Developmental Psychology
developingintelligence | February 4, 2008When do we learn to imagine the future, and how is that capacity based on imagining the past? How does this kind of "mental time travel" develop? Lagatutta's recent article in Child Development tracks the development of this impressive feat, thought by some to be uniquely human.
At 3 years of age, a variety of mental processes seem to undergo rapid development, including task-switching, theory of mind, linguistic generalization, and an understanding of time. Previous work by Lagatutta and colleagues showed that up to 39% of 3 year olds could attribute sadness in a story's character to that…
developingintelligence | January 10, 2008A new educational system called "Tools of the Mind" teaches not facts and figures, but rather focuses on cognitive skills in structured play. In the largest and most compelling study yet, exposure to this curriculum in the classroom drastically improves performance on a variety of psychometric and neuropsychological tests.
Vygotskian theory posits that children need to "learn to learn" - by mastering a set of mental tools which bootstrap their mental abilities, the same way that physical tools can extend physical abilities. The consequent "mental exercise" may strengthen the mind just like…
developingintelligence | January 3, 2008Over New Year's I had a brief discussion with a condensed-matter physicist who proclaimed that 1) "some developmental research is amazingly bad" and that 2) "they think they can tell what a baby has learned from what direction it looks," topping it all off with 3) "you guys don't even know what learning is!"
I won't argue with the first point (there are bad researchers in every field, even condensed matter physics), and I'm too lazy to bother with the third (although the 2000 Nobel prize committee might disagree), but the second point - on the technique of preferential looking - I just can't…
developingintelligence | January 2, 2008Play is more often simply observed than studied scientifically - play behaviors occur unpredictably and, when they do occur, are highly chaotic, making it very difficult to study them in the laboratory. Despite these challenges, new work is beginning to make play accessible from a rigorous scientific framework.
For example, a recent article by Schulz & Bonawitz takes Piaget's notion of play as a mechanism for understanding causal relationships and recasts it into a testable prediction: children should be more likely to play with an object about which they have incomplete or confounded…
developingintelligence | November 9, 2007Asperger's disorder is a subtype of autism, characterized by deficits in social interaction, delays in nonverbal communication and possibly also deficits in nonverbal IQ (such as on a test known as Block Design). However, a new study in Brain and Cognition challenges this latter claim - with surprising results.
Hayashi et al gave 17 children with Asperger's a test of fluid intelligence called the Raven's Progressive Matrices. Fluid intelligence is thought to reflect problem-solving ability, to show large individual differences, and to be a distinct construct from general intelligence ("g…
developingintelligence | November 5, 2007Aging is associated with some slow but measurable forms of cognitive decline, but there is debate over the type of cognitive changes taking place. A recent study by Rush, Barch & Braver uses a series of interesting tasks to clarify the nature of this cognitive decline. The results seem to show that changes in "context processing" - the ability to internally represent environmental cues to control thought and action - but not inhibition or processing speed underlie aging-related decrements in cognitive function. The work has implications for our understanding of and interventions for…
developingintelligence | November 1, 2007When one object passes in front of another we know that the occluded object has not vanished, and yet representations in our visual cortex have been assumed not to reflect this information. Instead, such "object permanence" information has been thought to require active maintenance, perhaps with help from prefrontal regions, thus explaining why young children (with underdeveloped prefrontal cortices) often fail to show behavior that is consistent with knowledge of object permanence.
A recent study by Hulme & Zeki elaborates this view by presenting 13 subjects in an fMRI scanner with…
developingintelligence | October 31, 2007Several high-profile studies have shown that bilingual children outperform their monolingual peers in terms of several cognitive abilities - including tests of verbal and nonverbal problem-solving, selective attention, flexibility (e.g., task-switching) and others. These studies have captured the public imagination and probably guided many moms to expose their kids to a second language.
