Subjective contours in stereoscopic space

Stereoscopic depth and subjective contour clarity were manipulated by varying the type of monocular configuration as well as magnitude and direction of disparity. The clarity of the subjective contours was influenced significantly by both magnitude and direction of disparity and by the type of monocular configuration. Subjective contours were always less clear when the objective monocular contour was discontinuous regardless of disparity. Stereoscopic depth estimates varied directly with magnitude and direction of disparity; however, depth magnitude reports were truncated when the disparity was carried by discontinuously defined patterns.     

Partial Knowledge of Word Meanings: Thematic and Taxonomic Representations

The type of information (taxonomic or thematic) available at different levels of knowledge was investigated. Following extensive norming to identify taxonomic and thematic associates of low-frequency nouns, participants determined if taxonomic or thematic associates were meaningfully related to target words at three levels of knowledge: target words they correctly defined (known), recognized as familiar (frontier), or mistakenly denied as part of the language (unknown). In another experiment, participants reported which type of relationship (taxonomic or thematic) was preferred. Results indicated that both types of information were available at all levels of knowledge. However, accuracy and preference were greater for taxonomic associates across word levels. A differential increase in available thematic information relative to taxonomic information was found. Implications for the acquisition and representation of word meanings are discussed.     

Infants’ responses to objects representing levels of word knowledge and categorical information

The effects of differing levels of word knowledge on infants’ sequential touching behaviors were investigated in two studies. In both, parent report was used to assess three levels of word knowledge: known, frontier, and unknown. In the first study, 14-month-old infants sequentially touched objects consistent with parents’ reports of their word knowledge. In the second study, 20-month-old infants sequentially touched objects by both conceptual category and reported level of word knowledge. It appears that even infants, like adults, can make distinctions among objects on the basis of their knowledge about the objects’ labels.     

Stress, Cortisol, and Externalizing Behavior in Adolescent Males: An Examination in the Context of Multisystemic Therapy

Stress and hypothalamic-pituitary-adrenal (HPA) axis dysregulation have been associated with externalizing behavior in adolescence, but few studies have examined these factors in a treatment context. This study investigated the relationship between stress, cortisol, and externalizing behavior among 120 adolescent males (mean age?=?15) receiving Multisystemic Therapy (MST). To examine the differential relationship of cortisol with various types of stressors, self-report measures assessed lifetime stress, current episodic stress, and daily hassles. Morning and afternoon cortisol samples were collected to examine whether the relationship between stress and treatment outcome depended on the youth's biological stress levels. Regression analyses indicated that awakening cortisol levels moderated the relationship between daily hassles and externalizing behaviors at post-treatment. More specifically, higher levels of daily hassles predicted worse outcomes only among adolescents with high levels of morning cortisol. In addition, lifetime stressors and afternoon measures of cortisol interacted to predict changes in caretaker reports of externalizing problems and youth arrests following treatment; lifetime stressors were positively associated with externalizing behavior when adolescents had low levels of afternoon cortisol. Implications for theory and future directions for evidence-based treatment are discussed.     

Trust Development: Testing a New Model in Undergraduate Roommate Relationships

Interpersonal trust is a vital component of social relationships. In this study the roles of parental attachment, perceived similarity of trustee to self, and social exchange processes in trust development were investigated longitudinally with randomly assigned, same-sex undergraduate roommates during emerging adulthood. A total of 214 first-year students completed weekly self-report measures during the first 5 weeks of the fall semester. Perceived similarity measured the second week and social exchange with roommates across the 5 weeks predicted participants’ trust in their roommate, with social exchange mediating the relation between perceived similarity and trust. Results highlight interrelations of social exchange and trust in established relationships.     

Personality disorder not otherwise specified: searching for an empirically based diagnostic threshold

The purpose of this paper is to propose a method for empirically investigating diagnostic criteria for personality disorder not otherwise specified (PDNOS). From a large, nonclinical sample of military recruits and undergraduate students who were screened for personality disorders (PDs), 572 completed the Structured Interview for DSM-IV Personality. Data from the interviewed group were used to identify a diagnostic threshold for PDNOS by comparing those who did (n = 88) and did not (n = 484) qualify for a PD diagnosis. For both groups, subjective distress increased and measures of social and occupational functioning decreased as a function of the number of PD criteria met. A classification and regression tree modeling procedure was applied using self-report scores on measures of mood, anxiety, and personality traits to arrive at probabilities for predicting the presence of a PD diagnosis based on the pattern of reported traits present. These probabilities were then used to derive an empirically based diagnostic threshold for PDNOS. In this sample, the most appropriate threshold for a PDNOS diagnosis appears to be the presence of 10 PD criteria for a person who does not qualify for a diagnosis of any other specific form of PD. This definition identified 5.5% of the young adults who were interviewed in this study.     

Type 2 tasks in the theory of signal detectability: Discrimination between correct and incorrect decisions

It has been known for over 40 years that there are two fundamentally different kinds of detection tasks in the theory of signal detectability. The Type 1 task is to distinguish between events defined independently of the observer; the Type 2 task is to distinguish between one’s own correct and incorrect decisions about those Type 1 events. For the Type 1 task, the behavior of the detector can be summarized by the traditional receiver operating characteristic (ROC) curve. This curve can be compared with a theoretical ROC curve, which can be generated from overlapping probability functions conditional on the Type 1 events on an appropriate decision axis. We show how to derive the probability functions underlying Type 2 decisions from those for the Type 1 task. ROC curves and the usual measures of performance are readily obtained from those Type 2 functions, and some relationships among various Type 1 and Type 2 performance measures are presented. We discuss the relationshiPbetween Type 1 and Type 2 confidence ratings and caution against the practice of presenting transformed Type 2 ratings as empirical Type 1 ratings.