OmniPlex Neural Data Acquisition System Software V 1.11
January 22, 2014

DALLAS, TX — (January 22, 2014) – Plexon Inc, the leader in advanced hardware and software solutions for neuroscience and behavioral research, announces the newest software release for its flagship OmniPlex® Neural Data Acquisition System – OmniPlex Software v1.11. This release now sets the default recording format to PL2 and contains the significant addition of the new Spectral view, timed recording options, robust statistics, t-distribution expectation maximization (TDEM) auto-sorting algorithm and faster processing among other improvements.

A simple yet significant change in this new release is that the recording file format now defaults to Plexon’s game-changing PL2 launched last year. The legacy PLX format is still supported; however, it is no longer the default. PL2 is supported by the latest versions of Offline Sorter (OFS), NeuroExplorer®, and Plexon’s MATLAB® and C/C++ file reading software development kits (SDKs) available online. It is important to make sure that the applications, scripts and other programs which are intended to be used to view and analyze recorded OmniPlex data are updated to the new PL2-compatible format. If in doubt, contact

OmniPlex 1.11 now also offers a sophisticated, visually rich, new view: the Spectral view. It displays a rolling color-coded spectrogram of the currently selected field potential (FP) channel, plus an animated spectral graph below it. This allows researchers to monitor changes in spectral content, such as increase in energy in a range of frequencies, as a function of time.

The PlexControl program within the OmniPlex Software now provides options for using robust statistics in the determination auto-thresholding and sorting parameters. The primary advantage of robust statistics is that they are more resistant to the effect of outliers. Some examples are the use of the median as a robust statistic instead of the mean, or the use of the median absolute deviation (MAD) instead of the standard deviation. Researchers will typically find that using robust statistics produces a more accurate estimate of the noise distribution, with the presence of spikes having less influence on the auto-thresholding process.

Previous releases of OmniPlex supported a single auto-sorting algorithm, known as valley seeking. Valley seeking is a non-parametric method based on local density measures, and gives very good results in many cases, but it is not always ideal. OmniPlex 1.11 supports an additional auto-sorting algorithm called t-distribution expectation maximization (TDEM). TDEM works on the assumption that the clusters in feature space (each cluster representing the spikes from one neuron) can be modeled as t-distributions, so that the entire set of clusters on each channel is a mixture of t-distributions. The TDEM algorithm solves a global optimization problem to find the set of t-distributions which best fit the observed clusters on each spike channel.

From a purely practical perspective, researchers will likely appreciate that timed recording options are now supported. Timing of the Start, Stop, Pause and Resume commands can be specified.

In addition to the expanded functionality listed above, several existing functions operate significantly faster in release 1.11. These include auto-thresholding, the initial calculation of the PCA projections (and manual PCA recalculation using the PCA button), and Delete All Units on All Channels. These performance improvements will be especially noticeable at high channel counts.

This latest download is available for Windows® 7 and XP platforms, and can be found on the OmniPlex System webpage, and at For more information regarding these or other improvements, please read the Release Notes contained within the install package.

About Plexon Inc
Plexon is a pioneer and leading innovator of custom, high performance data acquisition, behavior and analysis solutions specifically designed for scientific research. We collaborate with and supply thousands of customers including the most prestigious neuroscience laboratories around the globe driving new frontiers in areas including basic science, brain-machine interfaces (BMI), neurodegenerative diseases, addictive behaviors and neuroprosthetics. Plexon offers integrated solutions for in vivo neurophysiology, optogenetics and behavioral research — backed by its industry-leading commitment to quality and customer support.