42 research outputs found
Recommended from our members
Drama and discounting in the relational dynamics of corporate social responsibility
Employing theoretical resources from Transactional Analysis (TA) and drawing from interviews with managers dealing with social or environmental issues in their role, we explain how CSR activity provides a context for dramas in which actors may ignore, or discount aspects of self, others, and the contexts of their work as they maintain and reproduce the roles of Rescuers, Persecutors and Victims. In doing so, we add to knowledge about CSR by providing an explanation for how the contradictions of CSR are avoided in practice even when actors may be aware of them. Specifically, we theorise how CSR work can produce dramatic stories where adversity is apparently overcome, whilst little is actually achieved at the social level. We also add to the range of psychoanalytic tools used to account for organisational behaviours, emphasising how TA can explain the relational dynamics of CSR
Incremental grouping of image elements in vision
One important task for the visual system is to group image elements that belong to an object and to segregate them from other objects and the background. We here present an incremental grouping theory (IGT) that addresses the role of object-based attention in perceptual grouping at a psychological level and, at the same time, outlines the mechanisms for grouping at the neurophysiological level. The IGT proposes that there are two processes for perceptual grouping. The first process is base grouping and relies on neurons that are tuned to feature conjunctions. Base grouping is fast and occurs in parallel across the visual scene, but not all possible feature conjunctions can be coded as base groupings. If there are no neurons tuned to the relevant feature conjunctions, a second process called incremental grouping comes into play. Incremental grouping is a time-consuming and capacity-limited process that requires the gradual spread of enhanced neuronal activity across the representation of an object in the visual cortex. The spread of enhanced neuronal activity corresponds to the labeling of image elements with object-based attention
Transparent
N-channel enhancement mode Field-Effect Transistor (FET) in a plastic package usin
An improved method for acquiring cerebrovascular reactivity maps.
This study aims to improve the method used to produce cerebrovascular reactivity (CVR) maps by MRI. Previous methods have used a standard boxcar presentation of carbon dioxide (CO(2)). Here this is replaced with a sinusoidally modulated CO(2) stimulus. This allowed the use of Fourier analysis techniques to measure both the amplitude and phase delay of the BOLD CVR response, and hence characterize the arrival sequence of blood to different regions of the brain. This characterization revealed statistically significant relative delays between regions of the brain (ANOVA < 0.0001). In addition, post hoc comparison showed that the frontal (P < 0.001) and parietal (P = 0.004) lobes reacted earlier than the occipital lobe. Magn Reson Med, 2010. © 2010 Wiley-Liss, Inc
Measuring venous blood volume changes during activation using hyperoxia.
This study describes a novel method for measuring relative changes in venous cerebral blood volume (CBVv) using hyperoxia as a contrast agent. This method exploits the extravascular BOLD effect and its dependency on both task-related activation induced changes in venous blood oxygenation and changes due to breathing an oxygen enriched gas mixture. Changes in CBVv on activation can be estimated by comparing the change in transverse relaxation rate, R2*, due to hyperoxia in both baseline and activation states. Furthermore these measurements can be converted into a measure of the percentage change in CBVv. Experiments were performed to measure changes in a CBVv-weighted signal in response to a simple motor task. Both positive and negative changes in CBVv-weighted signal were detected in the positively activated BOLD region