Nascent Papers

Eni

A Comparative Study of Cognitive Functioning and Fiber Tract Integrity

Contributions

1. The paper presents a twofold comparison of cognitive test results and white matter integrity, in specific fiber tracts of CADASIL patients, by:

i.Comparing working memory test results with several quantitative tractography metrics of structural integrity in the SLF and the fornix

ii.Comparing motor control test results with the same metrics, in the SLF

2. The paper draws on the relationship between axial or radial diffusivity and the nature of axonal damage, to infer the prevalent type of damage in tracts affected by CADASIL

Results

1.

i. Working memory test results should correlate with most metrics, in the SLF. They should not however correlate as much with the metrics, in the fornix, since CADASIL affects SLF more drastically than it affects the fornix.

ii. In the SLF, motor control test results should not correlate with the metrics as highly as the working memory test results do.

2. Among the metrics, there should be a few that correlate more significantly than others with the cognitive test result. These correlations should provide clues abut the type of damage that CADASIL causes. Also, they will potentially bring out the most effective metrics for the assessment of white matter integrity in CADASIL patients.

Tentative Abstract In this study we investigate on the interdependence of cognitive test results and white matter integrity, as assessed by quantitative tractography metrics. Different fiber tracts in the brain are related to different congnitive functions, e.g. the SLF is related to working memory. Therefore atrophy in a certain tract leads to impaired performance in functions controlled by that tract. Knowing that CADASIL causes severe injury in the SLF, but not the fornix, we chose to compare the structural integrity of these tracts, as measured by several quatitative tractography metrics, against working memory test results and motor control test results. The n-back test was used to test working memory and the X-test was used to test motor control. The results of the n-back correlated well with the metrics, in the SLF. They did not correlate with the metrics, in the fornix. Among the metrics NTWLad expressed the highest correlation with the cognitive test results, sugesting that there is more axonal loss than demyelination in the tract. The results of the X-test did not correlate significantly with any of the metrics, in the SLF. These results confirm that there is a strong relationship among performance in cognitive tests and white matter health, measured by quantitative tractography. Furthermore, they draw some light on the nature of axonal damage caused by CADASIL.

Trevor

Tentative Title(s):

Extracting Semantic Content from Interaction Histories in 3D, Time-varying Visualizations

Interaction Histories for Collaboration, Search, and Prediction in 3D, Time-Varying Visualizations

Contributions:

1. Introduces a generalizable framework for automatically generating sharable, editable, searchable interaction histories in time-varying 3D applications.
2. Demonstrates utility of Relational Markov Models (RMMs) in extracting semantic information from interaction histories, useful for prediction and automation in scientific exploration.
3. Contributes the technical implementation details (software itself? open source project?) for applying said methods in pre-existing applications.

Results:

1. Techniques were applied in 3 existing applications: Animal kinematics from CT & X-ray, bat flight kinematics from light capture, and (__?? brain stuff, wrist stuff??, maybe infovis stuff like proteomics??___)
2. User evaluation of history generation matched user-defined histories in X% of cases. (Fully-automated, semi-automated, manual)
3. Collect data on collaboration? Anecdotal evidence on how tools were used for collaboration? (Need to get on this quickly, with new data sets that are actively being explored. Talk to Beth, Sharon.)
4. User study on task completion times with tools versus without tools.
5. Relational models evaluated against survey data. i.e. User was trying to uncover this in series of interactions, system interpreted interactions as this or that.

(Need to think more about how to objectify the previous two bullets.)

Abstract: TBD.

References:

Why interaction is more powerful than algorithms

Relational Markov Models and their Application to Adaptive Web Navigation

Visualizing Interaction History on a Collaborative Web Server

Distributed Cognition: Toward a New Foundation for Human-Computer Interaction Research

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Çağatay

Coloring 3d line fields using Boy’s real projective plane immersion

Abstract:

It’s often useful to visualize a line field, a function that sends each point P of the plane or of space to a line through P; such fields arise in the study of tensor fields, where the principal eigendirection at each point determines a line (but not a vector, since if v is an eigenvector, so is −v). To visualize such a field, we often assign a color to each line; thus we consider the coloring of line fields as a mapping from the real projective plane (RP2) to color space. Ideally, such a coloring scheme should be smooth and one-to-one, so that the color uniquely identifies the line; unfortunately, there is not such mapping. We introduce Boy’s surface, an immersion of the projective plane in 3D, as a model for coloring line fields, and show results from its application in visualizing orientation in diffusion tensor fields. This coloring method is smooth and one to one except on a set of measure zero (the double curve of Boy’s surface).

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