A novel paradigm reveals the role of reentrant visual processes in object substitution masking

Object substitution masking (OSM) occurs when an initial display of a target and mask continues with the mask alone, creating a mismatch between the reentrant hypothesis, triggered by the initial display, and the ongoing low-level activity. We tested the proposition that the critical factor in OSM is not whether the mask remains in view after target offset, but whether the representation of the mask is sufficiently stronger than that of the target when the reentrant signal arrives. In Experiment 1, a variable interstimulus interval (ISI) was inserted between the initial display and the mask alone. The trailing mask was presumed to selectively boost the strength of the mask representation relative to that of the target. As predicted, OSM occurred at intermediate ISIs, at which the mask was presented before the arrival of the reentrant signal, creating a mismatch, but not at long ISIs, at which a comparison between the reentrant signal and the low-level activity had already been made. Experiment 2, conducted in dark-adapted viewing, ruled out the possibility that low-level inhibitory contour interactions (metacontrast masking) had played a significant role in Experiment 1. Metacontrast masking was further ruled out in Experiment 3, in which the masking contours were reduced to four small dots. We concluded that OSM does not depend on extended presentation of the mask alone, but on a mismatch between the reentrant signals and the ongoing activity at the lower level. The present results place constraints on estimates of the timing of reentrant signals involved in OSM.     

COLLECTIVE RELIGIO‐SCIENTIFIC DISCUSSIONS ON ISLAM AND HIV/AIDS: I. BIOMEDICAL SCIENTISTS

During the 1990s, biomedical scientists and Muslim religious scholars collaborated to construe Islamic responses for the ethical questions raised by the AIDS pandemic. This is the first of a two‐part study examining this collective legal reasoning (ijtihād jamā‘ī). The main thesis is that the role of the biomedical scientists is not limited to presenting scientific information. They engaged in the human rights discourse pertinent to people living with HIV/AIDS, gave an account of the preventive strategy adopted by the World Health Organization, and offered an (Islamic) virtue‐based preventive model. Finally, these scientists tried to draft a number of Islamic legal rulings (a?kām), usually seen in Islamic jurisprudence as the exclusive business of Muslim religious scholars. This multilayered role played by the scientists reflects intriguing developments in the Islamic religio‐ethical discourse in general and in the field of Islamic jurisprudence in particular.     

On the labile memory buffer in the attentional blink: masking the T2 representation by onset transients mediates the AB

Report of a second target (T2) is impaired when presented within 500 ms of the first (T1). This attentional blink (AB) is known to cause a delay in T2 processing during which T2 must be stored in a labile memory buffer. We explored the buffer's characteristics using different types of masks after T2. These characteristics were inferred by determining what attributes of T2 are hindered by a given form of masking. In Experiments 1-3, trailing metacontrast and four-dot masks produced ABs of equal magnitudes, implicating the onset-transient triggered by the mask as the mechanism underlying the AB and strongly suggesting a locus in early vision. In Experiment 4, metacontrast and four-dot masks were presented in a common-onset masking (COM) paradigm in which a brief, combined display of T2 and the mask was followed by a longer display of the mask alone. COM is thought to occur late in the sequence of processing events. No AB occurred with COM, confirming the critical role of the mask's onset transients and ruling out a high-level locus for the labile memory buffer.     

Uterine Transplant: A Risk to Life or a Chance for Life?

Science and Engineering Ethics - Being inherently different from any other lifesaving organ transplant, uterine transplantation does not aim at saving lives but supporting the possibility to...     

Sexual Self-Esteem and Perfectionism in Women With and Without Overweight

The purpose of this study was to examine sexual self-esteem and perfectionism among Iranian women with and without overweight based on the role of age and education; and to investigate the relationships of sexual self-esteem, perfectionism, and body mass index in a sample of adult women. Participants were 200 women with and without overweight who were selected following a purposive sampling method from Shiraz City, Iran. A demographic questionnaire, Sexual Self-Esteem Inventory for Women (SSEI-W), and Perfectionism Inventory (PI) were used. Resulting data showed that women without overweight had higher total scores of sexual self-esteem and on the WWEI-W subscale of attractiveness compared with women who are overweight. Also, women who are overweight had higher total scores of perfectionism, as well as higher scores on subscales of interpersonal sensitivity and high standards for others compared to women without overweight. There was no significant effect for age and educational level on sexual self-esteem and perfectionism. The results demonstrated significantly negative relationships between overall sexual self-esteem, attractiveness subscale of sexual self-esteem, and body mass index. Also, the overall perfectionism and interpersonal sensitivity, striving for excellence, organization, and standards for others subscales of perfectionism had a significant positive relationship to the body mass index.     

Obsessive-compulsive disorder: beyond segregated cortico-striatal pathways

Obsessive-compulsive disorder (OCD) affects approximately 2-3% of the population and is characterized by recurrent intrusive thoughts (obsessions) and repetitive behaviors or mental acts (compulsions), typically performed in response to obsessions or related anxiety. In the past few decades, the prevailing models of OCD pathophysiology have focused on cortico-striatal circuitry. More recent neuroimaging evidence, however, points to critical involvement of the lateral and medial orbitofrontal cortices, the dorsal anterior cingulate cortex and amygdalo-cortical circuitry, in addition to cortico-striatal circuitry, in the pathophysiology of the disorder. In this review, we elaborate proposed features of OCD pathophysiology beyond the classic parallel cortico-striatal pathways and argue that this evidence suggests that fear extinction, in addition to behavioral inhibition, is impaired in OCD.     

A Model of Subjective Well-Being for Adolescents in High School

The aim of this study is to develop and test a subjective well-being model for adolescents in high school. A total of 255 adolescents in high school (131 female and 124 male) participated in this study. Data was collected by using the general needs satisfaction questionnaire, questionnaire for the strategies to increase subjective well-being, life satisfaction questionnaire and positive and negative affects questionnaire. The structural equation modelling method was used for analysis of the data. The results of the analysis showed that in the original model, the individual variables and the total effect of variables were directly and indirectly related to subjective well being of adolescents in high school. The direct and indirect effects of the independent variables to subjective well-being were found significant. The findings suggest that to enhance the subjective well-being of high school students, a combination of strategies and satisfaction of needs is essential.