A further investigation of category learning by inference

Categories are learned in many ways besides by classification, for example, by making inferences about classified items. One hypothesis is that classifications lead to the learning of features that distinguish categories, whereas inferences promote the learning of the internal structure of categories, such as the typical features. Experiment 1 included single-feature and full-feature classification tests following either classification or inference learning. Consistent with predictions, inference learners did better on the single tests but worse on the full tests. Experiment 2 further showed that inference learners, unlike classification learners, were no better at classifying items that they had seen at study compared with equally typical items they had not seen at study. Experiment 3 showed that features queried about during inference learning were classified better than ones not queried about, although even the latter features showed some learning on single-feature tests. The discussion focuses on how different types of category learning lead to different category representations.     

Effects of orientation on Rey complex figure performance

An experiment was performed that examined the impact of stimulus orientation on performance on the Rey complex figure. A total of 48 undergraduates (24 men, 24 women) were randomly assigned to one of four Rey figure orientation groups (0 degrees, 90 degrees, 180 degrees, and 270 degrees ). Participants followed standard procedures for the Rey figure, initially copying it in whatever orientation group they were assigned to. Next, all participants performed a 15-20 min lexical decision experiment, used as a filler task. Finally, and unbeknownest to them, participants were asked to recall as much of the figure as they could. As expected, results revealed a main effect of Task (F = 83.92, p < .01), in which copy performance was superior to recall performance. However, the main effect for orientation was not significant, nor did orientation interact with task (Fs < .68, ps > .57). The results are important from an applied setting, especially if testing conditions are less than optimal and a fixed stimulus position is not possible (e.g., testing at the bedside).     

Thought suppression in obsessive-compulsive disorder

Social cognition research has indicated that attempts to suppress thoughts can lead to a paradoxical increase in the frequency of that thought. This phenomenon has been a central component of cognitive-behavioural models of obsessive-compulsive disorder (OCD); however, research has yet to demonstrate deficient thought suppression ability in OCD patients. We examined whether individuals with OCD (OCs) exhibit a deficit in the ability to suppress thoughts. In Experiment 1, attempted thought suppression led to a paradoxical increase in self-reported thoughts for OCs, but not for nonanxious controls (NACs) or anxious controls (ACs). In order to rule out self-report biases, in Experiment 2 we utilized a lexical decision paradigm that measured priming strength of a target word under thought suppression conditions. Results paralleled those of Experiment 1: OCs showed decreased lexical decision latency of the 'suppressed' thought (thought to reflect either increased priming strength or disrupted processing of nonsuppressed thoughts), thus exhibiting a paradoxical effect of thought suppression. This effect was not seen in NACs or ACs. These findings suggest that deficits in cognitive inhibitory processes may underlie the intrusive, repetitive nature of clinical obsessions.     

Recasts in parents' language to their school-age children who stutter: a preliminary study

Language samples collected from 13 school-age children diagnosed as stutterers (CWS) in conversation with a parent and a similar corpus of data collected from a matched control group of 13 normally-fluent children (CWNS) were analyzed for the quality and quantity of recast usage in the parents' language. Recasts, a frequently studied type of child-directed language (CDL) pattern hypothesized to increase the length and complexity of young children's expressive language, have not been studied typically in older children's conversations with parents nor have they been studied in the CDL of parents of CWS. Comparisons of these samples revealed that both groups of parents were frequent users of imitations, as well as simple and complex type recasts. Indeed, the rank order of recast types used was identical for the two groups of caregivers. When parents' conversations with the CWS were analyzed further, it was noted that they were not more likely to focus on stuttered utterances as the utterances on which to base their recasts (i.e., "platform utterances") than on the child's fluently-produced utterances. These results suggest there is one additional conversation parameter for which there are evident similarities in the CDL used by parents of CWS and CWNS. Clinical implications gleaned from this preliminary study are discussed, as are suggestions for future study. EDUCATIONAL OBJECTIVES: The reader will learn about and be able to describe (1) the role of recasts in young children's language development; (2) the types of recasts that were observed in the conversations of parents of CWS and CWNS; and (3) the similarities observed in the recasts produced by parents of CWS and CWNS.     

