Chris Chatham
developingintelligence
Posts by this author
December 10, 2008
In an update to their groundbreaking earlier demonstration that high-IQ children initially show a thinner cortex, and later show an initially thicker one than their average-IQ peers, Shaw et al. have now documented those trajectories of cortical thickening which are invariant to socio-economic…
November 26, 2008
Play cognitive engineer: if you were designing an intelligent system, you'd probably use the same system to detect novelty as that used to detect familiarity. After all, one is simply the inverse of the other - so novelty can be thought of as a below-threshold value for some familiarity signal.…
November 25, 2008
To efficiently direct learning, it may be useful for the brain to attend to those items which are maximally novel - this novelty may obscure some predictive or rewarding value that has not yet been learned or exploited. This is widely acknowledged, usually in passing; but ambiguities in what…
October 3, 2008
What if training ourselves on one task yielded improvements in all other tasks we perform? This is the promise of the cognitive training movement, which is increasingly showing that such "far transfer" of training is indeed possible, while short of being "universal transfer." Interestingly, this…
September 30, 2008
If you said 1/1000, you've given the answer provided more often by second graders than by undergraduates. And you're also right.
Evidence from functional neuroimaging and developmental psychology indicate that the human brain possesses an abstract system for magnitude comparison, perhaps relying…
September 26, 2008
My friend Geoff once said that "all cognition is social." Smugly, I reminded myself that the conclusions of cognitive psychologists are drawn on evidence where social cues are kept constant. But even in the absence of confounding social cues, perhaps the underlying cognitive processes themselves…
September 15, 2008
Much has been written about the nonspatial functions of the parietal lobe, but these nonspatial functions are rarely evaluated as to whether they are also nonmotoric or reflect some covert form of spatial attention. Establishing whether the parietal lobe has truly nonmotoric and nonspatial…
September 12, 2008
Much evidence supports the idea that parietal cortex is involved in the simple maintenance of information, such as in object permanence paradigms (also here) and other tasks. This evidence is part of the justification for the "parietofrontal integration theory", which suggests that parietal areas…
September 3, 2008
Visual perception is constantly challenged by visual occlusion: objects in our environment constantly obscure one another, and seem to "disappear" when in fact they are nonetheless present.
Young infants begin to demonstrate a basic understanding of "object permanence" at some point during the…
September 2, 2008
An absence of evidence is not itself evidence for the absence of a particular effect. This simple problem - generally known as the problem of null effects - yields many difficulties in cognitive science, making it relatively easier to parcellate cognitive and neural processes into ever-finer…
August 29, 2008
Is it possible to form and execute motor intentions without being aware of when those intentions were formed? Precisely this pattern was observed by among (ha!) patients with parietal damage, as reported by Sirigu et al. They showed that patients with parietal damage are specifically impaired at…
August 28, 2008
Ideally, our real-world behavior is strongly determined by our context, for the simple reason that some behaviors are only appropriate in some situations (e.g., eating during an internal context of hunger, or using slang during an external context of casual interaction).
Context-inappropriate…
August 27, 2008
Parietal cortex is critical for the maintenance of object information over delays. This is true both in tests of working memory (e.g., 1, 2 and 3) as well as simple visual manipulations involving the occlusion of visible objects.
A great example is this study by Olson et al., who demonstrated…
August 26, 2008
Andersen et al discuss both the attentional and intentional aspects to the function of the intraparietal sulcus. What's the distinction between attention and intention?
First, let's talk about attention. The modal view, based on the biased competition model of Desimone and Duncan, and the Miller…
August 25, 2008
People often use the concept "hand-eye coordination" without appreciating its neural basis. Evidence collected by Andersen & colleagues over the past ten years indicates that different areas of parietal cortex are recruited to represent targets which require different effectors, all using a…
August 25, 2008
In their already-classic 2001 article, Miller & Cohen use a "train track" metaphor to illustrate the function of prefrontal cortex. The idea is that myriad learned associations interconnect sensory representations with motor commands (metaphorically, these are the "train tracks"). The…
July 15, 2008
To enhance any system, one first needs to identify its capacity-limiting factor(s). Human cognition is a highly complex and multiply constrained system, consisting of both independent and interdependent capacity-limitations. These "bottlenecks" in cognition are reviewed below as a coherent…
July 14, 2008
Most readers of this blog are probably familiar with "unilateral neglect," one of several behavioral manifestations of brain damage to the parietal lobe. Perhaps fewer readers are aware of other findings from unilateral neglect patients which are often omitted from classic descriptions of this…
July 8, 2008
How would an ideal behavioral method for cognitive enhancement actually affect the brain? Perhaps cognitive enhancement would be accompanied by more activity in the prefrontal cortex, indicating more successful engagement of control - or perhaps by less, indicating more efficient processing?…
July 7, 2008
Training high-level cognition or "executive function" is not always successful. Interestingly, some of the least robust training effects come from one of psychology's most robust paradigms - the Stroop task.
The Stroop task is simple to describe, but difficult to complete. In its simplest form,…
July 2, 2008
Klaus Oberauer has a fascinating paper from 2006 which seems to have been ignored by the cognitive training community. Oberaurer demonstrates how improper counterbalancing, ignorance of the power-law of practice, and confounds in the design of memory load tasks can substantially misconstrue the…
July 2, 2008
Self-selection refers to the fact that certain kinds of people may be drawn to certain kinds of lifestyles or practices (including participation in human research). When the effects of those lifestyles/practices are observed scientifically, they are confounded with myriad other factors which also…
July 1, 2008
How does meditation experience functionally change the brain, and what effects does this have on distractibility? These are the questions addressed in a 2006 PNAS article from Brefczynski-Lewis et al, who compare expert meditators (between 10,000 and 54,000 hours of meditation experience) with two…
June 30, 2008
Attention training through meditation can reduce the duration of the "attentional blink" - in which detection of a first rare target causes people to be unaware of a second target presented soon after the first - according to research by Slagter et al from PLoSBiology.
The attention blink effect…
June 27, 2008
As discussed earlier this week, meditation may be an alternative form of brain training - or "brain untraining" - that shows transfer to tasks requiring cognitive control. There have been a few updates to this fascinating line of research, not least of which is a fascinating paper by Amishi Jha…
June 25, 2008
In a fascinating review of the cognitive neuroscience of attention, authors Raz and Buhle note that most research on attention focuses on defining situations in which it is no longer required to perform a task - in other words, the automatization of thought and behavior. Yet relatively few studies…
June 17, 2008
Kevin at IQ's Corner has blogged about a new paper in PNAS showing that "working memory" training can improve measures of fluid intelligence - a capacity long thought to be relatively insensitive to experience, and intricately tied to the most complex human cognitions like reasoning, planning, and…
June 16, 2008
In a recent issue of Science, Dahlin et al report the results of an executive function training paradigm focused on the process of mental updating. "Updating" is thought to be one of the core executive functions (as determined through confirmatory factor analysis), is thought to rely on the…
June 13, 2008
Children can be notoriously constrained to the present, but a fascinating article in JEP:HPP by Vallesi & Shallice shows exactly how strong that constraint can be: in a study with 4-11 year-olds, they show that only children older than about 5 years will take advantage of additional time…
June 12, 2008
Could something be perceived if there is no sensory system which is dedicated to it? For everyone except parapsychologists, the obvious answer is no - but this raises questions about the ability to perceive short temporal intervals, for which there appears to be no dedicated sensory system.
In…