I coudn’t find an image of electrode drift for my slides, so here I quickly generated one. The only fancy thing is the usage of datetime to have minutes on the x-axis (I also made this post so I don’t forget this trick ;)) Thanks to Anna Lisa Gert for this dataset
A (short) laypersons summary TLDR; Using our data/paper you can find out how well your eye tracker is doing in measuring your favourite eye movement This newly published paper is open access and I share first co-author ship with the amazing Katharina Groß! In addition this project was done together with Inga Ibs and Peter König: A new comprehensive eye-tracking test battery concurrently evaluating the Pupil Labs glasses and the EyeLink 1000 We move our eyes about four times per second, which is more often than our heart beats! Many studie show that these eye movements are a window into…
I submitted this triptychon to the OHBM brain-art competition 2019. I used mouse myelin stains from the Brain Architecture Project and generated Rohrschach-Like creatures. I quite like how it turned out and I definitely want to do more in the future. I especially found the Allen Brain Atlas’ developmental mouse stains very cool – lots of potential there. If you are interested in other art pieces related to neuroscience feel free to check out my thesis-art collection – one piece for each student I supervised. Thanks to Ella Bosch & Anna Gert for latin & design advice!
The multiple comparison problem In neuroimaging analysis one often is confronted with many electrodes/voxels and many timepoints, and often performs a statistical test on each of these electrode/timepoint combinations. This leads to a massive multiple comparison problem, as the probability to find a false positive is greatly enhanced. In the following example we assume independence of all data points . For instance with only 10 electrodes/voxels and 10 timepoints and an alpha of 0.05, the probability for a false positive is: $$ p(significance^*|H_0) = 1-(1-0.05)^{10*10}=99.4 $$ *significance of at least one sample But electrodes/voxels and timepoints usually are not independent….
For the $i^2 c^2 s^3$ summer school I simulated quite a bit of data and analyzed them with several common multiple comparison methods. I used the SEREEGA toolbox for the simulation. All the MatLab-code can be found at the end of this post. In a follow-up blogpost I will extend the toolbox to continuous data that we can analyze with the unfold toolbox. First, I simulated data based on three effects: Two early dipoles representing the P100, one right lateralized for the N170 and a deep one for the P300. I added brown and white noise to the simulated epochs….
This was the result of a (inconclusive) test of how the blind spot fills in things
Introduction In my last lab we discussed findings on the periodicity of reaction times (e.g. referred in Van Rullen 2003). These studies are usually old (Starting with Harter 1968, Pöppel 1968), with small N and not many trials. There was also a extensive discussion in the Max-Planck Journal “Naturwissenschaften” in the 90s (mostly in German, e.g. Vorberg & Schwarz 1987). A methodological critique is from Vorberg & Schwarz 1987. More discussion in Gregson (Gregson, Vorberg, Schwarz 1988). A new method to analyse periodicity is proposed by Jokeit 1990. This is the newest research I could find on this topic. …
Some time ago I wrote a blog post on dummy & effect coding. I made some new plots to visualize why the interaction in sum/effect is coded as it is. Let’s take a typical 2×2 design. We have two 2-level factors $A$ and $B$ and we also allow for an interaction. $$y \sim A + B + A:B$$ We code A with -1 / 1 and B with -1 / 1 (depending on the level e.g. On=1, Off=-1) The interaction is coded as the multiplication of A and B: $A * B$. Therefore if $A$ and $B$ are both in…
I had this blog post as a draft for nearly a year now… and finally here it is: In my last lab we moved buildings. Good scientists we are we did measurements to see if the system works as intended… The EEG Systems An active 64 electrode system from BrainProducts called ActiCap A passive 128 electrode system from ANT, a tmsi REFA-8 with actively shielded cables A passive 128 electrode system from ANT, eegosport with actively shielded cables Disclaimer: All data shown here are from different subjects. Their individual alpha-peaks etc. will differ, we also switched methods a bit ActiCap…
I showed a student how I would improve a plot. The result is I think typical for what I would design. The details change for each paper and I do not have a specific “style” I wanted to emulate. I usually enjoy the before & after of other graphics, so here is mine: PS: The data shown in the plots are preliminary