Probing Lexical Ambiguity: Word Vectors Encode Number and Relatedness of Senses

Lexical ambiguity—the phenomenon of a single word having multiple, distinguishable senses—is pervasive in language. Both the degree of ambiguity of a word (roughly, its number of senses) and the relatedness of those senses have been found to have widespread effects on language acquisition and processing. Recently, distributional approaches to semantics, in which a word's meaning is determined by its contexts, have led to successful research quantifying the degree of ambiguity, but these measures have not distinguished between the ambiguity of words with multiple related senses versus multiple unrelated meanings. In this work, we present the first assessment of whether distributional meaning representations can capture the ambiguity structure of a word, including both the number and relatedness of senses. On a very large sample of English words, we find that some, but not all, distributional semantic representations that we test exhibit detectable differences between sets of monosemes (unambiguous words; N = 964), polysemes (with multiple related senses; N = 4,096), and homonyms (with multiple unrelated senses; N = 355). Our findings begin to answer open questions from earlier work regarding whether distributional semantic representations of words, which successfully capture various semantic relationships, also reflect fine-grained aspects of meaning structure that influence human behavior. Our findings emphasize the importance of measuring whether proposed lexical representations capture such distinctions: In addition to standard benchmarks that test the similarity structure of distributional semantic models, we need to also consider whether they have cognitively plausible ambiguity structure.     

The 10th Oxbridge varsity medical ethics debate-should we fear the rise of direct-to-consumer genetic testing?

In an increasingly data-driven age of medicine, do companies that offer genetic testing directly to patients represent an important part of personalising care, or a dangerous threat to privacy? Should we celebrate this new mechanism of patient involvement, or fear its implications?The Universities of Oxford and Cambridge addressed these issues in the 10th annual Medical Ethics Varsity Debate, through the motion: “This House Regrets the Rise of Direct-to-Consumer Genetic Testing”. This article summarises and extends key arguments made in the debate, exploring the impacts of such genetic testing on both the individual patient and broader society, with special consideration as to whether companies can ever truly guarantee anonymity of genetic data.     

Requencies and relations of body piercing and sexual experience in college students

This research examined the relation between having a body piercing and having engaged in premarital sexual intercourse. Data were gathered from a convenience sample of 450 college students. 72% were women; 85% were ages 18 to 22 years (M=20.9, SD=4.5), 80% were Euro-American. Women with piercings reported substantively and significantly greater frequency of sexual activity than college students without piercings. There were no significant differences in sexual experience between men with piercings and those without. These findings differ from previous research comparing the sexual activity of college students with and without tattoos.     

Chronic stress and sex differences on the recall of fear conditioning and extinction

Chronic stress effects and sex differences were examined on conditioned fear extinction. Male and female Sprague–Dawley rats were chronically stressed by restraint (6 h/d/21 d), conditioned to tone and footshock, followed by extinction after 1 h and 24 h delays. Chronic stress impaired the recall of fear extinction in males, as evidenced by high freezing to tone after the 24 h delay despite exposure to the previous 1 h delay extinction trials, and this effect was not due to ceiling effects from overtraining during conditioning. In contrast, chronic stress attenuated the recall of fear conditioning acquisition in females, regardless of exposure to the 1 h extinction exposure. Since freezing to tone was reinstated following unsignalled footshocks, the deficit in the stressed rats reflected impaired recall rather than impaired consolidation. Sex differences in fear conditioning and extinction were observed in nonstressed controls as well, with control females resisting extinction to tone. Analysis of contextual freezing showed that all groups (control, stress, male, female) increased freezing immediately after the first tone extinction trial, demonstrating contextual discrimination. These findings show that chronic stress and sex interact to influence fear conditioning, with chronic stress impairing the recall of delayed fear extinction in males to implicate the medial prefrontal cortex, disrupting the recall of the fear conditioning acquisition in females to implicate the amygdala, and nonstressed controls exhibiting sex differences in fear conditioning and extinction, which may involve the amygdala and/or corticosterone levels.     

Infants' representations of three-dimensional occluded objects

Infants' ability to represent objects has received significant attention from the developmental research community. With the advent of eye-tracking technology, detailed analysis of infants' looking patterns during object occlusion have revealed much about the nature of infants' representations. The current study continues this research by analyzing infants' looking patterns in a novel manner and by comparing infants' looking at a simple display in which a single three-dimensional (3D) object moves along a continuous trajectory to a more complex display in which two 3D objects undergo trajectories that are interrupted behind an occluder. Six-month-old infants saw an occlusion sequence in which a ball moved along a linear path, disappeared behind a rectangular screen, and then a ball (ball-ball event) or a box (ball-box event) emerged at the other edge. An eye-tracking system recorded infants' eye-movements during the event sequence. Results from examination of infants' attention to the occluder indicate that during the occlusion interval infants looked longer to the side of the occluder behind which the moving occluded object was located, shifting gaze from one side of the occluder to the other as the object(s) moved behind the screen. Furthermore, when events included two objects, infants attended to the spatiotemporal coordinates of the objects longer than when a single object was involved. These results provide clear evidence that infants' visual tracking is different in response to a one-object display than to a two-object display. Furthermore, this finding suggests that infants may require more focused attention to the hidden position of objects in more complex multiple-object displays and provides additional evidence that infants represent the spatial location of moving occluded objects.     

Theoretical and methodological issues with testing the SCCT and RIASEC models: Comment on Lent, Sheu, and Brown (2010) and Lubinski (2010)

The current article replies to comments made by Lent, Sheu, and Brown (2010) and Lubinski (2010) regarding the study "Interpreting the Interest-Efficacy Association From a RIASEC Perspective" (Armstrong & Vogel, 2009). The comments made by Lent et al. and Lubinski highlight a number of important theoretical and methodological issues, including the process of defining and differentiating between constructs, the assumptions underlying Holland's (1959, 1997) RIASEC (Realistic, Investigative, Artistic, Social, Enterprising, and Conventional types) model and interrelations among constructs specified in social cognitive career theory (SCCT), the importance of incremental validity for evaluating constructs, and methodological considerations when quantifying interest-efficacy correlations and for comparing models using multivariate statistical methods. On the basis of these comments and previous research on the SCCT and Holland models, we highlight the importance of considering multiple theoretical perspectives in vocational research and practice. Alternative structural models are outlined for examining the role of interests, self-efficacy, learning experiences, outcome expectations, personality, and cognitive abilities in the career choice and development process.     

Coordination,Triangulation, and Language Use

In this paper, I explore two contrasting conceptions of the social character of language. The first takes language to be grounded in social convention. The second, famously developed by Donald Davidson, takes language to be grounded in a social relation called triangulation. I aim both to clarify and to evaluate these two conceptions of language. First, I propose that Davidson’s triangulation-based story can be understood as the result of relaxing core features of conventionalism pertaining to both common-interest and diachronic stability—specifically, Davidson does not require uses of language to be self-perpetuating, in the way required by conventionalism, in order to be bona fide components of linguistic systems. Second, I argue that Davidson’s objections to conventionalism from language innovation and language variation fail, and that certain kinds of negative data in language use require an appeal to diachronic social relations. However, I also argue that recent work on communication in the absence of common interests and common knowledge highlights the need for broader non-conventional social relations like triangulation. In short, I suggest that the choice between coordination and triangulation is not either/or: that we need to appeal to both if we are adequately to explain the nature of language and its use.