Mark Dow

Research Assistant
Brain Development Lab, University of Oregon

e-mail: dow [at] uoregon.edu
*cell*541-954-6780**


Visual system mapping
Geek art, geometric images and algorithms
Geek software
My BDL and LCNI stuff, publications, presentations, etc.
My other stuff, some of
Other people's great stuff

    I work on software for image and functional MRI time series analysis, and currently am involved with fMRI projects involving retinotopy and visual spatial attention.

    These include 3-D surface extraction and segmentation algorithms, and volume navigation and editing tools that provide a framework for semi-automatic region of interest generation and landmark specification. The approach we are developing is based on edge/surface detection using Gaussian derivative filters, over-segmentation, and hierarchical region combination. The goal is to quickly identify primary surfaces, landmarks, and other image based features, and to use maps of these features to inform segmentation or parcellation of 3-D images.

    These fMRI experiments are designed to investigate the organization, operation, and plasticity of cortical areas involved in visual processing at large (20-80 degree) eccentricities. We use light guiding fibers to present flashing stimuli at peripheral locations during functional imaging. Retinotopically mapped visual areas and areas that preferentially respond to peripheral visual stimulation are identified. We are investigating the extent and organization of these visual areas, and how they are modulated by spatial attention. Comparison of hearing and congenitally deaf adults results will elucidate how visual cortical networks are modified and modulated by profoundly different auditory experience.
    These studies are done in collaboration with Greg Scott and James Dugan.

My deviantArt gallery

Space Software example volume and slice renderings

Space Software example animations

About Mark's fractal geek art

Simple recursive systems and fractal patterns

Thue-Morse sequence tilings

2x2 4-rotation cyclic L-systems

2x2 symmetric L-systems
Brigid's cross tessellations
Pell spirals

Oak cubes and hexagonal tilings
Binary fractal images

Mobius bands and tilings

Logarithmic spirals, waves and tilings

Universal motifs, tilings, knits, weaves and chains

Directional edge contrast motion illusion comparison

Minimal arrays containing all sub-array combinations of symbols

miscellaneous MRI related images

brain art fodder

Video motion estimation and quantification

  Publications:

 Scott, G., Dow, M., Neville, H. J. (2003). Human retinotopic mapping of the far periphery. Society for Neuroscience 2003 poster. [.pdf ]
 Dow, M., Nunnally, R. (2004). An edge based image segmentation method. ISMRM 2004 poster. [abstract .doc , poster .pdf ]

  Reports:

Dow, M., Dow, A. (2003). Measuring the earth's shape: Maximum solar elevation observations, through space and time. [ .ppt (13 MB)] [print/high res. version:  .ppt (32 MB)]
Dow, M. (2005). LCNI science meeting 2/9/05: BOLD localization of short visual events. [.ppt (8 MB)]

  miscellaneous, BDL and LCNI:

Psych 607 class resources , winter 2004

LCNI resources
LCNI historical
MATLAB class, summer 2008

Other projects

blog
Enzymind projects
Programmers Anonymous, an informal programming class I lead
Thermodynamic entropy and information, their relationship as I understand it
Dense Image Space, photographic/software project, in process
Math background, discrete math, math topics that are not in pre-college curriculum but should be

The Geometry Junkyard
Sean Michael Ragan, great ideas
Enzymind, Peter's online Laboratory (currently in development). My blog on this site, only occasinally.
deviantART, great art, searchable. Here are a few of my favorites.
Mathematical imagery, Jos Leys
The Brain From Top To Bottom, tour of human brain functional neuroanatomy
fMRI 4 Newbies, tutorials
Tatjana van Vark's instuments, particularly her The Harmonium for mechanical Fourier analysis and synthesis
Making Art the Otto Lange Way (I recommend subscribing to the blog through email)

Some great free software