Sarah E. Anderson

THE PHASE TRANSITION IN HUMAN COGNITION

This article attempts to build a bridge between cognitive psychology and computational neuroscience, perhaps allowing each group to understand the others theoretical insights and sympathize with the others methodological challenges. In briefly discussing a collection of conceptual demonstrations, neural network and dynamical system simulations, and human experimental results, we highlight the importance of the concept of phase transition to understand cognitive function. Our goal is to show that viewing cognition as a self-organizing process (involving phase transitions, criticality, and autocatalysis) affords a more natural explanation of these data over traditional approaches inspired by a sequence of linear filters (involving detection, recognition, and then response selection).

The role of grammatical aspect in the dynamics of spatial descriptions

What role does grammatical aspect play in the time course of understanding spatial language, in particular motion events? Although processing differences between past progressive (was walking) and simple past (walked) aspect suggest differences in prominence of certain semantic properties, details about the temporal dynamics of aspect processing have been largely ignored. The current work uses mouse-tracking [1] to explore spatial differences in motor output response to contextual descriptions and aspectual forms. Participants heard descriptions of terrain (difficult or easy) and motion events described with either the past progressive or simple past aspectual form while placing a character into a scene to match this description. Overall, terrain descriptions modulated responses to past progressive more than to simple past in the region of the screen corresponding to the path. These results, which suggest that perceptual simulation plays a role in the interpretation of grammatical form, provide new insights into the understanding of spatial descriptions that include motion.

The enactment of language: Decades of interactions between linguistic and motor processes

Abstract Many long-standing predominant theories of cognition have viewed higher levels of processing, such as language and cognition, as free from the influence of lower levels of processing, such as action and perception. However, many recent experiments have found evidence that the delineation between traditional modules is not so clean or precise, with motor output and language comprehension interacting much more fluidly than traditional theories predict. Evidence for this account includes findings of systematic activation of motor cortex while processing action words, as well as functional consequences of language on action and of action on language. It is worth noting that this recent spate of interest in the embodiment of cognition is not without historical precedence. Here, we will review such evidence coming from previous decades of research on the interaction between language and action, in addition to exploring the empirical results of these more recent experiments and methodologies. It seems to be the case, as evidenced from research in cognitive neuroscience and modeling, that motor representations and actions can influence language processing in predictable ways. Not only is there continuous competition between simultaneously active representations in language processing, with multiple sources of information interacting immediately, this competition is apparent in the motor output produced as a response to language.

Negation without symbols: the importance of recurrence and context in linguistic negation

A simple recurrent network with a perceptual simulation layer was trained on a corpus of affirmative and negated sentences. Linguistic negation can be encoded by the network via the inclusion (or absence) of features and categories associated with the senses, in one step, without the need for an explicit logical operation or for treating the negating word any differently than any other words. Visualizing negation as a trajectory in perceptual simulation space is explored in detail, and the implications for artificial intelligence, embodied computational models, and more practical implications of everyday use of negations are discussed.

On a compatibility between emergentism and reductionism

This article was downloaded by: [University of Memphis]On: 14 August 2008Access details: Access Details: [subscription number 788683960]Publisher Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House,37-41 Mortimer Street, London W1T 3JH, UK

Placental malperfusion as a possible mechanism of preterm birth in patients with Müllerian anomalies.

Abstract Objective: Müllerian anomalies are associated with increased risk of miscarriage, intrauterine growth restriction (IUGR) and preterm birth. While a commonly implicated cause is restricted expansion of endometrial cavity, alternatively it could be due to abnormal placentation. We sought to examine clinical and histopathologic factors associated with preterm delivery in women with Müllerian anomalies. Study design: One hundred and eleven singleton pregnancies in 85 women were analyzed retrospectively. There were 42 pregnancies with bicornaute, 24 with unicornuate, 24 with septate, 19 with didelphys and one each with arcuate and T-shaped uterus. Primary outcomes included gestational age at delivery, placental histopathology, placenta previa and accreta. Results: Twenty-eight (25.2%) of pregnancies were delivered prior to term. Of those, only 14 (50%) were due to preterm labor or preterm premature rupture of membranes (PPROM). Histological evidence of placental malperfusion was present in 22% of all pregnancies and those delivered at an earlier median gestational age [34 (IQR 31–37) vs. 37 weeks (IQR 34–39); P=0.001]. Malperfusion was more common in preterm than in full term births (46% vs. 14%; P=0.04). Conversely, inflammation was not more common in preterm compared to term deliveries (17.9% vs. 16.9%; P=0.89). Five pregnancies had placenta previa, three of which were complicated by accreta. Conclusion: Placental malperfusion, rather than inflammation, was more commonly associated with preterm births in women with uterine anomalies.