Summation priming in aphasia: evidence for alterations in semantic integration and activation

The present study used a lexical decision paradigm to study the summation of priming effects in normal and aphasic participants. The amount of priming produced by pairs of definitionally converging associative words was compared to the amount of priming produced by pairs of single associative words and non-words in two experiments in which the ISI between primes and targets varied from 200 ms (Experiment 1) to 600 ms (Experiment 2). Control subjects showed a pattern of additive summation priming at the short ISI and overadditive summation priming at the longer ISI. Broca's aphasics showed overadditive priming at the short ISI and no significant priming at the longer ISI; Wernicke's aphasics showed no significant priming at the short ISI and additive priming at the longer ISI. These results suggest that aphasics differ from normals in their ability to integrate the activation derived from multiple linguistic associations and may provide an account of some of the clinical phenomenology of these patients.     

Gender-related processes and drug use: self-expression with parents, peer group selection, and achievement motivation

This investigation examined gender differences in communication with parents, peer group selection, and academic motivation as related to drug use among adolescents (290 girls, 237 boys; age range = 12-19 years). For girls, increased self-expression with parents was associated with greater academic motivation, more academically motivated friends, fewer drug-using friends, and less overall drug use. For boys, self-expression was positively related to academic motivation. For both boys and girls, having drug-using friends predicted increased drug use, while having academically motivated friends predicted decreased drug use. For girls only, age and academic motivation predicted drug use as well. These findings indicate that peer group selection and academic motivation may mediate the relationship between drug use and parent-adolescent communication for girls only.     

Acceptance of and engagement in risky driving behaviors by teenagers

Data gathered from 1,430 teenage student drivers and 880 teenage traffic violators were used to examine the levels of exposure to risky driving behaviors and perceptions concerning the level of danger of such behaviors. For student drivers, 55% reported exposure to risky driving by being in a car with a driver engaging in such activities as drunk driving, drag racing, and reckless driving. For the traffic violators, 43% had been engaged in one or more of the risky driving behaviors. Teenagers who had been exposed to risky driving practices were more accepting of risky driving behaviors.     

Parenting Disruptive Preschoolers: Experiences of Mothers and Fathers

This study examined parental functioning and interactions with young children with Oppositional Defiant Disorder (ODD), with emphasis on differences between mothers and fathers in their responses to their child and in their unique contributions to the prediction of child disruptive behavior. Participants were 53 3- to 6-year olds with ODD who presented for treatment with two parents. Mothers reported more severe disruptive behavior and higher parenting stress than fathers. During parent-child interactions, mothers showed more responsiveness than fathers, even though children were more compliant during interactions with fathers. Regression analyses showed that fathers' parent-related stress was predictive of both mothers' and father's reports of disruptive child behavior; mothers' marital satisfaction was predictive of behavioral observations of child compliance with both mothers and fathers. This study revealed several important differences in the experiences of mothers versus fathers of disruptive children and indicates the importance of including the father in the child's assessment and treatment.     

Cognitive, Linguistic, and Social Aspects of Adults' Noun Definitions

Low-income, rural adults and middle-income, urban adults provided oral definitions for eight common nouns. Two general issues were addressed: (1) whether the rural adults' definitions would conform to the well-documented Aristotelian form typically found among middle-class, well-educated adults; and (2) whether different definitional types would emerge for two different noun classes, social vs. object nouns. Participants' definitions were examined for conceptual content and linguistic form. Among rural participants, the mean proportion of definitions conforming to the Aristotelian model was .13, contrasted with .69 for the urban participants. Also, rural adults were significantly less likely to cast definitions in the conventional linguistic form than were urban adults. On other measures of definitional skill as well, rural participants demonstrated less mastery. There were no significant differences in definitional form between social and object nouns. Various explanations for the findings are considered.     

Mapping from Sound to Meaning: Reduced Lexical Activation in Broca''s Aphasics

Recent studies of lexical access in Broca's aphasics suggest that lexical activation levels are reduced in these patients. The present study compared the performance of Broca's aphasics with that of normal subjects in an auditory semantic priming paradigm. Lexical decision times were measured in response to word targets preceded by an intact semantically related prime word ("cat"-"dog"), by a related prime in which one segment was acoustically altered to produce a poorer phonetic exemplar ("c*at"-"dog"), and by a semantically unrelated prime ("ring"-"dog"). The effects of the locus of the acoustic distortion within the prime word (initial or final position) and the presence of potential lexical competitors ("cat" --> /gaet/versus "coat" --> "goat") were examined. In normal subjects, the acoustic manipulations produce a small, short-lived reduction in semantic facilitation irrespective of the position of the distortion in the prime word or the presence of a voiced lexical competitor. In contrast, Broca's aphasics showed a large and lasting reduction in priming in response to word-initial acoustic distortions, but only a weak effect of word-final distortions on priming. In both phonetic positions, the effect of distortion was greater for prime words with a lexical competitor. These findings are compatible with the claim that Broca's aphasics have reduced lexical activation levels, which may result in a disruption of the bottom-up access of words on the basis of acoustic input as well as increased vulnerability to competition between acoustically similar lexical items.     

