Valid distinctions between conscious and unconscious perception?

In this commentary, we discuss the strengths and limitations of Snodgrass, Bernat, and Shevrin's (2004) theory of unconscious perception. Our commentary centers on the value of signal detection theory (SDT) to understanding the unconscious perception controversy, a value that Snodgrass et al. for the most part agree with (i.e., that most approaches to studying unconscious perception are invalid because they have confounded the criterion for detection with the criterion for awareness). However, we believe that their model relies on a somewhat restricted application of SDT. We discuss how SDTcan be better applied to provide the necessary tests to validate their model.     

Ethnicity, expressed emotion, attributions, and course of schizophrenia: family warmth matters

The authors examined the role of family factors and the course of schizophrenia by carrying out additional assessments and analyses in 2 previously published studies of Mexican American and Anglo American patients and families. The authors found partial support for an attributional model of relapse for families who are low in emotional overinvolvement. Attributions of control, criticism, and warmth together marginally predicted relapse. The data also indicated that for Mexican Americans, family warmth is a significant protective factor, whereas for Anglo Americans, family criticism is a significant risk factor. These findings suggest that the sociocultural context shapes the pathways by which family processes are related to the course of illness. Moreover, the warmth findings suggest that families may contribute to preventing relapse.     

The psychometric detection of schizotypy: do putative schizotypy indicators identify the same latent class?

The authors examined whether three indicators of Schizotypy, the Revised Social Anhedonia Scale (RSAS), Magical Ideation Scale (MIS), and Perceptual Aberration Scale (PAS), identify a common latent class or taxon as conceptualized by P. E. Meehl (1962, 1990). The separate and joint latent structures of these scales were evaluated using taxometric methods in two large, independent samples. Replicating prior findings, the RSAS and PAS each identified latent taxa with base rates approximating.10. Results for the taxonicity of the MIS were less consistent. Analyses of joint latent structure indicated that the RSAS-identified taxon was essentially independent of constructs measured by the PAS or MIS. Measures commonly thought to tap the same latent class, conjectured to be schizotypy, do not share this property.     

Assessing the causal structure of function

Theories typically emphasize affordances or intentions as the primary determinant of an object's perceived function. The HIPE theory assumes that people integrate both into causal models that produce functional attributions. In these models, an object's physical structure and an agent's action specify an affordance jointly, constituting the immediate causes of a perceived function. The object's design history and an agent's goal in using it constitute distant causes. When specified fully, the immediate causes are sufficient for determining the perceived function--distant causes have no effect (the causal proximity principle). When the immediate causes are ambiguous or unknown, distant causes produce inferences about the immediate causes, thereby affecting functional attributions indirectly (the causal updating principle). Seven experiments supported HIPE's predictions.     

Learning to optimize speed, accuracy, and energy expenditure: a framework for understanding speed-accuracy relations in goal-directed aiming

Over the last century, investigators have developed a number of models to explain the relation between speed and accuracy in target-directed manual aiming. The models vary in the extent to which they stress the importance of feedforward processes and the online use of sensory information (see D. Elliott, W. F. Helsen, & R. Chua, 2001, for a recent review). A common feature of those models is that the role of practice in optimizing speed, accuracy, and energy expenditure in goal-directed aiming is either ignored or minimized. The authors present a theoretical framework for understanding speed-accuracy tradeoffs that takes into account the strategic, trial-to-trial behavior of the performer. The strategic behavior enables individuals to maximize movement speed while minimizing error and energy expenditure.     

On the neurobiological investigation of language understanding in context

There are two significant problems in using functional neuroimaging methods to study language. Improving the state of functional brain imaging will depend on understanding how the dependent measure of brain imaging differs from behavioral dependent measures (the "dependent measure problem") and how the activation of the motor system may be confounded with non-motor aspects of processing in certain experimental designs (the "motor output problem"). To address these problems, it may be necessary to shift the focus of language research from the study of linguistic competence to the understanding of language use. This will require investigations of language processing in full multi-modal and environmental context, monitoring of natural behaviors, novel experimental design, and network-based analysis. Such a combined naturalistic approach could lead to tremendous new insights into language and the brain.     

Medical ethicists, human curiosities, and the new media midway

Medical ethicists have assumed a role in justifying public voyeurism of human "curiosities." This role has precedent in how scientists and natural philosophers once legitimized the marketing of museums of "human curiosities." At the beginning of the twentieth century, physicians dissociated themselves from entrepreneurial displays of persons with anomalies, and such commercial exhibits went into decline. Today, news media, principally on television, promote news features about persons that closely resemble the nineteenth century exhibits of human curiosities. Reporters solicit medical ethicists for soundbites to affirm the newsworthiness and propriety of public voyeurism of these medical stories. Ethicists' soundbites are usually ambiguous or self-evident and rarely enable viewers to morally engage the issues. The precedent of early twentieth century physicians disengaging from such exploitive public shows is a useful example for medical ethics.     

Psychological sequelae of remote exposure to the September 11th terrorist attacks in Canadians with and without panic

The purpose of the present investigation was to examine the psychological impact of remote exposure to the events and aftermath of the terrorist attacks in the USA on September 11th, 2001, and to assess what differences, if any, exist between individuals classified with probable panic disorder and those without. Telephone interviews were conducted with 122 residents of the capital city of the Canadian prairie province of Saskatchewan in spring 2002 in order to gather information regarding current mood, fears and avoidance behaviours as well as current post-traumatic stress disorder symptoms specific to September 11th. Consistent with previous findings and despite the remote nature of exposure, results indicated that the psychological well-being and behaviour of participants with probable panic disorder was more adversely affected by the events and aftermath of September 11th than those without panic disorder. These results suggest that remote viewing of traumatic events can have a significant and lingering impact on psychological well-being and behaviour and that these effects are more pronounced in those with panic disorder. Implications of the findings and future research directions are discussed.     

School-year employment among high school students: effects on academic, social, and physical functioning

This study describes the effects of different weekly work intensity levels on adolescent functioning in a sample of 3,083 high school students in rural South Texas, where economically disadvantaged and Hispanic youth are heavily represented. Anonymous surveys were conducted in 10th- and 12th-grade students' classrooms in 1995. The following effects were associated with long hours of weekly employment during the school year: (1) decreased performance/engagement in school and satisfaction with amount of leisure time, and (2) increased health risk behaviors and psychological stress. The effects of school-year work on academic factors and health behaviors differed by grade, but not by race/ethnicity, parent education, or race/ethnicity and parent education considered together. It was concluded that parents and professionals should continue to monitor the number of weekly hours that students work during the school year.     

Working memory for visual features and conjunctions in schizophrenia

The visual working memory (WM) storage capacity of patients with schizophrenia was investigated using a change detection paradigm. Participants were presented with 2, 3, 4, or 6 colored bars with testing of both single feature (color, orientation) and feature conjunction conditions. Patients performed significantly worse than controls at all set sizes but demonstrated normal feature binding. Unlike controls, patient WM capacity declined at set size 6 relative to set size 4. Impairments with subcapacity arrays suggest a deficit in task set maintenance: Greater impairment for supercapacity set sizes suggests a deficit in the ability to selectively encode information for WM storage. Thus, the WM impairment in schizophrenia appears to be a consequence of attentional deficits rather than a reduction in storage capacity.