brain

A trick to detect bad channel in NIRS data…

Some noise is easy to detect – simply plotting the time courses of NIRS signal, you will find the noise so out of range and you will discard the data. However, I find in some instances the noise level seems to be in the normal range but the dat
Xu Cui
35 sec read

Games used in human brain research [1]

The vast majority of studies on the relationship between human brain and behavior try to answer the “where” question: Where in the brain are the regions that are responsible for a particular task? For example, where is the finger movement
Xu Cui
1 min read

Near Infrared Spectroscopy (NIRS): List of manufactures

This post is under updating … The information is not complete Table can be found here: https://spreadsheets.google.com/spreadsheet/ccc?key=0AmI1wIXzRozHdFQzWHNQajI5eTlOeWRFd0tCT0hwYmc&hl=en_US Artinis OctaMon The m
Xu Cui
2 min read

What does a wavelet transform plot tell you?

Let’s say you collected some brain data (time series) using NIRS while the participants were performing a task (say finger tapping), and you use the wt function in the “Cross Wavelet and Wavelet Coherence Toolbox” (link dead. Please
Xu Cui
1 min read

Hyperbolic discounting emerges from the scalar property of interval…

Ten dollars today is more attractive than the same amount of money tomorrow and is consistent with the well known proverb, “a bird in the hand is worth two in the bush”. We all know that the value of a reward is discounted over time. How the value di
Xu Cui
16 sec read

Handy programs to visualize NIRS data (5): plot2

Let’s say you have two correlated variables, x and y. You may have more then one data points with x=10 and y=5. But if you do a scatter plot all these data points of the same value will become a single dot. You may want to use circles with size
Xu Cui
31 sec read

Handy programs to visualize NIRS data (4): wt

In case you need to visualize your time series in both time and frequency domain (or just frequency domain), you can use the wt (wavelet transform) function in the Cross Wavelet and Wavelet Coherence toolbox by Grinsted et al. I often find the color
Xu Cui
33 sec read

Handy programs to visualize NIRS data (3): plotFFT

Sometimes you wish to know the spectrum of a time series. plotFFT is a handy function for this purpose. You instantly know the power of the signal at each frequency. Here is an example on how to use this function: figure; plotFFT(randn(1,1000)); Sour
Xu Cui
11 sec read

Handy programs to visualize NIRS data (2): plotTopoMap

Often you need to view the spatial pattern of activation as in the example below. plotTopoMap allows you to do that. It probably only works for Hitachi devices where the spatial relationship between channels are known. In the above example, the activ
Xu Cui
37 sec read