Part of my work as a PhD candidate consists of measuring and analyzing brain waves. We do this by conducting so-called “ERPs”, i.e. “event-related potentials”. We record the EEG (Electroencephalogram) of participants and time-lock it to stimuli, the events. In order to get only the information that relates to the stimulus, a lot of repetitions are necessary. The brain waves of all those repetitions are then averaged, which filters out the “noise” as this is random and leaves only the constant reaction to our stimulus. As you can read on my “current project” site I am interested in the perception of speech sounds in individuals with aphasia, an acquired language disorder. In my experiment the participants are asked to watch a sequence of videos of someone uttering syllables. These can be so-called standard (occurring in 80% of the trials) or deviant (occurring in the other 20%) stimuli. They differ by only the initial speech sound (pa vs. ta or ka). On encountering a deviant stimulus participants should push a button. Whenever a new stimulus is started a marker is sent to the EEG, so the EEG can be related to the stimuli later on. However when I want to analyze...
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Ok, I admitted in the last post that my TikZ diagram was a lot less than optimal, because of too many repetitions in the code. So I decided to spend some time with the TikZ manual (really useful source of information), with the result that I learned about ‘for-loops’: For everything that needs to be carried out more than 1 time, a for-loop can be used. The concept is quite simple: In the follwing example an “ultra thick” line is drawn for a certain point \x from -6 to -6.5 on the y-axis. This is done for each of the points specified. \foreach \x in {0.35,1.54,2.73,3.92,5.11,6.3} \draw[ultra thick] (\x,-6) -- (\x,-6.5); This however can be simplified even more. Just mention the first 2 and the last of the desired points and the ones in between can be replaced with ”…”, as below. \foreach \x in {0.3,1.54,...,6.3} \draw[very thick] (\x,-6) -- (\x,-6.5); The complete picture looks just like the one before, the only difference is that I added some more connection lines, because it became so much easier. Also I changed the coordinates slightly, to improve the size of the final picture. Now it perfectly matches the text width in the...
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14 Sep 2010 » TikZ
Everything started with me wanting one of my diagrams to be more beautiful. I googled a lot and eventually found that TikZ would solve my one specific problem. So I installed the package and put the manual on my desktop (I need access as fast as possible). Soon I got the diagram I wanted and was amazed on how nice it looked. It really does matter if the font and style fit with the remaining document! So I decided that I should change all my diagrams to TikZ-diagrams (at least the ones not made with R, which already look very nice). It cost me quite some time and work, but once I saw the result I knew it was worth it. But… there was still one diagram I was hesitating to change. It took me quite some time to make it with dia and I was afraid of the time it would cost to redo it with TikZ, but eventually I surrendered to my urge to have not ‘all-but-one’, but rather ‘all’ diagrams in a nice style. Some hours later I was done and below you can see the result (click the image to see it bigger)… And here’s the...
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Last week I started using Linux - still very cautious, not messing with my Windows-installation. But off of my USB-stick it works quite well, I must say. So first I had to choose “which kind of Linux” I would like and I first decided to go for Debian, then choosing the stable variant and a GNOME desktop environment. Most things were working quite intuitively, but in the end I did need help with some hardware configuration (for example wireless network access). And apparently I didn’t pay enough attention as when using it on a second laptop I need help again getting wifi started. Next to “learning by doing” I also joined a 1st years Bachelor course on Linux, which they teach here at the University of Groningen. Well, I don’t attend the lectures, but do read the slides and do the exercises. The course started by teaching some basic Linux commands and later focuses on “Tekstmanipulatie” (that’s the title of the course), that means using Linux for linguistic purposes, namely working with texts. I’m afraid that this new ‘ambition’ will hinder my Ruby progress, but I guess it’s worth it. Maybe it was a little bit weird anyway to start...
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Today is my first official working day in my last year as a PhD candidate…
First of all I have to say it is unbelievable how fast 3 years can go by, I really feel like I just started. But, I didn’t. So today is the day “the end” starts. Lots and lots of writing to be done, luckily also still some testing and analyzing, just to keep a healthy balance. I now have a schedule for the upcoming year, with the first deadline for a chapter already passed… Luckily the chapter is also done. Next deadline is the end of october for two chapters: one on the theoretical background and one about my identification experiment. So that means I’ll focus on those two things during the upcoming two months, next to running the ERP experiment with some more patients and analyzing the results of it. Busy weeks ahead of me, but I’m still quite optimistic to manage my own deadlines.
Now it’s time to have some cake with colleagues who just had their birthdays, seems like a good way to start “the end”…
I just incorporated a blog into my website. This blog is (just as the website) hosted by GitHub and using jekyll. I will post entries on a non-regular basis, whenever I feel that something should be posted. More regular, though short, updates can be found in my Twitter feed, also on my blog.
So come back regularly to check whether there are any news.
On this site only the ten most recent posts are displayed. To see an overview of all posts, please visit the archive!
