Cognitive and metacognitive activity in mathematical problem solving: prefrontal and parietal patterns

Students were taught an algorithm for solving a new class of mathematical problems. Occasionally in the sequence of problems, they encountered exception problems that required that they extend the algorithm. Regular and exception problems were associated with different patterns of brain activation. Some regions showed a Cognitive pattern of being active only until the problem was solved and no difference between regular or exception problems. Other regions showed a Metacognitive pattern of greater activity for exception problems and activity that extended into the post-solution period, particularly when an error was made. The Cognitive regions included some of parietal and prefrontal regions associated with the triple-code theory of (Dehaene, S., Piazza, M., Pinel, P., & Cohen, L. (2003). Three parietal circuits for number processing. Cognitive Neuropsychology, 20, 487–506) and associated with algebra equation solving in the ACT-R theory (Anderson, J. R. (2005). Human symbol manipulation within an 911 integrated cognitive architecture. Cognitive science, 29, 313–342. Metacognitive regions included the superior prefrontal gyrus, the angular gyrus of the triple-code theory, and frontopolar regions.     

Invigorating ��Nanoethics��: Recommendations for Improving Deliberations in Taiwan and Beyond

Nanotechnology is the new(est) star in the high technologies sky. While nanotechnologies remain technologies of promise and potential, a growing number of nano-materials and nano-particle-reliant products are being produced. And although a growing number of academic, policy and industry reports are exploring nanotechnologies, there are very few genuine ethical assessments of nanotechnologies as they exist and might evolve in the coming years. Many questions have yet to be answered about the nature, development, and social and commercial deployment of nanotechnologies and what that means for the human condition and the preservation of our core values. We argue that the early and potentially risky nature of this interdisciplinary science does not justify a blinkered focus on risk assessment and management to the detriment of deep and ranging ethical evaluations. Much improved ethics evaluations must be undertaken, particularly in Taiwan where very little has happened despite grand expectations for, and funding of, the science. In this paper, we uncover the development imperatives for nanotechnologies, demonstrate the paucity of genuine nanoethics exercises, outline key questions for stakeholders undertaking nanoethics exercises to consider, and we articulate some preliminary actions for Taiwan (and other similarly situated jurisdictions).     

HIV-1 Infection, Neuroendocrine Abnormalities, and Clinical Outcomes

Different lines of evidence suggest that human immunodeficiency virus type 1 (HIV-1) infection is complicated by a variety of adverse effects on neuroendocrine systems. Soon after the discovery of HIV-1, reports began to appear suggesting that a number of neurotransmitter and neuroendocrine activities were negatively impacted by this infection. In 1987 it was observed that fine-needle aspiration of the lung in patients with acquired immunodeficiency syndrome resulted in syncopal reactions. Subsequently, an abnormality in the autonomic nervous system was reported in these patients. However, investigations in this area have remained limited due to the assumption that HIV-1-mediated activation of various endocrine systems was related to the major life stressor of living with a fatal disease. Evidence accumulated over the years has indicated, instead, that there are various other mechanisms in addition to life stressors that also play an important role in negatively impacting the neuroendocrine systems in this infection. This article examines various developments that have taken place in this area in order to provide avenues for future research.     

Moderator effects of cognitive ability and social support on the relation between race-related stress and quality of life in a community sample of black Americans

The current study examined the combined moderating effects of cognitive ability and social support on the relation between race-related stress and quality of life in a sample of Black Americans. Participants (N = 323) were administered the Wonderlic Personnel Test (WPT; E. F. Wonderlic Associates, Inc., 1983), the Multidimensional Social Support Scale (MDSS; Winefield, Winefield, & Tiggemann, 1992), the Index of Race-Related Stress-Brief (Utsey, 1999), and the WHOQOL-BREF (The WHO Group, 1998). The findings indicated that cognitive ability and social support, conjointly, moderated the relation between individual and cultural race-related stress and quality of life for Black Americans in the current sample. The paper concludes by discussing the study's findings, limitations, and by offering recommendations for future research related to this area of inquiry.     

