Running is the neurogenic and neurotrophic stimulus in environmental enrichment

Environmental enrichment (EE) increases dentate gyrus (DG) neurogenesis and brain-derived neurotrophic factor (BDNF) levels. However, running is considered an element of EE. To dissociate effects of physical activity and enrichment on hippocampal neurogenesis and BDNF levels, young female C57Bl/6 mice were housed under control, running, enrichment, or enrichment plus running conditions, and injected with bromodeoxyuridine. Cell genesis was assessed after 12 d and differentiation was analyzed 1 mo later. In addition, locomotor activity in the open field and hippocampal mature BDNF peptide levels were measured. Open-field adaptation was improved in all groups, compared to controls, but more so with running. New cell proliferation, survival, neuron number, and neurotrophin levels were enhanced only when running was accessible. We conclude that exercise is the critical factor mediating increased BDNF levels and adult hippocampal neurogenesis.     

Vividness of visual imagery and social desirable responding: correlations of the vividness of visual imagery questionnaire with the balanced inventory of desirable responding and the Marlowe–Crowne scale

Correlational research investigating the relationship between scores on self-report imagery questionnaires and measures of social desirable responding has shown only a weak association. However, researchers have argued that this research may have underestimated the size of the relationship because it relied primarily on the Marlowe-Crowne scale (MC; Crowne & Marlowe, Journal of Consulting Psychology, 24, 349-354, 1960), which loads primarily on the least relevant form of social desirable responding for this particular context, the moralistic bias. Here we report the analysis of data correlating the Vividness of Visual Imagery Questionnaire (VVIQ; Marks, Journal of Mental Imagery, 19, 153-166, 1973) with the Balanced Inventory of Desirable Responding (BIDR; Paulhus, 2002) and the MC scale under anonymous testing conditions. The VVIQ correlated significantly with the Self-Deceptive Enhancement (SDE) and Agency Management (AM) BIDR subscales and with the MC. The largest correlation was with SDE. The ability of SDE to predict VVIQ scores was not significantly enhanced by adding either AM or MC. Correlations between the VVIQ and BIDR egoistic scales were larger when the BIDR was continuously rather than dichotomously scored. This analysis indicates that the relationship between self-reported imagery and social desirable responding is likely to be stronger than previously thought.     

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...     

Orientation-selective adaptation during motion-induced blindness

When a global moving pattern is superimposed on high-contrast stationary or slowly moving stimuli, the latter occasionally disappear for periods of several seconds (motion-induced blindness, MIB). Here, an adaptation paradigm was used to determine if orientation-selective adaptation still occurs for the stimulus that is no longer visible. Two slowly drifting high-contrast Gabor patches were presented to observers. As soon as both patches disappeared, one was eliminated from the screen. After 2 s, two low-contrast Gabor patches were presented as tests at the same locations and observers were asked to report their orientations. The observers' performance was significantly higher when the orientation of the low-contrast test patch was orthogonal to the orientation of the high-contrast adapting patch (p < 0.0001) for the location where the patch was present during MIB, even though it was perceptually invisible. The observers' performance was not significantly different at the adjacent control location where the stimulus was absent during the MIB. Although no stimulus was visible at either location, orientation-selective adaptation was preserved only for the location at which the patch remained present. Since orientation information is processed in low-level visual areas such as the primary visual cortex (V1), we conclude that MIB originates in an area higher than V1.     

Delayed recall of fear extinction in rats with lesions of ventral medial prefrontal cortex

Extinction of auditory fear conditioning is thought to form a new memory. We previously found that rats with vmPFC lesions could extinguish fear to the tone within a session, but showed no recall of extinction 24 h later. One interpretation is that the vmPFC is the sole storage site of extinction memory. However, it is also possible that lesioned rats were unable to retrieve extinction memory stored in other structures. To determine if a latent extinction memory could be retrieved with additional training, we repeated the experiment but added an additional 5 d of extinction reminder trials. Replicating our previous findings, vmPFC-lesioned rats extinguished normally on day 1, but showed no recall of extinction on day 2. Over the next 5 d, however, lesioned rats showed significant savings in their rate of re-extinction. Thus, the vmPFC is not the only site where extinction memory is stored. Nevertheless, lesioned rats receiving only two extinction trials per day required twice as many days to initiate extinction as controls. Although recall of extinction is possible without the vmPFC, it is significantly delayed. We suggest that the vmPFC accelerates extinction by permitting access to recently learned extinction trials, thereby maximizing behavioral flexibility.     

Ethical leadership and organizational citizenship behaviours: the moderating role of organizational identification

This study examines whether the relationship between ethical leadership and organizational citizenship behaviours (OCBs) is contingent on organizational identification. Drawing on substitutes for leadership theory, the study proposes that the relationship between ethical leadership and OCBs will be attenuated when employees strongly identify with their organization. Using a sample of Egyptian banking sector employees, this proposition was tested with hierarchal linear modelling (HLM). The results revealed that the positive relationship between ethical leadership and OCBs was stronger for those lower in organizational identification than for those higher in identification. Overall, the findings of the study shed new light on the conditions through which ethical leadership enhances OCBs.     

Goals in Argumentation: A Proposal for the Analysis and Evaluation of Public Political Arguments

In this paper, I review and compare major literature on goals in argumentation scholarship, aiming to answer the question of how to take the different goals of arguers into account when analysing and evaluating public political arguments. On the basis of the review, I suggest to differentiate between the different goals along two important distinctions: first, distinguish between goals which are intrinsic to argumentation and goals which are extrinsic to it and second distinguish between goals of the act of arguing and goals of argumentative interactions. Furthermore, I propose to analyse public political arguments as multi-purposive activity types and reconstruct the argumentative exchanges as a series of simultaneous discussions. This enables us to examine public political arguments from a perspective in which the intrinsic goals of argumentation are in principle instrumental for the achievement of the socio-political purposes of argumentation, and consequently, it makes our assessment of the argumentative quality of the argument also indicative of the quality of the socio-political processes to which the arguments contribute.