developingintelligence | November 19, 2007Geoff Hinton has a new TiCS paper describing recent advances in algorithms used to train multilayered neural networks.
First, a little background: neural networks of a sufficient size can calculate any mathematical function (an infamous proof among neural network modelers). Unfortunately, the tricky part is figuring out how to set the connections in that network to calculate those functions.
This is where learning algorithms become necessary - unless you want to tweak each connection by hand until you get a working network (not a problem if you don't care how the brain works), then you…
developingintelligence | November 16, 2007Neuroesthetics seeks to identify the neural basis of aesthetic experience - how does the brain give rise to the perception of beauty? A new paper in Network indicates that artists consistently create works which contain the same statistical properties as natural scenes, even when the objects being depicted do not themselves contain such statistics when photographed.
Redies, Hanisch, Blickhan and Denzler review previous work demonstrating that the "spatial frequencies" of natural scenes (essentially, their spatial complexity) follow a 1/f power spectrum, where increased spatial complexity is…
developingintelligence | November 7, 2007Speech recognition remains a daunting challenge for computer programmers partly because the continuous speech stream is highly under-determined. For example take coarticulation, which refers to the fact that the auditory frequencies corresponding to a given letter are strongly influenced by the letters both preceding and following it - sometimes interpreted to mean that there is no invariant set of purely auditory characteristics defining any given letter. Thus it's difficult to recover the words that a person is saying, since each part of that word is influenced by the words surrounding it…
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 2, 2007Trueswell & Kim's paper in the Journal of Memory and Language describes a phenomenon known as "fast priming," in which a reading task is momentarily interrupted by a brief presentation of a "prime" word, usually lasting around 30 to 40 ms. The reading task then continues, and although subjects are typically unaware of the presentation of this word (usually describing it merely as a "flicker") the processing of subsequent words are influenced by many characteristics of the prime word, including its meaning as well as its sonic and orthographic characteristics.
Al Fin has an excellent…
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:…