Chris Chatham
developingintelligence
Posts by this author
I've been busy writing up a new paper, and expect the reviews back on another soon, so ... sorry for the lack of posts. But this should be of interest:
The Dana Foundation has just posted an interview with Terrence Sejnowki about his recent Science paper, "Foundations for a New Science of Learning…
Children assigned to chew sugar-free gum purportedly score 3% higher on standardized tests of math skills (as widely reported in the press). But is this just one of the 5% of all possible untrue hypotheses statistically guaranteed to have some significant result in its favor (in fact, it's worse…
The UCLA Neuroimaging Summer Education Program starts today at 8:30 am Pacific. Standard Time - and is going to be streaming live at this address (video embedded below). The schedule is quite impressive, including talks from Rick Buxton, Mark Cohen, Russ Poldrack, Vince Calhoun, and Jose Hanson…
How many times did Pavlov ring the bell before his dogs' meals until the dogs began to salivate? Surely, the number of experiences must make a difference, as anyone who's trained a dog would attest. As described in a brilliant article by C.R. Gallistel (in Psych. Review; preprint here), this has…
Don't think of a white bear. Doesn't work so well, does it? Yet under some circumstances, people appear to be able to do precisely this: as described last week, young adults are thought (by some) to actually suppress the neural activity related to to-be-ignored stimuli, and even delay the peak of…
An interesting video interview with the author of (the excellent) Mind Wars.
Here are direct links to the videos.
The cognitive neurosciences have had high frequency oscillations on the brain: so called "gamma-waves", as recorded on the scalp, have been linked to working memory processes (via their interaction with slower "theta waves"), to cognitive insight, and even to consciousness. (I think there's an…
By many current theories, we accomplish control over behavior by using the prefrontal cortex to "bias" the competitive dynamics playing out in the rest of the brain. By some models, this bias is positive - it helps the goal-relevant representations win the competition. By other models, the bias…
A new study suggests that physically stepping backwards may be associated with gains in the ability to deal with problematic situations. As newly reported in Psychological Science (hat tip to Hannah) by Koch, Holland, Hengstler & Knippenberg, people were better able to resolve interference in…
Every now and then, I read some science from some other dimension. That is, the methods are so unusual, the relevant theories so fringe, or the conclusions so startling that I feel like the authors must be building on work from a completely separate science, with its own theories and orthodoxy.…
There are three on-off light switches on the wall of the first floor of a building. One of the switches is initially off and controls an incandescent bulb in a lamp on the third floor of the building. The other two switches do not control the bulb or anything else (they are disconnected). How can…
Most computational models of working memory do not explicitly specify the role of the parietal cortex, despite an increasing number of observations that the parietal cortex is particularly important for working memory. A new paper in PNAS by Edin et al remedies this state of affairs by developing…
A number of previous behavioral and neuroimaging experiments, as well as computational models, support the idea that people can filter the contents of memory and perception so as to focus on only the information that's currently relevant. For example, in a visually-complex environment, distracting…
One theoretical model of the prefrontal cortex posits that we can achieve goal-directed behavior via "biased competition" - that is, representations of our current goals and context are maintained in the prefrontal cortex and exert an influence on downstream areas, ultimately biasing our behavior…
A principal insight from computational neuroscience for studies of higher-level cognition is rooted in the recurrent network architecture. Recurrent networks, very simply, are those composed of neurons that connect to themselves, enabling them to learn to maintain information over time that may be…
Guest Post by Seth Herd.
I disagree with many of Gary Marcus's theories, but I think that his book Kluge is important, entertaining, and even accurate. The book's main thesis is that if God had designed the human mind, He would've done a better job. I'm not all that interested in arguments…
When reading the title of this post, your knowledge of the world was sufficient to let you interpret the phrase "when pigs fly," but also alerted you to the fact that it is inconsistent with much of that world knowledge: clearly, pigs don't fly. A new study by Menenti, Petersson, Scheeringa…
A lot has been written about domain-general processing in prefrontal cortex, and a very old lesson often gets overlooked: there are very basic hemispheric asymmetries (particularly in PFC) that divide information processing by modality. A very nice study by Morimoto et al provide a nice reminder…
It's been said that psychology is a primitive discipline - stuck in the equivalent of pre-Newtonian physics. Supposedly we haven't discovered the basic principles underlying cognition, and are instead engaged in a kind of stamp collecting: arguing about probabilities that various pseudo-…
Reductionism in the neurosciences has been incredibly productive, but it has been difficult to reconstruct how high-level behaviors emerge from the myriad biological mechanisms discovered with such reductionistic methods. This is most clearly true in the case of the motor system, which has long…
Refining the Turing Test: If it looks like a human, plays like a human, fights like a human, it's probably a ....
Using your own child in developmental research: An ethical issue?
Mice, math and drugs: On science without understanding. How much will new data mining techniques subvert the…
An astonishing recent discovery in computational neuroscience is the relationship between dopamine and the "temporal differences" reinforcement learning algorithm (which Jake describes wonderfully here, and I've described in a little more detail here). The essential principle is that the…
Synaesthesia refers to the phenomenon where certain perceptual stimuli induce an unrelated and illusory perception - for example, a digit-color synaesthete may experience a sensation of the color green whenever exposed to the number 3. The relationships between the inducers and the induced…
"Priming" refers to a pervasive phenomenon in which the repetition of a particular stimulus, response, or thought process facilitates its subsequent use. Might this phenomenon extend to more "executive" capacities as well?
In a recent article from theJournal of Experimental Psychology: Human…
There's little evidence that "staging" the training of neural networks on language-like input - feeding them part of the problem space initially, and scaling that up as they learn - confers any consistent benefit in terms of their long term learning (as reviewed yesterday).
To summarize that post…
An early classic in computational neuroscience was a 1993 paper by Elman called "The Importance of Starting Small." The paper describes how initial limitations in a network's memory capacity could actually be beneficial to its learning of complex sentences, relative to networks that were "adult-…
The ability to suppress unwanted thoughts and actions is thought (by some) to be crucial in your ability to control behavior. However, alternative perspectives suggest that this emphasis on suppression or "inhibition" is misplaced. These perspectives, largely motivated by computational models of…
For the basics about multivariate fMRI "mind-reading" techniques, see the video below. Some of it is based on this 2007 Haynes et al paper from Current Biology, described in more detail following the video.
What Haynes et al have done is to ask 8 subjects to freely decide either to add or subtract…
New work by Minear & Shah shows that as little as 2 hours of practice can promote improvements in multitasking that generalize beyond the particular tasks trained. Specifically, they show that performance on individual tasks can be made more efficient while multitasking, but the efficiency of…
When you need to stop yourself from committing some response, do you simply freeze - like a deer in the headlights - or can you selectively inhibit only the undesired action? The question is important because the ability to stop or inhibit a planned or prepotent action may be a central feature of…