Amount of Learning and Signal Stability Modulate Emergence of Structure and Iconicity in Novel Signaling Systems

Iterated language learning experiments that explore the emergence of linguistic structure in the laboratory vary considerably in methodological implementation, limiting the generalizability of findings. Most studies also restrict themselves to exploring the emergence of combinatorial and compositional structure in isolation. Here, we use a novel signal space comprising binary auditory and visual sequences and manipulate the amount of learning and temporal stability of these signals. Participants had to learn signals for meanings differing in size, shape, and brightness; their productions in the test phase were transmitted to the next participant. Across transmission chains of 10 generations each, Experiment 1 varied how much learning of auditory signals took place, and Experiment 2 varied temporal stability of visual signals. We found that combinatorial structure emerged only for auditory signals, and iconicity emerged when the amount of learning was reduced, as an opportunity for rote-memorization hampers the exploration of the iconic affordances of the signal space. In addition, compositionality followed an inverted u-shaped trajectory raising across several generations before declining again toward the end of the transmission chains. This suggests that detection of systematic form-meaning linkages requires stable combinatorial units that can guide learners toward the structural properties of signals, but these combinatorial units had not yet emerged in these unfamiliar systems. Our findings underscore the importance of systematically manipulating training conditions and signal characteristics in iterated language learning experiments to study the interactions between the emergence of iconicity, combinatorial and compositional structure in novel signaling systems.     

Context and Perceptual Salience Influence the Formation of Novel Stereotypes via Cumulative Cultural Evolution

We use a transmission chain method to establish how context and category salience influence the formation of novel stereotypes through cumulative cultural evolution. We created novel alien targets by combining features from three category dimensions—color, movement, and shape—thereby creating social targets that were individually unique but that also shared category membership with other aliens (e.g., two aliens might be the same color and shape but move differently). At the start of the transmission chains each alien was randomly assigned attributes that described it (e.g., arrogant, caring, confident). Participants were given training on the alien‐attribute assignments and were then tested on their memory for these. The alien‐attribute assignments participants produced during test were used as the training materials for the next participant in the transmission chain. As information was repeatedly transmitted an increasingly simplified, learnable stereotype‐like structure emerged for targets who shared the same color, such that by the end of the chains targets who shared the same color were more likely to share the same attributes (a reanalysis of data from Martin et al., 2014 which we term Experiment 1). The apparent bias toward the formation of novel stereotypes around the color category dimension was also found for objects (Experiment 2). However, when the category dimension of color was made less salient, it no longer dominated the formation of novel stereotypes (Experiment 3). The current findings suggest that context and category salience influence category dimension salience, which in turn influences the cumulative cultural evolution of information.     

Associations Between Fathers’ and Mothers’ Psychopathology Symptoms,Parental Emotion Socialization,and Preschoolers’ Social-Emotional Development

In this study we tested whether the relation between fathers’ and mothers’ psychopathology symptoms and child social-emotional development was mediated by parents’ use of emotion talk about negative emotions in a sample of 241 two-parent families. Parents’ internalizing and externalizing problems were measured with the Adult Self Report and parental emotion talk was observed while they discussed a picture book with their children (child age: 3 years). Children’s parent-reported internalizing and externalizing problems and observed prosocial behaviors were assessed at the age of 3 years and again 12 months later. We found that mothers’ use of emotion talk partially mediated the positive association between fathers’ internalizing problems and child internalizing problems. Fathers’ internalizing problems predicted more elaborative mother–child discussions about negative emotions, which in turn predicted more internalizing problems in children a year later. Mothers’ externalizing problems directly predicted more internalizing and externalizing problems in children. These findings emphasize the importance of examining the consequences of parental psychological difficulties for child development from a family-wide perspective.     

Making Choices: Ethical Decisions in a Global Context

The changing milieu of research—increasingly global, interdisciplinary and collaborative—prompts greater emphasis on cultural context and upon partnership with international scholars and diverse community groups. Ethics training, however, tends to ignore the cross-cultural challenges of making ethical choices. This paper confronts those challenges by presenting a new curricular model developed by an international team. It examines ethics across a very broad range of situations, using case studies and employing the perspectives of social science, humanities and the sciences. The course has been developed and taught in a highly collaborative way, involving researchers and students at Zhejiang University, the Indian Institute of Technology, Bombay and Brown University. The article presents the curricular modules of the course, learning outcomes, an assessment framework developed for the project, and a discussion of evaluation findings.