Connectionist Models and Linguistic Theory: Investigations of Stress Systems in Language

We question the widespread assumption that linguistic theory should guide the formulation of mechanistic accounts of human language processing. We develop a pseudo-linguistic theory for the domain of linguistic stress, based on observation of the learning behavior of a perceptron exposed to a variety of stress patterns. There are significant similarities between our analysis of perception stress learning and metrical phonology, the linguistic theory of human stress. Both approaches attempt to identify salient characteristics of the stress systems under examination without reference to the workings of the underlying processor. Our theory and computer simulations exhibit some strikingly suggestive correspondences with metrical theory. We show, however, that our high-level pseudo-linguistic account bears no causal relation to processing in the perception, and provides little insight into the nature of this processing. Because of the persuasive similarities between the nature of our theory and linguistic theorizing, we suggest that linguistic theory may be in much the same position. Contrary to the usual assumption, it may not provide useful guidance in attempts to identify processing mechanisms underlying human language.     

��Screw Health��: Representations of Sex as a Health-Promoting Activity in Medical and Popular Literature

Recently, scientific and popular press articles have begun to represent sex as a health-promoting activity. A number of scientific studies have identified possible health benefits of sexual activity, including increased lifespan and decreased risk of certain types of cancers. These scientific findings have been widely reported on in the popular press. This "sex for health" discourse claims that sexual activity leads to quantifiable physical and mental health benefits in areas not directly related to sexuality. Analyzing this discourse provides an opportunity to better understand both broader health promotion discourses and current norms and anxieties about sexuality. In this article, I place this "sex for health" discourse within the context of broader health promotion discourses and within the context of a number of historical and contemporary discourses connecting health and sexuality. I argue that although the "sex for health" discourse may serve to de-stigmatize sexual activity for some, it may also increase pressure on others to be sexually active and may further pathologize sexual "dysfunction." In addition, these representations often serve to further privilege a normative form of sexual behavior - coitus in the context of a monogamous heterosexual partnership - at the expense of non-normative sexual desires, identities, and practices.     

Caudate nucleus-dependent response strategies in a virtual navigation task are associated with lower basal cortisol and impaired episodic memory

The present research examined the relationship between endogenous glucocorticoids, navigational strategies in a virtual navigation task, and performance on standard neuropsychological assessments of memory. Healthy young adult participants (N = 66, mean age: 21.7) were tested on the 4 on 8 virtual maze (4/8 VM) and standard neuropsychological tests such as the Rey-Osterrieth Complex Figure (RO) and the Rey Auditory Verbal Learning Task (RAVLT), which measure episodic memory. The 4/8 VM differentiates between navigational strategies, where participants either use a hippocampal-dependent spatial strategy by building relationships between landmarks, or a caudate nucleus-dependent stimulus–response strategy by automatizing a pattern of open and closed arms to learn the location of objects within the maze. Degree of stress was assessed by administering the Perceived Stress Scale (PSS) questionnaire. Cortisol samples were taken on two consecutive days upon waking, 30 min after waking, at 11 am, 4 pm, and 9 pm. There was a significant difference in basal levels of cortisol between spatial and response learners. Interestingly, response learners had significantly lower cortisol levels throughout the day. The two groups did not differ in terms of perceived stress as measured with the PSS questionnaire. Moreover, there was no significant correlation between PSS scores and salivary cortisol levels, indicating that the higher cortisol levels in the spatial group were not associated with greater perceived stress. In addition, participants who spontaneously used a spatial strategy performed significantly better on the RAVLT and RO. These data indicate that the cortisol levels in the spatial group may be optimal in terms of episodic memory performance whereas the cortisol levels in the response group may be associated with poorer memory. These results are suggestive of an inverted U-shaped curve describing the effects of basal levels of circulating cortisol on memory in young adults.     

Prior distributions on symmetric groups

Fully and partially ranked data arise in a variety of contexts. From a Bayesian perspective, attention has focused on distance-based models; in particular, the Mallows model and extensions thereof. In this paper, a class of prior distributions, the Binary Tree, is developed on the symmetric group. The attractive features of the class are: it provides a closed-form solution to the posterior distribution; and a simple way to interpret the parameters of the prior distribution. The advantages of the proposed method are illustrated by comparing it to metric-based models using data analyzed by other researchers in this context.This revised article was published online in August 2005 with the PDF paginated correctly.     

