these functions should be mutually exclusive. For instance,…
September 13, 2010
There's a ton of super-interesting transcranial magnetic stimulation work coming out these days (e.g., here, here, here, here, here, and here) and much of it pertains to a very particular "paired-pulse" form of TMS (ppTMS). Before diving into the new work, I wanted a basic crash course on what we…
August 13, 2010
There are a few fascinating papers to come out recently that I won't have time to cover in detail, but which people may find interesting. References and abstracts after the jump:
Watson & Strayer (2010). Supertaskers: Profiles in extraordinary multitasking ability. Psychon Bull Rev.
Abstract…
August 12, 2010
Two seemingly contradictory trends characterize brain development during childhood and adolescence:
Diffuse to focal: a shift from relatively diffuse recruitment of neural regions to more focal and specific patterns of activity, whether in terms of the number of regions recruited, or the magnitude…
July 27, 2010
"What we're seeking is not just one algorithm or one cool new trick - we're seeking a platform technology. In other words, we're not seeking the entirety of a collection of point solutions, what we're seeking is a platform technology on which we can build a wide variety of solutions."
Dharmendra…
July 23, 2010
Decisions can be hard: the conflict you face in any decision can be increased if option A is not that much better than option B, or if option A is newly worse than option B. And then there are are just bad decisions, maybe hard only in retrospect. As illustrated by a 2009 J Neurosci article from…
July 22, 2010
Recent work has leveraged increasingly sophisticated computational models of neural processing as a way of predicting the BOLD response on a trial-by-trial basis. The core idea behind much of this work is that reinforcement learning is a good model for the way the brain learns about its…
July 15, 2010
Swarming Quadrocopters?
Nanomagnetic remote control of animal behavior.
Blogs are data-mined for personality research.
Vote for method of the year! (My vote is for induced pluripotency)
If you think that the less competent you are, the more competent you think you are, then you are incompetent.…
July 14, 2010
How can we enhance perception, learning, memory, and cognitive control? Any answer to this question will require a better understanding of the way they are best enhanced: through cognitive change in early development.
But we can't stop there. We also want to know more about the neural substrates…
July 13, 2010
A nice 2010 Human Brain Mapping paper by Church, Petersen & Schlaggar covers a number of interpretational issues confronting modern neuroimaging. Their particular application is pediatric neuroimaging (I will also use developmental examples), but the general issues apply to nearly all fMRI…
July 13, 2010
A 2010 FINS paper from Cohen et al. demonstrates that multivariate patterns in neural recruitment during response inhibition across the brain are significantly predictive of response inhibition ability and age of the scanned subject, and shows that other factors (such as response variability and…
July 12, 2010
What if we got the organization of prefrontal cortex all wrong - maybe even backwards? That seems to be a conclusion one might draw from a 2010 Neuroimage paper by Yoshida, Funakoshi, & Ishii. But that would be the wrong conclusion: thanks to an ingenious mistake, Yoshida et al have…
July 9, 2010
Hierarchical views of prefrontal organization posit that some information processing principle, and not just task difficulty, determines which areas of prefrontal cortex will be recruited in a given task. Virtually all information processing accounts of the prefrontal hierarchy are agreed on this…
July 9, 2010
How does the brain deal with the need to pursue multiple goals simultaneously, particularly if they are associated with different reward values?
One idea, perhaps far-fetched, is that the brain might divvy up responsibility for tracking these goals & rewards: for example, the left hemisphere…
July 8, 2010
In the early days of functional magnetic resonance imaging (fMRI), researchers were eager to point out that the hemodynamic response measured by fMRI may correspond rather directly to neural firing. Recently, a number of researchers have attempted to remind the larger neuroimaging community that…
July 8, 2010
When I started this blog back in '06, new hypotheses were appearing on a possible functional architecture of the lateral prefrontal cortex - a recently-evolved brain area implicated in high-level cognitive functions like planning, analogical reasoning, and cognitive control. Since then, these…
January 7, 2010
A fascinating paper from Gradinaru et al describes a genetically engineered mouse model of Parkinson's disease that expresses a photoreceptor in the neurons of a particular part of the brain - the subthalamic nucleus (STN). This area is widely thought to be the central target of the immensely…
September 25, 2009
A number of very smart people (and smart communities) seem like they might be under the impression that the "voodoo correlations" scandal in the neuroimaging community is somehow related to recent work by Bennett et al, who used fMRI to show task-related neural activity in a dead fish.
These two…
September 25, 2009
Something's afoot when a massively parallel and distributed system shows a bottleneck in performance. We've known that numerous bottlenecks plague cognition since the 1940's, but only with recent advances in neuroimaging have we been able to say whether these bottlenecks reflect the intrusion of…