Chris Chatham
developingintelligence
Posts by this author
May 30, 2007
While the "modal model of memory" is still widely taught and accepted as a general theory, an enormous amount of recent research has focused on how short-term memory enables higher cognitive processes like those involved in planning, goals, and executive functions. Yet this research has revealed…
May 29, 2007
The capacity to use and manipulate symbols has been heralded as a uniquely human capacity (although we know at least a few cases where that seems untrue). The cognitive processes involved in symbol use have proven difficult to understand, perhaps because reductionist scientific methods seem to…
May 25, 2007
Highlights from recent brain blogging:
First, a new edition of Encephalon.
Physicalism and Panpsychism - a book review by Jerry Fodor. Looks like a pretty nice book...
And here, Fodor explains mental representation to his aunt.
Silicon smackdown - an article in the June Scientific American talks…
May 24, 2007
Many will agree that algebra is difficult to learn - it involves planning, problem-solving, the manipulation of symbols, and the application of abstract rules. Although it's tempting to imagine a specialized region of the brain for each of these processes, they may actually recruit roughly the…
May 18, 2007
Recent highlights from the best in brain blogging:
Who knew? These videos will tell you how the mind works (supposedly).
The origins of the old myth that we use only 10% of our "brain power".
A woman awakens from a coma with a reversed sense of directionality.
Restoring sight in the blind with…
May 17, 2007
Prospective memory is "remembering to remember." Despite the pervasiveness of this requirement in real-life, we know surprisingly little about the topic. In their new book, McDaniel & Einstein provide a direly needed review of this fascinating new field, providing important information for…
May 16, 2007
The analytic depth of cognitive neuroscience is, in many ways, a curse. Those aspects of high-level cognition most relevant to real-world applications are the least understood at a neurobiological level, and those mechanisms that are well-understood neurobiologically are too simple to inform real…
May 15, 2007
It could be argued that any single level of scientific analysis is at once too simple (since there are always important emergent phenomena at higher levels) and also too complex (poorly-understood phenomena inevitably lurk at lower levels). If I wanted to kick the sacred cow of science again, as I…
May 14, 2007
Theories with the fewest assumptions are often preferred to those positing more, a heuristic often called "Occam's razor." This kind of argument has been used on both sides of the creationism vs. evolution debate (is natural selection or divine creation the more parsimonious theory?) and in at…
May 9, 2007
"Where is it, this present? It has melted in our grasp, fled ere we could touch it, gone in the instant of becoming." - William James, 1890
Extremely dangerous, traumatic, or surprising moments are often accompanied by reports that time seemed to "slow down" or "fly by." The perceptual basis of…
May 7, 2007
Hemispatial neglect might be the most striking example of brain trauma's cognitive effects: patients with damage to right parietal regions appear unaware of the left half of space. For example, they'll often shave only the right side of their face, will only eat food from the right half of their…
May 3, 2007
In his famous essay, Thomas Nagel suggested that science's reductionist methods can never provide a complete understanding of the "subjective qualities" of consciousness. To illustrate this problem, he wrote that there was "no reason to suppose that" we would ever be able to comprehend what it's…
May 2, 2007
What neural mechanisms underlie "fluid intelligence," the ability to reason and solve novel problems? This is the question addressed by Gray et al. in Nature Neuroscience. The authors begin by suggesting that fluid intelligence (aka, gF) is related to both attentional control and active…
April 27, 2007
Early neuropsychology research indicated that long-term memory and short-term memory were separable - in other words, long-term memory could be impaired by damage to the hippocampus without any corresponding deficits in short-term memory. However, this idea has come under scrutiny in recent years…
April 26, 2007
People are remarkably bad at switching tasks - and research focusing on this fact has isolated a network of brain regions that are involved in task-switching (I'll call it the "frontal task network" for short). One of the stranger findings to emerge from this literature is the fact that we're…
April 25, 2007
A lack of clear definitions for terms like "intelligence" and "consciousness" plagues any serious discussion of those concepts. A recent article by Seth, Baars & Edelman argues for a core set of 17 properties that are characteristic of consciousness, and could be used in the "diagnosis" of…
April 24, 2007
Ever heard that "you're born with all the brain cells you'll ever have"? It turns out that could be a good thing - if it were true. A new study shows that at least in some circumstances, neurogenesis actually impairs memory performance.
To understand why this might be the case, consider that…
April 20, 2007
Have you ever momentarily forgotten the name of a specific place, or person, despite being able to recall many things about the name (for example the first few letters, or the number of syllables)? Chances are, if you've experienced this "tip-of-the-tongue" phenomenon, you've also had the word…
April 19, 2007
Children are famously bad at considering the future consequences of their actions, but some evidence suggests this criticism is slightly off-the-mark: they may not even comprehend "time" in the same way adults do. A variety of findings from multiple lines of research tentatively support this…
April 18, 2007
What better way to start out than some cool visual illusions known as hybrid images.
It's a short jump from visual illusions to mass delusions.
Is the benefit of exercise a similar mass delusion, a kind of population-level placebo effect?
How do we turn perception into action? It may involve…
April 17, 2007
Your body's bilateral symmetry statistically predicts your health, probability of schizotypy and depression, number of sexual partners, and resting metabolic rate (particularly if you are male). Bodily symmetry may reflect "developmental stability" - i.e., influences like disease, mutation and…
April 16, 2007
Among nature's most impressive feats of engineering is the remarkably flexible and self-optimizing quality of human cognition. People seem to dynamically determine whether speed or accuracy is of utmost importance in a certain task, or whether they should continue with a current approach or begin…
April 11, 2007
Very early in the history of artificial intelligence research, it was apparent that cognitive agents needed to be able to maximize reward by changing their behavior. But this leads to a "credit-assignment" problem: how does the agent know which of its actions led to the reward? An early solution…
April 10, 2007
Right now, you're blind at one particular part of your visual field - because you have no photoreceptors at the location on your retina where the optic nerve begins its journey to visual cortex. Normally, you're unaware of this blind spot because of perceptual "filling-in" - a mechanism by which…
April 9, 2007
Given a fixed amount of computational power in designing an intelligent system, there is a necessary tradeoff between how many resources are devoted solely to the current task, and how many resources are devoted to monitoring for information that may be important but is not necessarily relevant to…
April 5, 2007
"To understand ourselves, we must embrace the alien." - PZ Meyers
One difficulty in understanding consciousness is the fact that we know of only one species that certainly possesses it: humans. A new article by Jennifer Mather suggests that octopi may also possess consciousness, despite the vastly…
April 4, 2007
"Instead of trying to produce a programme to simulate the adult mind, why not rather try to produce one which simulates the child's?" - Alan Turing (Computing Machinery, p456)
One of the defining features of childhood cognition is "behaving without thinking." Not surprisingly, developmental…
April 3, 2007
How does the brain exert flexible control over behavior? One idea is that high-level areas of the brain self-organize representations that lead to reward in a certain task, in a sense by "programming" or "executing" a pattern of activity that controls activity in more posterior and domain-specific…
April 2, 2007
Everyone does something they later regret. Can you ever intentionally forget that you did it? The idea of memory repression has rarely been considered within scientific psychology, but the processes involved in intentional forgetting (also covered last week) are the focus of a recent article by…
March 29, 2007
Recent highlights from the best in brain-blogging:
Is our sense of morality localized to the ventromedial prefrontal cortex?
More reasons for caution when beginning sentences with the phrase; "Only humans are cognitively capable of ......."
Are wild monkeys in a stone-age of their own?
Spatial…