Chris Chatham
developingintelligence
Posts by this author
September 21, 2007
The word "noise" comes from the latin nausea, meaning disgust or annoyance. But in the phenomenon known as stochastic resonance, noise can actually be a good thing: it can serve as a signal amplifier in thresholded systems.
This phenomenon is not nearly as arcane as it sounds. The image above (…
September 20, 2007
Can information be directed to different networks in the brain depending on the "transmission frequency", like the channels on a TV? A 2006 Cerebral Cortex paper reveals that this may not be as absurd as it sounds.
A relatively new technique in cognitive neuroscience is the use of frequency…
September 19, 2007
In the "motion standstill" illusion, a rapidly moving object is perceived as motionless, and yet not blurred. This means that color, depth, and shape are accurately processed while the motion system fails: in fact, subjects are no better at detecting the direction of motion than chance.
At…
September 14, 2007
The claim that language processing can be carried out by purely "general purpose" information processing mechanisms in the brain - rather than relying on language-specific module(s) - may seem contradicted by a slew of recent neuroimaging studies demonstrating what appears to be a visual "word form…
September 10, 2007
An article in last week's Nature describes a highly experimental - but also highly promising - new treatment for patients who have undergone massive traumatic brain injury.
These patients are typically left in a "minimally conscious" state, showing little to no responsiveness to verbal commands,…
August 27, 2007
In the Dimensional Change Card sorting (DCCS) task, 3-year-olds can usually sort cards successfully by a first rule - whether by shape, color, size, etc. When asked to switch then to another rule, most 3-year-olds will perseverate by continuing to sort cards according to the first and now-…
August 24, 2007
A long story short...
My PhD advisor, a developmental psychologist, recently had her first baby - unfortunately, this baby was born with the long-segment form of Hirschsprung's Disease. This means that Max has only 25 cm of ganglionated intestine; to survive he needs to mainline fatty acids a…
August 16, 2007
Steve Grand, author of "Creation: Life and How to Make It" as well as a principal designer behind the groundbreaking artificial life game "Creatures", was recently interviewed over at MLU.
It covers a smattering of topics: recent proposals for a completely synthetic lifeform; analog computation;…
August 13, 2007
What are the effects of prolonged boredom, for example as experienced by 17 months of interplanetary travel? This is the question investigated by a new European Space Agency project in which 12 volunteers will be locked in an isolation tank for 500 days. (In the comments, A.R. points out that…
August 7, 2007
Having just returned from a 3 week vacation to purchase (and then move into) a new home, I am finally now able to get back to posting. Here's just a very small subset of the best in brain-blogging while I was away:
Fundamental limitations in predicting individual differences: the margin of error…
July 13, 2007
Well, maybe it's "exotic" only to neuroscientists. Inhibitory structure in neocortex has usually been seen as fairly homogenous and simple, where the wide variety of inhibitory interneuron types was viewed as misleading: at bottom, they all perform a simple regulatory function of keeping only a…
July 11, 2007
For fans of scientific eye candy, the Nikon Small World competition is hard to beat - and this year, they've opened up the voting process to the public. Vote on your favorites but be careful - you can't revise your vote on a picture once it's cast!
July 9, 2007
Researchers at Duke University have recently invented a technique for improving the spatial resolution of magnetic resonance imaging (MRI) by a factor of nearly 100,000x. Whereas routine clinical MRI scans contain 3-dimensional pixels ("voxels") approximately 1mm x 1mm x 1mm, this new technique…
July 3, 2007
The Neurophilosophy blog recently migrated to scienceblogs.com and the first post is an excellent edition of Encephalon. Check it out.
June 28, 2007
In 1948, Alan Turing wrote: "An unwillingness to admit the possibility that mankind can have any rivals in intellectual power occurs as much amongst intellectual people as amongst others: they have more to lose." Accordingly, comprehensive comparisons between the intellectual powers of great apes…
June 27, 2007
Though widely separated in terms of both neuroanatomical location and evolutionary development, there are surprising parallels between parietal cortex and the hippocampus:
- Both structures are important for spatial cognition, although parietal cortex is thought to maintain a "self-centered" map of…
June 26, 2007
The best from recent cognitive/brain blogs:
Suspect someone's lying to you? Ask for the story in reverse order. Psyblog also has some suggestions.
A sober look at mind-reading fMRI pattern classification techniques over at Mind Hacks.
Nabokovian reviews a new computational model of short term…
June 26, 2007
Can you move a single matchstick to form a valid mathematical statement equation?
No sticks can be discarded, an isolated slanted stick cannot be interpreted as I (one), and a V (five) symbol must always be composed of two slanted sticks. UPDATE: The only valid symbols are Roman numerals and…
June 25, 2007
Functional magnetic resonance imaging (fMRI) has captured the popular imagination since its introduction in the early 1990s, at least partially because of the stunningly beautiful images it generates. Although it has mostly used to identify brain regions involved in specific cognitive operations,…
June 21, 2007
Though anatomically heterogenous, the human prefrontal cortex seems to perform a rather general function: it actively maintains context representations to guide and control behavior. What, then, is the reason for the anatomical diversity within this region of the brain?
Some theories suggest…
June 18, 2007
How does your brain represent the feelings and thoughts that are a part of conscious experience? Even the simplest aspects of this question are still a matter of heated debate, reflecting science's continuing uncertainty about "the neural code." The fact is that we still don't have a clear…
June 13, 2007
What was your 6th birthday party like?
If you successfully retrieved that memory, you may now be ever so slightly less able to remember your other childhood birthdays. A variety of behavioral evidence has shown that such "retrieval induced forgetting" of strongly competing memories is…
June 12, 2007
Children have often been claimed to blend reality and fantasy, but according to some this is a wild exaggeration of the truth. For example, renowned child researchers have written that "even the very youngest children already are perfectly able to discriminate between the imaginary and the real"…
June 11, 2007
Symbols redirect attention - in some ways, that is their intended purpose - but this "reorienting" is a surprisingly literal and involuntary effect. Even when we know symbols are irrelevant to our current circumstances, they still influence our behavior.
A simple experiment demonstrates this…
June 8, 2007
Recent highlights from the best in brain blogging:
"Brain training" games that are actually fun! Also check out the Lumosity blog. It seems like they understand the reward structure of good games.
Tonal similarities between music and language.
Genetic differences between speakers of tonal and non…
June 7, 2007
The neural processing of color, shape, and location appears to be widely separated in the brain, and yet our subjective experience of the world is highly coherent: we perceive colored shapes in particular locations. How do these distributed representation about visual features get brought or "…
June 6, 2007
Some people experience an intermingling of the senses, known as synaesthesia, in which certain shapes become combined or "bound with" certain colors, or that certain colors are strongly associated with certain sounds. Of course, in healthy normal adults, color and shape become bound together only…
June 5, 2007
How do you know what's where? Cognitive psychologists believe this requires "binding" - the ability to associate certain colors or shapes with each other and with certain locations in space, giving rise to a coherent perception of the world. It turns out that at least one unlucky person lacks…
June 4, 2007
Suppose that one day your computer's hard drive stops working, but everything else about the machine is fine. Your friend has an identical computer in which the hard drive works fine, but the keyboard suddenly stopped working. Based on this "double dissociation" between the two different problems…
May 31, 2007
Imagination allows us to escape our current time, place, or perspective in favor of an alternative context, whether that may be fanciful or mundane. So imagination is a mechanism for specifying and maintaining a context that differs from our more immediate and stimulus-driven experiences or…