Consolidation of complex events via reinstatement in posterior cingulate cortex

It is well-established that active rehearsal increases the efficacy of memory consolidation. It is also known that complex events are interpreted with reference to prior knowledge. However, comparatively little attention has been given to the neural underpinnings of these effects. In healthy adult humans, we investigated the impact of effortful, active rehearsal on memory for events by showing people several short video clips and then asking them to recall these clips, either aloud (Experiment 1) or silently while in an MRI scanner (Experiment 2). In both experiments, actively rehearsed clips were remembered in far greater detail than unrehearsed clips when tested a week later. In Experiment 1, highly similar descriptions of events were produced across retrieval trials, suggesting a degree of semanticization of the memories had taken place. In Experiment 2, spatial patterns of BOLD signal in medial temporal and posterior midline regions were correlated when encoding and rehearsing the same video. Moreover, the strength of this correlation in the posterior cingulate predicted the amount of information subsequently recalled. This is likely to reflect a strengthening of the representation of the video's content. We argue that these representations combine both new episodic information and stored semantic knowledge (or "schemas"). We therefore suggest that posterior midline structures aid consolidation by reinstating and strengthening the associations between episodic details and more generic schematic information. This leads to the creation of coherent memory representations of lifelike, complex events that are resistant to forgetting, but somewhat inflexible and semantic-like in nature

An EMG & Motion Analysis Study of the Elliptical Trainer

Background and Purpose The purpose of this study is to describe lower extremity muscle activity and joint range of motion while moving both forward and backward on an elliptical trainer at minimum and maximum inclines. Subjects Ten healthy subjects (7 female and 3 male) gave informed consent to voluntarily participate in this study. Methods A single group experimental design was used. A maximum contraction was performed for comparison measure and electromyographic (EMG) data was collected while the subjects performed the stride at the specified variables. Results The vastus lateralis was the most active of all the muscles throughout the entire experiment. The gluteus maxim us had, on average, the least amount of muscle activity. The biceps femoris was more active during forward stride than backward stride while the rectus femoris was more active during the backward stride. Conclusion and Discussion The results of this study are inconsistent with the manufacturer\u27s claims

Predicting Patterns of Information Systems Alignment in Entrepreneurial Organizations

Organizations expend a great deal of effort managing their information system resources as they try to achieve information systems alignment (ISA), but relatively little is known about the different ways in which alignment changes over time in different organizations or what factors predict which kinds of changes are likely to occur. The purpose of this paper is to examine the factors that predict the patterns of ISA change in entrepreneurial organizations. An in-depth examination of the alignment process was conducted using two retrospective case studies. Continuous Change Theory and Punctuated Equilibrium Theory were used to explore ISA patterns in the two organizations. Longitudinal qualitative and quantitative data from the two organizations were used to compare the predictive ability of the two theories regarding ISA changes over time. Results suggest that two factors, organizational inertia and institutionalism, predict the likelihood of an entrepreneurial organization following one ISA change pattern over another

The Influence of Knowledge Management on Business Value in IT Projects: A Theoretical Model

This paper develops a theoretical model to explain the relationships between knowledge management and business value in IT-enabled business projects. It draws upon a wide range of literatures including project management, management information systems, software engineering, organization and management theory, organizational behaviour and strategy. The overall model comprises two sub-models. The first shows how the alignment of three project-based knowledges directly influences business value. The second shows how four knowledge-based concepts, knowledge management, knowledge stock, enabling environment, and knowledge practices, combine to create the project-based knowledges. Together these two sub-models provide an overall model of the causal system through which knowledge management influences business value. This research makes contributions to the research into IT Projects by (1) integrating fragmented literatures which connect knowledge management and project success; and (2) proposing for discussion a predictive model in which knowledge management influences business value. It has the potential when further developed to clarify what project managers can do to manage knowledge in a systematic way