Specific-token effects in screening tasks: possible implications for aviation security

Screeners at airport security checkpoints perform an important categorization task in which they search for threat items in complex x-ray images. But little is known about how the processes of categorization stand up to visual complexity. The authors filled this research gap with screening tasks in which participants searched for members of target categories in visual displays. The authors found that when targets were sampled with replacement and repetition, participant screeners relied on recognizing familiar targets and had great difficulty using category-general knowledge. The authors observed a "heartbeat" in detection performance--it improved while test images repeated but dropped sharply when unfamiliar targets from the same categories appeared. This reliance on familiarity illuminates the processes of categorization under conditions of visual complexity and suggests limits on those processes. This reliance also has implications for the training and evaluation of screeners in the field.     

An implicit test of the associations between children and sex in pedophiles

Pedophiles are motivated to disguise their thoughts and feelings about their sexual beliefs and attraction toward children. New developments using implicit measures of associations have been successful in accessing socially stigmatic beliefs, even in cases in which the participant is resistant to this disclosure. Using an implicit measure, the authors show that pedophiles have an association between children and sex, whereas nonpedophilic offenders have an association between adults and sex. The task can therefore identify a core cognitive abnormality that may underpin some pedophilic deviant sexual behavior.     

Adult age differences in distinctive processing: the modality effect on false recall

Age differences in distinctive processing were investigated by examining the effects of study presentation modality on false recall in younger and older adults using the Deese/Roediger and McDermott paradigm. Participants were presented with study words either visually or auditorily. Older adults did not show the typical reduction in false recall after visual, compared to auditory, study presentation (R.E. Smith & R.R. Hunt, 1998). The authors interpret these results as evidence of reduced distinctive processing on the part of older adults.     

From the lexicon to expectations about kinds: a role for associative learning

In the novel noun generalization task, 2 1/2-year-old children display generalized expectations about how solid and nonsolid things are named, extending names for never-before-encountered solids by shape and for never-before-encountered nonsolids by material. This distinction between solids and nonsolids has been interpreted in terms of an ontological distinction between objects and substances. Nine simulations and behavioral experiments tested the hypothesis that these expectations arise from the correlations characterizing early learned noun categories. In the simulation studies, connectionist networks were trained on noun vocabularies modeled after those of children. These networks formed generalized expectations about solids and nonsolids that match children's performances in the novel noun generalization task in the very different languages of English and Japanese. The simulations also generate new predictions supported by new experiments with children. Implications are discussed in terms of children's development of distinctions between kinds of categories and in terms of the nature of this knowledge.     

Superior performance of blind compared with sighted individuals on bimanual estimations of object size

Five preliminary experiments on sighted individuals revealed marked overestimation on an object size-estimation task using a bimanual response. These experiments ruled out the possibility that overestimation was due to the mode of visual presentation (whether two-dimensional or three-dimensional), the input modality (visual or kinesthetic), or the influence of other visual cues. The main experiment then investigated whether these distortions are due to visual experience by using a variant of the same task to test 24 blind and 24 sighted control participants. Remarkably, the sighted control participants overestimated object size, on average, but the blind participants did not. A follow-up experiment demonstrated that visual memory was the primary influence causing the size over-estimations. We conclude that blind individuals are more accurate than sighted individuals in representing the size of familiar objects because they rely on manual representations, which are less influenced by visual experience than are visual memory representations.     

On the complexity of quantifying construct validity

To validate a measure of a construct is to validate a theory: The process includes theory specification, theory elaboration, choice of methods, choice of research design, reliance on necessary auxiliary theories, and empirical observation. Evaluating the success of the process is likely to be enhanced through quantification. To date, scientists have quantified the final step of empirical observation, but earlier steps in the validation process appear more difficult to measure. In this issue, D. Westen and R. Rosenthal (2005) emphasize that threats to validity are often methodological ones that precede empirical observation. Yet, their earlier attempt to quantify construct validity focused only on the final, empirical observation step of the process. For that reason, it can produce positive results despite real theoretical and methodological threats to validity. Nonetheless, the laudable attempt by these distinguished authors to quantify construct validity reminds us of the complexity of the construct validation process.     

Fragment memories mark the end of childhood amnesia

Adults described and dated two kinds of first remembrances: a personal event memory (the recollection of a personal episode that had occurred at some time in some place) and a memory fragment (an isolated memory moment having no event context and remembered, perhaps, as an image, a behavior, or an emotion). First fragment memories were judged to have originated substantially earlier in life than first event memories--approximately 3 1/3 years of age for first fragment memories versus roughly 4 years of age for first event memories. We conclude that the end of childhood amnesia is marked not by our earliest episodic memories, but by the earliest remembered fragments of childhood experiences.     

Emotional Responses to APO E Genotype Disclosure for Alzheimer Disease

The purpose of our study is to assess the emotional responses to disclosing APO E genotype to asymptomatic older adults at increased risk for Alzheimer disease (AD). This is a longitudinal cohort study of volunteer subjects who were aged 50 years or over, asymptomatic for (AD), had a family history of AD, passed a psychological assessment, and participated in pre- and post-test genetic counseling and three follow-up visits over 10 months. We analyzed responses by three emotional constructs: depressed, worried, and relieved. Three hundred and twenty-eight subjects were screened, 76 received their APO E genotype. When emotional responses occurred it was immediate, between baseline and the 1 month follow-up. Emotional reactions did not change significantly past 1 month. Our results suggest that for emotionally stable persons, disclosing results of their APO E genotype, high risk subjects did not report more depression or worry and low risk subjects felt relieved by knowing the results. Future studies should evaluate the risks of disclosure to family members involved in the diagnostic work-up of a relative and include subjects from a broader range of emotional stability and socioeconomic background.     

Development of a school-wide behavior program in a public middle school: an illustration of deployment-focused intervention development, stage 1

School-wide behavior management systems can improve academic performance and behavior in middle schools, and they should have positive effects on students with ADHD. Unfortunately, evidence-based, school-wide behavior management systems have not been widely adopted because of problems with feasibility, acceptability, and sustainability. The Deployment-Focused Model of Intervention Development and Testing has been proposed as a promising method of bridging the gap between research and practice settings. A key aspect of the model is to involve the persons most likely to deliver the service (e.g., teachers) in the intervention development process from the very beginning. To illustrate this process, the authors describe the planning and implementation of a school-wide program designed to improve behavior in a public middle school.     

Never getting to zero: Elementary school students' understanding of the infinite divisibility of number and matter

Clinical interviews administered to third- to sixth-graders explored children's conceptualizations of rational number and of certain extensive physical quantities. We found within child consistency in reasoning about diverse aspects of rational number. Children's spontaneous acknowledgement of the existence of numbers between 0 and 1 was strongly related to their induction that numbers are infinitely divisible in the sense that they can be repeatedly divided without ever getting to zero. Their conceptualizing number as infinitely divisible was strongly related to their having a model of fraction notation based on division and to their successful judgment of the relative magnitudes of fractions and decimals. In addition, their understanding number as infinitely divisible was strongly related to their understanding physical quantities as infinitely divisible. These results support a conceptual change account of knowledge acquisition, involving two-way mappings between the domains of number and physical quantity.