Visual short-term memory for sequential arrays

The capacity of visual short-term memory (VSTM) for a single visual display has been investigated in past research, but VSTM for multiple sequential arrays has been explored only recently. In this study, we investigate the capacity of VSTM across two sequential arrays separated by a variable stimulus onset asynchrony (SOA). VSTM for spatial locations (Experiment 1), colors (Experiments 2-4), orientations (Experiments 3 and 4), and conjunction of color and orientation (Experiment 4) were tested, with the SOA across the two sequential arrays varying from 100 to 1,500 msec. We find that VSTM for the trailing array is much better than VSTM for the leading array, but when averaged across the two arrays VSTM has a constant capacity independent of the SOA. We suggest that multiple displays compete for retention in VSTM and that separating information into two temporally discrete groups does not enhance the overall capacity of VSTM.     

Visual short-term memory for two sequential arrays: One integrated representation or two separate representations?

Two dot arrays, each containing a different set of six randomly selected locations from a 5 × 5 matrix, were presented briefly and were separated by an interstimulus interval (ISI) of 0, 200, 500, or 1,500 msec. Subjects were asked to remember these locations and to report whether a probe dot matched the locations in memory. To find out whether the subjects had formed an integrated representation of the two arrays, the probe dot was accompanied by matrix elements from the first array, from the second array, or from both arrays. Memory for Array 1 was significantly impaired when the retrieval context was drawn from Array 2, and vice versa, suggesting that the two arrays were represented separately. This effect was observed only at an ISI of 500 msec or longer. We propose that as Array 1 is better consolidated, its representation becomes more separated from that of Array 2.     

Impact of personality disorders on treatment outcome for female assault survivors with chronic posttraumatic stress disorder

This study examined the impact of comorbid personality disorders on the outcome of cognitive behavioral treatment for women with chronic posttraumatic stress disorder (PTSD). Seventy-five adult women with PTSD resulting from rape or nonsexual assault in adulthood or sexual abuse in childhood were treated with prolonged exposure with or without cognitive restructuring. Assessment of personality disorders found that 39% of participants met DSM-IV criteria for some personality disorder diagnosis. No difference was found between women with and without personality disorders on the prevalence of PTSD at the end of treatment. Participants with a personality disorder were less likely to attain good end-state functioning, but this may be attributable to the fact that they started off slightly worse than those without personality disorders. Finally, the comorbid patients treated by community therapists fared as well or better than those treated by cognitive behavioral treatment experts in posttreatment prevalence of PTSD and end-state functioning.     

HIV-1 infection and its impact on the HPA axis, cytokines, and cognition

Immediately after infection, Human immunodeficiency virus, type 1 (HIV-1) enters the central nervous system (CNS) and is localized in highest concentration in the hippocampus and basal ganglia. Since these areas are associated with HPA axis and autonomic activities as well as cognition, it has been hypothesized that these functions will be impacted adversely in HIV-1 infection. In the treatment of HIV infection, although the highly potent antiretroviral (HAART) drugs have been effective in reducing peripheral viral load and prolonging life expectancy, these drugs do not cross the blood-brain barrier in therapeutic concentrations. Therefore, it has been proposed that the beneficial effects of HAART on the CNS will be limited. Our investigations on seropositive individuals, showing hypo-reactivity of the autonomic system and HPA axis activity suggest that HIV-1 infection is a model of chronic stress. Furthermore, an elevated baseline TNF-alpha level as well as its increased reactivity to an alpha-adrenergic challenge among HIV-1+ individuals, may lead to additional neurodegeneration. It is proposed that the effects of HIV-1 infection on the brain will have implications for neurocognitive and mental health functioning in seropositive individuals even in patients undergoing HAART therapy. These outcomes may result in the need to develop facilities for long term "care-giving".     

Procedural learning in perceptual categorization

In two experiments, observers learned two types of category structures: those in which perfect accuracy could be achieved via some explicit rule-based strategy and those in which perfect accuracy required integrating information from separate perceptual dimensions at some predecisional stage. At the end of training, some observers were required to switch their hands on the response keys, whereas the assignment of categories to response keys was switched for other observers. With the rule-based category structures, neither change in response instructions interfered with categorization accuracy. However, with the information-integration structures, switching response key assignments interfered with categorization performance, but switching hands did not. These results are consistent with the hypothesis that abstract category labels are learned in rule-based categorization, whereas response positions are learned in information-integration categorization. The association to response positions also supports the hypothesis of a procedural-learning-based component to information integration categorization.