But a new article in Developmental Science suggests that these impressive results may be somewhat overblown: bilingual children may be likely to come from wealthier families than monolingual children (EDIT:…
developingintelligence | October 2, 2007Children are often thought to be imaginative and fanciful, not only in their perception of the world but also in the veridicality of their memories. It may therefore be surprising that a robust method for eliciting false memories in adults is actually ineffective in children. In fact, children even tend to show better performance than adults in terms of false recall in the DRM paradigm, a task in which a list of words must be remembered where every word in each list is strongly associated with a word that is not presented in each list. Adults tend to show a robust tendency to incorrectly…
developingintelligence | September 26, 2007Infantile "amnesia" refers to the apparent absence or weakness of memories formed at ages younger than 3 or 4. Some evidence indicates that these early-life memories are not actually lost or forgotten, but are rather merely mislabeled or otherwise inaccessible to adult cognition. One potential reason for this inaccessibility is that adults tend to use language in encoding and retrieving memories, and this strategy may not be sufficient for retrieving memories formed in early-life, which may have been encoded before language is firmly entrenched in the developing brain. A recent study in…
developingintelligence | September 24, 2007What processes allow us to execute delayed intentions? This ability, known as prospective memory, is often considered to have two constituent parts: a prospective component which involves forming the intention and possibly maintaining it until action execution, and a retrospective component which involves retrieving this intention, if that intention is not successfully and continuously maintained until the moment of action execution.
These components can be easily illustrated. Imagine yourself in a situation where prospective memory is required: while at work, you realize that you need to…
developingintelligence | September 14, 2007The 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" area in the left fusiform gyrus of the temporal lobe. By all appearances, this region is highly specialized for word processing. But this evidence causes a predicament for more than just domain-generalists; those who advocate an evolved language module may also be challenged by these results,…
developingintelligence | August 27, 2007In 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-irrelevant rule. This occurs even when the current rule is repeated every single time they're asked to sort a card! Children will even correctly repeat the name of the rule they should be using, and then proceed to actually sort the card by the old rule.
By age 4, however, most kids are able to…
developingintelligence | June 28, 2007In 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 and humans are rare - perhaps because we feel safe in assuming that the human intellect is superior to that of other primates. But recent work suggests this assumption may not be entirely sound, as described below.
For example, a recent New Scientist article (via NeuroEthics) contains a provocative…
developingintelligence | June 12, 2007Children 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" and certainly a lot of recent research tentatively supports that idea.
Still, it seems intuitively surprising that children should be so good at knowing the real from the imagined. Nearly everyone - even grown adults - has had the experience of saying (or thinking) something, and afterwards…
developingintelligence | May 29, 2007The 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 decompose this rich domain into a variety of smaller components, none of which seems to capture the most important or abstract characteristics of symbol use (as discussed previously).
So, it's important to specify how the simpler and better-understood aspects of symbol processing may interact and give…
developingintelligence | May 15, 2007It 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 did yesterday, I'd suggest that parsimony can be a misleading principle here too: whatever data is used to evaluate a theory may not include phenomena occurring at other levels of analysis that may be relevant to the theory. So inevitably, the simplest theory (i.e., the one with the fewest…
developingintelligence | May 14, 2007Theories 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 least one reductio ad absurdum argument against religion. Simple theories have many advantages: they are often falsifiable or motivate various predictions, and can be easily communicated as well as widely understood.
But there are numerous reasons to suspect that this simple "theory of theories" is…
developingintelligence | May 7, 2007Hemispatial 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 plate, and when asked to copy a variety of drawings will include only their right half.
As you can tell from these examples, right parietal cortex is particularly important for our understanding of space. Although left parietal cortex may be involved in similar computations, the right-sided region…
developingintelligence | April 19, 2007Children 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 surprising claim about the limitations of children's cognition.
Based on the delay of gratification literature, we know that children will reliably choose "less now" rather than "more later" - even at relatively short delays. Children may not be able to adequately represent the value of a future reward…