Serotonin transporter (5-HTTLPR) genotype, childhood abuse, and suicide attempts in adult psychiatric inpatients

There is growing evidence that a functional polymorphism in the serotonin transporter gene (5-HTTLPR) moderates the impact of negative life events (e.g., childhood abuse) on the development of depression. However, it is unclear whether the gene x environment interaction predicts suicide attempts specifically. In addition, previous studies have not examined different forms of childhood abuse separately. In the current study, we found that 5-HTTLPR genotype moderated the link between childhood physical and sexual, but not emotional, abuse and adult psychiatric inpatients' histories of suicide attempts.     

Motion-perception deficits and reading impairment: it's the noise, not the motion

We tested the hypothesis that deficits on sensory-processing tasks frequently associated with poor reading and dyslexia are the result of impairments in external-noise exclusion, rather than motion perception or magnocellular processing. We compared the motion-direction discrimination thresholds of adults and children with good or poor reading performance, using coherent-motion displays embedded in external noise. Both adults and children who were poor readers had higher thresholds than their respective peers in the presence of high external noise, but not in the presence of low external noise or when the signal was clearly demarcated. Adults' performance in high external noise correlated with their general reading ability, whereas children's performance correlated with their language and verbal abilities. The results support the hypothesis that noise-exclusion deficits impair reading and language development and suggest that the impact of such deficits on the development of reading skills changes with age.     

Memories of uncertain origin: dreamt or real?

The existence of a memory whose origin, real or dreamt, was uncertain was reported by just over half of an undergraduate sample of 358. Each respondent described one such memory if they had one. The memories were typically of mundane events, although 10 respondents described possible crimes. Respondents were often concerned to resolve the origin of these memories. Their plausibility, vividness, and how well the events fitted into one's life were often considered by the respondents, but where resolution occurred it was frequently based on evidence obtained from the physical or social environment. The reported qualities of the event did not correlate with whether the respondent thought it more likely to have been originally a dream or a real event.     

The ties that keep us bound: Top-down influences on the persistence of shape-from-motion

The phenomenon of perceptual persistence after the motion stops in shape-from-motion displays (SFM) was used to study the influence of prior knowledge on the maintenance of a percept in awareness. In SFM displays an object composed of discontinuous line segments are embedded in a background of randomly oriented lines. The object only becomes perceptible when the line segments that compose the object and the lines that compose the background move in counterphase. Critically, once the movement of the line segments stops, the percept of the object persists for a short period of time. In the present study, perceptual persistence for digits exceeded that reported for nonsense shapes composed of the same line segments. This result is taken as evidence that the processes involved in the persistence of SFM, and therefore sustained perception, are sensitive to top-down influences.     

Expert face coding: Configural and component coding of own-race and other-race faces

Configural and holistic coding are hallmarks of face perception. Although recent studies have shown that own-race faces are coded more holistically than other-race faces, the evidence for better configural coding of own-race faces is equivocal. We directly measured configural and component coding of own- and other-race male faces in Caucasian and Chinese participants. We manipulated individual features (components) or their spatial relations (configurations) using a novel morphing method to vary difficulty parametrically and tested sensitivity to these changes in a sequential matching task. Both configural and component coding were better for upright own-race than for upright other-race faces. Inversion impaired detection of configural changes more than it did detection of component changes, but also impaired performance more for easier discriminations,independent of type of change. These results challenge explanations of face expertise that rely solely on configural and holistic processing, and also call into question the widespread interpretation of large inversion decrements as diagnostic of configural coding.     

A team-taught interdisciplinary approach to engineering ethics

This paper outlines the development and implementation of a new course in Engineering Ethics at the University of Tennessee. This is a three-semester-hour course and is jointly taught by an engineering professor and a philosophy professor. While traditional pedagogical techniques such as case studies, position papers, and classroom discussions are used, additional activities such as developing a code of ethics and student-developed scenarios are employed to encourage critical thinking. Among the topics addressed in the course are engineering as a profession and its role in society; ethical successes and failures; risk, safety, and the environment; professional responsibilities; credit and intellectual property; and international concerns. The most significant aspect of the course is that it brings both engineering and non-engineering points of view to the topics at hand. This is accomplished in two ways. First, as mentioned previously, it is team-taught by engineering faculty with an interest in ethical and societal issues, and by philosophy faculty with expertise in the field of professional ethics and an interest in science and technology. Second, the course is offered to both engineers and non-engineers. This mix of students requires that all students must be able to explain their technical and ethical decisions in a non-technical manner. Work teams are structured to maximize interdisciplinary interaction and to foster insights by each student into the professional commitments and attitudes of others. An earlier version of this paper was presented at the 2005 conference, Ethics and Social Responsibility in Engineering and Technology, Linking Workplace Ethics and Education, co-hosted by Gonzaga University and Loyola Marymount University, Los Angeles, CA, USA, 9–10 June 2005.     

Decision and experience: why don't we choose what makes us happy?

Recent years have witnessed a growing interest among psychologists and other social scientists in subjective well-being and happiness. Here we review selected contributions to this development from the literature on behavioral-decision theory. In particular, we examine many, somewhat surprising, findings that show people systematically fail to predict or choose what maximizes their happiness, and we look at reasons why they fail to do so. These findings challenge a fundamental assumption that underlies popular support for consumer sovereignty and other forms of autonomy in decision-making (e.g. marriage choice), namely, the assumption that people are able to make choices in their own best interests.     

Aging, encoding fluency, and metacognitive monitoring

Encoding fluency (how rapidly one generates a mediator for a new association) may be a cue used to judge one's own learning. To evaluate age differences in utilization of this cue, older and younger adults were instructed to use interactive imagery to study paired associates, pressing a button to indicate when an image had been formed for a given pair. A judgment of learning (JOL) was also made immediately after each pair had been studied. Hence, at least two cues pertaining to encoding fluency-whether an image had been formed (a diagnostic cue) and the latency of formation (a nondiagnostic one)-were available when making JOLs. Age equivalence was found in JOL accuracy, and JOLs for both age groups were positively related to imagery formation and were negatively related to the latency of image formation. Moreover, subjectively judged latency correlated higher with JOLs than actual (objective) latency, supporting the hypothesis that perceived fluency is a cue used in constructing JOLs.     

The selective disruption of spatial working memory by eye movements

In the late 1970s/early 1980s, Baddeley and colleagues conducted a series of experiments investigating the role of eye movements in visual working memory. Although only described briefly in a book (Baddeley, 1986), these studies have influenced a remarkable number of empirical and theoretical developments in fields ranging from experimental psychology to human neuropsychology to nonhuman primate electrophysiology. This paper presents, in full detail, three critical studies from this series, together with a recently performed study that includes a level of eye movement measurement and control that was not available for the older studies. Together, the results demonstrate several facts about the sensitivity of visuospatial working memory to eye movements. First, it is eye movement control, not movement per se, that produces the disruptive effects. Second, these effects are limited to working memory for locations and do not generalize to visual working memory for shapes. Third, they can be isolated to the storage/maintenance components of working memory (e.g., to the delay period of the delayed-recognition task). These facts have important implications for models of visual working memory.