Phonological memory and vocabulary learning in children with focal lesions

Eleven children with early focal lesions were compared with 70 age-matched controls to assess their performance in repeating non-words, in learning new words, and in immediate serial recall, a triad of abilities that are believed to share a dependence on serial ordering mechanisms (e.g.,; ). Results for the experimental group were also compared with other assessments previously reported for the same children by. The children with brain injury showed substantial impairment relative to controls in the experimental tasks, in contrast with relatively unimpaired performance on measures of vocabulary and non-verbal intelligence. The relationships between word learning, non-word repetition, and immediate serial recall were similar to those observed in several other populations. These results support previous reports that there are persistent processing impairments following early brain injury, despite developmental plasticity. They also suggest that word learning, non-word repetition, and immediate serial recall may be relatively demanding tasks, and that their relationship is a fundamental aspect of the cognitive system.     

Simultaneous and successive syntheses and linguistic processes1

The present study investigated the relationships between simultaneous and successive modes of cognitive processing and performance on word association, ambiguities and class inclusion tasks in a sample of 60 grade three children. Simultaneous processing was significantly related to class inclusion performance and to comprehension of lexical ambiguities. There was also some evidence of a relationship between paradigmatic responding on the word association task and simultaneous processing. Successive processing was significantly related to surface structure and underlying structure ambiguities and was also involved in class inclusion performance. These results are consistent with hypotheses derived from the neurolinguistic theories of Luria and Jakobson.     

Late effects of malnutrition on cognitive competence1

Does an episode of malnutrition, leading to hospitalization, further depress the intellectual performance of children from the disadvantaged economic and social class? An attempt was made to answer this by first tracing a group of children in Colombo, Sri Lanka, who had been hospitalized for marasmus and kwashiorkor 6 to 7 years ago and comparing them on tests of cognitive functions with a group of children from their neighborhood, matched on age and sex. There were 42 index children and 42 controls in the study. Thirty-three siblings of these index children were also compared with another group of 33 age and sex-matched neighborhood children. The results showed little difference between the groups on nine tests of cognitive functions and a strong relationship between the child's years of attendance at school and the cognitive tests. It was concluded that as far as the cognitive functions measured by the present tests are concerned, an episode of severe malnutrition perhaps does not do any more harm than chronic undernutrition does to disadvataged children.     

SYLLOGISTIC REASONING AMONG SCHOOL CHILDREN FROM CANADA AND SIERRA LEONE

Solution of 3-term syllogisms was examined in the context of culture and IQ. Children from elementary schools in Edmonton and Freetown were divided into high and low on the basis of their scores on Coloured Progressive Matrices. In each culture, those with higher scores on Progressive Matrices were expected to do better on syllogistic reasoning than those with lower scores. Across cultures, no difference in performance was expected. In terms of the relation of syllogistic reasoning to simultaneous and successive processing, both processes were expected to be involved in the solution of syllogisms. The results confirmed these hypotheses. It was also indicated that the children from Freetown were better than Edmonton's in syllogisms, dispelling any doubts in regard to their competence in ‘verbal’ reasoning.     

Simultaneous and successive syntheses and intelligence

Recent studies on information processing have developed an alternative model of mental abilities which constitutes an integration of Russian clinical research and North American factor analytic research. This model proposes that information may be processed in a simultaneous synthesis or a successive synthesis. The present study examines variations in these syntheses in three intelligence groups in order to identify the types of information processing characteristic of different intelligence groups. A stratified sampling of verbal and nonverbal IQ was used to select 60 boys of age 9–10 in each of three verbal IQ ranges: 71–90, 91–110, and 111–130. A battery of tests used in previous research was administered to all subjects. Multivariate analyses of variance and discriminant analyses indicated that the IQ groups differed markedly on tests used to identify simultaneous synthesis, most notably Raven's Progressive Matrices, and differed slightly less on tests of successive synthesis. Factor analyses of the test intercorrelations for each group revealed more factorial invariance across the IQ groups than had been suggested by a previous exploratory study. It was concluded that strong individual differences exist in simultaneous and successive syntheses over the major portion of the standardized intelligence range, and no high degree of specialization of information processing was characteristic of an intelligence group.