First Recorded Spikes on the OLPC

While Greg and Evan have been working on modifying the Measure program on the OLPC (one laptop per child) in order to view and store neural data (the current build can’t store data, and it needs a trigger function and better visualization), Tim has been experimenting with the Audacity program. This is the same program we use on our PCs and Macs to view the neural data; the program is open source and has excellent signal processing capabilities (Tim has even written songs using this program).

Audacity is in its first OLPC build (you have to launch it from the terminal), but it works!

In the picture above, you can see the SpikerBox (with a cockroach leg on it) going to the microphone input of the OLPC, and Audacity displaying the neural data. The three bursts in the center of the display are when I blew on the barbs of the cockroach leg, causing an evoked discharge in the nerves. The software works well enough for demos, but there are three things we would like to see:

1) Fixing the play-through function during monitoring and recording. Listening to the output through the computer speakers while Audacity is recording is important for our teaching purposes. Turning on “Software Playthrough” causes Audacity to only record 1/2 second then crash.

2) Saving the recorded data in the journal of the OLPC. From the save menu of Audacity, you cannot navigate to the

/home/olpc/.,sugar/default/datastore/store

directory (which is the journal directory), as the .sugar folder is invisible in Audacity. Right now we are saving to the Audacity applications folder.

3) This is a minor thing, but wrapping the Audacity program so that it can be loaded from the main OLPC application page (rather than the terminal) would be nice.

Stayed tuned. We continue our labor of love…

Above is a screenshot from the OLPC. You can see the spontaneous discharge nicely (as well as when I blew on the leg on the right side of the display). Having received my chops in Mammalian Extracellular Neurophysiology, I am amazed at the signal to noise ratio of invertebrate neurons. Cockroaches have it going on!