Suicidal behavior among urban,African American young adults

The objectives of the present study were four-fold. First, to determine the lifetime, last year, and 6-month prevalence and demographic correlates of suicidal behavior in a defined population of urban, African American young adults. Second, to determine the degree of mental health service utilization among attempters. Third, to study the comorbidity between mental disorders and suicidal behavior, along with the variation in the numbers and types of psychiatric disorders associated with attempts versus ideation only. Fourth, to examine gender differences in the psychiatric diagnoses associated with attempts and ideation. Data relevant to each of these objectives were gathered through structured interviews of 1,157 economically disadvantaged, African American young adults. Lifetime, last year, and 6-month prevalence rates for attempts were 5.3%, 1.2%, and 0.4%, respectively, whereas the lifetime and 6-month prevalence of ideation were 14% and 1.9%, respectively. Approximately two thirds of those who reported lifetime ideation, and a similar proportion of those who reported lifetime attempts, had a history of at least one lifetime psychiatric disorder. There were no gender differences in terms of the degree of risk for suicidal behavior (ideation or attempts) associated with any of the comorbid psychiatric diagnoses assessed. Despite the severity of most attempts, few attempters received mental health services in their lifetime or at the time of their most recent attempt.     

The psychology of telling murder stories: do we think in scripts,exemplars, or prototypes?

According to the story model of Pennington and Hastie, jurors collect information at trial and modify it with general knowledge to create case stories. Schank and Ableson argue that human memory is organized to tell and understand stories. However, Finkel and Groscup questioned the use of manipulated, experimenter-constructed narratives to demonstrate the existence of multiple prototypical crime stories. We interviewed 76 jury eligible, death qualified citizens and asked them to imagine a first-degree murder scenario, describing the events that led to the killing. We coded the presence of dichotomous variables in the resulting stories and identified at least three shared story prototypes using cluster and profile analysis. We conclude that people do not store crime stories as simple prototypes and comment on the implications of this finding for legal decision-making.     

Psychology Experiment Authoring Kit (PEAK): Formal usability testing of an easy-to-use method for creating computerized experiments

In academic courses in which one task for the students is to understand empirical methodology and the nature of scientific inquiry, the ability of students to create and implement their own experiments allows them to take intellectual ownership of, and greatly facilitates, the learning process. The Psychology Experiment Authoring Kit (PEAK) is a novel spreadsheet-based interface allowing students and researchers with rudimentary spreadsheet skills to create cognitive and cognitive neuroscience experiments in minutes. Students fill in a spreadsheet listing of independent variables and stimuli, insert columns that represent experimental objects such as slides (presenting text, pictures, and sounds) and feedback displays to create complete experiments, all within a single spreadsheet. The application then executes experiments with centisecond precision. Formal usability testing was done in two stages: (1) detailed coding of 10 individual subjects in one-on-one experimenter/subject videotaped sessions and (2) classroom testing of 64 undergraduates. In both individual and classroom testing, the students learned to effectively use PEAK within 2 h, and were able to create a lexical decision experiment in under 10 min. Findings from the individual testing in Stage 1 resulted in significant changes to documentation and training materials and identification of bugs to be corrected. Stage 2 testing identified additional bugs to be corrected and new features to be considered to facilitate student understanding of the experiment model. Such testing will improve the approach with each semester. The students were typically able to create their own projects in 2 h.     

PsychMate: Providing psychology majors the tools to do real experiments and learn empirical methods

PsychMate is a set of software tools for undergraduate psychology students to run, develop, and analyze computerized experiments. It includes 30 psychological experiments in the areas of perception, cognition, social psychology, human factors, and cognitive neuroscience. Students run experiments themselves and see basic results immediately. The automatic spreadsheet analysis forms allow them to aggregate data and create analyses, presentations, and Web pages with a single click. Students can use the Psychology Experiment Authoring Kit experiment editor to create their own experiments in minutes and run experiments with other students using Web-based experiment-management tools. The Brain-Tutor and BrainViewer applications teach brain anatomy and permit students to analyze fMRI brain imaging data from subjects who have performed the same memory experiments in which they participated. PsychMate has been used in 83 classes in which 1,533 students submitted 5,464 completed experiments with few (less than 1%) requests for help and a very positive rating of the research experience.